Hi, I have a 21W8553 scanspeak woofer and I would like to build a small sub for my av setup.
I googled but found no results...
Can somebody help me out with box build (TL vs vented vs closed)? or point me some links?
Unfortunately, I don't have much knowledge of loudpseaker building, nor access to a measure equipment
Will it be hard to build a subwoofer?
Thanks
AeoN
PS. Speakers spec:
Characteristic sensitivity (2.83V / 1m) : 90 dB
Recommended frequency range : 26 - 3000 Hz
Free air resonance frequency, fs : 23 Hz
DC resistance, Re : 5.5 ohm
Voice coil inductance, Le : 0.2 mH
Effective piston area, Sd : 220 cm²
Moving mass incl. air, md : 20.5 g
Mechanical loss, Rm : 1.7 Ns/m
Force factor, BL : 8.0 Tm
Equivalent volume, Vas : 160 ltr.
Mechanical Q-factor, Qms : 1.7
Electrical Q-factor, Qes : 0.25
Total Q-factor, Qts : 0.22
Excursion, lin./max. : ±6.5 / ±10 mm
Voice coil diameter : 42 mm
Rated power handling : 90w RMS / 130 W max
Net weight : 2.4 kg
I googled but found no results...
Can somebody help me out with box build (TL vs vented vs closed)? or point me some links?
Unfortunately, I don't have much knowledge of loudpseaker building, nor access to a measure equipment
Will it be hard to build a subwoofer?
Thanks
AeoN
PS. Speakers spec:
Characteristic sensitivity (2.83V / 1m) : 90 dB
Recommended frequency range : 26 - 3000 Hz
Free air resonance frequency, fs : 23 Hz
DC resistance, Re : 5.5 ohm
Voice coil inductance, Le : 0.2 mH
Effective piston area, Sd : 220 cm²
Moving mass incl. air, md : 20.5 g
Mechanical loss, Rm : 1.7 Ns/m
Force factor, BL : 8.0 Tm
Equivalent volume, Vas : 160 ltr.
Mechanical Q-factor, Qms : 1.7
Electrical Q-factor, Qes : 0.25
Total Q-factor, Qts : 0.22
Excursion, lin./max. : ±6.5 / ±10 mm
Voice coil diameter : 42 mm
Rated power handling : 90w RMS / 130 W max
Net weight : 2.4 kg
The reason you are not finding any hits when you google is probably because that driver is not designed for subwoofer applications. What do you have for mains, and what do you expect the sub to do? The speaker you have is more at home with a double bass viol than it is with an exploding dinasaur.
In a sealed box it won't go nearly low enough without a lot of EQ, which pulls the power handling down. The standard "boost" available in plate amps would not have the right shape anyway. A TL would probably not qualify for "small."
A vented or passive radiator "EBS" alignment would appear to be indicated. "EBS" (extended bass shelf) means that the alignment is over-damped and has a rising frequency response throughout the subwoofer range. "Boost" from the plate amp, "room lift", and the fact that you are crossing over to the mains at a fairly low frequency, all conspire to flatten out the response.
An EBS vented box would have a pretty long vent.
So a passive radiator EBS alignment is what's left. Ideally you would want an amp with boost at your tuning frequency (30Hz?) and a 24 db/octave low pass filter. A sharp filter is desirable to help kill the rising response. Parts Express has a 200 watt plate amp with an (unadvertised) 24db per octave lowpass filter, and I think they can tell you how to swap out a couple of resistors to effect the necessary boost.
What you will wind up with is something similar to a Peerless XLS passive radiator system, except it would not go as low. The XLS driver *is* designed for subwoofer applications. You might just want to sell the ScanSpeak and buy an XLS. They are manufactured by the same company, BTW.
Through the miracle of the internet, a dozen good folks will now demonstrate why I am completely wrong. That's okay. What little I know, I learned right here.
In a sealed box it won't go nearly low enough without a lot of EQ, which pulls the power handling down. The standard "boost" available in plate amps would not have the right shape anyway. A TL would probably not qualify for "small."
A vented or passive radiator "EBS" alignment would appear to be indicated. "EBS" (extended bass shelf) means that the alignment is over-damped and has a rising frequency response throughout the subwoofer range. "Boost" from the plate amp, "room lift", and the fact that you are crossing over to the mains at a fairly low frequency, all conspire to flatten out the response.
An EBS vented box would have a pretty long vent.
So a passive radiator EBS alignment is what's left. Ideally you would want an amp with boost at your tuning frequency (30Hz?) and a 24 db/octave low pass filter. A sharp filter is desirable to help kill the rising response. Parts Express has a 200 watt plate amp with an (unadvertised) 24db per octave lowpass filter, and I think they can tell you how to swap out a couple of resistors to effect the necessary boost.
What you will wind up with is something similar to a Peerless XLS passive radiator system, except it would not go as low. The XLS driver *is* designed for subwoofer applications. You might just want to sell the ScanSpeak and buy an XLS. They are manufactured by the same company, BTW.
Through the miracle of the internet, a dozen good folks will now demonstrate why I am completely wrong. That's okay. What little I know, I learned right here.
As Dave has pointed out, the SS 8" midbass driver isn't really subwoofer material. It just doesn't move enough air. It's the speaker equivalent of one of those snobby restaurants where you pay a pile of money for a snack sized meal. A hamburger and chips are more likely to satisfy your appetite!
EBS is going to place too much of a demand for excursion on the driver and will take away a bit midbass punch, which will have the overall effect of sounding like it has less output! It will also increase the necessary size.
You could probably get a pair of these to work nicely in a stereo pair of TLs. I do hesitate to recommend this alignment due to the low Qts but I believe it was shown in a previous thread that this is not an impediment. This driver is known for its bass and as its a woofer it can extend into the midrange. It would work well as a woofer in a 3 way speaker and could easily get a useable inroom response down to 25 Hz with decent output with a pair of them in a medium sized room.
I expect it will be more articulate than most subs. A pair will move a similar amount of air to my TLs, which is more than enough to satisfy most people for movies. However, in a sub, the tendency is to crank it up. I just don't think this is the driver for a sub! (Btw, I'm adding subs to my mains)
EBS is going to place too much of a demand for excursion on the driver and will take away a bit midbass punch, which will have the overall effect of sounding like it has less output! It will also increase the necessary size.
You could probably get a pair of these to work nicely in a stereo pair of TLs. I do hesitate to recommend this alignment due to the low Qts but I believe it was shown in a previous thread that this is not an impediment. This driver is known for its bass and as its a woofer it can extend into the midrange. It would work well as a woofer in a 3 way speaker and could easily get a useable inroom response down to 25 Hz with decent output with a pair of them in a medium sized room.
I expect it will be more articulate than most subs. A pair will move a similar amount of air to my TLs, which is more than enough to satisfy most people for movies. However, in a sub, the tendency is to crank it up. I just don't think this is the driver for a sub! (Btw, I'm adding subs to my mains)
Wow, I didn't know there was such a thing as a SS subwoofer :O
It looks quite impressive. Decent excursion (13mm xmax) and low LeVC. I'm a little curious to find out a little more, in particular what the cone material is.
Even this driver, however, only just makes the grade as a sub as far as output is concerned. Curious is the response - probably more honestly presented than most but it's far from smooth.
It looks quite impressive. Decent excursion (13mm xmax) and low LeVC. I'm a little curious to find out a little more, in particular what the cone material is.
Even this driver, however, only just makes the grade as a sub as far as output is concerned. Curious is the response - probably more honestly presented than most but it's far from smooth.
Try with Peerless subwoofer drivers . They are fast , powerfull ... On their site you have parameters for sealed, bass reflex and passive radiator box. Passive radiators look identical , but they don´t have magnets and coils. Look for "Danish sound technology" site on Yahoo or Google.
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If you are talking USD then that's very pricey. Seems a bit like having gold plated pipes to your dunny! Very expensive way to move air. The box is also quite big for a 10" driver, must be an EBS, giving up some of the stuff you can hear to try to ge the stuff you can't hear, and probably can't feel as it won't be able to reproduce with any authority.
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