Conference napalm::guitar

    I'm a closed back, NO ports man...it keeps a tight, punchy, well
    defined bass response.  Ports fluff out the bass too much IMO.
    Open backs are even worse than ports, but if you're playing jazz you
    want that sound.
    
    B.

I'm with Buck.  Open backs and cabs with ports seem to lose low-end 
bass response.  Closed cabs are my preference.  I've played thru
Marshalls and Peavy cabs and find them both pretty good.

I like to have either two cabs, or one stereo cab.  I guess the latest Marshall
design will be wired so that you have a choice of running (2)2x12's or (1)4x12.
Ergo, you can run mono or stereo.

Does anyone know how to wire a cab so that you can have a "output" for 
jumping to other cabs (making an array ?).  I've thought of doing this
simply because my amp only supports 4 cabs.  Also, the jump would need to
be parallel so as not to load down the amp with too much impedence.
Anyone know what I'm trying desperately to say ??

;)

The laney's I've heard were sealed, no ports

My Rivera cab is sealed with ports

the Rivera is a big softer bass wise...

the Laney's have crunchy bass

I like the laneys

dbii

> I'm with Buck.  Open backs and cabs with ports seem to lose low-end 
> bass response.  

    ?????
    The whole *idea* of ports is to increase bass response.  Which is why
    ported cabs are the most common type of bass cab.
    
> Does anyone know how to wire a cab so that you can have a "output" for 
> jumping to other cabs (making an array ?).  I've thought of doing this
> simply because my amp only supports 4 cabs.  Also, the jump would need to
> be parallel so as not to load down the amp with too much impedence.
    
    Just add a second jack to the cab, if it only has one, and wire it in
    parallel (is this too obvious?).  Geez, only 4 cabs, whaddya need more
    than four cabs for?
    
    In case it is too obvious:  Wire the second jack so that you have two
    wires, one from each of the wiring lugs to the corresponding lug on the
    existing jack.  That's parallel.
    
    							Brian

    It was my understanding that a cabinet needed ports so the speaker
    wouldn't tear from pressure. I'm redoing a cabinet now to be used
    with a bass guitar, should I block the ports or leave them open.
    
    
               ( just when you think you know the answers)

    Ports *do* increase bass response...but the increase, IMHO, makes the
    bass response for distorted guitar less defined in that freq. range.
    I like a nice, tight low end...one with lots of CHUNK

    
    Re: .5
    
    Ports are not to "relieve pressure", they are used to create a
    resonance in the low end, much in the way blowing across a bottle
    causes a resonance at a particular frequency.
    
    The idea is to tune the port about an octave below where the speaker's
    low end response falls off in open air.  What you end up with is most
    of the air is pushed from the port rather than the front of the cone in
    the bottom octave.
    
    As far as "mushy" bass, or loss of definition, part of that is due to
    the driver.  Try using an EV or JBL instead of a Celestion, and you may
    find the bass to be tighter.  Of course, then you lose all that great
    Clestion "character"......
    
    BTW the technical term for a sealed (guitar) cab is "infinite baffle".  
    Some sealed hi-fi speakers use "acoustic suspension" technology, but I
    have yet to see a guitar cab of that type.
    
    							Brian

    I heard somewhere that sealed cabs are also designed to limit
    the movement of the cone, and that small leaks in these cabs can
    cause speaker damage (e.g. air is 'pumped' into the cab and the cone
    extends too far out of the front!).
    
    Richard.

Yeah, I didn't mean to say LESS bass response...Just different bass
response.  

Example:

-Take a ported or open cab.
-Pull a low e and depress joy-stick until the
 string goes slack.
-Do the same with a sealed cab; big difference.

It really shows up with a distorted sound.  Instead of the bass 'washing 
over you' as in a ported/open cab, the bass from a sealed cab will punch 
you in the chest and stop yer heart.  ;)

jc

    re: .2
    	Do it the right way!
    	One *head* per cabinet, unless you're running Marshalls, then
    	run two heads per cabinet so when the first one does a smoke
    	show, you still have a back-up amp.   
    
    NOTE:   Many MANY  >>-->   ;^)   ;^)   ;^)   ;^)
          
    
                      
    Fred (who feels that *one* 4 x 12" cabinet is enough to kill small 
    	  animals with)

    >	Do it the right way!
    > 	One *head* per cabinet, unless you're running Marshalls, then
    >	run two heads per cabinet so when the first one does a smoke
    >	show, you still have a back-up amp.   
    
    But the Marshall configuration guide suggests you plug BOTH heads
    into 1 cab each and slave them!  ;^)

    My open back Kitty provides PLENTY of bass!  I can imagine if it was
    sealed & ported, probably register on the Richter Scale!
    
    Mike

    I've had both open and sealed cabinets, and I prefer the sealed type
    for rock.  I don't ever remember playing through a ported cab, so I
    can't comment on them.
    
    I've had 2 4-12 cabs, one Marshall and the other a home-made job with
    Gauss speakers.  The Marshall had a great sound, but had too much
    bottom to really make me happy.  Like any Marshall that I've ever
    heard, it was very directional.  Stand right in front of it and it
    would take your head off.  Move 2 feet to the side and it's like
    someone put ear plugs in your ears. 
    
    
    My favorite speak cabinet of all time was the 6-10 sealed cab.  It had
    a massive punch and was less boomy than a 4-12 cabinet.  The down side
    was the weight!  I used both Traynor and home-grown 6-10 cabinets, and
    they weighed a ton.  The SVT 8-10 cabinet was a REALLY hairy beast.
    
    I'm using a 4-10 sealed cab (Marshall) now and I like it lots.  It has
    a great punch and it's pretty light.  It, too, is very directional.
    
    
    Kevin
    

Yeah, no kidding !

In some of the smaller venues I've played in I'd be standing within 3' of my 
Marshalls and could hear nothing but everyone else in the band...So I turn up 
and I'm blasting the others in the band off the stage.  The sound would
shoot right between my legs and I'd never hear a note.

Someone ought to design a cab that disperses (sp?) the sound more evenly !
A cross between a Bose 900 series and a Marshall slant.  ;)

In Marshalls defense though, you might remember that they had a "wall-of-sound"
in mind, not a single...10' high and 20' long = 200sqft of sound pressure.
More like Judas Priests set up.

I really appreciated the sound of Judas Priest in concert.  The had their 
stage two tiers high with the whole back of the stage lined with Marshall 
three-high straight fronts...On BOTH tiers.  Granted, they probably weren't 
using it all, but what a sight !  

<Insert Pic of Coop with jaws hanging open and hair 
 flying due to the sound pressure - here!>

jc

>In Marshalls defense though, you might remember that they had a "wall-of-sound"
>in mind, not a single...10' high and 20' long = 200sqft of sound pressure.
    
    Actually, Marshall had nothing of the sort in mind.  You may recall
    that the 4-12 cabs came out in the mid-60s.  Jim Marshall was a jazz
    drummer for pete's sake, he has commented in the past that he was quite
    surprised when he found out what people were *doing* with his amps.  He
    was just trying to cash in on the scarcity of Fenders in the UK in the
    60s.
    
    Maybe you just left out yer  8^)  8^)  8^) , eh?
    
    							Brian

>Someone ought to design a cab that disperses (sp?) the sound more evenly !
>A cross between a Bose 900 series and a Marshall slant.  ;)
    
    Bose utilizes ports for bass in their 901 series.  They had to do this
    since the 9 drivers inside are only 5" in diameter.
    
    Mike

    Good topic. I 've wanted to know more about this kind of thing.
    
    I play a Fender Super Six - 6 10's @ 100watts. It's an open back and
    curiously enough Kevin, it's loaded with Traynors and one original
    Fender (Jensen?). From time to time, I've thought about replacing the
    speakers with something else and or enclosing the back (since it's a
    combo, I'd have to install a fan no doubt). But the thing is I keep
    saying to myself " yeah it might be cool, BUT I like it the way it is".
    
    There's this great American philosophy that if SOME is good enough,
    MORE must be better.  I always seem compelled to change the damn thing
    cause because "it must be better". But when I get down to it, it's
    really a function of $. I see Music Emporium is getting $136 per 10".
    Funny how money can keep you from makin a damn fool of yourself
    sometimes, eh?
    
    Sakman

    Maybe a Kitty -> Q-verb -> Metaltronix -> Ohm Walsh driver???
    
    Edd

	Personally, I like the open back sound of a Twin Reverb.
	I use ported sealed back cabinets for the PA system, but
	I find that I can't hear what I really sound like (yes,
	it blasts right out at leg level) unless some sound comes
	out of the back. As it is, I'm often more trebly than I might
	suspect (You get used to this fairly quickly & learn to adjust).

	I play both 6 string & Bass thru my Twin (I use a double neck
	6/bass) & it does quite well for both (I never play then both 
	at the same time - I only have 2 hands). 

								Jens

    I like my sealed Marshall cab (I think Coop does too ...).  I've
    recently been playing out of a 2x12" Bullfrog cabinet and it's ported.
    I really can't tell much difference other than the volume.  Which
    brings me to another point ...
    
    Of all the bands I've been in, it seems that *someone* is always
    griping about my volume.  The most I've ever used is a 100W amp and a
    4x12" cab.  Even in big clubs I had to listen to the "turn it down"
    blues.  How do you guys with big rigs get by with it ... do you run the
    rig at "2" or just not hook up all the cabs, or is your soundman deaf
    AND mute ?
    
    Scary (who's tamed his Kitty to 60W, running a 2x12" cab and will STILL
    be too loud this weekend ..... :^(
    

    -1
    
    Of all the bands I've been in, it seems that *someone* is always
    >griping about my volume.  The most I've ever used is a 100W amp and a
    >4x12" cab.  Even in big clubs I had to listen to the "turn it down"
    >blues.  How do you guys with big rigs get by with it ... do you run the
    >rig at "2" or just not hook up all the cabs, or is your soundman deaf
    >AND mute ?
    
    The latter!
    ;^)
    
    Well, to appreciate my stage volume, I mount my cabs up on something,
    towards ear level...really changes your perspective on tone and 
    overall volume!  This relates to what dbii said about 110db of guitar
    blowing thru your legs from a very directional Marshall 4x12 cab!
    Get those cabs UP people...it'll teach ya how to control feedback, if
    anything!
    
    ;^)

Yes, soundmen gripe at guitarists for their hi-levels.  The deal is, you have to
be able to trust your soundmans opinion, and do what he sez. (Agagagagagaga,
I can't believe *I'm* saying this! ;)  Seems to me I've flipped off my share.
What Buck said is a good point !  Get the cabs up more towards your face, and
you'll suddenly see how loud you are.

Recently I played a large club and had my rig up on a riser.  I was playing with
my volume set pretty low in comparison to some of the smaller clubs, because I 
could hear my stuff better.  Yep, I run my rig on "two".  Tired it on four once
and blew out a wall.  ;)

jc

    
    I'd have to say that Marshalls are the most directional cabinets that I've
    played through.  Thay also happen to be my favs.
    
    Ampeg made some nice 4-12 cabs, but talk about big+heavy!  I played a
    friends SVT with the two 8-10 cabinets in an empty gym.  If there was a
    louder amp on the earth in 1973, I had never heard it.  Ampeg cabs go
    pretty cheap in the want ads.
    
    In the early 70's, Peavey speakers had a reputation for blowing out, at
    least that's what I heard.  However, I'd have to say that I've never
    heard of someone blowing a Scorpion, Scorpion+, or Black Widow speaker. 
    Not exactly warm speakers, but not wimpy!  As mentioned, a Peavey 4-12
    Celestion cab could be a good deal.  
    
    Fender cabs never really seemed to make it in the high-volume arena.
    I've used a Fender 2-12 cabinet that I really liked.  It was small
    enough to lug around without too much grief.  I always wondered why the
    old Bassman cab was so big.  There was certainly more room in there for
    more than 2-12's.
    
    The old Kustom padded cabs were cool!  They were pretty heavy, but they
    had good casters and handles that made moving them easier.  I remember
    different combinations of 2-12's, 2-12's + horn, etc.  That horn was
    nasty for guitar, but keyboard players seemed to love 'em.  In the
    larger cabs, that horn was at ear height. 
    
    
    Kevin
     
    
      

RE -.1> Nasty horn

Yessir !  I played my rig thru a Big ole Kustom pleated job with two
15's and one horn.  It didn't sound *that* bad, but that horn will 
make your ears bleed.  Perhaps if you laid it on it's side... ;)

jc

    One thing on the directional topic that I used to like is the old Twin
    Reverbs had the metal legs that would let you tilt the amp back and
    have the sound hit you in the face if you wanted it.
    
    I wish my Boogie had that.  In small rooms (i.e. where we practice) I
    tilt it (1x12 Simul-Class) back against the wall so I'm not too loud. 
    It's an open back cabinet, I like the sound a lot, but have never heard
    it through a closed or ported cabinet.
    
    Good topic, it's givin me some ideas (like I need to spend more
    money... 8^0  )
    
    Will

    
    	I saw Stevie Ray Vaughn (sp?) on Austin City Limits
    	a couple of times. The first time he had his amps behind
    	him and you could tell that it was LOUD by the sound of
    	his guitar feeding into his vocal mic as he sang. The
    	second time I saw him on ACL, he had two wedges, loaded
    	with what looked to be JBL's, on the floor to his right.
    	The heads were stacked behind him. Having the amps side-
    	stage can give the soundman AND the audience a break if
    	you tend to play loud. Besides, the rest of the band can
    	hear you much better. :^)
    	
    
    	Neal-blown-away-frequently-by-KH/Marshall/Hiwatt/Laney/etc-stacks

re: more dispersion

The Rivera Q-cab was designed to address this.

The 2-12's are set up at slight angles to promote dispersion

If you set the cab up vertically you get vertical dispersion, nice when you 
have to stand on top of your rig, if you set it up horizontal...

you get the picture right?

dbii

I've seen Stevie Ray twice in the past year and both times he had a big 
sheet of plexiglass (or something clear) hanging in front of his amps to 
block off the sound.  Looked like it was about 4 or 5 feet in front of the 
amps.

Seemed like a senseable way to do it if you want to run them really hot 
for the tone, but still be able to mike them up and keep a decent stage 
volume.

Greg

Ya know, I often hear the people in here talking about cabs and speakers and 
such, and I guess they really can tell the difference. But I gotta admit - it 
really doesn't make a whole lot of difference to me! 

I mean, unless the cab is a *real* piece of junk, I notice that my choice of
guitars, my amps, and my personal settings all have such an effect upon my 
sound, that I think the overall input of the cab is minimal. 

Now, I suppose that in a studio situation, where you are trying to perfect a 
sound, it might have more of an effect. But it seems that in a live band 
situation, does it really matter *all* that much whether I'm playing through 
Celestions vs. Black Widows vs. whatever?

Alan S.

    
    RE:-.1
    
    I think that different speakers and how they're set up; especially
    closed or open backs really do make an audible differences, Alan.
    
    If you try listening to the bottom half of my Boogie 4x12 which is
    closed back with EV's, it will sound deeper, louder(since the closed 
    environment forces the speaker to project the sound forwad), yet "mellow"er 
    than the top half.  The top half is open back with Celestians and it 
    sounds crunchier, not as loud(sound projects backward as well as
    forward), and not as deep as the EV's.
    
    Also, having an open back would make your speaker "free resonate".  I'm 
    not entirely sure how this effects the sound yet.  Anyone care to
    comment?
    
    Another interesting point; sound reinforcing fiberglass.  When I took
    them out of a home made 2x10" speaker enclosure, it sounded different.  
    With in in, the sound was tighter and more mid-rangy, but without it,
    the bass had more of a presence.  When using it as a practice guitar
    cab, I left the fiberglass in, and when I used them as bass driving 
    speakers in my car, I took them out.  I also had to enclose the top
    half, which was resonating freely and bass was distorting since I had
    it crossed over at 2K Hz.
    
    J-Dot                                                      

    I've got a slant cab with 25wt Celestions on the way from the Marshall 
    factory and I'm psyched!!  Those cabs are *so* sweet!

    Alan, guitar speaker cabs really DO sound different.  You could take
    the speakers out of one cabinet and put them in another and they would
    probably not sound the same at all.  The design of the cabinet, depth,
    presence (or lack) of baffles makes a BIG difference.
   
    You would probably have to redo your eq settings if you started using a
    different speaker cabinet.
    
    Kevin
    

    -1
    
    I wholeheartedly agree!  I've played thru Ampeg 4x12's, Marshall's,
    Hiwatt 4x12's, Peavey (yes, I admit), all equipped with Celestion
    spks and ALL of em sounded different!  Way different.  Something about
    that original Marshall design that I liked the sound of the best.

    I avoid aiming my Marshall(s) right at the sound man due to directional
    projection of the cabs. If they are aimed right at him, thats all he
    will hear and he will tend to cut me back on the mix. Sometimes I will
    side stage them.
    
    Dennis
    
    

    Good idea - an old band of mine *always* had the guitar cabs at a 45
    degree angle in relation to the soundman/front of stage.  'Course the
    drummer caught h*ll, but the overall mix was much better ...
    
    Scary

    -1
    
    My drummers can NEVER hear me...Hahahaha, they must be among the lucky
    ones!  ;^)
    
    Buck, always pretty loud (even moreso with 2 50WT Marshalls)

    There are always serious dead spots on stage, that's why a band really
    has to be tight to pull things off live.  Usually at practice, you set
    up so YOU can hear each other, but in a live situation, the crowd must
    have the best seat and the band suffers.  The idea I mentioned earlier
    about having the amps angled in toward the drummer works pretty nice.
    
    Scary

    How about an angled cabinet? Not angled up like the Marshalls and such
    copies, but angled from side to side. I figure any combination of two
    or more speakers, in pairs mounted at say a 22.5 degree angle to each
    other, where the dispersion angle from each driver overlaps a few feet
    in front of the cab. You'd get a wider coverage, the other band
    members could hear you and you them if they had the same and the crowd
    wouldn't be overpowered by any one person they happened to be in front
    of. Eh? What say ye dudes?
    
                          _________________
                          |               |
                          |               |
                          |_             -   
                            ---        ---
                              ---------
    
    
               Band member        You          Band member
    
    
                  ( Can't draw it any better on terminal)
    
    Sakman

    A company already did that...I forget the name, but the angled a
    Marshall-style cabinet just like that...not sure how it sounded 
    though.  Def Lef used em for a while.
    
    B.

    That's sort of what the Rivera Q-Cab is like...
    
    
    How about this semi-religious issue?
    
    What's better for lead 10's or 12's?
    
    
    dbii
    

    That probably depends on the head - My Kitty M3 is real bassy, so it
    would probbly do better with 10's.  My Marshall is real thin so 12's
    would do better ... ?    So, who makes 11" Celestions ... agagaga
    
    Scary (who should be in bed right now ...)

    >> What's better for lead, 10's or 12's
    
    Are you tying to start a holy war or what ??
    
    I guess it depends on what type of music your into and what your'
    personal taste dictates. I think a combination might work best.
    It seems to work the best for Bass (ie. 1x15" and 2x10" combination)
    It also looks great  (o
    			   /:{()>
                         (o
    
    Mark
    
    

    Looking through the Mesa Boogie catalog I now beliweve the best
    speaker combination from both sound and portability is one of 
    their 1x12 open-back cabs atop a 1x12 closed-back theile-ported
    cab. These cabs are relatively small, and not too heavy, but
    can produce a nice fat wall of sound. They are available in
    several differant finishes (black, blonde, hardwood), and with 
    your choice of EV, Celestian, or Mesa Black shadows.
    
    Will all the small compact cars on the road, I am surprised that
    so many people are still using stacks of 4x12 cabs. 
    
    Mark
    

At the risk of sounding ignorant, could someone please explain to me what
"Thiele porting" in a speaker cabinet is?  I know it's some sort of cabinet
design for sealed cabinets that's supposed to increase efficiency, but I'd
like a more specific explanation then that.

ADVthanksANCE,
Greg

    Well Greg,
    
    	I wish I could answer your question accurately. All I know is
    that over the years several companies have tried their hand at 
    speaker cab design (JBL, Altec-Lansing, Klipsch, Theile, Cerwin-
    Vega, etc.).  The whole idea of porting allows you to down-size
    a speaker cab, and tune it's resonant frequency so it produces
    a nice tight bass response. Thiele seems to have come up with the
    best design, and published some standard algorhythms for calculating
    cab size, port size, and everyone these days seems to prefer the
    Thiele designs and fomulas. I'm not even sure if Thiele is in the
    business of making speaker cabs anymore, but their designs have
    stood the test of time.
    
    Most of the Thiele designed cabs I have seen have a rectangular 
    port running vertically up one side. The port seems to taper into
    the cabinet (almost the shape of a radial horn).  Altec Lansing
    "Voice of the theater" cabs used a cynindrically-shaped port, which
    was tuned by experimenting with differant lengths compared with
    the cabs efficiency curve. 
    
    Perhaps someone can offer a better explanation of Thiele porting.
    
    Mark

    
    Let's all get confused.
    
    There is a hi-fi speaker company named Thiele.  As far as I know, they
    do not make any speakers for MI applications.
    
    There was also a physicist named Thiele who sometime in the past (40s,
    maybe?) published a number of mathematical equations for optimizing
    cabinets to drivers for optimum efficiency and frequency response. 
    These are sometimes caled "Thiele-Small parameters" (who knows what the
    heck Small is for, another physicist or what..)
    
    Anyway, in the 70s, EV started working with cabinets designed to these
    parameters.  They even published free plans.  Go look at a Joe's Salami
    cab, a Sonic cab, a Boogie cab, a Dan Eaton cab 8^)  8^), hey, they all
    look exactly like those EV plans.....hmmmm.
    
    The actual shape of the port is immaterial.  The EV plans have a
    "shelf" mounted below the driver, than below the shelf is the port
    itself.  A "plug" can be inserted to tune the cabinet lower (at a cost
    of less efficiency).  But my EAW cab, also Thiele-aligned, has
    tubes for ports.  What makes it Thiele aligned is that the cab and port
    dimensions were arrived at with the Thiele equations.
    
    Most people call small cube-shaped cabs that look like the EV design
    "Thiele cubes".  It's about as technically accurate as calling the
    whammy on your Strat a "tremelo" when it's really a *vibrato*.
    
    							Brian

    
    
    	I built (a couple of months ago) a single 12 extension cab for my
    sooooper 60, and I'm starting to get frustrated with the amount of
    volume control that I have over the speaker cab.  I used to slave one
    guitar amp to the other and I had complete volume control over my
    second amp (preamp out to main amp in)... but I ummmmmm sold it when I
    bought my 60 cos I didn't think I'd need it any more.  So here' my
    question.... should I get rid of this speaker cab and look for another
    Fender transistor amp to slave to my super or is therea way for me to
    get better volume control other than using the "one amp as extension
    speaker" method.   I only play at home (still) but I really prefer the
    sound from speakers that are separated as opposed to using a single
    amp.
    
    
    Steve (chillin)

        
Why?  .....but it would seem easier to pick up a mono power amp for 
your extension speaker....and run your slave out or preamp out into the 
power amp..........if I understand what your doing.......why bother
for the dog? :^) or is it for the neighbors? ;^)


							Rick

    
    
    
    	.49 thanks Rick.. I thought about a power amp, but here are the
    problems with that for me:
    
    1. Doesn't allow me to balance the cab output "down"
    2. If I wind up getting another combo amp it could be a back-up (for
    what I don't know yet)
    
    	Yep, the dog is a very discerning listener!!
    
    
    Steve

    
        
    1. Doesn't allow me to balance the cab output "down"

Huh? sure it does,as the volume control on a power amp controls input
gain so your extra cab can be at a lower volume. Or am I misunderstanding?

    2. If I wind up getting another combo amp it could be a back-up (for
    what I don't know yet)
    
Or it could set you up for a stereo amp setup.....

    	Yep, the dog is a very discerning listener!!
    
One of my dogs use to sing along anytime I played harp.....she keep on singing
out of harmony and wanted a larger % of the profits.... she retired to
a farm somewhere in New Hampshire......:^) I now have one that's just an 
audience.......:^)

    
    
    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>    
        
    1. Doesn't allow me to balance the cab output "down"

Huh? sure it does,as the volume control on a power amp controls input
gain so your extra cab can be at a lower volume. Or am I misunderstanding?
    
    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
    
    
    	Oh yeah.. (DUH) sorry...  thanks!
    
    
    Steve

	I have asked a few guitar noters individually, but I thought I'd
    open this up to guitar noters in general for concensus...
    
	I'm planning on building something for my new Dean Markley amp over the 
    holidays.  I was thinking of a 2X10 or perhaps two cabs with a 10 in each 
    of them (the top one with a slant front?).  The idea for the separate cabs 
    is to have something small I can take out for rehearsal purposes.  I've 
    thought of mounting a piezo tweeter in one of the cabs and have it on a 
    switch that can take it out of the circuit.  The idea behind this is to be 
    able to use the cab(s) for acoustic guitar work as well as electric.  
    What do you all think of that idea?

	I am curious if anyone has buit guitar cabs.  I have a suspision that 
    there doesn't seem to be any mystery about cab volume for electric guitar 
    cabs.  Since they're closed cabs and people seem to interchange speakers 
    (out stock, in celestions...) often enough, it would seem that the size of 
    a guitar cab is fairly arbitrary.  Any thoughts on this?
    
    Dan
    

>        I'm planning on building something for my new Dean Markley amp over the 
>    holidays.  I was thinking of a 2X10 or perhaps two cabs with a 10 in each 
>    of them (the top one with a slant front?).  The idea for the separate cabs 
>    is to have something small I can take out for rehearsal purposes.  I've 
>    thought of mounting a piezo tweeter in one of the cabs and have it on a 
>    switch that can take it out of the circuit.  The idea behind this is to be 
>    able to use the cab(s) for acoustic guitar work as well as electric.  
>    What do you all think of that idea?

Dan,

	I have built many cabs, and I agree that you don't have to be too 
carefull about dimensions.

I would suggest you build a semi closed design similar to the Fender twin.
(look up the dimensions for their 2 by ten model)

I have just built a small cab with two 10 inch speakers, and it sounds fine.

The dimensions were about (from memory) 22 inches wide by 16 high by 10 deep.

I filled the back in with two slats of wood leaving a gap of about 3inches
running left to right.

I have a larger cab with a high power 12 inch speaker, but it lost a lot of 
the highs, so I fitted two piezo horns, but wired in a pot. Piezo's take very 
little current so you only need a 1 or 2 watt pot.

Accoustic guitars will benefit from using these.

With this I can vary the amount of treble energy, and it has made a great 
improvement. 

Dave

    I remember reading somewhere that the volume of the speaker cabinet for
    most efficiency has to do with the size and throw of the speaker being
    used.  I don't know the formula though.
    
    I'm no expert, but I've seen a couple of different plans for cabs using
    10in speakers and they both used about 1 cubic foot of airspace per
    speaker.
    
    Hope this helps,
    Greg

    
    	If it's anything like consumer stereo gear, there's a set
    	of formulas that should be used to calculate box volume
    	for a certain speaker [or speakers] such that the sound
    	is at its best.
    
    	You need manufacturer's specs on the speaker to plug into
    	the formula ... if I can find the info, I'll let you know.
    
    							GTI
    

    I have some general speaker cab formulas in a book I got from Rat
    Shack...  Funny thing, though, when I apply these formulas and come up
    with a basic volume, its never the same as the manufacturer's
    recommended cabinet volume.  
    
    	I like the thing about 1 cubic foot per 10" speaker - that looks
    about right when you look at the cabinets available in music stores.
    
    	FWIW, Greg, what are the dimensions of your 2X10 cab?
    
    	thanks,
    
    	Dan
    

    Other than personal prefference, what's the difference between buying a
    Marshall cab loaded with Celestions and a brand "X" loaded with the
    same speakers (for less money) ?  Basically, a box is a box, right ?
    
    Scary (ozite kid ...)

    
    ElectroVoice publishes plans for Thiele-aligned (:== cab volume calculated
    by using these formulas from a speaker cat named A.N.Thiele) cabs.  I've
    built 36 cabinets over the years: 12's, 15's, and even two 18's (for a
    reggae bass player).   I've never built a Thiele cabinet for a 10in spkr,
    but I know EV makes 10's, so I'm _assuming_ they make plans for a 10 cab.
    Just so we're clear, this would mean two individual cabinets, although
    I once built two 12in Thiele boxes siamesed together.  IMHO, having
    two cabs is preferable because of the flexibility.
    
    Basic construction is 3/4 birch ply (expensive, but no voids) with 
    stiffening members added (3/4in X 2in fir).  All Thiele boxes have
    a removable plug that changes the port characteristics and therefore
    affects the low frequency repsonse of the cab. They are moderately
    difficult to build correctly.  A 12in cab costs about $75 in materials,
    not including the speaker or any covering for the outside (eg Ozite),
    but does include a 'drunk proof' grill.  These babies are TOUGH: I once
    dropped a 12 down a flight of stairs at the Old Port Tavern in Portland,
    ME.  Sucker still worked.
    
    I'd rate the tone out of these cabs as 'smooth'; if'n you want to 
    play metal or 'edgier' music in general, use that open back design
    mentioned in previous replies.
    
    I'd be glad to share the plans I have, plus some hints I picked up
    by building a bunch.
    
    
     

>    I have some general speaker cab formulas in a book I got from Rat
>    Shack...  Funny thing, though, when I apply these formulas and come up
>    with a basic volume, its never the same as the manufacturer's
>    recommended cabinet volume.  
>    
>        I like the thing about 1 cubic foot per 10" speaker - that looks
>    about right when you look at the cabinets available in music stores.

  Yep ! I agree, seems to me that manufacturers do all the math, then work out 
what they can get away with or what "sounds" right.

Look at Boogie, it is *simply* a 12inch speaker with a cab wrapped around it.

A lot of the formulae are fine for Hi-Fi but no use for guitars. You would 
probably end up with a bass bin for each speaker !

One other point about building......(this is basic but just in case.....)

I use three quarter inch chipboard and I glue and screw every inside surface
with a 1inch cross sectional area batten ie.

			|	|
		 +-----+|	|
	batten	 |     ||side	|-----------+ screw
		 +-----||	|
--------------------------------+
		bottom		|
				|
--------------------------------+
  			   |
         		   |
			   |
			   |
			   +
			screw

If you are not going to cover the cabinet, simply screw from the inside 
through the battens.

This will give you a very solid cab.

Sorry about telling you how to suck eggs! 

Dave

    One other thing...
    
    Does anyone know the effect two speakers have on each other in a single
    cab?  All the formulas in my books seem to deal only with single
    drivers in a cab.  Are there any adjustments that are commonly known to
    be made when estimating cabinet volume?
    
    	Dan
    

    and another thing (I'm just full of questions today, hmmm?)
    
    	Is there any magic in the idea that speakers should be parallel or
    perpendicular to the floor?  I was just thinking that if I offset the
    two ten inch speakers a bit from parallel to the floor, I could make
    the cab a standard rack width (seeing that the head is a rack-mount).
    
    	Any thoughts on this?
    
    	Dan

As for multiple speakers in a cabinet, make sure that they are wired
in phase: For Parallel  + to +, and Minus to Minus, for Series + to minus,
then + to the center tap of the Jack, Minus to the ground.

You can check this with a 1 1/2 volt battery. Make sure that all of your
speakers jump the same direction when you connect the battery to the 
terminals. 

If you don't do this, your cabinets will sound mighty weak once you turn the
volume up.

Note: A red or white dot may be used to indicate the + terminal on the
speaker.

Always connect the + sides of any speakers to the center tap of your connector
and the minus to the ground. Same thing with any horns or piezos.

								Jens

I've noticed that a few amps warn not to connect the speakers to 
actual amplifier ground. )I guess this means that the output is 
floating.) In any case, the amplifier's speaker connector terminals 
are the right place to connect, regardless. On most amps, one side
is connected to ground.

rjb

>>I've noticed that a few amps warn not to connect the speakers to 
>>actual amplifier ground. 

	What I ment was to use the 2 connections that are supplied from
	the amplifier. Ie, the phone jack in the back of your amplifier
	that is where you plug your speakers in, and the phone jack
	that you put on the back of your speaker cabinet. Phone Jacks
	(1/4 inch jacks used on high impedance guitars) have a center
	connection and a ground (the sheild) connection. This is what
	I was referring to.

	You are correct about the ground on the case not always being 
	the same as the ground for the amplifier. Bridged Amplifiers actually
	connect 2 amplifiers, with one amplifier output to each lead
	of the 2 speaker connections. In this case, there really is no
	chassis ground that you connect to & you'll definately test the
	short circuit capability of one of the amplifiers is you are not
	careful. I alway vote on the side of caution & never assume that
	the output driver stage is connected to the chassis in some way. 

								Jens

    Anyone listening ??
    
    I took the Ampeg 4x12 I have and ripped out two of the four Eminence
    speakers that were in it and replaced them with two PAS (Pro Audio
    Systems) 12" 150wt drivers.  WOW !  What a difference !
    
    Also,
    
    Where the bass response on the cab used to be "mushy" at best, I
    thought I'd rip out all the fiberglass baffling that was in there.
    When I was done, I had made a mega-thumpy cab out of one that was way 
    too soft for my tastes.  
    
    Unfortunatey, I think I now have a 12ohm cab.  See, the PAS speakers
    were 4ohm, and the Eminence were 8ohm.  The cab was wired so that if
    there is one jack plugged in, all four speakers run giving a 16 ohm 
    load...If both jacks had plugs, then there were (2)2x12's running at
    8 ohm.  Well, now that I've replaced two of the 8ohms with 4 ohm
    speakers, what do I have now ??   Each "side" has (1) 8ohm, and (1)
    4ohm speaker...
    
    jc (Who's knowledge of Ohms law is lacking...)

    FWIW, those aren't Eminence speakers that were in that cab.  The guy
    that reconed 'em for me said they were CTS.  
    
    I'm surprised that removing the fiberglass baffling helped, I was told
    (in this notesfile) that it was pretty much manditory for sealed
    cabinets.  
    
    Greg

    It's almost that the sound is reverberating around in there now.
    I can't explain why, it just made a vast improvement in the low
    -end.  Strange.
    
    Check it out tonight

    Let's see, the general rule for impedance is this:
    
    loads in series sum. R1 + R2 + R3 + R4 RTotal.
    
    For instance, if you placed all four speakers in series, the total
    impedance would be 8+8+4+4=24ohms.
    
    For loads in parallel:
    
                      1                            1              1
    Rtotal = ------------------------- = --------------------- = --- = 1.333 
             1/R1 + 1/R2 + 1/R3 + 1/R4   1/8 + 1/8 + 1/4 + 1/4   6/8
    
    
    Obviously, 1.333 ohms is not a safe load to connect to an amp. The
    obvious solution is a series/parallel circuit, but you still will have
    to settle for one of about 4 circuits.
    
    If you place an 8 ohm speaker in series with a 4 ohm, you have a 12 ohm
    circuit. Two 12 ohm circuits in parallel will give you a 6 ohm load.
    This is probably the best circuit to use. It is in a safe range between
    4 and 8 ohms. 
    
    Other possible scenarios:
    
    	2 4 ohm speakers in series = 8 ohms.
    
    place this series circuit in parallel with the other two 8 ohm speakers.
    The resulting total (nominal) impedance will be:
    
                   1            1
    Rtotal = --------------- = --- = 2.666 ohms
             1/8 + 1/8 + 1/8   3/8
    
    Again this is too low to be safely used with an amp. Another scenario
    is to place an 8 ohm speaker in parellel with a 4. This is a 2.666
    ohm circuit. Place two of these circuit in series, and you get about
    6 ohms again (actually 5.333 ohms). 
    
    I can't think of any other scenarios that would work better. I think the
    earlier circuit (with the 8 ohm and 4 ohm in series) will work best at
    an even 6 ohms.
    
    TTFN
    
    Mark

    
    
    
    	ooooooooookay!  How about this... hee hee  I just got this coool EV
    speaker to replace my old distorted one... so if wanted a clean sound
    AND a dirty sound.. could I use an A/B box to switch between speakers
    or would that fall under category of messing around with the load on
    a tube amp...
    
    
    Gree Vee

>    
>        ooooooooookay!  How about this... hee hee  I just got this coool EV
>    speaker to replace my old distorted one... so if wanted a clean sound
>    AND a dirty sound.. could I use an A/B box to switch between speakers
>    or would that fall under category of messing around with the load on
>    a tube amp...
>    
>    
>    Gree Vee


In haste.....

Yep you could do that BUT be sure to get a make before break type of switch to 
ensure your amp does not "see" an open circuit for a split second as you 
switch across.

Dave Litten

    
    
    
    
    	Thanks, Dave.. this is great!! Really helpful, I'm not kidding.. I
    could have exploded my new amp by now... Pluuuuuus, I can't wait to go
    into music stores and find the crankiest sales persons I can find and
    say: "S'cuse me, dude does this A/B box have a make before break
    swicth??"  Agagagagagagaga... Is there, by chance, a way that I could
    id a switch just by lookin at er??  Make before break switch sounds
    suspiciously like the name of a 60s dance tune that I used to love, but
    I've burned out so much gray that I can't remember..
    
    Casually
    Greve Unit!!!  Saddam Tousaint!!!  Ello, Ello!!

>    Is there, by chance, a way that I could id a switch just by 
     lookin at er??  

Steve,

	Generally no,  the make before break is simply the internal mechanism 
of the switch as you flip it over. If the store has a technical description 
they should be able to advise you as this physical function is quite important 
dependant upon the customers application.

From my limited knowldge of tube output stages, I believe if you have the amp 
output open circuit (even for a second), the action of the transformer causes
a very large voltage spike to appear at the anode(s) of the output tubes and 
this causes the primary of the output transformer to break down and arc across
its windings. Once done, the transformer has to be trashed.

Make before break looks electrically like this.........

		       b
		       o------------Speaker A-------------+
		      ^					  |
		   a /					  |
AMP OUTPUT----------o					  |
							  |
			c				  |
                       o------------Speaker B-------+     |
						    |     |
ground						    |     |
----------------------------------------------------+-----+

Your switch will take the amp output a,  from b to c. A make before break will 
mechanically connect b to c, for a fraction of a second as it switches over 
(putting both speakers in parallel for a fraction of a second, but keeping the 
amp "looking" at a reasonable impedance. A break before make for example, 
would have the wiper (a) "looking" at fresh air, mid way between b, and c, for 
a fraction of a second thereby producing the above mentioned spike.

This is basic stuff....sorry if I have laboured it !!.....but your amp will be 
pleased as well as your pocket !

Dave_who has just purchased a Fender s/b (jap) 50's re-ish Tele as a sister 
for my 70's strat,and stayed up all last night dribbling and playing on it...

    
    
    
    
    
    	Thanks a lot, Dave wicked helpful.....  I git it, I'm going to qiut
    this speaker switching craziness and start trying to learn how to play
    my instrument!
    
    
    Regards,
    Steve

	I'm thinking of taking the 2 12" EVs outta my old
	AMPEG combo and building two 1x12 cabs for them.  
	I want to be able to use one or both cabs, depending 
	on what I'm doing.

	Since I've never done this, can someone provide me 
	with a good design, parts list and instructions?


	Thanks,
	Mike

    ElectroVoice will give you a great set of plans.  Write and ask for the
    plans for a Thiele (pronounced 'Teal') enclosure suitable for 12in
    speakers.  I think the enclosure model number is TL606, but I might be
    off a few digits.
    
    If you run into problems getting 'em, post a note and I'll dig through
    my archives to see if I can locate a set of plans.  I've built about 40
    of these things in various sizes and would be glad to offer
    advice/help/etc., assuming you live within driving distance of Maynard.
    

    A while back, jc re-furbished his 2x12 "ADA" cabs and clone-Marshall
    cab with this cool-looking, coordinated snake-skin tolex covering.
    Some dude in CO did it for him.
    
    I'm looking to have my Marshall cabs re-tolexed (they're *trashed*!).
    Does *anyone* out there in note-land know of ANYONE in the Mass area
    that does cabinet re-finishing work, etc?
    
    Buck, not sure where to turn

    I don't know anyone in MA that does that, but you might check into
    shops that build custom cabinets.  That's what the place that did
    Coop's cabinets main business is, but they also do repair/refurbishing
    work as well.
    
    gh

I have a question about the size of a 2x10" cabinet.  I'm in the market for one
of these (or a 2x12") to go with my 60-watt Fender head, and I've been dismayed
by the size of the cabs I've looked at.  You'd think that if you added up:

	2 * (10 inches per speaker)
	3 inches between speakers
	2 * (2 inches on the outer edge of each speaker)
	2 inches cabinet thickness
	==========================
        29 inches width

and if you added up:

	10 inches speaker height
	2 * (2 inches above/below each speaker)
	2 inches cabinet thinkness
	===========================
	16 inches height

This comes out to be a 16" x 29" box.  However, all the cabinets I've seen are
much larger than this.  Of course, I'm assuming minimal spacing between
speakers and between the speakers and the box.  The equations for proper
speaker response may in fact require larger spacings and/or enclosure volume.

What's the deal?  I'm looking for a lightweight, small cabinet.  Does such a
thing exist?  Recommendations?  Should I give up and just get a single 12"
speaker cab?

thanks,

adam

    If they're sealed cabinets, they need about 1 cubic foot of airspace
    behind a 10in speaker for it to operate efficiently.  If it's an open
    back, then it doesn't matter.
    
    Greg

re:         <<< Note 1799.81 by GOES11::G_HOUSE "With I was ocean size" >>>

>    If they're sealed cabinets, they need about 1 cubic foot of airspace
>    behind a 10in speaker for it to operate efficiently.  If it's an open
>    back, then it doesn't matter.

OK, so if this is the case, than using my reference of 16"x29", that only
requires a 0.3 foot (~4 inches) depth to satisfy your 1 ft^3 requirement.  So,
assuming you have a "normal" depth of 8-10 inches, there's plenty more than 1
cu. ft. with a 16"x29" front.

So, the question still begs - have I not looked hard enough to find that gem of
a cabinet I am looking for?

thanks,

adam

  I've got the smallest 2x10" cab I've ever seen, and it happens to be for
  sale right now...   :-)

  It's a Peavey cab, and shares the same standard "footprint" of Peavey gear.
  I don't have the measurements handy, but it is small.  I can find out the
  extact dimensions if you're interested.

  -- Sam

    Adam,
    
    From the 1983 Fender guitar amp catalog, they used to make both a
    2x10 and a 4x10 cab to match your concert head.  The 2x10 cab (from
    their specs) was 23 5/8" W x 16 1/2" H x 11 1/2" D. 
    
    I don't think they make those models anymore (like the concert head)
    but you might find one in a used/vintage shop. Cambridge Music usually
    has a good selection of old fender amps & cabs.
    
    /Steve

Isn't Coop's 2x12 still for sale?  Or did he unload it already???

Or how about an ADA 2x12?

FWIW, I didn't like the selection and the prices I've seen of 2x10 back about
5 years ago, and ended up building one myself from scratch.  It cost me about 
$115 for raw materials(including 2 Pyledriver speakers) and about 12 hours 
of work with just handtools(I wished I had a powered screwdriver, it woulda 
saved half of my time).  I was pretty happy with the result, and a friend of 
a friend ended up buying it from me for $75 to use with his PA equipment.

Jmystr

re:          <<< Note 1799.85 by CSC32::H_SO "Redline? What redline?" >>>

> Isn't Coop's 2x12 still for sale?  Or did he unload it already???

   Nope!  He "unload"ed THEM already.  To me.

> Or how about an ADA 2x12?

   Good choice.  Can't find a price on them anywhere.  FYI, if you're
   in the Springs the Music Exchange has a ABC "ADA like" 2x12 they claim
   is brand new, with a $379 price tag on it.  I'm sure they'd haggle.

   Carvin makes a 2x10 (model V210), 25x16x15 (WxDxH) which was on sale
   for $219 last month.  Don't know what the regular price is.

   Carvin's "ADA like" 2x12 (model V212) is 16x14x30, and was on sale for
   $249.

   Oh, and by the way, I checked the dimensions on my Peavey 2x10, which
   is for sale, and it's 24x13x14.

   -- Sam

If you want sizing ratio's, the inside of the box should be .6:1:1.6,
where you figure out the size of 1, and work your way back from there.
I would also estimate that you might have real tone problems if you don't 
have at least 1 1/2 cubic feet of free air (you could port it, however). 

The ratio has been a general rule since the late 1940's.

							Jens

re:      <<< Note 1799.87 by BSS::STPALY::MOLLER "Fix it before it breaks" >>>
>                           -< This might help some >-
>
>If you want sizing ratio's, the inside of the box should be .6:1:1.6,
>where you figure out the size of 1, and work your way back from there.
>I would also estimate that you might have real tone problems if you don't 
>have at least 1 1/2 cubic feet of free air (you could port it, however). 

You mean 0.6 : 1.0 : 1.6 proportional to D : H : W?

thanks,

adam

>You mean 0.6 : 1.0 : 1.6 proportional to D : H : W?

Yes. Take a quick look at the Radio Shack book, and it will give you
some general sizing ideas for different sized speakers. Many equations
for sizing haven't changed much since the 1940's, and unless you are
planning to build an exotic cabinet, the internal dimensions and porting
suggestions in the $6.00 (approx U.S. Dollars) book from Radio Shack 
should do you quite well. I realize that the book is aimed at the sterio
speaker market, but the dimensions are valid for all speaker types.
In general, the big thing that I would consider in making cabinets for 
band use is the materials - I use 5/8 inch plywood, and I brace the joints
on all edges. All my speaker systems have the speakers front mounted and
lately, I've used stamped steel grills to cover them. I cover my cabinets
in Ozite (indoor/outdoor carpet) - in any of Light Gray, Dark Gray or
Blue (Black would look nice also, but tends to show dirt more easily).

You might want to order a 'Le Parts Express' catalog to get a feel for 
available speakers and other parts (if you don't have a Local Source that
is reasonably priced - I buy from a place here in Colorado Springs that
re-cones speakers, called the Speaker Shop & often pick up speakers that
the owner re-cones and re-sells. I've gotten great deals on speakers from
8 inches up thru 15's for exceptional prices, check to see if you have
a Speaker Re-coning shop in your area first before checking out other
places, you may be able to double your amount of speakers for the same
money).

							Jens

	I have a friend who is looking to build some ported speaker cabs
	and two ( at least ) stage monitors. He all the math necessary
	to calculate the cab dimensions/port length etc, but you have to
	do tons of stuff to reach the end result. Does anyone know of or
	have software which crunches all the numbers for you ?

	regards,
				Nik.

    
    
    
    A spreadsheet is the perfect tool for this kind of thing (speaking from
    personal experience).  Enter the formulas one time, then screw around
    with the numbers until you get something that approaches practicality.
    
    
    

    I remember seeing references to such a thing in the ::AUDIO conference. 
    Try asking/searching there.
    \Gary

    
         Can anyone offer a comment/review/anything on the Mesa-B
    4x12's?
    
    Thanks,
    Kev --
    

    Does it count if I had a Mesa 4x12T ??????
    
    I personally liked the tone from my Fender 2x12 better than the
    lifeless tone of my Mesa 4x12. It was loaded with 2 Celestions
    and 2 Mesa Vintage drivers. I replaced the Mesa Vintage drovers
    with Altec's, but it didn't improve the tone much. I bought it
    originally to match my Mk2c (60/100 watt) head, but I ended up 
    selling it and going back to my Fender 2x12 cab. My Mesa 4x12 was 
    also ALOT heavier than a standard Marshall 4x12 which was another 
    factor for me selling it (read this as it was too much work to lug 
    around for $60/night gigs).
    
    Tone? I didn't like it in a band environment as much as my Altec loaded
    Fender 2x12. Although at the store (using less volume) it sounded alot 
    better.
    
    
    Have a GREAT day,
    		  Fred (who may go to a 1x12 cabinet for that "compact look")
    
    
    ;^)'s

    RE: -.1
    
    Thanks Steve! You just saved me time and $$$$$.
    
    	I betcha my wife would thank you too!
    
    
    		Fred

    More is better in my book when it comes to speakers.  To me, a 2x12
    almost always sounds better then a 1x12.  When I was using Marshall
    4x10 cabinets, I'd use one for rehearsals, and 2 for "gigs".  With one,
    the sound was kinda thin, with two it was much bigger and better (even
    a the same relative volume).
    
    Greg

I was in the Guitar Center (Boston) yesterday and noticed that they
had new Ampeg 4x12 cabs with Eminence speakers on sale for $299.

Is this a good deal?  Any comments?

Geoff

    *I* think so...
    
    I've had good luck with Emminence AND Ampeg.
    
    jc

    I have an Ampeg Celestrian (sp?) loaded system and it is awesome
    as far as I'm concerned. I bought it last year at Guitar Center for
    $299.00 no buyers remorce what so ever! go for it!
    

    I donno about the new stuff, but I had an old Ampeg 4x12 cab and it was
    built like a tank.  Slightly smaller then most 4x12s too.  I don't
    remember what it was loaded with, but it sounded fine to my ear.
    
    Greg
    

    Note the connection here - Greg HAD an Ampeg, then *I* had an ampeg...
    
    It had emminence speakers in it.
    
    jc

RE: .103

   Well...I *have* :-) :-) 2 Ampegs.

I've partially completed my Ampeg quest.  I managed to locate 2 Ampeg V4
heads.  (One of the original early 70s design, and the other of the later
mid-70s design.)

I saw the ad for the Ampeg cabinets, and I was really tempted.  However, a
new house and the stuff that goes along with it will make it wait for a bit.

I'm still keeping an eye out for some original V4 cabinets, but I won't be
able to do much until the spring.  Sigh.

- Mark

>    Note the connection here - Greg HAD an Ampeg, then *I* had an ampeg...
    
    Wish I had that one back too...you let it go for a SONG!
    
    Greg

    Yep, thats the bad part - any 4x12 that doesn't say Marshall on it
    goes cheap.  :-(
    
    jc

    Yep...  'specially if it doesn't have Celestions in it.  Can't fight
    the trends!
    
    Greg

    Even if they do, if it doesn't have the M word on the front,
    drop the price or continue to own it.  :-)
    
    jc

    
    I have a Peavey 4x10 speaker cab with an open back.  I'm wondering 
    if it's feasible to close the back of the cab altogether creating
    a closed cabinet.  What type of impact would this have on the 
    speakers ?
    
     Lv

    
    On the speakers... not much. On the sound of the cabinet, quite
    a bit. The cabinet and components were designed to be open back,
    by closing the back you drastically alter the design. You may,
    or may not, like the result... but it is impossible to predict
    exactly what the result will be.
    
    -b

    RE: <<< Note 1799.109 by OCTAVE::VIGNEAULT "Minister of chiles" >>>
                        -< Closing an open speaker cabinet .. >-
    
    Larry,
                      
    Go ahead and close it up, there shouldn't be a problem physically.
    Mesa's been offering an "optional" piece of wood to seal up their
    4x12" cabinets that are offered in a half open back version.
    
    I'd use a single piece of wood to close up the back though. Try it out 
    and see if you like the sound. If you don't, you can always put the 
    original piece back and you're back to where you started from. Make
    sure your drivers are screwed in tight before you close up the back.
    This is one major problem with Peavey amps. I use a drop of "loctite"
    to keep the screws from backing out on all my amps. It works!
    
    Go for it and have fun!!!
    
    		Fred

    
    The Peavey cab is open about 1/3rd in the back. I may just close
    it up as you suggested and see what the end result is.  I'd like
    to see if I can get a little more bottom end out of the cabinet
    by doing so.  At any rate, I probably won't do it within the next 
    couple of weeks, but if I do, I'll post a followup as to the 
    results.  Thanks for the tip on securing the drivers also.
    
     Lv

    Larry - 
    
    I should think that closing up the back WILL tighten and extend the
    bass response some - but use a healthy slab of wood and make it it fits
    tight!  Let  us know how it goes!
    jc

    If the back is sealed up, how will the cabinet breathe? It's a
    non-ported cab, right? 
    
    Not only will you affect the sound of the cabinet by sealing it up,
    but you will affect the drivers physical responses as well.
    
    As previously said. Try it out. You won't break anything, but I
    expect that overall you'll like it better the way it is.
    
    Larry

    
    Well, as it turns out, I won't be doing anything to it. The way Peavey
    assembled the back doesn't allow you to easily remove the upper or
    lower pieces of wood. The access screws are beneath the tweed covering
    and it would be messy trying to remove it.  I'll just leave it as is,
    it still sounds great.
    
     Lv