www.megadrum.info

I have been having a lot of fun with Megadrum for almost a year now

I started using Megadrum on my old Toshiba laptop (Pentium-M 2.0Ghz 1024Mb ) connected to a Terratec aureon Firewire external sound card and EasyDrummer as softsynth.

A friend, who is a musician (not a drummer) came over a few moths ago and he immediately noticed the delay between the hit on the kit and the sound from the PC
I measured the delay with my scope and it was 25 milliseconds, after tweaking the PC I got it optimized to about 20 Ms and accepted that lower latency was not possible with this computer.

Now I have recently both a faster PC (Pentium E5300 dual core 2,6Ghz 4096Mb) and expected it to be faster.
An other friend came over, he is a drummer, he immediately started whining about the delay

I pulled out my scope again, delay 18Ms, to give you an idea, that’s like hitting your snare drum and the speaker which is producing the sound is placed 6 meters or 18 feet away from you.

Tonight I decided to further analyze the cause of this delay, so I connected my synthesizer thru Midi to my Megadrum,
delay around 10Ms, what Does my hardware synth have 8Ms latency???
To make sure I measured the delay between the piezo and the midi out data.
To my surprise there is a huge variation in latency on the Megadrum midi out port.
The average latency is around 4Ms worst is about 8Ms, latency is measured on the piezo from trigger > 1.0Volt – Midi data last bit send.

Megadrum firmware version is 20090729.
Measurements taken after Megadrum startup with right button pressed.

Below you find the worst scope reading, the picture shows all settings.

I hope there is a way to improve Megadrum performance.
Please advice.

Thanks in advance,
Rob.

If you haven't already, try the latest ASIO drivers. If that doesn't do it then you may need a quality sound card. I get delay in my old Dell that drives me crazy, but I am resigned to the fact that I am just stuck with it.

jman 31 wrote:If you haven't already, try the latest ASIO drivers. If that doesn't do it then you may need a quality sound card. I get delay in my old Dell that drives me crazy, but I am resigned to the fact that I am just stuck with it.

Thank you for your answer Jman,

Please read the above again, I'm refering to the time Megadrum takes to put out midi, thats before the computer or synthesizer.
Did you have measured your latency? or did anyone else?

1. You can play with Latency (global) and MinScan (per input) settings.
2. It is possible to achieve under 5ms latency with a good sound card and proper ASIO drivers.
3. Upgrade to the latest MegaDrum firmware.
4. It takes 3ms for sound to travel 1m in the air.

Sorry man, no I haven't measured this. I just breezed through your post without reading it carefully!

dmitri wrote:1. You can play with Latency (global) and MinScan (per input) settings.
2. It is possible to achieve under 5ms latency with a good sound card and proper ASIO drivers.
3. Upgrade to the latest MegaDrum firmware.
4. It takes 3ms for sound to travel 1m in the air.

Hi dmitri,

Will do, I'll post results later.

Thanks.

jman 31 wrote:Sorry man, no I haven't measured this. I just breezed through your post without reading it carefully!

No problem man

As a guide, MegaDrum's internal latency can very between MinScan to MinScan+Latency.
Lowering Latency too much will degrade overall performance (due to Atmega's performance limits, so Atmega644 at 20MHz is better in this respect).
Lowring MinScan too much may result in bad level precision for the input.

dmitri wrote:As a guide, MegaDrum's internal latency can very between MinScan to MinScan+Latency.
Lowering Latency too much will degrade overall performance (due to Atmega's performance limits, so Atmega644 at 20MHz is better in this respect).
Lowring MinScan too much may result in bad level precision for the input.

Last time I updated firmware (few months ago as you can see by my version) I managed to corrupt my bootloader (v2).
I needed to reprogram the atmega32 with an ISP cable.
After that I got a little scared for updating the firmware, my fear has become reality now ,
I’m no longer able to program over USB, not with Midi-ox or MCT.
The display shows “update finished” for ever, rebooting leaves the display blank.

So I guess that popping in a Atmega644 with a 20Mhz crystal would decrease latency and also solve my programming problems?

Thank you for your advice.


Rob.

Megadrum hardware is just as good if not better than any MIDI device you can get - bar none.

Any computer hardware from the last 7 years that can play a DVD can monitor MIDI without a hitch. MIDI communication speed was based on the commonly available (cheap) watch crystal, and man, this is really slow, about 365 times slower than the first USB devices.

You have a problem with the consumer computer revolution - oh, then you must have a problem with latency too. But lets not assign these problems to MIDI!

[edit] I seems to have a bee in mi bonnet don't I luv...