maybe
but higher Qts and higher Vas together really pulls up the box size
would work better for IB designs
for smaller boxes in general, I think you need a max Qts of around 0.33 and a max Vas of about 100
one reason why many sub drivers have high Qts is that its easy to make them go very deep
high Qts also means less control, so it presents certain compromises ... looks good on paper, but ...
And so a tapped horn is the only one to get deep with small speakers who have a low qts/strong motor.
the visatons have qts 0.34 but also high vas of 220 liters, only in compound I get the volume low with two drivers or if one driver then -3 db gets in 28 hz with 110 liters but ppsl have two speakers for canceling and more spl watt.
I have them in a linkwitch dipole and she play very deep here, it can let the doors rattle.
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dont know..6th order bandpass ought to work ok with low Qts woofer ?
yeah, I thought it could be nice for bass guitar, but then...two woofers in one box means big and heavy, so...
but I am thinking about a single woofer SL
6th order bandpass front port may be calculated such that it ends with just a hole, or a slot.......I dare not mention Carlson ...my plan is to use detachable baffle to try different slot openings
but thats OT, sorry ....cheers
and good luck with your projects
These woofers are maybe good for OB, like a ripole, 4 15 inch of them each channel will give enough spl
MTX Europe - RT15-04
MTX Europe - RT15-04
PPSL could be done with any even amount of drivers, just make the plenum taller.
Positive voltage applied should move all the cones toward the plenum.
They could be wired series, parallel, or series parallel, as long as the reversed cones are wired in reverse polarity.
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Why not face the conus to each other like in a ripole, it lowers the Fs and ups the qts, but like a ripole, who has on front as on back of the woofers a small plenum, the ppsl has a big box on outside the plenum. my test with a small plenum without a box did not lower the Fs but I think this is because of the faul measuring, I need a small amp with limp, and i did use only the ouput of the soundcard headphone output.
I have still the push pull dipoles from linkwitz, she sound well, very low bass extension, a ripole I have never tryed, but hear not so good things about it on some places, a tapped horn maybe, I will try all, horns I did have for a long time, she are still for my ears the best, fast and dynamic, the dipole, no slam, but very open eary bass low efficienty and danger for the woofer (xmax damage).... I think still to go make a two 18 inch dipole sub. totally 2670 Sd give 86 dB 1 watt is acceptable, still xmax damage if not carefull, but the stiff membrane will help autocompress or how you call that...
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Oke I have make a 6th order highpassed PPSL and maybe we don't need the high pass as the slot have impact, how i don't now before I have build it.
I go drawn the box in sketchup.
The box is ex plenum 230 liters, I can do 200 liters then I have -3 dB 18 Hz.
It is for home use, not PA so I am curieus about how much hifi this is.
picture of the plenum this is the right way? but plenum needs the same width as the box? and depth just to fit speakers?
This ventel alignment is B6 with High pass filter.
thanks.
I go drawn the box in sketchup.
The box is ex plenum 230 liters, I can do 200 liters then I have -3 dB 18 Hz.
It is for home use, not PA so I am curieus about how much hifi this is.
picture of the plenum this is the right way? but plenum needs the same width as the box? and depth just to fit speakers?
This ventel alignment is B6 with High pass filter.
thanks.
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slot effect/impact is very interesting indeed, for this, and in general
but what do you mean by highpassed
slot effect/impact is very interesting indeed, for this, and in general
but what do you mean by highpassed
with highpassed I mean this.
Vented Box with Active 2nd Order High-Pass Filter
This is a vented box with the addition of an active 2nd order (12 dB/octave) high-pass filter in front of the amplifier. The filter usually has a Q of about 2. The result of adding the active filter is a further extending of the bass response up to an octave below Fs and a 6th order or 36 dB/octave low-frequency cutoff rate.
When designed properly, this type of vented box can handle more power because of the protection afforded by the steeper cutoff rate. However, this advantage can be undone by higher excursion in the passband in some cases. Vented boxes with active 2nd order high-pass filters like the ones calculated in BassBox Pro are sometimes referred to as having a “B6” alignment. This heralds back to the 6th order Butterworth alignment originally described by A. N. Thiele. However, BassBox Pro allows the user to control the filter parameters (Fx, Qx) and accepts a wider variety of drivers, resulting in response shapes that may not resemble a Butterworth shape.
Copyright 1992-98 by Harris Technologies, Inc.
With a Qts=0.312 and a Q=2 filter at Fs=Fb=Faux the system will be a B6. Other values will be quite similar but technically be called a C6, and will have a small amount of ripple.
It may also be desirable to reduce the Q of the filter to allow for some 'room gain'. I used to build a system with a filter Q=1 at 30hz and it measured flat in a typical room even though the design called for a Q=2.
It may also be desirable to reduce the Q of the filter to allow for some 'room gain'. I used to build a system with a filter Q=1 at 30hz and it measured flat in a typical room even though the design called for a Q=2.
Hi djk I have still some question, I use two 330 Sd woofers and I get max 152 cm2 before the tunnel get to long now it is already 72.7 cm and so I have to go up on the back of the enclosure some say here do go not longer then 85 cm.
I can get port noise if to small, but 4 x 38 cm long is enough I hope.
Do someone has problems with boxpro 6 it looks that sometimes it do not update the calculations on my windows 7 64 bit pc maybe there is a bad version.
thanks all.
I can get port noise if to small, but 4 x 38 cm long is enough I hope.
Do someone has problems with boxpro 6 it looks that sometimes it do not update the calculations on my windows 7 64 bit pc maybe there is a bad version.
thanks all.
Oscar,
DSL's TH-812 uses an in-line PP loading that probably would work better than the plenum you suggested.
Even if it did not work better, it would be a lot easier to build
You're probably right, but this is for the trunk of a car where I need the most compact solution possible (for a tapped horn).
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