Ventilation for soffit mounted speakers

[yellowfever]

Moving house soon and as I can't take the 'studio' with me, am going to convert one half of a double garage at the new place. Planning on soffit mounting the speakers as Mr Sayers detail (which I can't find at present) but a bit worried on heat build-up. I can see the air path in at the bottom, out at the top, but is there a way to tell if the amps are getting enough ventilation to keep them cool? I felt the back of the speakers (Mackie HR624's) which are currently on floor stands and was surprised at how warm they were. Thanks.

[BriHar]

Get a couple of those In/Out thermometers - the kind you can get for cars as accessories are fine. Mount the external temperature probe in the soffit where the Amp is and have the display show the Ext temperature - this way you can constantly monitor the temperatures, in fact some of the fancier thermometers may have an alarm - not sure. I use one of these for monitoring the temperature in my Isobox. Unfortunately the thermometers don't have 2 probes which is why you'll need two devices.

Also, make sure you don't pack insulation too close to the Amps - give them plenty of air space and keep the ventilation routes as short and simple as possible.

[yellowfever]

That's a very good idea thanks.
I was also curious about the science as well, how you know you're getting air movement through the void?

[Soundman2020]

I was also curious about the science as well, how you know you're getting air movement through the void?

As long as you have a clear air path from floor to ceiling, as shown in John's design, then convection will take care of keeping the air moving. And if you have a temperature sensor in there, which shows that the temperature is staying within the range recommended by the manufacturer, then you are getting enough airflow, and enough cooling. Of course, if the thermometer shows temperatures rising, then you need to either enlarge the air passage or force cool air through it somehow.

- Stuart -

[yellowfever]

Ah, good old convection. I wondered that. Thanks Stuart.

Now for more research, more design, more sketches.

[Soundman2020]

Now for more research, more design, more sketches.

Welcome to the wonderful world of studio design!

- Stuart -

[yellowfever]

Welcome to the wonderful world of studio design!

Yup. The devil is in the detail, or something like that! I think I read that studio build is about 90% design, 10% construction??

Me and a friend built a single room 'control room' in my garden from scratch a couple of years ago. I got really good results mix wise, but the isolation left a little to be desired Still, as I say with my mixes 'my next one shall be better than my last'

[AlexW]

Interested in this topic. I soffited a pair of Adam S3A's and I've had amp and driver failures on now 3 occasions. I'm suspecting the culprit is overheating. It's an unconditioned space and though the soffit enclosures aren't fully enclosed; I'm likely not getting enough dissipation through convection. I have some OC 703 panels in there to tame reflections, but they're not right on top of the speakers or anything.

Have other folks experienced this and found a remedy? Would fans hooked up to the monitor power circuits get air moving sufficiently? There's a window behind the space I use for access that I could use a small AC unit with if necessary.

[Soundman2020]

How is your ventilation path arranged through your soffit? Do you have a clear path for air to get in through the bottom somewhere, flow past the rear of the S3A, then exit through the top again? You do need a full clear path like that, with no obstructions in it, and it should be at least half the width of the speaker (hopefully full width, if you can manage that), and at least an inch deep (more if possible). If you have something like that, then natural convection should take care of pulling enough air past the rear to keep it cool. The inlet should be near the floor, where the air is cooler, and the outlet up near the ceiling.

If you already have that and still are not getting enough cooling, then a small fan might be the way to go. There are very quite fans made for computers that you could use for that. Some of then 120mm (and bigger) fans have speed controls, so you can turn them down to be even quieter. A couple of those should do the trick.

- Stuart -

[AlexW]

Cheers Stuart. The bottom is similar to John's standard design with a vented rectangle covered with burlap. The top is not enclosed; but it's a bit of circuitous path getting out of there. I have a front wall that extends up to a false ceiling (the ceiling in the room I treated/converted was sloped, so I put in a drop ceiling composed of 1 x 12 boards that spans the room at a fixed elevation; so the exit air needs to transition that path--roughly 8-ft or so-- to exit out. I'll see if I can get a photo posted. In any case, I don't see any real reasons other than potential heat issues that I would be epxeriencing as many component failures as I have--and it's getting a bit annoying as extracting the speakers out is difficult; and then I need to truck them from San Diego up to North Hollywood to get them fixed, in addition to just the expense of repair. I want to make this next time (I currently have one out) the last time.

[Soundman2020]

but it's a bit of circuitous path getting out of there. I have a front wall that extends up to a false ceiling (the ceiling in the room I treated/converted was sloped, so I put in a drop ceiling composed of 1 x 12 boards that spans the room at a fixed elevation; so the exit air needs to transition that path--roughly 8-ft or so-- to exit out.

I'm trying to picture that, and if I understand it correctly, you are venting into the space between the original ceiling and the drop ceiling? If that's the way it is, then it is understandable that it is overheating: there is no air flow through there!

In order for air to flow, there has to be a complete circuit, but you don't have that. The air inlet is inside the ROOM, but the outlet is inside the CEILING, with no return path. There's no place for the air to go up there, so it doesn't move at all. The air cannot get back from above your drop ceiling into the room. Even if there are gaps up their around the drop ceiling, there's still no reason for the air to want return by convection. I'm betting that the static pressure is pretty high with such a path, beyond what convection can handle.

That's why you see on John's designs that there is a slot in the front panel of the soffit, up high, to vent the air back into the room, so there is a complete circuit. In many cases he hides that vent some place, but it is still there, bring air back into the room.

So I'd suggest that you re-route your ventilation path so that it terminates inside the room, not inside the ceiling.

- Stuart -

[AlexW]

The drop ceiling ends once it gets past my mix position and there's a gap between the false ceiling and actual that slopes from about 3-in to 6-in or so; covered in burlap as well--so it is open, but a circuitous path as I mentioined. I'll upload a photo and maybe we can strategize where to put a vent--I could likely add one to my soffit panels if that makes sense; though I'm still leaning towards some type of forced ventillation to insure I get it all sorted.

[AlexW]

Here's a shot of what I was talking about at the terminus of the drop ceiling:



And here is a shot of one of the actual soffits.



That front wall to the left is slotted and there's really nothing behind it (just some random panels of OC 703) so that should be on ok path for heat to get out. I'm a bit worried I've just got a wonky speaker--I know the last failure was the one on the left side; and it's the one that's gone down before. The one on the right's been ok.

The window behind the wall is good size (probably a 3 x 4 or 4 x 5 slider). I've got a shade on it, but maybe the sun in the afternoon is hitting it and heating up that entire area; and the left cubicle in that case could be seeing the most direct impingement.

/edti--yikes! This forum doesn't auto-resize photos; brb

[Soundman2020]

Here's a shot of what I was talking about at the terminus of the drop ceiling:

Ahh! Ok, I see what you are saying. And I guess that the area behind that cloth is filled with insulation?

Jut a question here: why did you do it like that? It would have been better to angle that front section more, taking it right up to the ceiling with no gaps.

I'll upload a photo and maybe we can strategize where to put a vent--I could likely add one to my soffit panels if that makes sense;

You do have space to do that, if you want: an inch or two down form the top edge would be fine.

That front wall to the left is slotted and there's really nothing behind it (just some random panels of OC 703) so that should be on ok path for heat to get out.

That's an unusual arrangement, acoustically! If it is a true slot wall, then it would have to be a fully sealed cavity behind the slats, that does not open out into the speaker soffits. If the cavity at the back is open to the speakers, then it isn't a slot wall: just a bunch of reflective bits of wood with gaps between. Either way, its unusual to have that between the speakers. Any particular reason for doing that?

yikes! This forum doesn't auto-resize photos;

Yup! That's why we ask (in the "rules for posting") that all photos be no more than 750 pixels wide. We did try the auto-resizing thing at one point: I don't recall why John dropped that, but there was some issue with it. I'll check the controls and see if it can be implemented again.

- Stuart -

[AlexW]

Thanks Stuart. I worked with John a bit on the original design. He had a cloud rather than a drop ceiling; but both concepts are essentially meant to deal with an existing celing in the room that slopes left to right. I angled the ceiling from the front wall at what I thought was necessary to avoid reflections (can't recall now--the build was several years ago); and then just terminated it once it got past my mix position. It coudln't really be carried all the way to meet the existing ceiling due to the sloping.

As far as the front wall goes--it wasn't intended to be a true slot wall. There is some insulation behind it for absoroption. Can't recall where I got that from. Would I be better off with a solid panel across there? You are correct that it's not a sealed cavity--the soffit cubicles are connected to it as well.

At any rate, I'm thinking at this point to cut slots in my soffit panels at the top; and then go ahead and install some ventiallation fans in the cavity.