Wierd bug or something I'm doing wrong?

When I have 2 or more similar loops running over each other the overall sound changes each time the loop is triggered. I've recorded some examples for you to hear what I'm talking about;

http://www.base615.dircon.co.uk/loop.mp3 : the full 4 bar sequence

http://www.base615.dircon.co.uk/track1.mp3 : Only track 1 playing (straight drum loop)

http://www.base615.dircon.co.uk/track2.mp3 : Only track 2 playing (same drum loop with following filter applied - high pass, freq 25, res 100, att 0)

The drum loop is 2 bars long so is triggered twice, step edit info for the 2 tracks are;

TRACK1:
001.01.00 P:A01( 37) T: 0 D: 8 V:127
003.01.00 P:A01( 37) T: 0 D: 8 V:127

TRACK2:
001.01.00 P:A03( 42) T: 0 D: 7 V:127
003.01.00 P:A03( 42) T: 0 D: 7 V:127

I've copied bars 1 and 2 to bars 3 and 4 in both tracks so the second triggering of the sounds should be identical. As you can hear in track1.mp3 and track2.mp3, the second trigering sounds identical, it only happens when they are layered on top of each other.

I've tried this with different drum loops and it always does this.

Any ideas?

Craig

it's actually doing what it is supposed to. nothing is wrong.

you're using an eq'd version of a sample layered over itself. what you're hearing is the phase shift between the layered samples.

analog eq works by manipulating phase. like taking a phaser pedal and turning the rate completely off. if you do that in a particular spot, you can boost or cut, say, 500 hz or whatever. im sure there are other ways it works too, but that's generally how analog eq works.

digital eq does the same thing but instead of shifing phase it uses comb filtering (delay).

they both work in a similar fashion and if ive made any sense you'll understand why you're hearing phasing in your track.

it's also possible that the mpc is inducing latency while processing the filtered track. 2 identical sounds that happen at very slightly different times will also produce a phasing sound - eq or no eq.

hmm i hope this made sense.. im testing my new robot butler while typing this

Thanks for your reply. In that case how do I get the first 2 bars to sound exactly the same as the second 2 bars? It's the same 2 samples being triggered at exactly the same times, I don't understand why it will sound different every time.

Craig

as long as you have the 2 loops running concurrently, with one being eq'd, you're gonna hear phasing.

Playing back two identical audio files will produce phasing/comb filter effects, unless they're locked and starting from the same sample within the file, in which case you'll get a level boost. In other words, what you think is happening: "the same 2 samples being triggered at exactly the same times " ...is not, they're off and the actual amount varies with each trig. Hence the difference in sound, which is useful, only that you'd like to control it.

The nature of midi does not allow this, but you can do it in standard audio sequencers/multitrackers, which you might not be interested in on the other hand. Then there's the alternative of making a mix, a new sample of the two, mono or stereo. All but the most basic audio editing software is capable of that. So what you want to do is possible but requires some 'offline' editing.

..And if you have a (preferably analogue) phaser where you can turn off the modulation, spend some hours sampling things thru it. I promise you, there's good stuff!

(several edits to this post. sorry.)

Somethin u doin wrong!