A Thread for those interested in PPSL enclosures

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djk

djk

R.I.P
Joined 2001
Hey, I built two sets of that layout as double 18s about 20 years ago.

The first set were tuned to 38hz for PA work and worked swell to the 250hz crossover point. The second set were 6th order tuned to 28hz and after destroying two sets of drivers (the magnets came loose on the first set and started 'clanking') were re-tuned to 40hz.
 
E

epa

Member
Joined 2010
kees52 said:
I have the wsp 26s woofers I did want to build this box for home theatre, but always I get to long pipes, because the woofers has low FS of 19 hz, but do the slot trow down the speaker fs and rise the qts yes or no, because some people way it stays the same, I have then need to measure in a slot alone to see what happens, or we make a small slot facing the speakers like in a ripole and look what happens.

the thiele small of this speakers.

maybe you can try them for me in HR, thanks, nut the box get really big, I do use basbox pro to test a normal vented box, and it go low but so long a pipe..

Rated power 110 Watt
Maximum power 140 Watt
Nominal impedance Z 8 Ohm
Frequency response fc - 7000 Hz
Mean sound pressure level 91 dB (1 W/1 m)
Excursion limit 22 mm
Resonance frequency fs 19 Hz
Magnetic induction 1 Tesla
Magnetic flux 1250 µ Weber
Height of front pole-plate 8 mm
Voice coil diameter 5 cm
Height of winding 1,45 cm
Cutout diameter 23,3 cm
Net weight 2,5 kg
D.C. resistance Rdc 5,7 Ohm
Mechanical Q factor Qms 3,19
Electrical Q factor Qes 0,38
Total Q factor Qts 0,34
Equivalent volume Vas 230 l
Effective piston area Sd 330 cm2
Dynamically moved mass Mms 42 g
Force factor Bxl 8,7 T · m
Inductance of the voice coil L 1,2 mH
Click to expand...
i wil give it a go tomorrow
 
K

kees52

Member
Joined 2009
Hi Epa

I like small, and bandwith is for say 20 to 150 Hz, I will go over around 100 Hz.

make it so volume is not to big, but I think this is difficult with 20 Hz, I say try the best
you can, I have hornresp and now a little how to work with it maybe you can help some with this.

I have now here the plenum alone where I want to measure the two woofers in it but why not use a plenum a la ripole who conusses face eacht other the magnet structure is both in the box, I have that not seen yet and maybe it works better for home theatre use.

thanks

kees
 
E

epa

Member
Joined 2010
its diffecult to get this driver to play low.
250 lts tuned at 20 hz .not verry small:eek:
if you punch the numbers from in the input screen,you cam play with the wizzard yourself.
click on the pic left bottom x to enlarge pic.
kees%20ppsl.jpg
 
K

kees52

Member
Joined 2009
epa said:
its diffecult to get this driver to play low.
250 lts tuned at 20 hz .not verry small:eek:
if you punch the numbers from in the input screen,you cam play with the wizzard yourself.
click on the pic left bottom x to enlarge pic.
kees%20ppsl.jpg
Click to expand...

Thanks , I had also that same idea, a normal vented box was already 200 plus liters. but if I halve the vas then it get smaller, like a isobaric way and go low, but that is not a ppsl anymore.

high Sd and smaller VAS will work oke here.

thanks for your attemt I go play. the output on hornresp is good, 250 liters is big but if one box used, the rest is ob then it is oke, it has
good output I see.

How have I to involve the S1 S2 S3 in the box itself (misschien kan je dat even mailen via hier in nederlands, dank je alvast), and the slot? how do it act as we mass load the cones like in the ripole, I think that we then have to experiment with it, a slot who has the conus face each other, magnets in the box..



The peak at 200 plus hz can be easely cope with, to use a euhh zuigkring.

photo is the slot I did make for measuring.
 
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K

kees52

Member
Joined 2009
epa said:
its diffecult to get this driver to play low.
250 lts tuned at 20 hz .not verry small:eek:
if you punch the numbers from in the input screen,you cam play with the wizzard yourself.
click on the pic left bottom x to enlarge pic.
kees%20ppsl.jpg
Click to expand...

Thanks , I had also that same idea, a normal vented box was already 200 plus liters. but if I halve the vas then it get smaller, like a isobaric way and go low, but that is not a ppsl anymore.

high Sd and smaller VAS will work oke here.

thanks for your attemt I go play.

photo is the slot I did make for measuring.
 

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K

kees52

Member
Joined 2009
Hi Epa

I have fill in the hornresp, I get lower spl, and I have change the VRC to 150 and get this,
not 20 hz without loss but 25 hz - 1 dB is there what is most of the time enough I think.

Afcourse if i did it the right way, your simulation is 95 dB?? did I something wrong.

the vrc is 150 I have lowered that after the test for as you see it and think this is the problem, maybe I have a old version of hornresp it is 21.30

thanks
 

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K

kees52

Member
Joined 2009
How have I connect the speakers in a ppsl box, in fase or out fase. I have test the slot the woofers go from 19 hz to 29 hz in it, when as a ripole it go from 29 to 22 hz.

I measure with limp and use the output of the audio card I think I need a 10 watt amp for it to do good.


thanks
 
K

kees52

Member
Joined 2009
Ohh ahh I had a old version of hornresp 21.30 the new one is give other results but not wht epa has, so what is wrong, and how do i interpret hornresp in a PPSL box.

Is it not better use a speaker with a lower vas? then the box will be smaller. it is quite big with this woofers, and I need two for a ppsl.

thanks.
 
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