Originally Posted by TNM
have the latest drivers helped with low latency performance at all?
Ok - I have been following this thread and am simply surprised at your problems with Duet mostly concerning the issue of latency. I was an extreme early adopter of native recording and dumped my Pro Tools system probably a couple years to early (RISK days, PPC, OS8-9) but since OSX and all intel based macs I found that latency in a native system became very manageable even when you where using software monitoring.
The exceptions for me are rare and usually very large DSP dense sessions using CPU hungry third party software instruments using large samples and/or I had become fixed on some of Logic's very well done mastering plug-ins (Linear Phase EQ - Adaptive Limiter etc). I realized there where limits that needed attention to detail to manage latency while monitoring through software. The solution in this situations was using the Low Latency monitoring functions of nearly every audio interface in the industry. In those early days - the RME Nubus solution saved me as their Low Latency monitoring was excellent.
Here is a quick detail list of what will affect latency
High Sample rates - you need to know that 96K at 32 samples in Logic is ultra low latency that takes some 'juice' to produce. This will give you a 3.6 ms round trip latency - that's really low for USB. At 44.1 at 32 samples it would be 4.3 ms. Still really low. With USB anything around 5 is excellent. If you can hear 5ms - then you need to use the interfaces low latency mode.
Mastering Plug-ins in Logic - when tracking mute or don't use plugins on your output and master faders.
Third Party Plugins and Instruments - some of my favorite companies (such as NI) are notorious for really poor buffer performance. Because playing software instruments is the one aspect that a low latency setting will not assist, this is my biggest pet peeve. In some RARE situations I have had to freeze tracks to get back some headroom.
Old CPU's - using old OSX. It has to be 10.6.3 or later if you are using USB. It has to be an Intel based Mac. Simple. This is all common sense in my opinion
Low Latency Setting. This is simply routing the audio input back to the output of an audio interface before the software. Most interfaces have it. The only drag with this setting is you should turn off software monitoring and then the signal is dry. There is a simple fix for this in Logic. Simply leave software monitoring on and when you set up a fader for tracking don't insert effects but rather use sends to aux faders with effects inserted there. Turn off the tracking faders output (temporarily) and then track. You will heard the audio input via the device (sub 1ms latency) but the software tracking fader will still have the sends active. The returns from the Aux's going to your outputs. All latency to the FX's via the sends will now be pre-delay. There are other ways to set this up that are a tiny bit slicker but I think you get the idea. I use this rarely. My favorite thing about Pro Tools HD Native etc.. it that this style of low latency tracking is seamless in the system. Avid go it right with their PCI systems.
As you can see, I really dislike the latency myths and mistakes out there, there are limits, there are reasons and there are solutions. You may need a new CPU or you may have a broken interface and you may need to examine how you are tracking and with what tools. All I know is the Duet is a pretty excellent box and with a 2X2 box, latency should be an afterthought and a non issue.