In Between Phaze-

Baby · Posted: Thu May 04, 2006 3:50 pm Post subject: In Between Phaze-

Hello all-

This is post #1 so I should hope to make a good introduction. I am the new proud owner of a G2 as I have passed along my NM1. There are things I miss about it, but this is not the time or topic.

Lurking I heard mention of the concept of an all pass filter which sparked my memory to a reference:

http://www.littlelabs.com/ibp.html

and

http://www.littlelabs.com/IBPMAN.pdf
(large file)

All pass filters for adjusting the phase relationship between 2 signals.

Thinking that the G2 can do anything, I started working on a patch. Here is what a final version would look like. To really hear it in action, attach the Osc to both inputs and put the uneffected into the mixer before the output.

I dont have the crossover right at all. I cant seem to figure out how to make one filter track up and the other down. I'm doing all of this by ear right now. It seems too phase shifty.

It would be nice to do it with my Nord and not have to buy the box. He does live about a block away...

Anyone's help of input would be kind.

Thanks!

Babyhead

IBP.pch2

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blue hell · Posted: Thu May 04, 2006 4:12 pm Post subject:

Hi Baby,

I should read the articles you pointed to, after such a nice introduction, but I didn't, maybe I will Very Happy

Still ... the patch has potential, there are some nice things going on, not all the time, but it makes surprises every now and then.

Baby · Posted: Thu May 04, 2006 5:35 pm Post subject:

Thanks for the reply!

I'm looking to use this patch to correct phase problems between 2 sources, like acoustic guitar and vocals or especially DI an mic for bass.

The pdf has an interesting article about what phase really is... Jon Little is a hero in some tech circles.

I'd really like to figure out how to build a crossover that tracks correctly. If anyone has some suggestions on how to make the HPF and LPF track to the same frequency and not have a nasty phase shift...well... It would be bitchener if the frequency could be displayed, but I think that might require a future G2 editor.

Thoughts?

This also might be made into a cool phaser...

-Babyhead

ian-s · Posted: Thu May 04, 2006 6:17 pm Post subject:

I don't have any external audio plugged in so I cant listen to your patch. The FltMulti, bp out in 6dB mode is the type of allpass you want*. Two of those and some switches and you could knock off the IBP. Add a delay and you could have time and phase alignment at once.

Rob also makes an allpass with a 6dB lowpass and a couple of mixers.