polk plate amp and 8 Klipsch drivers....what to do???

[jmillerdoc]

Hello,
I have acquired many interesting drivers and electronics over the years which have been gathering dust too long. I wanted to put together a subwoofer with some parts I have on hand. I was hoping for some ideas and assistance here.

I have to work with 2 Polk plate amps (200w each) from a pair of RT2000p speakers and 8 (eight) Klipsch 8" sub drivers.

The specs for the subs I have are from ApexJr:

Vas 29.46 L, Fs 45.7406, Qts 0.4644, Qes 0.5429, Qms 3.2134, Re 2.99, Le 0.5439mH, 89.98 dB 1w/1m, BL 6.23 Tesla Meters

I wanted a single enclosure using as many of the subs I can with the smallest footprint possible. I am flexible (very).

Thanks for your thoughts and advice!
Jeff

 

[neddludd]

the fs is a little high and the Qts is slightly high for ported but should manage if tuned low enough.

i would get winisd or similar and take a look for yourself. Even use winisd online punch in fs qts etc and get an idea.
8 woofers means +9dB sensitivity due to cone area. I prefer smaller multiples thant huge monoliths.
Do you know the Xmax(excursion) ?

 

[jmillerdoc]

Woofer Tester measurements

the fs is a little high and the Qts is slightly high for ported but should manage if tuned low enough.

i would get winisd or similar and take a look for yourself. Even use winisd online punch in fs qts etc and get an idea.
8 woofers means +9dB sensitivity due to cone area. I prefer smaller multiples thant huge monoliths.
Do you know the Xmax(excursion) ?

I don't have the Xmax but I do have the Woofer Tester measurements I forgot about earlier when I posted the first time (from ApexJr website). These were don on the drivers in hand by the individual I purchased them from. I have included them here attached .pdf

Where can I find winisd online?
Jeff

 

[picowallspeaker]

Hi ! I wish I had 8 drivers to play with ! Are those real subs or just woofers ? I'm asking because lot of people call "sub" anything bigger than 2". The problem is IMHO their low Z and the fact that they should be matched to be sure they work at best in the same enclosure . Serial-parallel connection (betterarallel then serial ) would give about 4 Ohm.I'm talking about two boxes for stereo application.
Putting them in a big box with two big vents (B3 alignment) would work ,I guess.
But my idea was to put them in a faceted solid structure (like a pyramid with triangular base ) which is part of a big horn , working till 3-400 Hz . Well ,that's a 2 or 3 way design ,not a sub...

 

[bjorno]

I was hoping for some ideas and assistance here.

Hi Jeff,

IMO, The drivers are most suitable for closed box designs where each needs at least a cu.ft. of internal volume resulting in a minimum 8 cu.ft./ 8 Ohm speaker not utilizing the full potential of your two plate amps and the speaker footprint wouldn’t be small.

For smoothest in room FR response you need at least 3 boxes, preferably at least one main sub near a corner and two or more placed elsewhere. For main sub use and low extension I recommend building T-TQWP’s to be placed near corners using 2 drivers in series in two boxes with a footprint about 1.25 sq. ft.

b

 

[jmillerdoc]

Ya know....these are woofers, not subs. I still have the original 8" Polk drivers the plate amps were ment to drive. I still have the original ports too. I could build 2 seperate subs with these, just need to figure the original volume of the cabs and make some boxes up.

This still leaves me with the 8 Klipsch drivers.......maybe for some WWWWMT 3 ways. I have some tweeters that would keep up with the SPL of 4 of the woofers, just need to find a cheap high eff mid and a good xover design.

Jeff

 

[neddludd]

Get winisd pro and enter in the data, have a look. I dont think anyones going to do it all for you

The larger your main speakers, the more likely your panel modes will be resonating IN BAND which you dont want. Id make the speakers producing the 300hz-3khz in particular as small as possible, or make alot of effort to control modes. After hearing some silver iris 15" coaxials on small open baffles my ears havent been as happy since/

 

[bentoronto]

Pity, 8 is the wrong number.

You want 16 (or maybe 9), half facing forward, series-parallel, in a big sealed box with motional feedback.

Does the resonance of the unit or the system change when there are a whole bunch? I can't remember.

 

[neddludd]

Pity, 8 is the wrong number.

You want 16 (or maybe 9), half facing forward, series-parallel, in a big sealed box with motional feedback.

Does the resonance of the unit or the system change when there are a whole bunch? I can't remember.

No the Fs doesnt change. You could use motional feedback yes,it looks like youd have to DIY it though. If you listen at sane volumes they wont be quite as nonlinear as running 2 x 8"s at their limit anyway.

 

[dangus]

I'm just going to throw out the idea of a low profile sub that could sit on edge behind a couch, or lie on the floor, maybe with a second row of seating on top. Or, maybe tapped horns with 2 drivers per horn.