Re: Macbook and Macbook por Audio loss when plugged into a specific usb port
Re: Macbook and Macbook por Audio loss when plugged into a specific usb port
- Subject: Re: Macbook and Macbook por Audio loss when plugged into a specific usb port
- From: Andy Peters <email@hidden>
- Date: Mon, 29 Jan 2007 15:51:38 -0700
On Jan 28, 2007, at 3:43 PM, Herbie Robinson wrote:
At 6:00 PM -0500 1/25/07, email@hidden wrote:
Here is a HUGE problem alot of macbook owners are having with the
whole macbook line (pro included). If we plug in a usb audio
device like Serato scratch live (standard software in the dj
world) or ProTools M-Box, (again a standard in the music
industry), We get usb dropouts when we touch the keyboard or
trackpad after it sits for more than 10 seconds (This means we
lose connection to the box for a second and the audio cuts out).
This is because on the new line of macbooks they have routed the
keyboard and mouse through the usb port as you can see in the
system profiler. All the tests that I and other people have done
show that after about 10 seconds of no use on the keyboard and
trackpad they actually either go into a standby mode or go to
sleep and then when you go to use it, it wakes up and draws enough
power and/or data from the usb port to cause the audio interface
to drop out for a second. Does anyone know a way or have any
suggestions on how to keep the keyboard and trackpad on and not
cause it to go to sleep every 10 seconds. I would expect better
quality out of a $2500 laptop that claims to be great for audio
products and alot of people who own them can't even use one of the
usb ports for audio interfaces which really sucks. Never had this
problem with any of the ibook or powerbook lines. Apple, Someone,
Please help, the audio community is begging for an os update that
keeps the keyboard/trackpad on.
Reliability wasn't one of the design points for USB; so, I don't
know why you are surprised...
You might try an external HUB (sic) with its own power supply to
see if power is the problem -- it would help to eliminate power
issues. If power really is the problem, there probably isn't much
Apple software can do about it.
Doesn't sound like a power problem to me; it sounds like the drivers
are putting something to sleep.
Power problems with USB audio devices connected directly to the
computer are quite common; although, the usual problem is noise,
not glitches. The fix for USB power problems is to use an external
HUB with it's (sic) own power supply.
Some wall-warts have noisier power supplies than what's inside the
computer, so beware.
Also, Digi et. al. tend to recommend that you not plug your audio
device into a hub. They don't say why, but I suspect it's due to
bandwidth-sharing issues and added latency.
It's better to use Firewire for professional work.
It's nice if that option is available.
It sounds more like the problem is that the USB bus gets re-
enumerated when a new device gets "plugged in" and that probably
forces all the devices to re-initialize.
That statement is completely wrong. The new device gets enumerated;
devices already connected are not disturbed.
That could be fixed with a power management option to keep the
devices on-line (you have checked, right).
Not relevant.
-a
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