IT guys and engineers - vibrating a PC with a sub...

[MDV]

So, I got a much better sounding monitoring setup by moving my speakers around (speaker placement is VITAL - Ben told me that and all my experience since has done nothing but prove it right, so thanks Ben). Hearing things in the low end of almost everything that I've played on it so far that I've never heard before, and everything else is so much more clear....anyway, I digress

...

My sub is now on the bottom shelf of my PC desk (little shelf about 6 inches or so off the ground). My PC, shiny, blisteringly fast, quite expensive PC is on another shelf on the desk. The sub, however, is hardly a toy - its an adam sub 8 and it can kick out some serious sound. (Which, on the plus side, means I can now use the timbre and level of resonance of my nuts as an audio diagnostic tool 'hmm, lets see what its like loud.....my nuts aint shakin', maybe I need a bit more 80hz in that bass...' anyway, I digress again)

I've put it (the PC) on a sheet of 25mm acoustic foam, but when the music is loud I can still feel the sides of the case vibrate.

So, my main worry is sticking 30 through 120 hz through hard drives. The HDs are hard mounted to the PCs chassis, and the box itself is pretty heavy and doesnt seem to be oscillating very much at all (mainly the big, flat, thin walls of it, rather than the whole unit bouncing around) so I dont know how much vibrational energy is actually getting through to the components, but I am nervous of it and wondered what you fellas think the risk of some slight jostling around of the HDs (or anything else in there - I dont expect it will cause much else much harm?) will do?

Should I be scared?

Of course 'if youre worried about it, move the bloody thing', but thats easier said than done - that part of the room is very densely packed and given cable runs theres maybe 1 other place I can put it, and that would mean moving a tonne of stuff and crossing my fingers that the cables can make it.

[MrBump]

Dunno. 

All the environments I've supported, and there have been many, have been pretty much vibration free - server rooms, front office environments etc.

The "less moving parts is more" rule seems to apply - there are so many components in that expensive box of yours that exposure to excessive vibrations CAN'T be a good thing, intuitively.  But I've got no real world experience to back that up.

Probably need more of a mechanical engineering perspective.

Or move the PC...

:)

Mark.

[JDC]

damn an IT topic where I haven't got a single clue!!! you deserve a medal!!!

other than move it I'd say get a solid state hard drive but those are more than a bit expensive, you can get vibration absorbing hard drive mounts that go in a CD drive bay

hard drives and magnets don't mix either!

[Dmoney]

I'd go with the shock absorbing mounts.

I know Sony XDCAM professional DVD writing cameras record straight to DVD (if I recall correctly, or that was the plan). They are designed to be rugged but the laser array is only mounted on shock absorbing rubber bungs.

could be worth a try. Although there are probably quite a few parts prone to vibration. solder joints etc?

[Oli]

The distance between the read heads and the platters of a hard disk is very small-- one scr@pe could ruin your drive.... unfortunately i've had a drive die because the heads dropped onto the platter surface, and it scratched the drive up so much that not even data recovery specialists could retrieve anything.... i'd take the case panels off, and feel the drives when playing stuff through the sub; see if there is any noticable vibration difference, and make a judgement on whether it's severe or not :)

[MDV]

Thanks guys.

I think I've averted it, or convinced myself it'll be OK - subs on the floor now (I'll add some isolation once I've made it) and the pc is where it was, and its still shaking much the same way. Maybe a little less.

It was never that far from the PC anyway, and I figure that it was probably transmitting vibration into it all the time (or when loud), and the same with the last PC, which is now in the lounge and I'm using it right now, its fine, and has been 2 feet from the same sub for about a year (and this has unsecured HDs; they just float around in the slot and would probably be more susceptible to any structure-borne vibrations cos I guess they'd rattle a bit).

So, I've convinced myself its all ok :lol:

Thanks for the input - if I get scared of it again I'll get those shockmounts (good suggestion with the checking the HDs direct oli, too, thanks).

[Denim n Leather]

Putting a sub on any kind of shelf or within a cabinet is a bad idea. There are ways around this, which I usually design from the ground up, when working with a client that has space limitations.

[MDV]

Well, I took the shelf out (which is the same width as the sub and about 20% longer when flipped 90 degrees), put 50mm of acoustic foam under it and put it on the floor - its in the same basic place, but now ~55mm off the ground on a pad. The subs facing into the room, and the actual cone is just a little behind the edge of the desk, so the reflections from the desk will, I imagine, be minimal.

I can discern differences in levels between this and the previous location using a sine wave generator, but it sounds basically the same playing back tunes and my decibleometer has 40 through 160hz all within +/-about 3 or 4 db.

Any more sensible?

[Denim n Leather]

Hmmm. +/- 4dB is a huge shift when it comes to mixing. As long as you are used to the quirkiness you should be okay, though -- a large part of mixing is knowing what your system can and can't do, working with that in mind, and then checking the ref against a really good, neutral system, a total POS system, and as many  in-between as you can get your hands on.

You may want to look into an Auralex GRAMMA or similar for the sub. Those platforms work WONDERS for low freqs.

[MDV]

I have a gramma under my cab. It is indeed good stuff. It was the gramma (a hard surface on top of acoustic foam) that I was emulating with the shelf+foam pad.

+/-4 (thats being cautious, I think its less than that, but its not more than that) is about the best I can get/have ever had, but when mixing I do reference on headphones (several of them) and in the system in the lounge (untreated room, OK system (NAD amp, B&W DM602s, placed as well as the room and stuff in it allows)). I also get up, wander round and listen to the rest of the room, listen in the other chairs that people I'm recording/mixing for sit in, that sort of thing. I dont trust one position and one system to do all the work - I just need it to do most of it :lol:

I'm also gonna hook up my little JBL control 1Gs - very modest things, not very good at all, but I can use them as a 'normal' system. I'll even place them idiotically, in imitation of how I see most people placing their speakers (without any thought whatsoever). I figure if I've got a good mix it should at least not have any big standout problems on that either, no?

Anywho, I know where the problems are in the spectrum, and can work with it. I think :lol:

The main benefit of the new location over the old (I had the sub in the corner, past the right speaker) is stereo resolution and the clarity in the low end. I couldnt quite get a completely balanced stereo field, as I was forced to have a pretty high crossover so that I could control a huge ~130hz spike my room has (which is now not a problem, its a dip round 80 thats the biggest deviation from linear now) by letting that come from all the speakers. It made the right thicker and weighter sounding, and threw off the EQ balance between them, while making the low end level-sih, but murky.

Now its between the two I can hear pitch and note envelopes in the low end MUCH better, and its about as linear in my main position as it was before, so while its not optimal, I think I can (and I will) work with it (unless you have any better advice)

FWIW the system in question is the most neutral I have any access to!

[Denim n Leather]

Dude, you would have an anneurysm if you saw the "speakers" I work with. And you would probably have another one if you saw the systems I check my mixes on.

Once you have the room sorted and the equipment placed as good as the situation allows, it all comes down to the man behind the controls, not the controls themselves.

[MDV]

I damn near had an anneurysm seeing photos of some of the speakers you work with :lol:

I dont even want to think about that. I aint getting any Grand Utopias any time soon, or an environment that would be worth putting them in so I'm just going to put it from my mind!

And word. See sig. I'm at least dimly aware of this already (doesnt mean that one shouldnt try to get the best tools, though, no?).

I've got some recording coming up - planning to redo and rewrite one of my old tracks and doing some more work for a local band - I'll see if I can do any better with the new setup.

Now, I need to listen to it some more - no point having a monitor setup youre unfamiliar with the sound of!

[shobet]

Ahh welcome to my world! http://blogs.sun.com/brendan/entry/unusual_disk_latency so there you go noise can increase latency during hard drive writes.

[MDV]

Interesting. So it probably is affecting them, but I'm still no wiser as to whether its damaging them?

[shobet]

I doubt you're doing any great harm to them, consider DJs who use their laptops in clubs, I'm sure you're not running at those volumes and it's not like you're kicking the case?

I suspect that if the case is vibrating then components within will be vibrating, so over time these vibrations may shorten the lifespan of the drive. 

Just make sure you have a backup solution that you use regularly.