6th bandpass with slave.?

[m4dm4n]

in room respons



The yellow is 2st w8-740c in sealed, purple 1st w8-740c 6th order bandpass and grey is 1st w8-740 in vented. The sealed box will bottom out at 30hz.

Is it possible to do this design with 6th order and use a slave to tune the rear chamber ?


The groupdelay is just a bit higher at 50-150hz, but will this mess up the result ?

[BassAwdyO]

Interesting response curve on the sealed and vented enclosures, I am curious why there is such a rolloff above 100hz. The sealed enclosure also seems to be amazingly flat down to even 15hz. I'd imagine you have the an EQ/Filter on winISD enabled? Im having trouble on what you mean by tuning the rear chamber with a slave? I've never heard that term before. Please explain

[m4dm4n]

In Winisd you can use filters and EQ, yes =)

the rolloff above 100hz is a LP butterworth at 80hz. Because aditionall filters give a higher groupdelay so i just wanna see how much worse it get's.


Yes the sealed got a response down to 15hz, but that´s in a room measuring 4.3m x 4m. In winisd you can add roomgain by adding a linkwitz transformer and use this values =
F0 = 345 / (largest distance in room *2) ex. 345 / 4.3 x 2 = 40.11hz
Fp = 15
Q0 = 0.707
Qp = 0.707


tuning the chamber that have a 23.48hz,, That's almost impossible to do in a 14.4liter box,, But if you use a slave it's possible.

As mentioned above, the sealed got 2 element, and the vented and bandpass got only 1 element. (Tangband W8-740c)

[BassAwdyO]

I'd assume you mean Passive Radiator by slave? Sorry I've never heard the term slave before. If you do mean Passive radiator I would say, SURE you could definately tune the rear chamber with it instead of a port! It will give you a slight response difference due to the notch in Frequency response at PR resonance. It will also give you a difference in group delay (another dip at PR resonance). It really shouldnt be an audible difference versus using a port, except no port turbulence! PR's are alot more expensive than ports, but they have their advantages. I personally dislike bandpass enclosures. I'd much rather use a sealed, vented, PR, or TL. Vented and PR will give you the best low frequency extension (without going crazy on Xmax). You'll need a Low pass filter with a bandpass design despite the 12db/octave rolloff on the high end. Once you get above the F3 on the high end the port basically doesnt exist to the driver so the driver acts as if its in a bandpass enclosure without ports. this causes extreme panel vibration (a very bad thing)

[m4dm4n]

yes PR =)
Called "slav" in swedish, slave in english.

I've tested with a PR now and i don't know if i like the build. You can't hear if the speaker is in "damage" area
typical bandpass ^ . I'll stick to sealed and PR design from now.

? ? How many G does the PR accelerate ? ?
I've heard 60 G for speaker cone, but the PR should not accelerate that fast i believe.