recording monitoring latency

If someone could help me with this, I'd appreciate it. Especially if you have a Presonus interface. I'm getting latency when I monitor while I record. It's an ugly, phasey metallic sound. I've got Reaper's Request block size set to 64 - I set it that low because higher settings sound worse. I've got my interface buffer set to 64 as well. Presonus Firestudio Mobile. The driver's up to date. Windows 7 SP1 64-bit. Reaper 4.77 64-bit. BTW, I get different results depending on whether Record Monitoring is set to ON, OFF or AUTO. What do those settings do? I've only ever used Reaper for MIDI stuff, but last night I started using it for recording audio. I need to be able to monitor while I'm tracking if I want to use the click. I haven't even gotten as far as overdubbing yet.

Sounds like phase cancellation from having two identical signals playing at slightly different times. Go to the presonus mixer and mute all the input tracks except "software". They are being monitored in Reaper, so you don't need another direct monitor there.

No prob. :) It's pretty easy to understand though. Your audio interface takes inputs and turns each input into a digital signal. If you didn't have a DAW you would need that mixer to output the signals back to the hardware output for you to hear them so they make that default. You want the signals only thru Reaper, so you must disable their default course or get those nasty comb-filtering doubles...

No, I understand, really. It's a mindfuck that took me a long time to sort. But when you do understand, it's simple. Audio routing is identical to pipes routing water flow. Just ignore that stupid mixer for now. It's moot when you have a DAW. Otherwise it tries to do the job of your DAW so people without DAWs buying the product will be likely to hear *something* when they first plug it in.