Tube Amp Archive

Hello,

So Making headway with a 2-channel 20/20 watt plexi stereo guitar amp in a Twin Reverb size cabinet.

I really wanted to pick your brains about expectations (either real or imagined is fine) when 2 speakers are receiving signals from stereo reverb and delay pedals, typical of the good pedals we see out there now ( strymon, Keeley, UA, etc..)

Would you expect to have any substantial inter-action between the speakers in an open back combo cabinet similar to the size and shape of a Twin Reverb? My instincts (for what that is worth) tell me that there is probably some level of interaction but, I'm in no place at this point to have an accurate expectation of what and how much that would be - destructive vs constructive, phase anomalies that could cause unintentional coloration of the sound, etc....

The idea is to mic the right channel speaker and pan to right side of PA, as well as mic the left channel speaker and panning that to the left side of the PA, with the hope that there is a fairly robust phantom center for the direct guitar signal, with a good, wide and deep stereo image of the processed time-based effects that these nice reverb, delay and chorus pedal are capable of generating. Where the speakers will be fairly close miced, I"m thinking the speaker interaction will not have a profound effect compared to say, what you might hear standing away from the speakers a fair distance. But in my head I wondering if say, installing a baffle or separation of sorts between the speakers would or could provide a little bit of positive isolation between the speakers that could help maintain the soverienty of the signals hitting the speakers from the time-based pedal outputs.

I'd really be interested in what your take is on that aspect of my up and coming stereo plexi in a Twin Reverb cabinet.

Thank you, and happy holidays.

Best,
Phil pjd3

The only complaint I've had about two speakers interacting is when I had my 2x12 cabinet set vertically (Dumble style) and played standing up near the speaker. I heard comb filtering. Whereas setting the cabinet horizontally sounded better.

If your speakers are identical, you should get a center guitar image, while stereo reverb and delay can widen the overall image.

Hi xtian.

Yup. Speakers with be identical, amps are as identical as I can make them be, and each speaker will be miced with the same mic equa-distantly and with the mic angle that I believe to provide the best speaker pickup with perhaps a good rejection of the adjacent speaker.

Thanks for your comment.

Best,

PJD3 Phil

I would think that the interaction would be minimal, as the cab is open back, and each speaker is close miked. I suppose a divider would provide a greater degree of isolation but I don't think it would be audibly different. Sounds like the kind of experiment I would do when I had time on my side.

...pulling up a chair, popcorn at the ready...

Separation may be enhanced using a "V" front baffle.

xtian wrote: ↑Mon Dec 23, 2024 10:17 pm The only complaint I've had about two speakers interacting is when I had my 2x12 cabinet set vertically (Dumble style) and played standing up near the speaker. I heard comb filtering. Whereas setting the cabinet horizontally sounded better.

If your speakers are identical, you should get a center guitar image, while stereo reverb and delay can widen the overall image.

I have to agree that comb filtering is a problem -- with two out of phase speakers in close proximity it sounds bad. OTOH if you can get some distance between them then the comb filtering helps to widen the overall image for reverb, delay and phase shifting.

When I was experimenting with a DIY WDW system for stage use I liked to use two little combo amps at the far sides of the stage for the wet sources with the main dry amp in the middle. IMO WDW systems never sound good without adequate separation of the wet sides of the signal.

edit: I use WDW as an acronym for wet-dry-wet