DIY home subwoofer - Tilted Forum Project Discussion Community

canuckguy · 09-17-2005, 09:10 AM

I currently have two subwoofers for my home theater/music room, one is a paradigm ps-1200 that i've had for years. Great subwoofer, tons of bass, musical, but ugly, the plain old black box has got to go. I also have a custom built subwoofer from my university days. It has 2 JL audio 12" subs powered by a robust adcom amp with a paradigm x-30 for the crossover but it too is ugly and has some signs of wear after many moves.

I was thinking of making another custom subwoofer (getting rid of the existing) and was curious if anyone here dabbles in this hobby. I was thinking either a box with two 15" subs, or four 12", or possibly say eight 10" subwoofers. Extension and flow are what I hope to achieve, SPL is a nice trade off with going with the multiple drivers, but it is more for getting even lower in 10-50hz range.

The box size is not really an issue, as i have a dedicated room for the HT so there is no wife-acceptance-factor involved. Anyone have an thoughts on driver size, what brand of subs to go with? Any other input or suggestions or general discussion would be great. I would like to go with an IB design but I don't have a good enough location to do it.

flat5 · 10-12-2005, 04:42 PM

You like the speakers so make them less ugly.
Paint or something.

canuckguy · 10-14-2005, 11:17 AM

Too late, the old box met my hammer and foot last week. Still debating on what the new one will be, no hurry at this time as still using acouple of paradigm ps-1200's for now. Still missing the true low end though.

jujueye · 10-17-2005, 12:53 PM

For me, I would stick with two 15s. The 4x12 thing woudl be nice, but that really would take some large boxes and even more space. Don't do it! Take your driver type, get the specs on it, and plug them in to some free speaker building software on the Interweb. Even a 2x12 with a properly designed box should get you to the sub 20Hz range.

canuckguy · 10-21-2005, 05:16 PM

Going over the total cone displacement and like you said huge box size that I will be using 2 15" if I decide to go with a box. But I am now thinking I might go IB (infinite baffle) similar to this. I think I have enough room under a stair well that vents into my laundry room.

http://white.hometheatertalk.com/tips/ib.htm

jujueye · 10-21-2005, 09:12 PM

Which speakers will you be using? Make sure your drivers will work for an infinite baffle system. I know in the car audio industry, subs made for that kind of work (likely hung off of the rear deck) will have a smaller Q factor and some different parameters. The smaller Q will obviously affect the over all sound.

On the other hand, it wouldn't take too long to mock this up and give it a try! Without sealing all of the corners, etc, you could get a good idea how it might sound. If it's good, it could be better as you tune the enclosure and seal parts up. Keeping the sound from vibrating other parts of your home would be difficult.

Oh, one more thing: if you can borrow a sub 9now that the other one is long gone..!) make sure you try it in the same spot where this outlet will be. No sub, regardless of cost, will sound it's best if placed in the wrong part of the room. Tuning is the difference between, "hey, neat" and "HOLY ***T!!!"

canuckguy · 10-22-2005, 08:28 AM

Not sure on the drivers to be used yet, will probably get them from partsexpress.com. They have a good selection of free air drivers. I have done some testing so far in terms of placement. Surprising none of the corners of my listening room provide an even response at the listening position. I get a very boomy peak at 40-50hz and the true low end does not get any boost that you would normally get from corner loading.
There is one location that would be perfect but it is just not practical to have the subwoofer in this location. Where the "throat" of the IB would enter the room provides some boost as it is about 1.5 meter from the rear left corner. So many variables, I think like you said I could try a temp box and see what happens. If I do go with the IB option I will have to double the drivers, minimum that would be useful would be 4 15". And all those pesky room vibrations throught the house....

jujueye · 10-23-2005, 03:31 PM

Sounds like you know what you're doing. Good job. Free air stuff is exactly what I meant. And you've done all the right testing...I'll just clam up now because you're doing a great job. Corners. Feh. Difficult to work with even though I agree that you can get some horn loading benefit out of them. Oh well.

Another testing method I remember reading about which made me scratch my head: put the sub where you would sit, and then put yourself or the meter where you want to have the sub. The room modes, I believe, can be affected in either direction and this can give you a rough idea of where a good starting place might be. I've never tried it, but I think it has some merit.

Finally, I have herad some high end stuff with dual pairs of woofers in separate boxes. Yes, two boxes with double the drivers. Instead of building a monstrous box for all four drivers, maybe two boxes with two drivers each might keep the box size small enough and maybe a little more manageable. No, tuning two boxes in the room is not easier...pretty obvious it would be tougher, but it would keep from having to deal with a coffee table sized unit.

...on the other hand, that would be pretty cool...I seem to remember some high end speaker mfr making a sub that was obviously built to be in a large room because it was enormous, but I dont remember who it was...

jujueye · 10-23-2005, 03:40 PM

why is this here twice? Well, then. let's make this worth it since I can't delete this post.

http://www.royaldevice.com/10amello.jpg

This is The RD Audio Room during set-up: Woofer mounting phase into the SUBHORN compression chamber. The woofers are mounted in the floor with a gigantic horn load scheme.

Rest of the page is here: http://www.royaldevice.com/custom.htm

canuckguy · 10-25-2005, 03:29 PM

Thanks again for the info. The method you mention about moving the subwoofer to your seated position and then move around the room to find the best extension and most spl is how I determined my location. I remember reading that in sound and vision years ago. Works like a charm!

09-17-2005, 09:10 AM	#1 (permalink)
canuckguy I read your emails. Location: earth	DIY home subwoofer I currently have two subwoofers for my home theater/music room, one is a paradigm ps-1200 that i've had for years. Great subwoofer, tons of bass, musical, but ugly, the plain old black box has got to go. I also have a custom built subwoofer from my university days. It has 2 JL audio 12" subs powered by a robust adcom amp with a paradigm x-30 for the crossover but it too is ugly and has some signs of wear after many moves. I was thinking of making another custom subwoofer (getting rid of the existing) and was curious if anyone here dabbles in this hobby. I was thinking either a box with two 15" subs, or four 12", or possibly say eight 10" subwoofers. Extension and flow are what I hope to achieve, SPL is a nice trade off with going with the multiple drivers, but it is more for getting even lower in 10-50hz range. The box size is not really an issue, as i have a dedicated room for the HT so there is no wife-acceptance-factor involved. Anyone have an thoughts on driver size, what brand of subs to go with? Any other input or suggestions or general discussion would be great. I would like to go with an IB design but I don't have a good enough location to do it.

10-23-2005, 03:40 PM	#9 (permalink)
jujueye alpaca lunch for the trip Location: in my computer	why is this here twice? Well, then. let's make this worth it since I can't delete this post. http://www.royaldevice.com/10amello.jpg This is The RD Audio Room during set-up: Woofer mounting phase into the SUBHORN compression chamber. The woofers are mounted in the floor with a gigantic horn load scheme. Rest of the page is here: http://www.royaldevice.com/custom.htm Last edited by jujueye; 11-20-2005 at 11:51 PM..

10-12-2005, 04:42 PM	#2 (permalink)
flat5 Very Insignificant Pawn Location: Amsterdam, NL	You like the speakers so make them less ugly. Paint or something.

10-14-2005, 11:17 AM	#3 (permalink)
canuckguy I read your emails. Location: earth	Too late, the old box met my hammer and foot last week. Still debating on what the new one will be, no hurry at this time as still using acouple of paradigm ps-1200's for now. Still missing the true low end though.

10-17-2005, 12:53 PM	#4 (permalink)
jujueye alpaca lunch for the trip Location: in my computer	For me, I would stick with two 15s. The 4x12 thing woudl be nice, but that really would take some large boxes and even more space. Don't do it! Take your driver type, get the specs on it, and plug them in to some free speaker building software on the Interweb. Even a 2x12 with a properly designed box should get you to the sub 20Hz range.

10-21-2005, 05:16 PM	#5 (permalink)
canuckguy I read your emails. Location: earth	Going over the total cone displacement and like you said huge box size that I will be using 2 15" if I decide to go with a box. But I am now thinking I might go IB (infinite baffle) similar to this. I think I have enough room under a stair well that vents into my laundry room. http://white.hometheatertalk.com/tips/ib.htm

10-21-2005, 09:12 PM	#6 (permalink)
jujueye alpaca lunch for the trip Location: in my computer	Which speakers will you be using? Make sure your drivers will work for an infinite baffle system. I know in the car audio industry, subs made for that kind of work (likely hung off of the rear deck) will have a smaller Q factor and some different parameters. The smaller Q will obviously affect the over all sound. On the other hand, it wouldn't take too long to mock this up and give it a try! Without sealing all of the corners, etc, you could get a good idea how it might sound. If it's good, it could be better as you tune the enclosure and seal parts up. Keeping the sound from vibrating other parts of your home would be difficult. Oh, one more thing: if you can borrow a sub 9now that the other one is long gone..!) make sure you try it in the same spot where this outlet will be. No sub, regardless of cost, will sound it's best if placed in the wrong part of the room. Tuning is the difference between, "hey, neat" and "HOLY ***T!!!"

10-22-2005, 08:28 AM	#7 (permalink)
canuckguy I read your emails. Location: earth	Not sure on the drivers to be used yet, will probably get them from partsexpress.com. They have a good selection of free air drivers. I have done some testing so far in terms of placement. Surprising none of the corners of my listening room provide an even response at the listening position. I get a very boomy peak at 40-50hz and the true low end does not get any boost that you would normally get from corner loading. There is one location that would be perfect but it is just not practical to have the subwoofer in this location. Where the "throat" of the IB would enter the room provides some boost as it is about 1.5 meter from the rear left corner. So many variables, I think like you said I could try a temp box and see what happens. If I do go with the IB option I will have to double the drivers, minimum that would be useful would be 4 15". And all those pesky room vibrations throught the house....

10-23-2005, 03:31 PM	#8 (permalink)
jujueye alpaca lunch for the trip Location: in my computer	Sounds like you know what you're doing. Good job. Free air stuff is exactly what I meant. And you've done all the right testing...I'll just clam up now because you're doing a great job. Corners. Feh. Difficult to work with even though I agree that you can get some horn loading benefit out of them. Oh well. Another testing method I remember reading about which made me scratch my head: put the sub where you would sit, and then put yourself or the meter where you want to have the sub. The room modes, I believe, can be affected in either direction and this can give you a rough idea of where a good starting place might be. I've never tried it, but I think it has some merit. Finally, I have herad some high end stuff with dual pairs of woofers in separate boxes. Yes, two boxes with double the drivers. Instead of building a monstrous box for all four drivers, maybe two boxes with two drivers each might keep the box size small enough and maybe a little more manageable. No, tuning two boxes in the room is not easier...pretty obvious it would be tougher, but it would keep from having to deal with a coffee table sized unit. ...on the other hand, that would be pretty cool...I seem to remember some high end speaker mfr making a sub that was obviously built to be in a large room because it was enormous, but I dont remember who it was...

10-25-2005, 03:29 PM	#10 (permalink)
canuckguy I read your emails. Location: earth	Thanks again for the info. The method you mention about moving the subwoofer to your seated position and then move around the room to find the best extension and most spl is how I determined my location. I remember reading that in sound and vision years ago. Works like a charm!