Computer on top of subwoofer

Q

quiktake

Gawd
Joined
Feb 22, 2011
Messages
573
Hello.

In order to save space I was thinking to put my atx sized HTPC on top of my home built 100 pound subwoofer.

What would be the negatives to this?
 
vibration. things loosen up due to vibration. optical drives and standard hard drives will have read/write errors. the case may walk off the enclosure after a while.
 
I would consider this only if the computer was running with a SSD. Or then again if your subwoofer is a weak POS it won't rattle the computer anyway :D
 
Buy or either build a small rack/stand and place the pc on it. If you are in a pinch use a milk crate and be happy. I would never put anything on top a sub woofer as you are asking for trouble.
 
I wouldn't recommend it unless you put some sort of shelf on top of it such that the PC isn't directly touching the subwoofer (and the shelf must be supported by the floor or wall, not the subwoofer).
 
LeninGHOLA said:
A well built subwoofer will not have cabinet vibration.
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Quoting this for truth. If you have noticeable cabinet vibration then your subwoofer is poorly constructed. It should be fine on top as long as nothing is EM sensitive if the magnet is unshielded. Any shelves will simply resonate from the pressure wave the subwoofer creates as if they were directly attached to the sub anyway. If you can put your hand on the cabinet when your sub is playing all out and the vibration is anything other than minimal you need to work on the enclosure. Better yet put your keys on it, they shouldn't jingle or move at all. If they do, it's back to the drawing board.

If you simply want to protect the PC from the pressure wave I'd recommend a foam pad to absorb and anttenuate any induced vibration in the case.
 
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Mine is on top of a sub. I do have some decent isolation pads and a platform for it. The sub barely vibrates anyway. The only dangerous spot is anywhere in front of it lol.
 
Don't know about your sub but mine has huge magnets in it, i don't want them any where near my pc.
 
Yeah, my sub doesn't vibrate at all. It's as solid as a tank. My wall vibrates more than the sub itself. If the sub is vibrating that means it is transfering force to the air. I figure the magnestism isn't an issue except for the hard drives. But inside of a typical hard drive is a very small but very, very powerful magnet. So, I figure the magnetic field of the sub affect will be minimal at most.

I can seem to find anyone ever actually seeing a problem accept for misaligning optics in DVD drives over time, which isn't reall an issue.

I will probably support the receiver and htpc on risers with dampening foam. That will increase ventilation, reduce any possible vibration and create distance from the magnetic field of the sub.


I figure if cars can survive all the subwoofer action, than house-hold electronics can handle it as well within reason
 
B00nie said:
What about the vibration of the walls and the floor then?
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Different materials, different construction, different resonances. A properly constructed subwoofer cabinet is inert from just over DC to 80+hz.
 
quiktake said:
Yeah, my sub doesn't vibrate at all. It's as solid as a tank. My wall vibrates more than the sub itself. If the sub is vibrating that means it is transfering force to the air. I figure the magnestism isn't an issue except for the hard drives. But inside of a typical hard drive is a very small but very, very powerful magnet. So, I figure the magnetic field of the sub affect will be minimal at most.

I can seem to find anyone ever actually seeing a problem accept for misaligning optics in DVD drives over time, which isn't reall an issue.

I will probably support the receiver and htpc on risers with dampening foam. That will increase ventilation, reduce any possible vibration and create distance from the magnetic field of the sub.


I figure if cars can survive all the subwoofer action, than house-hold electronics can handle it as well within reason
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What subwoofer do you have?
 
If you guys can't feel vibration from your subwoofers when you sit on them, your subwoofers are junk... Even if it's 200Lbs, it's still going to vibrate enough that you shouldn't put a PC on it. Enough that the PC would immediately die? Likely not. But enough to make it a bad idea over time.

Not a single one of you could come up with a cabinet that my AV15X + O-Audio 500W amp couldn't make vibrate. Even if you use concrete. It doesn't vibrate enough that it's audible (at least not notably so), but if you sit on your sub, you will feel it. As would a PC.
 
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LeninGHOLA said:
Different materials, different construction, different resonances. A properly constructed subwoofer cabinet is inert from just over DC to 80+hz.
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My horn bass isn't even a sub but the tools fall off the window lids in my garage if I turn it up.
 
dandragonrage said:
If you guys can't feel vibration from your subwoofers when you sit on them, your subwoofers are junk... Even if it's 200Lbs, it's still going to vibrate enough that you shouldn't put a PC on it. Enough that the PC would immediately die? Likely not. But enough to make it a bad idea over time.

Not a single one of you could come up with a cabinet that my AV15X + O-Audio 500W amp couldn't make vibrate. Even if you use concrete. It doesn't vibrate enough that it's audible (at least not notably so), but if you sit on your sub, you will feel it. As would a PC.
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That's not factually accurate. The cabinet should not vibrate, you're likely just feeling the sound waves. If the cabinet itself suffers from mechanical vibration, it was not constructed properly.
 
B00nie said:
My horn bass isn't even a sub but the tools fall off the window lids in my garage if I turn it up.
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Yea, sound waves hitting proper resonance for materials in your room.

- to all, if your subwoofer "walks", something is wrong. If it vibrates, that will cause massive distortion.
 
LeninGHOLA said:
That's not factually accurate. The cabinet should not vibrate, you're likely just feeling the sound waves. If the cabinet itself suffers from mechanical vibration, it was not constructed properly.
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You can never fully stop the vibration. Only keep it within acceptable limits. Go sit on your subwoofer and crank it up. You WILL feel it (even if you're sitting backwards so the subwoofer driver isn't behind your legs). Period. You can talk about what causes that as much as you want (a discussion that doesn't interest me in the slightest), but it doesn't change the facts. If you put a PC on top of a subwoofer, the PC WILL experience significantly more vibration than if it were not on a subwoofer. PCs with mechanical HDDs are very sensitive to vibration.

If you can't feel it, your subwoofer is weak.
 
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dandragonrage said:
You can never fully stop the vibration. Only keep it within acceptable limits. Go sit on your subwoofer and crank it up. You WILL feel it (even if you're sitting backwards so the subwoofer driver isn't behind your legs). Period. You can talk about what causes that as much as you want (a discussion that doesn't interest me in the slightest), but it doesn't change the facts. If you put a PC on top of a subwoofer, the PC WILL experience significantly more vibration than if it were not on a subwoofer. PCs with mechanical HDDs are very sensitive to vibration.

If you can't feel it, your subwoofer is weak.
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Still completely false. SOME subwoofers experience mechanical vibration due to design flaws. Resonant frequency of MDF or void free ply are well above the frequencies you normally play a subwoofer at. This is simple physics. With proper bracing, baffles and thickness, subwoofers are inert. This is why DC-80hz are not localized.

What you may be experiencing is that resonant frequency being fed back into your subwoofer cabinet by not being isolated from the floor.

http://www.youtube.com/watch?v=ilxNuhomirU

This isn't anywhere near a top end sub, yet is inert.
 
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dandragonrage said:
You can never fully stop the vibration. Only keep it within acceptable limits. Go sit on your subwoofer and crank it up. You WILL feel it (even if you're sitting backwards so the subwoofer driver isn't behind your legs). Period. You can talk about what causes that as much as you want (a discussion that doesn't interest me in the slightest), but it doesn't change the facts. If you put a PC on top of a subwoofer, the PC WILL experience significantly more vibration than if it were not on a subwoofer. PCs with mechanical HDDs are very sensitive to vibration.

If you can't feel it, your subwoofer is weak.
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lol *whoosh* that went completely over your head didn't it?

to counter your argument, especially the last line,

If you CAN feel it, your subwoofer is shit.

I can leave a thumb tack on top of cabinet in my room and when I play the sub loud if will rattle all over the place because of the vibrations, but if I leave the thumb tack on top of the subwoofer it doesn't rattle at all. Yet, if I put my hand on the sub I can feel the sonic vibrations.

That's the point Leningola was trying to make. Your sub shouldn't be vibrating mechanically. :D

*EDIT* just want to add, that in case you think my subwoofer is weak, well, I need a seperate 300W amplifier to drive it :)
 
reaper12 said:
lol *whoosh* that went completely over your head didn't it?

to counter your argument, especially the last line,

If you CAN feel it, your subwoofer is shit.

I can leave a thumb tack on top of cabinet in my room and when I play the sub loud if will rattle all over the place because of the vibrations, but if I leave the thumb tack on top of the subwoofer it doesn't rattle at all. Yet, if I put my hand on the sub I can feel the sonic vibrations.

That's the point Leningola was trying to make. Your sub shouldn't be vibrating mechanically. :D

*EDIT* just want to add, that in case you think my subwoofer is weak, well, I need a seperate 300W amplifier to drive it :)
Click to expand...

Like I said, I didn't make any claims as to why it happens, nor am I interested in discussing that... it happens. Regardless of how. I've made enough subwoofers and I've made cabinets of 2 3/4" sheets of MDF bonded together, which is VERY heavy. You can sit there and try and nitpick "well it's not a mechanical vibration," or whatever, I don't care. Fact is I've sat on almost every subwoofer I ever made at some point or another, and with every single one I can feel it. Yet it's not audible vibration on any of them. You can discuss what causes what to vibrate, but the fact is subwoofers cause things to vibrate. Discussing why it happens is just a waste of time here. The reason why doesn't matter. That's why I ignored it in my last reply, and will continue to do so.

HDDs are just very sensitive to vibration in general, far more than we are. I've put plenty of things on top of a subwoofer. I just wouldn't make a HDD one of those things. We're talking about sub-millimeter clearances in some of the mechanical parts. My point is not that there's a lot of vibration, but that it barely takes any to potentially cause a drive to fail. Enclosures are not ideal. Yes, when build properly they are sturdy. I'm not claiming subwoofers hop around on my floor from vibration. I'm saying the world isn't perfect and you can never stop 100% of the vibration.
 
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So, back to the meat of the matter.

Mechanical vibration will harm your electronics. Your subs is unlikely to be creating mechanical vibration (as confirmed by the OP as well). Sound waves should not harm your electronics, unless you are pushing incredible SPL (think 130dB++). Otherwise, your amplifier would be damaged in the process.

I'd think about switching to solid state drives, though. Subwoofer magnets can be very strong.
 
dandragonrage said:
Like I said, I didn't make any claims as to why it happens, nor am I interested in discussing that... it happens. Regardless of how. I've made enough subwoofers and I've made cabinets of 2 3/4" sheets of MDF bonded together, which is VERY heavy. You can sit there and try and nitpick "well it's not a mechanical vibration," or whatever, I don't care. Fact is I've sat on almost every subwoofer I ever made at some point or another, and with every single one I can feel it.
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If unbraced, or improperly braced, the thickness of your MDF can't make up for it.

I'm not nitpicking. I'm offering the OP scientifically verified information.
 
LeninGHOLA said:
If unbraced, or improperly braced, the thickness of your MDF can't make up for it.
Click to expand...

lol... just stop assuming how I make my enclosures man. Your assumption that I don't use bracing is unfounded and incorrect. My enclosures are sturdy and the vibration felt is not strong and yes some degree of it is indirect such as from sound waves. But my enclosures, like all enclosures, are not ideal/perfect. There is always going to be some small amount of vibration. It's not something I ever notice, but I still wouldn't put a computer on it. My subwoofer is 15", has about an inch of peak (so about 2" peak-peak) of excursion, and is being driven by a quality 500w amp. It SLAMS. HARD. Not sure what you have experience with, but I doubt it's anything as beefy as this.

I've heard plenty of poorly built subs that have some serious vibration due to bad drivers and/or cabinets. That's not the claim I'm making. It doesn't take that much vibration to harm a HDD.

I'm done with this thread. Go put your computers on your subwoofers. I don't care.
 
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I'm not assuming your sub is unbraced, nor am I making any assumptions about the way you build your subs. I'm pointing out that bracing makes a massive difference.

This isn't a pissing match. I'm offering scientifically verified facts for the OP.
 
dandragonrage said:
Like I said, I didn't make any claims as to why it happens, nor am I interested in discussing that... it happens. Regardless of how. I've made enough subwoofers and I've made cabinets of 2 3/4" sheets of MDF bonded together, which is VERY heavy. You can sit there and try and nitpick "well it's not a mechanical vibration," or whatever, I don't care. Fact is I've sat on almost every subwoofer I ever made at some point or another, and with every single one I can feel it. Yet it's not audible vibration on any of them. You can discuss what causes what to vibrate, but the fact is subwoofers cause things to vibrate. Discussing why it happens is just a waste of time here. The reason why doesn't matter. That's why I ignored it in my last reply, and will continue to do so.

HDDs are just very sensitive to vibration in general, far more than we are. I've put plenty of things on top of a subwoofer. I just wouldn't make a HDD one of those things. We're talking about sub-millimeter clearances in some of the mechanical parts. My point is not that there's a lot of vibration, but that it barely takes any to potentially cause a drive to fail. Enclosures are not ideal. Yes, when build properly they are sturdy. I'm not claiming subwoofers hop around on my floor from vibration. I'm saying the world isn't perfect and you can never stop 100% of the vibration.
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Sorry but if you aren't interested in discussing this, then why post in this thread?

And I am not "nit picking" lol I am stating facts subwoofer housings shouldn't vibrate. You just ignored completely what I said. If I put my hand on the sub I can feel it, but, it's not vibration because if it was vibration the tacks I put on top of it would be vibrating as well, but they aren't moving at all!!

You make subwoofers? Remind me never to buy one from you. I am not presuming how you make them, just by our very comments here show you don't seem to understand what's going on.

dandragonrage said:
lol... just stop assuming how I make my enclosures man. Your assumption that I don't use bracing is unfounded and incorrect. My enclosures are sturdy and the vibration felt is not strong and yes some degree of it is indirect such as from sound waves. But my enclosures, like all enclosures, are not ideal/perfect. There is always going to be some small amount of vibration. It's not something I ever notice, but I still wouldn't put a computer on it. My subwoofer is 15", has about an inch of peak (so about 2" peak-peak) of excursion, and is being driven by a quality 500w amp. It SLAMS. HARD. Not sure what you have experience with, but I doubt it's anything as beefy as this.

I've heard plenty of poorly built subs that have some serious vibration due to bad drivers and/or cabinets. That's not the claim I'm making. It doesn't take that much vibration to harm a HDD.

I'm done with this thread. Go put your computers on your subwoofers. I don't care.
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And this is where you are wrong again. Chances are that if you have the computer in the same room as the sub it's probably experiencing more vibration than it would if it was on the sub. (a properly made sub of course)
 
LeninGHOLA said:
I'm not assuming your sub is unbraced, nor am I making any assumptions about the way you build your subs. I'm pointing out that bracing makes a massive difference.

This isn't a pissing match. I'm offering scientifically verified facts for the OP.
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Interesting video you posted earlier in this thread. I tried the coins balanced on edge on top of my sub, it's from XTZ, and they didn't fall :D

But if I put them on top of my computer case and play the music loud, they fall nearly straight way :p
 
reaper12 said:
Interesting video you posted earlier in this thread. I tried the coins balanced on edge on top of my sub, it's from XTZ, and they didn't fall :D

But if I put them on top of my computer case and play the music loud, they fall nearly straight way :p
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My sub will not do the coin trick because apparently my carpet isn't 100% level, but the water trick works fine.
 
The closer you are to a subwoofer playing loud, the more chance you have of damaging your hearing.
I agree you'd think this would translate to a bad place to put your PC, but...

My Satellite PVR sits on top of my subwoofer with a 22" display sat on top and has for 3 years+. Its over 4 years old now and works flawlessly. Its on for about 16 hours per day + when it records.
There was nowhere else to put it convenient enough so I took the risk, worked out great.

My PC is about 5cm from my subwoofer running 3 mechanical hard drives, the oldest of which is also over 4 years old. This is on 24 hours per day, the hard drives never sleep as I found drives fail more when put to sleep. Its been like this for 2 years, no drive failures or problems in that time.

Read into it what you will :)
 
If you were really worried, or if you had a bad sub, you could use rubber feet to isolate the PC from the sub.
 
Edit: I'll let what was said regarding sub vibrations be, hopefully the video posted is more than enough evidence for anyone being mislead by certain posts.
 
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LeninGHOLA said:
So, back to the meat of the matter.

Mechanical vibration will harm your electronics. Your subs is unlikely to be creating mechanical vibration (as confirmed by the OP as well). Sound waves should not harm your electronics, unless you are pushing incredible SPL (think 130dB++). Otherwise, your amplifier would be damaged in the process.

I'd think about switching to solid state drives, though. Subwoofer magnets can be very strong.
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Subwoofer magnets are not strong enough to mess with even mechanic hard drives for most setups. Only if you take off all the shielding from the subwoofer by exposing it to the hard drive DIRECTLY (such as putting the hard drive directly on top of the magnet and perhaps only when the HDD is in seek mode) against its casing and maybe then it could mess with it. Even then the magnetic field of the large subwoofer magnet isn't strong enough to immediately destroy the information on the HDD as it might take weeks and months before it fully damages the drive. Only a powerful electromagnet (and I mean POWERFUL) could instantly damage/erase a drive. I own a bunch of very powerful rare earth magnets (the kind that if you bring two together they crush your hands into ground chuck if you don't respect them , very dangerous in untrained hands) and they are only about 10 feet from my computer and have zero effect on it.

My 12 inch Polk sits RIGHT next to my desktop tower. The tower itself is very sturdy and weights about 55 pounds filled with components. Hasn't effected anything. It rumbled some lose screws at first but I hunted them down and fixed that problem.

In general most modern sub's (not counting DIY) are shielded and very safe near computers.

I would be much more worried that the mechanical vibration would damage or shake loose things you do not want disturbed.
 
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You could try looking up if you can find some of the mechanical tolerances posted by HDD/optical drive manufacturers. Not sure how sensitive they are to vibration in that frequency

As far as magnetic interference, I can confirm what Godmachine stated. The sub's magnets should have virtually no influence on the HDD platters. Look up on google hard drive coercivity. It takes very strong electromagnets to mess up a HDD
 
reaper12 said:
lol *whoosh* that went completely over your head didn't it?

to counter your argument, especially the last line,

If you CAN feel it, your subwoofer is shit.
Click to expand...

So when my walls vibrate hard enough for tools to drop, the subwoofer is shit if it's not somehow magically locked steady and only the rest of the universe vibrates? :D

By the way I have a 2500W amp and 100+db/2,83V sensitivity if you're wondering.
 
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B00nie said:
So when my walls vibrate hard enough for tools to drop, the subwoofer is shit if it's not somehow magically locked steady and only the rest of the universe vibrates? :D

By the way I have a 2500W amp and 100+db/2,83V sensitivity if you're wondering.
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LOL What? Sounds like this went over your head too, :D We are taking about the subwoofer housing vibrating, you know the actual sub. Just in case you missed it, a sub shouldn't vibrate at all. The walls of your house, on the other hand, will.
 
OP here. I checked the sub again. I tried the water test. Even with bass pounding, I had trouble getting water to move. If I rest my hand on the sub, I can feel very, very, very slight vibration, but not enough to effect electronic equipment. It would take a very long time I think to affect anything.

Checking around the web, it seems that everyone recommends NOT putting a receiver or computer on top of a sub, but no one has ever actually had a problem from it. Biggest issue is using a DVD player or blu-ray player and getting the optics misaligned over time. Some guy had a 40 year Sansui crap out on a sub after a couple years, but that would be hard to determine if caused by the sub.

I think it is pretty safe to put things on a well built heavy sub. NOT on top of anything you could buy at BestBuy.
 
wooferserver.jpg


That's my file server (in the super lanboy case) sitting right across a particle board wall from my biggest pair of speakers, a pair of JBL L100T's. They aren't subs, but the 12" 2214H woofers have 10lbs+ magnets attached to them. I can rattle books off the bookshelf located on the lower floor of the house. I've had it in this arrangement for 5+ years with no issues.

Nenu said:
The closer you are to a subwoofer playing loud, the more chance you have of damaging your hearing.
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What is the basis of this statement?

Human hearing is most sensitive around the vocal frequencies.

714px-FletcherMunson_ELC.svg.png


This is why OSHA lists all of it's noise exposure guidelines using A-weighting measurments

666px-Acoustic_weighting_curves.svg.png


Someone screaming in your ear, for example, would be more likely to cause hearing damage than just about any subwoofer.
 
GotNoRice said:
What is the basis of this statement?
Click to expand...
Common sense and my own accident.
The closer you are to a radial source of power, the stronger it is.
I accidentally damaged an ear years ago when I went to turn my subwoofer down, it was playing loud.
I leaned over it and caught a strong beat.
For years my ear felt odd if there was more than light bass playing, its not bad now, but I am very cautious.

Human hearing is most sensitive around the vocal frequencies.

714px-FletcherMunson_ELC.svg.png


This is why OSHA lists all of it's noise exposure guidelines using A-weighting measurments

666px-Acoustic_weighting_curves.svg.png


Someone screaming in your ear, for example, would be more likely to cause hearing damage than just about any subwoofer.
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How does that stop loud bass damaging your ear?
You cite an example of the response of other frequencies as a reason why bass cant cause damage.
 
Nenu said:
You cite an example of the response of other frequencies as a reason why bass cant cause damage.
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You'll notice that nowhere in my post did I make that claim. You should probably try just a little bit harder not to just straight-up make stuff up that no one ever said when posting a response. Just a thought.

Typical subwoofer frequencies are, out of the entire audible frequency spectrum, among the least likely to cause hearing damage. It's obviously not impossible, but unless you're at a subwoofer competition or something you're much more likely to experience damage to your hearing from other parts of the spectrum, even at lower levels.
 
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