15" speaker in a Twin Reverb. Off-center or centered?
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- G. Robertson
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15" speaker in a Twin Reverb. Off-center or centered?
I've read about locating single speakers off-center in open-back combo cabinets to reduce standing waves, resonances, etc. Any merit to doing this? I'm about to make a single 15" baffle board to mount my Altec 418 in my '68 Twin Reverb.
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The Fender Twin Custom w/ 15" is off-center - by quite a bit. Don't know if there is anything to it or not.
I would not think it would matter for an open-back cabinet.
http://www.fender.com/guitar-amplifiers ... ml#start=1
I would not think it would matter for an open-back cabinet.
http://www.fender.com/guitar-amplifiers ... ml#start=1
- Bill A. Moore
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Re: 15
In a practical sense? And in a Twin Reverb amp? No, none whatsoever.G. Robertson wrote:I've read about locating single speakers off-center in open-back combo cabinets to reduce standing waves, resonances, etc. Any merit to doing this?
It's done both to avoid the output transformer and to counterbalance the power transformer.
Last edited by Lane Gray on 25 Feb 2015 8:06 am, edited 1 time in total.
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- Tim Whitlock
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You may be able to center it depending on the speaker but Lane is right, it carries better offset. I had to offset mine so that the transformer could reside between two of the spokes in the speaker.
As an FYI - www.mojotone.com quoted me $90 plus shipping to build a 15" Twin Reverb baffle, complete with grille cloth of your choice. You might want to contact them. I like to DIY but I could hardly build one myself for cheaper than that, if I include my time in the cost.
As an FYI - www.mojotone.com quoted me $90 plus shipping to build a 15" Twin Reverb baffle, complete with grille cloth of your choice. You might want to contact them. I like to DIY but I could hardly build one myself for cheaper than that, if I include my time in the cost.
- Jack Stoner
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I had an AB768 chassis Twin Reverb (I think a 70 model). It came with two JBL D-120F's. I replaced the speakers with one JBL K-130 4 Ohm. It had to be off centered because of the transformer.
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Re: 15
My experience is the opposite. I just redid an amp so the single speaker was centered and it was an improvement. It can be tricky to center a speaker in a combo but it can be done.G. Robertson wrote:I've read about locating single speakers off-center in open-back combo cabinets to reduce standing waves, resonances, etc. Any merit to doing this? I'm about to make a single 15" baffle board to mount my Altec 418 in my '68 Twin Reverb.
Bob
- Bill A. Moore
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- Keith Murrow
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I don't see how I could have centered the speaker in my '73. Hard to see in this picture, but the transformer comes really close to sticking into one of the openings in the speaker's frame.
It's not particularly balanced in this configuration, although not badly out-of-balance.
My hat's off to anyone with good enough ears to hear a significant tone difference from moving a speaker a few inches in a shallow, open-backed cabinet.
It's not particularly balanced in this configuration, although not badly out-of-balance.
My hat's off to anyone with good enough ears to hear a significant tone difference from moving a speaker a few inches in a shallow, open-backed cabinet.
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