Fun With Feedback loops

I originally posted this on ProToolsUsers.org

*******************Warning**********************
This post is for those that know how to setup effects using Aux In tracks and using sends to send audio to the effects. In addition, at least a basic understanding of using the automation playlists and editing the automation is a must. If you don’t have a grasp of how to add effects in Pro Tools using Aux In tracks and sends, or using automation, then please don’t attempt the following until you do.
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Here is a delay trick that is great fun (see the caution below before trying this, especially if your new to audio production):

1. Setup a delay on and Aux in (hereafter Aux1) track and set the delay time (maybe to an 1/8 note or 1/4 note) and then set the feedback to 0%, turn off all LPF etc. so that it is a simple delay
2. Pick an audio track that you want to add a delay effect to, create the send to the Aux 1 delay. You'll probably want to automate your send so that only ONE word at key places in the song are sent to the delay
3. Put a 1-band eq before the delay plug-in on Aux1, and set it to a high shelf, set to 5k and reduce by 2dB (you can certainly experiment with this part). Be careful when boosting a frequency as the added gain can cause problems in the feedback loop that your about to create.
4. Create another Aux track (hereafter Aux2), add a delay plug-in, and set the delay to the same delay amount to the same as Aux1, and set the feedback to 0%, turn off all LPFs etc. so that it is a simple delay as well.
5. Put a 1-band eq before the delay plug-in on Aux2, and set it to a high shelf, set to 5k and reduced gain by 2dB on this as well.
6. Create a send on Aux1 that will send that delay to the delay on Aux2, make sure to keep the level lower around -20 to maybe -10, but what is too much depends on the EQ setting (as this IS a feedback loop -> BE CAREFUL and be ready to lower the volume of your speakers at any moment, especially the noobs)
7. Create a send on Aux2 that will send that delay back to the delay on Aux1, again make sure to keep the level lower (-20 to maybe -10) (as again this IS a feedback loop)

Now you have a repeating delay that each repeat looses some high end. You can really have fun by changing the EQ to a peaking filter and boosting (careful, not too much) a certain frequency and listen how each repeat gets weaker in volume but that frequency band gets stronger. You can also insert a pitch adjuster in place of the delay or in addition so that each repeat goes up or down in pitch. GREAT FUN!!!!!!!!!! The possibilities are endless.

AGAIN BE VERY CAREFUL OF FEEDBACK LOOPS. You might want to start to set this up using headphones that are just sitting on your shoulders NOT ON YOUR EARS.