Subject: Re: [AUDITORY] MIDI Drum Pads: Delay and temporal resolution From: Julius Smith <jos@xxxxxxxx> Date: Wed, 19 Jun 2013 01:13:47 -0700 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY><html> <body> <font size=3>Apparently one can get a tap-to-sound latency of 5.8 ms in iOS:<br><br> <a href="http://www.synthtopia.com/content/2011/12/03/developer-it-is-not-possible-to-play-music-on-an-android-phone/" eudora="autourl"> http://www.synthtopia.com/content/2011/12/03/developer-it-is-not-possible-to-play-music-on-an-android-phone/<br> <br> </a>To get below 1 ms I would probably connect a piezo film to an Arduino or something like that.<br><br> - Julius<br><br> At 10:04 PM 6/18/2013, SKoT McDonald wrote:<br> <blockquote type=cite class=cite cite="">In 2006 at FXpansion, we made measurements of different drum module's latencies as part of an investigation into why certain users were experiencing bad latency with their e-drum kits when using our BFD range of drum software.<br><br> We found that Roland TD-20s were quite slow - it seems their propitiatory COSM modelling of impacts added 1-2 ms, even for MIDI-only event output; positional information was sent before the note onset in the form of MIDI CC messages - each 3-byte MIDI message adds 1ms - and some pads were sending 2-3 MIDI CC messages (hihats in particular!). The TD20 of the time had no USB MIDI option.<br><br> A Yamaha DTX kit by contrast had less pre-processing of impacts, a USB connection for MIDI, and less MIDI CC positional information, which I think you could switch off too - this made the Yamaha "brains" about 3-4 ms faster to get a MIDI Note to the sequencer or instrument on your computer.<br><br> Our audio devices tended to be high end, such as RME Firefaces with 64 sample buffers (~1.5ms @xxxxxxxx 44.1kHz).<br><br> Considering that ~6ms is the border of average human timing discernment, we found "rhythmically highly trained" subjects, like drummers, were capable of being put off by the TD-20's lag, despite being the highest priced kit in the market. We hassled Roland for many years to at least add a MIDI USB connection...<br><br> Cheers,<br><br> SKoT McDonald<br><br> <br><br> On 18/06/2013 7:09 PM, Andre Holzapfel wrote:<br> <blockquote type=cite class=cite cite="">Dear Benjamin,<br><br> we will have a paper in this years SMC conference related to the acquisition of tapping data using software implemented at INESC TEC in Porto.<br><br> We did an experiment to determine the overall latency when using a MIDI interface (Roland Handsonic HPD-10) connected through a Digidesign USB sound card to a 2012 iMac. The obtained latency was 17ms. I do not know how much you can gain by using more high end interfaces, but I would agree with the previous response, that it is very unlikely to get even close to sub-millisecond accuracy using MIDI.<br><br> Please let me know about your further investigations, contact me if you like to obtain the paper in advance.<br><br> Best,<br><br> Andre Holzapfel<br><br> <br> Quoting Benjamin Schultz <benjamin.schultz@xxxxxxxx>:<br><br> <blockquote type=cite class=cite cite="">Dear Auditory List,<br><br> I am currently looking at purchasing a MIDI Drum Pad for experimental research involving finger tapping. There appears to be very little information regarding how much of a time delay there is between the pads being tapped and the sound being produced (via external MIDI devices or the drum pad's internal sequencer).<br><br> I'm looking to have the smallest time delay possible (sub-millisecond would be ideal). Does anyone have any advice about the best device to use and what kinds of time delays I should expect from the device? Their unit of pulses per quarter note does not appear to be very informative.<br><br> Kind regards,<br><br> Dr. Benjamin G. Schultz<br> Post-doctoral Fellow<br><br> Sequence Production Lab<br> McGill University<br> Stewart Biology Building<br> 1205 Dr. Penfield Ave., Montreal H3A 1B1<br> Montreal, Quebec H3A 1B1<br> Canada<br> Tel.: 514-398-5270<br> Fax: 514-398-4896<br><br> Email: benjamin.schultz@xxxxxxxx<br> <a href="http://www.mcgill.ca/spl/members/currentmembers#SCHULTZ" eudora="autourl"> http://www.mcgill.ca/spl/members/currentmembers#SCHULTZ</a> <<a href="http://www.mcgill.ca/spl/members/currentmembers#SCHULTZ" eudora="autourl"> http://www.mcgill.ca/spl/members/currentmembers%23SCHULTZ</a>> <br><br> </blockquote><br><br> <br> ----------------------------------------------------------------<br> This message was sent using IMP, the Internet Messaging Program.</blockquote></blockquote> <x-sigsep><p></x-sigsep> <br> Julius O. Smith III <jos@xxxxxxxx><br> Prof. of Music and Assoc. Prof. (by courtesy) of Electrical Engineering<br> CCRMA, Stanford University<br> <a href="http://ccrma.stanford.edu/~jos/" eudora="autourl"> http://ccrma.stanford.edu/~jos/</a> </font></body> </html>