Sorry, you mean to say that they're using different dome materials for the different impedance versions?
That's an odd question.. he he. No and I'm not sure why you are asking. So had to check the Fr response for both. The 8ohm has less cone breakup above 20kHz@60 degree. The only reason this exist - in my mind - is less motor control on the 4ohm. Its not an issue bellow 20kHz, but non the less, interesting to see. Thanks for pointing it out 🙂
2x MW16TX-8: Sealed vs Aperiodic vs Ported (Bass reflex) - Simulated
Ql is the Q-value due to unwanted enclosure and woofer leakage losses
Qa is the Q-value due to enclosure damping material (or absorption losses)
Qp is the Q-value due to port losses
In normal cases Ql is in the range 5-20. Ql is 7 in most cases, but 15 to 30 if the enclosure has very little leakage. Ql may be 7 even with an enclosure with no leakage because the driver unit itself may have leakages.
A box with moderate lining has a Qa of about 30. A heavily stuffed box can have a Qa of 3. Qa is 7 for about a half-filled enclosure.
A perfect port will have absolutely no losses in which case Qp is very large. A good port, one which does not significantly restrict air flow, has about 100 of Q-value.
***
For the sealed cab, I used a Ql = 30 to simulate a very tight cab.
For the aperiodic cab, I used a Ql = 1.9 which kept the Group Delay bellow 3ms.
For the ported cab, I used a Ql = 30 just like for the sealed.
Keep an eye on the phase response (gray curve in the impedance column), impedance and group delay (transient response)
***
Which enclosure would you build and why ?
Click the X in the bottom left corner for full size.
Ql is the Q-value due to unwanted enclosure and woofer leakage losses
Qa is the Q-value due to enclosure damping material (or absorption losses)
Qp is the Q-value due to port losses
In normal cases Ql is in the range 5-20. Ql is 7 in most cases, but 15 to 30 if the enclosure has very little leakage. Ql may be 7 even with an enclosure with no leakage because the driver unit itself may have leakages.
A box with moderate lining has a Qa of about 30. A heavily stuffed box can have a Qa of 3. Qa is 7 for about a half-filled enclosure.
A perfect port will have absolutely no losses in which case Qp is very large. A good port, one which does not significantly restrict air flow, has about 100 of Q-value.
***
For the sealed cab, I used a Ql = 30 to simulate a very tight cab.
For the aperiodic cab, I used a Ql = 1.9 which kept the Group Delay bellow 3ms.
For the ported cab, I used a Ql = 30 just like for the sealed.
Keep an eye on the phase response (gray curve in the impedance column), impedance and group delay (transient response)
***
Which enclosure would you build and why ?
Click the X in the bottom left corner for full size.
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Americans celebrate Thanksgiving at this time of year so that would explain some absences, yes.
I know there isn't much information currently to be handed out, but that does not mean I don't want it... LOL.
And I'm spoiled with frequent updates 🙂
And I'm spoiled with frequent updates 🙂
Just noticed on the SB Acoustics site all the “coming” models including the textrene woofers and tweeters are marked as “pre-order”, only one that is not is the dome mid for some reason.
I hope they don't do diy kits with these tbh. Just to supply them as raw drivers wd be enough.
Looking at the specs for the 4ohm.. this is an excellent driver! Opens possibilities for designs that wd be difficult to achieve with other drivers
Looking at the specs for the 4ohm.. this is an excellent driver! Opens possibilities for designs that wd be difficult to achieve with other drivers
Can I ask a question to SB, if they are still following.
The cone construction looks a little like a double cone, to reach the voicecoil. Where wd the acoustic centre be, for time alignment?
The cone construction looks a little like a double cone, to reach the voicecoil. Where wd the acoustic centre be, for time alignment?
Due to the complex part of the impedance, the center varies with frequency - most probably. Better prototype and measure.
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Will probably be similar to MR 5" satori.
Wd like to see a company do a dedicated mid with a surround similar to Bowers and Wilkins
I would wait with the wow reaction until they are available from other vendors. Don't complain yet unless you have heard them. There is no 3rd party measurement or proper listening reviews yet. If the performance is top notch, then the price might be justified. Its a new material, some new (perhaps) motor features etc.
SB has typically been very aware of the price point vs performance of their products. So if that pre-order is reflective of typical retail pricing, then they have to believe they have something quite special.
Well there's absolutely nothing expensive about the textreme cone. It's carbon fibre. As cheap as they come really and not hard to manufacture either.
We'll have to see if the performance is there. Still, it's not value for money.
We'll have to see if the performance is there. Still, it's not value for money.