I had a narrow face ppsl. It was the test bed b4 I plunked down the cash for 4 x 18's. That box was maybe 20" wide, it had 2 x 12" rockford fosgate subs, and was maybe 36" deep. The slot port was on the side running top of box to bottom, but was almost the length of the box. If you want a ported box that's tuned to 30hz or below, and you move a bit of air (dual 12's with 4mm xmax), it is tough to have a large enough port that's long enough to fit in the box. But, you could do a passive radiator.....
What did my 18's look like ?
Well, I had a sheet over it.
It was so big that people never suspected it was the subs.
They'd stand in front of it and say "Where are the subs?" thinking there is a box thing maybe the size of a velodyne box. But the 4' wide x 24" tall x 36" deep (2 boxes stacked one on the other) is huge. I'll see if I can post some pics this weekend.
Norman
What did my 18's look like ?
Well, I had a sheet over it.
It was so big that people never suspected it was the subs.
They'd stand in front of it and say "Where are the subs?" thinking there is a box thing maybe the size of a velodyne box. But the 4' wide x 24" tall x 36" deep (2 boxes stacked one on the other) is huge. I'll see if I can post some pics this weekend.
Norman
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here's a picture
okay, here's a picture of subs, the second one is behind him.
The guy is 5'10", 240lbs, construction build frame.
Norman
okay, here's a picture of subs, the second one is behind him.
The guy is 5'10", 240lbs, construction build frame.
Norman
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Well I finally started cutting plywood. It took me a while to get going.
Well being new at wood working I have a tendency to over think things. I bought a router table extension for my table saw and thought a 45° Lock Miter Router Bit would be the perfect way of joining the corners without showing an edge. Well I learned all about tear out. So I gave up on that. So now I am using butt joints. Maybe some pics next week when I start screwing it together.
Any assembly hints?
j
Well being new at wood working I have a tendency to over think things. I bought a router table extension for my table saw and thought a 45° Lock Miter Router Bit would be the perfect way of joining the corners without showing an edge. Well I learned all about tear out. So I gave up on that. So now I am using butt joints. Maybe some pics next week when I start screwing it together.
Any assembly hints?
j
premium glue and clamps. (screws always help)
Nothing else is really as important and most of the joint stuff is just overkill extra wasted time.
Nothing else is really as important and most of the joint stuff is just overkill extra wasted time.
Does anyone know of the lowest tuned PPSL ever built??
Im only interested in HT (I want the lowest octaves) and Im always curious about different subwoofer designs.
Im only interested in HT (I want the lowest octaves) and Im always curious about different subwoofer designs.
Any special glue?
I am planning on painting them. I want the corners to be good. Need to find out how to seal the ends of the plywood so the paint will look good.
I am planning on painting them. I want the corners to be good. Need to find out how to seal the ends of the plywood so the paint will look good.
Man those butt joints are ugly!
At one time I made a pair of PPSL with a centrally located slot with a 'V" shaped grill that looked way cool.
At one time I made a pair of PPSL with a centrally located slot with a 'V" shaped grill that looked way cool.
I'm thinking of doing something like this, using the woofer (or subwoofer) as a tv stand. Gemme audio uses 15's crossed 6db near 200hz to some weeny 5" 2 ways, but I was thinking that or maybe some 15's ppsl as a slot in the middle crossed 100-200hz.
There are some dayton 15" 390hf's at partsexpress for around $173 each (87db 1w/1m). They have 14mm xmax, 3 shorting paths (rings?), and you could run 2 in 11ft3 for a qtc .707 sealed with fsb=f3=30hz. That's one of the lowest qtc .707 f3's sealed that I've found in a while in a decent sized box. Should be an awesome rumbler.
Dayton Audio RSS390HF-4 15" Reference HF Subwoofer 4 Ohm 295-468
here's a link to the gemme sound "phenix green gem" system (I don't think it is made anymore). Single cap on midrange, single cap on what looks to be a fostex ft96h. Beautiful woodwork. Time aligned 6db slopes, not flattening volume. Hand made in New York. Just a bad time 2009-now to try to pitch something like that when everyones investments and property values are in the toilet and jobs are downsizing, etc.
Ears-On with the $50,000 Gemme Audio Phenix Green Gem loudspeakers | TechCrunch
Gemme Audio's Green Gem Loudspeaker System A huge leap into the stratosphere of high-end audio. Review By Rick Becker
Norman
There are some dayton 15" 390hf's at partsexpress for around $173 each (87db 1w/1m). They have 14mm xmax, 3 shorting paths (rings?), and you could run 2 in 11ft3 for a qtc .707 sealed with fsb=f3=30hz. That's one of the lowest qtc .707 f3's sealed that I've found in a while in a decent sized box. Should be an awesome rumbler.
Dayton Audio RSS390HF-4 15" Reference HF Subwoofer 4 Ohm 295-468
here's a link to the gemme sound "phenix green gem" system (I don't think it is made anymore). Single cap on midrange, single cap on what looks to be a fostex ft96h. Beautiful woodwork. Time aligned 6db slopes, not flattening volume. Hand made in New York. Just a bad time 2009-now to try to pitch something like that when everyones investments and property values are in the toilet and jobs are downsizing, etc.
Ears-On with the $50,000 Gemme Audio Phenix Green Gem loudspeakers | TechCrunch
Gemme Audio's Green Gem Loudspeaker System A huge leap into the stratosphere of high-end audio. Review By Rick Becker
Norman
The coupling mustbe as tight as possible for the ghigher frequencies to work.
I ordder to work you must be withing 1/4W of the second harmonic of the highest frequency to intent the box to work at.
Yours look way to big.
You might even have to slant the plenum like EV did with the MTS-1, it was crossed at 800hz.
Les Hudson has run some very high crossover points too, but his plenums are very compact.
I ordder to work you must be withing 1/4W of the second harmonic of the highest frequency to intent the box to work at.
Yours look way to big.
You might even have to slant the plenum like EV did with the MTS-1, it was crossed at 800hz.
Les Hudson has run some very high crossover points too, but his plenums are very compact.
ppsl exit area
Well, I thought that might be the case, so why did i do these as such ? Because, i did not want to restrict the exit area. I made it that size to equal 2x SD of one driver. Evidently, a big mistake. Thankyou kindly, for you prompt reply. I'll do another ppsl next summer, but with very close coupled 15's.
p.s. I heard a pair of Les' ppsl's down in Atlanta- they were awesum!
Well, I thought that might be the case, so why did i do these as such ? Because, i did not want to restrict the exit area. I made it that size to equal 2x SD of one driver. Evidently, a big mistake. Thankyou kindly, for you prompt reply. I'll do another ppsl next summer, but with very close coupled 15's.
p.s. I heard a pair of Les' ppsl's down in Atlanta- they were awesum!
"I heard a pair of Les' ppsl's down in Atlanta- they were awesum! "
Great, at least you have an idea of what to expect.
Also, if using with a subwoofer, it might be a good idea to go for a sealed system to avoid the group delay issues associated with a vented system. Venting is not an issue without a sub, but with a low crossover point to a sub, and venting of the mid-bass, the phase/delay can get funny.
Great, at least you have an idea of what to expect.
Also, if using with a subwoofer, it might be a good idea to go for a sealed system to avoid the group delay issues associated with a vented system. Venting is not an issue without a sub, but with a low crossover point to a sub, and venting of the mid-bass, the phase/delay can get funny.
In addition to djk's reply about spacing to get higher frequencies than subwoofer, looking at your box, the rear of the drivers are not sharing a common enclosure. You have seem to have 2 drivers in totally seperate boxes. You need to have the drivers share the same enclosure.
see post #60 if I am confusing you, ppsl.
http://www.diyaudio.com/forums/subwoofers/177905-thread-those-interested-ppsl-enclosures-6.html
see post #60 if I am confusing you, ppsl.
http://www.diyaudio.com/forums/subwoofers/177905-thread-those-interested-ppsl-enclosures-6.html
Sorry to interrupt but it can work Norman, as long the tolerances of the TS parameters between the two drivers are very close and the boxes behind the drivers have exact the same volume...
But realistically, only top (expensive) drivers have such small tolerances and Scott seems to have 'forgotten' to make up the volume differences made by the drivers...
But realistically, only top (expensive) drivers have such small tolerances and Scott seems to have 'forgotten' to make up the volume differences made by the drivers...