Noise when using Powered USB Hub to connect Audio Interface

[MediaGuy]

Hi All - I'm new here - and I really have NO IDEA where to post this - and if this is the wrong place - please forgive me, and please let me know.

I am a Media guy, and I LOVE Raspberry Pi2 - So, I couldn't resist trying to try getting a DAW to work with Audacity on the Raspberry Pi.

I got Audacity installed and working, no problems there. I'm running UbuntuMATE on Raspberry Pi2, BTW - beautiful OS for RPi2.

Natually the RPi2 can't power my Focusrite Scarlett SOLO by itself, so I plugged it in through a Powered USB HUB, and it detected it immediately, plays desktop sounds out perfectly.

My issue comes when I try to record through Audacity - it records a HORRIBLE noise at FULL LEVEL - no matter if the mic is plugged in, or Phantom Power is turned on or not -

Without the SOLO connected, Audacity records clean (ZERO LEVEL) sound file. no noise -

So the noise is coming from the powered hub is my guess, but since RPi2 wont power the SOLO by itself, I can't test that theory.

Any thoughts?? Again, I realize this is probably not the right forum, or category for this question, but since I am using Audacity, on a RPi2 to try my little experiment, I thought I'd see what you thought.

Thanks for your time.

MedisGuy

[kozikowski]

We stopped recommending powered hubs for USB devices/microphones because they can cause more entertaining troubles than they solve. Some hubs "know" they they're connected to a computer by the DC in the cable. We know this,because many hubs automatically switch to computer power if you lose the wall brick. That seems like a good idea, but it kind of defeats the purpose of the wall power.

Anyway, if your computer supplies no DC at all, I would't be shocked if the hub couldn't figure out what to do.

Does the combination work on your mum's computer?

Koz

[steve]

I think this board is as good as any

I know that one of the developers managed to get Audacity working on a Pi. He built Audacity from source, (which apparently was an extremely slow process), and the result was Audacity that "sort of worked". He was still left with the problem that the Pi is a bit too underpowered to run Audacity very well.

One of the problems with USB sound cards is that if the CPU is under too much stress, the USB audio stream can "break", which may either cause the device to be disconnected, or will corrupt the data (full-scale noise). It appears that you got the latter.

I've not tried running Audacity on a Pi, but it seems that the Pi can "almost" handle the job, but it is very borderline. If you want to persist in your efforts, you could try an even lighter version of Linux, perhaps just using X11 and WM2, or "openbox" or other ultra lightweight window manager.

[MediaGuy]

We stopped recommending powered hubs for USB devices/microphones because they can cause more entertaining troubles than they solve. Some hubs "know" they they're connected to a computer by the DC in the cable. We know this,because many hubs automatically switch to computer power if you lose the wall brick. That seems like a good idea, but it kind of defeats the purpose of the wall power.

Anyway, if your computer supplies no DC at all, I would't be shocked if the hub couldn't figure out what to do.

The Hub seems to be working - BTW - tried 2 different powered hubs to be sure it wasn't isolated to just one - but the fact that Ubuntu can not only see the connection, but registers it immediately as a Focusrite SOLO Audio device - and as I mentioned - I can head computer sounds very cleanly through headphones attached to the SOLO.

Not certain what the Noise is, but I really wish that the Pi had enough juice to power it by itself so I could be sure.

[MediaGuy]

I think this board is as good as any

I know that one of the developers managed to get Audacity working on a Pi. He built Audacity from source, (which apparently was an extremely slow process), and the result was Audacity that "sort of worked". He was still left with the problem that the Pi is a bit too underpowered to run Audacity very well.

One of the problems with USB sound cards is that if the CPU is under too much stress, the USB audio stream can "break", which may either cause the device to be disconnected, or will corrupt the data (full-scale noise). It appears that you got the latter.

I've not tried running Audacity on a Pi, but it seems that the Pi can "almost" handle the job, but it is very borderline. If you want to persist in your efforts, you could try an even lighter version of Linux, perhaps just using X11 and WM2, or "openbox" or other ultra lightweight window manager.

I might try one of the lighter distros to see if it's just UbuntoMATE that is having issues, but if that turns out to be the case, it will be sad because I really like the GUI of MATE as opposed to Raspian, or any of the others.

I do know that Audacity does freeze on me if I push it too hard, and thats due to the nature of the Pi, as opposed to Audacity, I believe. That may be resolved if I try a lighter distro as you suggested.

[kozikowski]

Do you have an eventual production goal, or are you just messin' with it?

Koz

[MediaGuy]

Do you have an eventual production goal, or are you just messin' with it?

Koz

Well, I already have a Windows 7 solution that works - I was trying to see if I could get the Pi to work as an alternative NOISELESS solution for the sound booth. Both my laptop and my desktop fans are being picked up in the mic. I'm liking the portability of it as well, being so small and light -

Long and short of it is I'm kindof playing around with it - as I said , I di have a solution that works beautifully, as long as I keep the PC outside the booth... but I'd like to see this run...

Thanks for your help

[kozikowski]

Both my laptop and my desktop fans are being picked up in the mic.

A number of people found relief by putting their machine outside the booth and using a remote monitor inside so they can keep track of their sound levels.

Everybody who does this in a serious manner gets inexorably dragged into making a studio.

"I don't need a studio, I just need a comfortable, air conditioned, quiet room with no echoes."

Koz

[MediaGuy]

Everybody who does this in a serious manner gets inexorably dragged into making a studio.

I agree, and that is coming... working on a home made closet studio (slowly) ...

My mic is way too sensitive to not have some sort of room treatment. But I'm trying to work as cheaply as possible at this point, and what I choose to bring into the closet with me needs to be quiet. (hence the Raspberry Pi solution).

My desktop system is way too big, and permanently settled in the family room to try to relocate (shared by the entire family). So I can't drag it into (or just outside) the closet at this point.

I'm serious about getting started, but not at the level where I ready to tick off my entire family just yet. I'm sure that day is coming though...

I refuse to give up on the Pi solution, I also have a Banana Pi that is not currently being used, maybe I'll give that a try. If I have to purchase another small footprint PC to use, I will but I'd rather not spend more than $50-$100 for it, and I have the Pis available so I thought I'd see if that would work.