Home theater super experts

[VetteLT193]

I have an odd setup, and I'm attempting to put my subwoofer in the attic which happens to be above my living room. I just don't have a spot for it elsewhere.

I tried it open in there, and as I pretty much expected, it does nothing for me.

I'm thinking about building a box around it, insulating it, and putting an A/C vent below it so the sound can transmit down instead of into the attic.

The question is, how big to build the box? I have a 100 watt down firing 10" woofer in its own box. Do I make the 'build over' box just large enough to fit, or do I make it larger? or ? Do I still sit it down firing, considering it will down fire over my head? or should I turn it on its side or upside down?

It's tough to do the math on something that no one else has.

[mrfixxall]

I have an odd setup, and I'm attempting to put my subwoofer in the attic which happens to be above my living room. I just don't have a spot for it elsewhere.
I tried it open in there, and as I pretty much expected, it does nothing for me.
I'm thinking about building a box around it, insulating it, and putting an A/C vent below it so the sound can transmit down instead of into the attic.
The question is, how big to build the box? I have a 100 watt down firing 10" woofer in its own box. Do I make the 'build over' box just large enough to fit, or do I make it larger? or ? Do I still sit it down firing, considering it will down fire over my head? or should I turn it on its side or upside down?
It's tough to do the math on something that no one else has.


vette you ca put it into a sealed box with a port in it and vent it down,in my rockford days we use to call it a isobaric box..if you make the port the rite size with pvc you can change the hertzs for multi boom boom:)kinda like a vented box sounds..

[txtaz]

If the woofer is in it's own box, you don't need another one around it unless you have some reason for it or it is ported in the rear. If it's ported in the rear, build a box large enough that the woofer box sits against one side of the outer box (the side opposite the port) and leave about 3" air space above the port and the other side. The air space (for the port) and woofer should both be able to vent through whatever fixture you put in the ceiling. You will loose efficiency doing it this way no matter how you do it. You can also build your own sub box to replace the one you have. Google "building sub boxes". There are lots of designs and car boxes work fine in the home (same concept and engineering).

Ports are what give sub boxes efficiency. I used to have a monster amp to drive my sub, now I get away with a 100w powered sub just fine.

Let us know how it comes out.

[Carl C]

Your speakers are already in boxes. Do they have vents? I would cut a hole in the ceiling and cover with speaker grill fabric and find a way to support the sub directly over the opening. If there is a vent make sure the hole is big enough to not cover it. If you can't support the sub directly on the drywall then your vent idea will work but you will also need to extend the speaker box vent to the grill. Anyway you will need to cut a hole in the ceiling or you will muffle away most of the bass. The wifey will get over it. Should sound great. I made my own down firing subs out of top end 15" 4 ohm automotive drivers. I made a pair and power them with the most powerful home amp Kenwood ever made (ttbomk) @ 220 watts per channel rms into 8 ohms; 350 watts per channel rms into 4 ohms. Sealed boxes sound tighter but need more power. The sealed box dampens the cone movement. I also have top end transducers in my two recliners. Here are some pics. (I also made the component rack since I couldn't find a side by side rack)

[MOP]

My 30+ year old Cerwin Vega woofer died a few weeks back, I got a deal on the monster below but am wondering how my tired old 100 per channel will drive it. It calls for a 2.5 cu in box but it will be stuffed in the 2 cu in box like it or not. My Bose 401 puppy mains are only about 15 and still hanging in!

[Barry Eller]

Will you have celling problems from the booming? Such as sheet rock or plaster cracking?

I have the Bose Acoustimass 10 speaker system. The Acoustimass module does more than just the bass, it has a lot of the midrange as well. The five 2 speaker satellites (5.1 surround sound) don't take up any room, but the module is big. It has downward firing subwoofers and I have hardwood floors and my house is off-grade. I have to turn the bass and presence to the minimum settings or the mirrors and paintings on my walls vibrate. http://www.bose.com/controller?url=/shop_online/home_theater/home_theater_speakers/acoustimass_10/index.jsp

I don't have the answer, but I'm not sure how it would sound coming from the celling. Just my opinion.

[Carl C]

A while back in one of my audio magazines there was a guy who built a wood shaft going down into the basement with a grate on the floor above. He lined two sides of the shaft with subs, all in the basement and had a bass port from hell! Just another option. Big subs need big power though. (like boats)

[Barry Eller]

A while back in one of my audio magazines there was a guy who built a wood shaft going down into the basement with a grate on the floor above. He lined two sides of the shaft with subs, all in the basement and had a bass port from hell! Just another option. Big subs need big power though. (like boats)

No basements in Gulf Breeze, Florida!

I have a Kenwood VR-6060 home theater/audio receiver. I got it because it has a phono input. I have a large vinyl collection and a Bang-Olufsen linear turntable.

It is 6.1 capable and has 100 watts per chanel X 6 channels. It drives my Bose system very well.

[VetteLT193]

I have zero room for the acoustomass setup either.

I was thinking if I put a box around the sub box and insulated it I could just put an A/C vent below the sub and no one would know what it was. Will putting it in another box screw the sound up though? that's the main question. I don't want to spend a bunch of time building a box to find out that I screwed up the math.

The sub I have now is a down firing and it is also ported on the bottom.

I haven't used it in a few years because of my odd room setup but I really want the bass back. I have 8" speakers so they are ok, but not nearly like it was with the sub.

[Barry Eller]

Your speakers are already in boxes. Do they have vents? I would cut a hole in the ceiling and cover with speaker grill fabric and find a way to support the sub directly over the opening. If there is a vent make sure the hole is big enough to not cover it. If you can't support the sub directly on the drywall then your vent idea will work but you will also need to extend the speaker box vent to the grill. Anyway you will need to cut a hole in the ceiling or you will muffle away most of the bass. The wifey will get over it. Should sound great. I made my own down firing subs out of top end 15" 4 ohm automotive drivers. I made a pair and power them with the most powerful home amp Kenwood ever made (ttbomk) @ 220 watts per channel rms into 8 ohms; 350 watts per channel rms into 4 ohms. Sealed boxes sound tighter but need more power. The sealed box dampens the cone movement. I also have top end transducers in my two recliners. Here are some pics. (I also made the component rack since I couldn't find a side by side rack)
Carl, your stereo set up reminds me of the old Maxwell Cassette tape adds!!!:biggrin.:

[Carl C]

Carl, your stereo set up reminds me of the old Maxwell Cassette tape adds!!!:biggrin.:

Hehe. Yeah, I've never totalled up my wattage but it's quite a bit. My goal was to be able to make my house sound like a nightclub. Goal accomplished!

[CHACHI]

Barry, Maxell.

Ken

[The Hedgehog]

[QUOTE=MOP;517283]My 30+ year old Cerwin Vega woofer died a few weeks back, I got a deal on the monster below but am wondering how my tired old 100 per channel will drive it. It calls for a 2.5 cu in box but it will be stuffed in the 2 cu in box like it or not. My Bose 401 puppy mains are only about 15 and still hanging in![/QUOTE

Yes indeed. I still have a few things like that holding on. It is boomy but LOUD. Hard to get rid of it.

[txtaz]

[I still have a few things like that holding on. It is boomy but LOUD. Hard to get rid of it.

Like a pair of vintage '64 Phillips XP10's? I had to bridge 2 Carver amps just to get the 15" subs working. Needless to say they are going in the wall of the new house. OK RT, I can already hear ya. Stop it.

Vette, If you have a down firing sub and port, mount it and make a grill. I don't think an AC vent will do it (not big enough). Make something nice and custom and says "Hey, Look up!"

I'm getting ready to do custom fiberglass enclosure for the Advantage to mount the front speakers. I'll post specs and pics.

[Barry Eller]

Barry, Maxell.

Ken

Ken, it's been a while since I saw one!:wink:

[Ghost]

People beat me to most of what I would have said. I would add/emphasize some sort of vibration dampening in the mounting. Maybe some sorbothane (can you still get that) mounts or something, some shag carpet at least, as I think the drywall of a ceiling might not hold up well. My corner horns practially need inch thick marine plywood wall sections behind them, and my guess is your subwoofer will be similar, and isn't even sitting on the floor anymore.

Mike