New/Tedious Adventures In Bi-Amping

Post by **Doog** » Sun Nov 13, 2011 10:07 pm

A pretty boring and niche topic here, but I thought I'd share for my bi-amping bros.

Often times when running a two-amp setup, you'll get problems where the amps or speakers are out of phase or the room is doing odd things; all causing phase cancellation, making your shit sound weedy and swooshy. Not cool, especially if you don't want to sound weedy and swooshy.

To illustrate my awesome solution to this in a live situation (which I'll be using from now on in Casa Bonita), I ran my pedalboard into 2 channels on my mixer, panned hard left and right.

► Show Spoiler

Check out what a difference adding a tiny bit of delay to the left guitar makes. I'm using a Behringer delay pedal set to the lowest delay time possible (switched on and off, starting 0:13), but it makes your shit sound all beefy without being echoy.

The delay between the two amps avoids these phase issues, with the added bonus of a slight thickening effect, much like the "Double Tracking" delay on the Polychorus, pour examplÃ©.

In a live situation, you don't have the ability to hard pan each amp into the audience's earholes, making the phase issue even more of a problem in a real life live situation. THIS'LL SORT Y'ALL OUT!

Bacchus · Post by **Bacchus** » Sun Nov 13, 2011 10:14 pm

excellent work.

Post by **Mike** » Mon Nov 14, 2011 8:45 am

Wahey - sounds PHATBEATS

gaybear · Post by **gaybear** » Mon Nov 14, 2011 9:48 am

not a boring thread at all, and as far as niche topics go, it would seem to fit the forum title pretty well.

stewart · Post by **stewart** » Mon Nov 14, 2011 5:05 pm

for some reason i can't get the file to play on safari so will have to install firefox on the new computer to hear it BUT! i suspect i'm going to regret selling you that delay pedal!

stewart · Post by **stewart** » Mon Nov 14, 2011 5:30 pm

NickS · Post by **NickS** » Mon Nov 14, 2011 5:52 pm

My Firefox says it needs a plug-in but won't do anything about it.

Post by **Doog** » Mon Nov 14, 2011 6:34 pm

Lolz, sorry Stew.

Here's a direct link to the mp3, y'all: http://bestnetworx.com/uploader/files/3/BiAmping.mp3

stewart · Post by **stewart** » Mon Nov 14, 2011 6:59 pm

NickS wrote:My Firefox says it needs a plug-in but won't do anything about it.

plug-in here- http://www.interoperabilitybridges.com/ ... n-download

jumbledupthinking · Post by **jumbledupthinking** » Mon Nov 14, 2011 9:21 pm

Not tedious at all. That sounds fucking amaze-balls. Good work!

(I knew there was a good reason for keeping 2 delays on my board)

ekwatts · Post by **ekwatts** » Mon Nov 14, 2011 10:56 pm

Excellent work, Doog. Been considering the 2-amp route just recently.

avj · Post by **avj** » Tue Nov 15, 2011 5:34 am

This is the complete opposite of boring! Very cool stuff, and something I had never considered when bi-amping for a short spell.

Thanks loads for taking the time to do the short clip as well. It was a fantastic journey that took me from a simple nod of confirmation after reading the explainy-words to a full-on, all-limbs-risen rejoice.

stewart · Post by **stewart** » Tue Nov 15, 2011 9:23 am

i tried this last night at rehearsal with a SMMwH and it didn't work all that well. sounded better without it. will try some more in-depth experiments at a later date...

Post by **Doog** » Tue Nov 15, 2011 8:17 pm

Glad youses guys found it useful!

stewart wrote:i tried this last night at rehearsal with a SMMwH and it didn't work all that well. sounded better without it. will try some more in-depth experiments at a later date...

It really needs hardly any delay at all, according to the manual, the lowest delay time available (which I'm using) is 32ms. The SMMwH apparently goes from 1.8ms to 3150ms on the delay dial so finding the sweet spot might be tricky.

You're putting the delay in your "2nd amp only" FX line with the SMMwH set all the way to WET, right?

stewart · Post by **stewart** » Tue Nov 15, 2011 9:01 pm

Doog wrote:You're putting the delay in your "2nd amp only" FX line with the SMMwH set all the way to WET, right?

aye. it didn't sound bad or anything, just not noticeably beefier. it was more focussed and direct without it. i'd like to have another go next week, i only spent 5 minutes twiddling with it as we were setting up.

Post by **Doog** » Tue Nov 15, 2011 9:31 pm

The further apart your amps are horizontally, the more noticeable the effect will be; if you've got 'em stacked like you do live, it might not make such a difference, to be honest.

stewart · Post by **stewart** » Tue Nov 15, 2011 9:43 pm

aha, probably part of the praaablem right there.

lorez · Post by **lorez** » Tue Nov 15, 2011 11:55 pm

I was going to ask about where you were stood between the amps as this would have an affect but if you are stacking them then try splitting them. in the sound files Doog mentions that they are panned hard left & right which with the delay really helps with beefiness. I think this is a great technique and I used to use something similar when recording and time was tight to create a multitracking type sound and doing double tracking/overdubs wasn't a possibility.

moogmusic · Post by **moogmusic** » Tue Nov 22, 2011 11:14 am

This is quite an interesting one to me. For preamping, I use a GT-8 running two different amp models in stereo and then either plug them into the returns of two different amps or, if I'm using my own kit, either side of my EL50/50 and then into one or two cabs. Using the two different amps models definitely thickens the sound but I've never noticed any phase issues, although this could be because both my signals are being generated in the same way so they don't have the chance to get out of phase.

Presumably, the delay trick could, if the delay was short enough, could cause phase cancelling as opposed to eliminating it and it would all depend on the amp placings, the acoustics if the space and the position of the listener?

Rhysyrhys · Post by **Rhysyrhys** » Tue Nov 22, 2011 11:51 am

moogmusic wrote:This is quite an interesting one to me. For preamping, I use a GT-8 running two different amp models in stereo and then either plug them into the returns of two different amps or, if I'm using my own kit, either side of my EL50/50 and then into one or two cabs. Using the two different amps models definitely thickens the sound but I've never noticed any phase issues, although this could be because both my signals are being generated in the same way so they don't have the chance to get out of phase.

Presumably, the delay trick could, if the delay was short enough, could cause phase cancelling as opposed to eliminating it and it would all depend on the amp placings, the acoustics if the space and the position of the listener?

In theory yes. If signal could be delayed so that the + and - phases of the complex signal would line up. I'm pretty sure thats a part of why you get certain phase issues in complex set ups, like a recording studio, during installation. The signal is delayed by the amount of routing/RAM capacity or speed/<insert bottleneck here>, which ends up with it arriving at the disk or tape fractionally slower than another instance of itself.