Re: [LAU] midi triggering delay

From: andy baxter <andy@email-addr-hidden-online.co.uk>
Date: Tue Sep 08 2009 - 12:14:24 EEST

andy baxter wrote:
> Hi all,
>
> I'm trying to get my usb midi keyboard (an edirol PCR 800) working with
> my good laptop (a 1400 MHz core 2 thinkpad X61s). I have jackd running
> with 8 msec latency and no xruns using an onboard intel HDA sound card.
> When I hook up qsynth (fluidsynth) to the keyboard's alsa midi output,
> the notes are triggered with a slight (<0.1s?), and variable time delay.
> Sometimes the note plays immediately on pressing the key; sometimes
> there is a noticeable delay. This does not happen when I use the same
> setup on my old laptop (a 1400 Mhz single core dell).
>
>
OK, I have tried the following:

- using a program which turns the computer keyboard into a virtual midi
device. This makes the sound much more immediate. Having tried this, the
contrast makes it obvious that there is still a problem with delays from
the edirol keyboard.
- running qsynth using the alsa driver. No difference - when I play from
the edirol keyboard there are still noticeable and annoying delays.
- running qsynth as root (using alsa). Again no difference.
- using zynaddsubfx instead of qsynth (again with alsa). Again, there
are noticeable delays.

This makes me think that the problem is to do with the usb midi driver
or the usb hardware on my new laptop - maybe an interrupts issue? I'm
not sure how to get round this though. I'm wondering if getting a
cardbus usb adapter would help?

andy

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Received on Tue Sep 8 16:15:02 2009

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