Problems with hum (mac) & sound proofing!

[Twothai]

Hi,

I wonder if anyone could give me a little advice?

Firstly, I'm running a G4 based studio from my bedroom, I noticed a hum coming through my speakers (active reveals) which seems to have increased recently, I have narrowed it down to the computer, but it doesn't seem to be the soundcard as when I turn the soundcard off it still occurs - it also happens whilst the mac is booting so I'm guessing that it is an earthing problem, does anyone have any ideas as to how to get rid of it / reduce it? There was also a spate about two weeks ago where my computer was acting very peculiarly and made a lot of noise (i think the fan) and wouldn't boot - although I'm unsure if this has anything to do with it.
There are about 15 plugs all running off one socket so I thought this was the problem but when I plugged in just the mixer with speakers and mac it still happened so I just don't know... help! lol

Secondly, I'm just about to move into a flat within a block and as such I can't make as much noise as I used to - any ideas for soundproofing my room? Esp where bass is concerned which tends to leap through ceilings! Someone suggesting putting the speakers on concrete blocks which I haven't tried yet - anyone any experience on this one I can't drastically modify the room as it's rented!

I would be eternally grateful if someone knew how to solve either problem.

Cheers

 

[Twothai]

First problem solved! (Hum)

Hello again,

In a moment of genius (or luck!) I found out that the problem was caused by the break out box from the soundcard being on or anywhere near the computer monitor! I have moved it away and the hum has gone!!!
It's daft that something so simple was causing me so many problems!
But anyway, hopefully others that experience the same will read this and save a lot of time!

Any advice on the sound proofing issue would be gratefully received!

Take it easy

 

[RICK FITZPATRICK]

Hello Twothai, glad you found the source of the hum.

In regards to soundproofing, this is something that is not so easily solved. In fact, when it comes to low frequency, it is actually very difficult to isolate. There are only two ways to attenuate sound by isolation. Mass and decoupling. Both of which require stringent construction techniques and they are NOT cheap. And in a rented space, depending on the level you mix at, it is virtually impossible if you cannot alter the existing space. The only other alternatives are lower the volume, or use headphones.
For isolation of the source, such as a singer, or a small guitar amp, you can build a booth if you have room and require that much iso. But for mixing through speakers in a rented flat, I'm afraid there isn't much you can do but turn the volume down, as structural transmission and poor transmission loss through the existing walls, ceiling and floor membranes are the usual culprits, all of which must be reinforced by either adding mass to the existing assemblys(walls etc), AND-OR building a structure that is actually a room with-in a room.....not something that can usually be done in a rented living space. Some may recomend limp mass barriers, which may work to an extent, but again, they are NOT cheap.

Some things you can do to help, are decouple your speakers from direct contact with whatever they are sitting on, which is usually a desk or table, which in turn are directly coupled to the floor. Use a couple of mouse pads or some rigid fiberglass, such as Owens Corning 703. Or you might purchase or make some decoupled speaker stands too. Next, move your setup away from walls that are seperating your space from the neighbors. That may be easier said than done, without knowing your layout, or if you have neighbors surrounding your space. Also, you might construct some "gobos" to put behind you mixing station, which may help to some extent, if they are room height, and are lined with 3" or 4" 703 with a 3/4" MDF back on them, or something to that extent, but I wouldn't say this will solve your problem without knowing your complete scenario. Well, sorry for the bad news, but if someone else has a solution, I'd be glad to hear it. Usually, low budget or no budget, rented space, adjacent neighbors only seperated by a wall, floor, or ceiling, and typical residential type construction with no sound attenuation materials make for a terrible combination to soundproof. Even under the best conditions, isolation of low frequency is an exercise in physics, and if not done correctly, can waste a LOT of money and time. Within your constraints, I would consider headphones, or lower volume.

fitZ

 

[DDev]

Rick has some good, practical advice there. To elaborate on a couple of things, DO NOT think that placing your monitors on cement blocks with do anything to help you out UNLESS you isolate the bottom of the speakers from the top of the blocks with something like Rick suggested (a couple of thick rubber mouse pads) or the MoPads that Auralex sells. Then all you've really done is created a cheap monitor stand.

Otherwise, there is not much you can do to reduce bass frequency leakage without a lot of work and major construction. You would be talking about floating floors with extra walls constructed on top of the floating floors to decouple from the surrounding room, ...............

Good luck!!
Darryl.....

 

[Twothai]

Hi,

Thanks to both of you for replying, I guess the only solution will be to keep the noise down a bit, either that or continuously annoy the neighbours! lol Well, I probably ought not to do that I guess, I'll certainly try the mouse mat idea though, and will move the speakers away from any interconnecting walls I must admit I didn't really fancy lugging two slabs of concrete about anyway!
Unfortunately, I can't make any alterations to the room as it is rented and I'm not sure that the landlord would appreciate me building him a third bedroom inside the second! It sounds like an expensive venture anyway! My only other idea was to hang throws up at random places around the room but I guess that's just used to reduce the reverberations in a studio and wouldn't help much with the booming bass coming through the ceiling!
Thanks for both of your input, I'll see how it goes, we'll be living right next to a tube station anyway, so hopefully the neighbours will be pretty noise-immune!
Headphones it is then! Damnit!

Thanks again