Postby Stringpark » Wed Nov 30, 2011 5:28 am
Thank you all for the replies, they have all really helped. I did some more playing around after posting and I figured I'd post the results in case someone else with a similar setup finds it useful. First, the driver. The Alesis IO|2 (original version) came with an Alesis ASIO driver on CD (though ASIO4All is what they now have as the IO|2 driver for download on their website). I have both this driver and ASIO4All loaded. I ran a hard loop between the analog out/in of the interface and using Cubase, did some latency testing. Between the two drivers, ASIO4all came in a little faster (by a millisecond or so as I recall), even when both were set to the same sample rate and number of buffers. I did a LOT of testing and its been a few days now, but to the best of my recollection, the overall round trip delay for audio was about 10ms or so with ASIO4all. This was at a buffer of 256 as the 192 from my original post turned out to be a little too optimistic once the drummer really got going. I did a hard loop test through the S/PDIF connections and was surprised to see that it was about a millisecond slower than analog. Also, its worth noting that the buffer settings in the drop down "I/O Settings" in Eco do seem to have an effect on things, though they don't directly change the value in the ASIO driver control panel. For example, if the drop down buffer setting is 256, I get pops when I run the buffer down to 128 in the ASIO control panel. 128 is too low of a number for my setup, but if I change the Eco drop down setting to 128 to match the ASIO control panel setting, it actually pops less than when the drop down was set to 256.
Using Cubase again, I did some Midi latency testing with a hard loop on the interface. Here I measured about 3ms. So, assuming that I can divide that measurement in two to get just my input midi latency and divide my 10ms of audio latency in two to get just my output audio latency, then I'm coming up with about 6 to 7ms of total latency.
Next, I wanted to mention that I turned off my page file. This made a noticeable improvement in the pops and clicks (confirming that my 5400 RPM drive was struggling to meet the data demand). Lastly, I was getting just a slight pop on a fairly consistent basis even with little drumming activity. I selected an option in the ASIO4all control panel saying something about "force WDM to 16 bit". For some reason, this stopped that particular pop.
So, I'm pleased to report that I got to debut the new rig to our drummer tonight and it worked well. There is virtually no distinguishable difference in the timing of the Eco sounds vs the internal Roland sounds. Our drummer was pleased with the "responsiveness" of Eco (referencing the velocity layers I believe) vs the internal sounds of the TD-10 brain and with a little mixing, it sounded absolutely ridiculous! I still detected a very occasional pop, so I may look at the 7200 RPM drive. I noticed that multiple people mentioned an external drive and I assume there may be an advantage to having the sample data on a different drive from the OS. If so, is this still an advantage if the external drive is connected via firewire vs replacing the OS drive with a 7200 drive that would be connected via SATA? I have firewire available on the pc as well as a PCMCIA slot (so I guess I could get esata if needed).
Thanks again!