is there any reason why I shouldn't use an empty amp cabinet as an extension cabinet?

Alex W

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I have quite a few 10" speakers lying around that I'd like to put to use in an open-back extension cab. I am considering purchasing a cabinet for this purpose and am leaning toward a combo amplifier cabinet rather than a proper extension cabinet. My reasoning is that even though I am not currently looking to buy another amp, it would allow me the option of purchasing a corresponding chassis-only amp to install. I don't see any downside to this other than the cabinet without the chassis may look a little funny. The cabinet would be for home use, not on stage, FWIW. Is there something I am neglecting to consider?
 
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rdjones

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If it's a blackface style or similar with an opening toward the upper front edge it will effect the low end response in a way that may raise the lowest usable frequency.
A tweed style with the slot at the rear may be better for this reason and have a better appearance.
There's no other reason I can think of that should keep you from trying it.

"Think Ahead, Plan Ahead", get a cabinet that may match a chassis that you might consider for a "kit" or project. :cool:
 

FenderLover

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Do it. I've even re-configured them backwards. When there's a front panel slant, I turn it around and make a new baffle for the back side and leave the front open.
 

yegbert

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Is an amplifier cabinet one that is made with an integral opening, i.e. part of the same cabinet which houses the speaker(s)? If so, wouldn’t it be a one-trick pony, suitable for containing an amp of that exact size only? And wouldn’t that opening look empty without an amp in it?

Or are you thinking of a piggyback-style cabinet which is essentially a speaker-only cabinet; more or less separate from an amp, and on top of which an amp can be placed or mounted?

I have one of those separate piggyback-style speaker cabinets that was made for a BF Bassman, which I use for a SF Bassman and a BF Bandmaster. It has tilt back legs and screw nuts in it for those amps of both widths, retrofitted with additional ones for the Bandmaster; and I made a second speaker panel with two 15” Italian Jensens for it.
 

Alex W

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If it's a blackface style or similar with an opening toward the upper front edge it will effect the low end response in a way that may raise the lowest usable frequency.
A tweed style with the slot at the rear may be better for this reason and have a better appearance.
There's no other reason I can think of that should keep you from trying it.

"Think Ahead, Plan Ahead", get a cabinet that may match a chassis that you might consider for a "kit" or project. :cool:

I am considering a tweed style cab mainly, like a Super or a Bassman.
 

Timbresmith1

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I have quite a few 10" speakers lying around that I'd like to put to use in an open-back extension cab. I am considering purchasing a cabinet for this purpose and am leaning toward an amplifier cabinet rather than an proper extension cabinet. My reasoning is that even though I am not currently looking to buy another amp, it would allow me the option of purchasing a corresponding chassis-only amp to install. I don't see any downside to this other than the cabinet without the chassis may look a little funny. The cabinet would be for home use, not on stage, FWIW. Is there something I am neglecting to consider?
Go for it. Maybe block off the front chassis slot on a bf cab. Fender used to make them that way. They are rare, but they exist. Seen them in person in Del Rev size.
 

Alex W

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Is an amplifier cabinet one that is made with an integral opening, i.e. part of the same cabinet which houses the speaker(s)? If so, wouldn’t it be a one-trick pony, suitable for containing an amp of that exact size only? And wouldn’t that opening look empty without an amp in it?

Or are you thinking of a piggyback-style cabinet which is essentially a speaker-only cabinet; more or less separate from an amp, and on top of which an amp can be placed or mounted?

I have one of those separate piggyback-style speaker cabinets that was made for a BF Bassman, which I use for a SF Bassman and a BF Bandmaster. It has tilt back legs and screw nuts in it for those amps of both widths, retrofitted with additional ones for the Bandmaster; and I made a second speaker panel with two 15” Italian Jensens for it.

Yes an amplifier cabinet is meant to house the chassis of an amplifier in addition to one or more speakers. Also, yes, it would accept a particular chassis such as a tweed Bassman or tweed Super, although one could probably get a boutique amp builder to make you an X amp circuit in a Y-sized chassis box if you wanted. That said, I would most likely get the amp to match the cabinet if and when I ever decided to order an amp. In the meantime I would use the cabinet with a separate amp head.
 

Telekarster

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I have an old Gorilla amp that I was gonna toss, cause it was just a POS... then I thought "Hey, wait! I'll gut the thing and make a speaker cab outta it!" I haven't done it yet but it's on my to-do list ;) Answer - Yes... yes you can ;)
 

W.L.Weller

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I completely endorse getting a tweed Bassman cabinet as the first step toward getting a tweed Bassman.

You could make a separate "back door" with a speaker jack and save the "amp" panels for when you get/make the Bassman chassis. Just mind the impedances, series/parallel (or parallel/series) with 4 speakers of the same impedance will equal the impedance of one speaker.
 

JSMac

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I'm using an old Peavey box for a 12" extension cab. I considered making a panel to cover the chassis opening but it never happened. I wonder how much difference that would make. I guess I could experiment by temporarily sticking something in there.

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schmee

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I have quite a few 10" speakers lying around that I'd like to put to use in an open-back extension cab. I am considering purchasing a cabinet for this purpose and am leaning toward a combo amplifier cabinet rather than a proper extension cabinet. My reasoning is that even though I am not currently looking to buy another amp, it would allow me the option of purchasing a corresponding chassis-only amp to install. I don't see any downside to this other than the cabinet without the chassis may look a little funny. The cabinet would be for home use, not on stage, FWIW. Is there something I am neglecting to consider?
No reason at all. I have done it many times. The upper chassis opening (like on a Fender cab) doesn't seem to change sound much , probably because the back is so wide open. I'd have to A/B it to know for sure.I have a Super Reverb cab set up to use as an extension right now, although I haven't used it much in years.
I have filled the chassis slot before though, just for better looks, it's not hard to do like below, I cover it with Tolex.:
 

ScottJPatrick

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I have converted several 'blackface' style combos into speaker cabs, I usually strip everything off the amp chassis and then tape over all the holes except one on the rear that I use as the input jack socket. Don't know if it changes anything sonically but it certainly looks a lot better than leaving a big gap there. Peavey Backstage/Bandit type amps are great for converting as the baffle can be removed making it a lot easier to replace the speaker.
 

roadjunkie59

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I bought this off of Allen amps sometime ways back loaded it with some Weber ten inch ferromax 3 of them and used it as an extension cab and it worked until Mr Allen sold me a prototype Class Act that he built out of an Accomplice chassis. Still have it.
 

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Tim S

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It’s one thing to re-purpose an existing combo cabinet you have lying around, but I wouldn’t buy an empty combo cab with the intention of using it without an amp chassis mounted in it.

I’d buy a purpose-build speaker cab. If an amp chassis comes by my way at a later date, then I’d find a housing for it and throw it on top of the speaker cab.
 

Ringo

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I have used old combo amp cabs for speaker cabinets , they work fine. This was a very beat up old Ampeg 2-12 combo , I filled in the wood where the chassis mounted and covered in some green gator tolex. I should have kept it, it sounded great, was a bit heavy though.
 

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24 track

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I have an old fender JAM cab that i loaded with a 12" 8 Ohm I use for one of my test speakers works great , I also have G-Dec 8" I have on the repair desk 8 Ohm as well, If it works for you Rock on
 

JeffBlue

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I had acquired a Carvin Bel Air amp that had the power output board had arced. I removed the amp chassis and installed a Peavey Rockmaster preamp in it's place. I'm using it with my Fender Bandmaster Reverb amp head and it sounds excellent.
 

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The Angle

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I've done this several times with inexpensive SS practice amps that originally had 8-inch speakers. I toss the guts, install a new full-size baffle for a 10-inch speaker, add grill cloth and an input jack, and it's ready to play. As long as it's open-backed, the cabinet size doesn't matter much. Used SS practice amps can be had for a fraction of what a new cabinet costs. Although if you want one with a nice tweed covering, then an inexpensive practice amp probably isn't an option. But again, as long as we're talking about an open-backed cabinet, the dimensions of the box aren't very important. The new baffle needs to be good and solid.
 




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