Audax HM100CO: Designing an Enclosure Around It

[Karl71]

I have recently become interested in the Audax HM100CO as a bass/midwoofer driver for a mini monitor, to be paired with one of the Vifa 1 In. ring radiators. The Audax has a Qtc of .21. A crossover freq. of around 2500 Hz has been suggested, with a 6dB crossover on the woofer and a 12 dB crossover on the tweeter. I might also use the LEAP service available through Madisound.

Audax's own spec sheet recommends a vented enclosure of 10 L. In order to compensate for the volume taken up by the drivers, vent, and crossover (although these may be mounted outside of the box), I am thinking that a gross volume of 12 L should work.

This is my first vented two-way. I have built a full-range and two two-way sealed speakers. Given my preferences and experience with sealed speakers, I prefer the best transient respone over bass response. I would use a Paradigm PDR8 sub to bring up the bottom end.

I am asking for advice from anyone who has worked with this driver in a similar fashion. What has worked for you?

BTW, are there any calculators for determining interior box dimensions, (not volume)?

Regards,

Karl

[bjorno]

Originally Posted by Karl71

I am asking for advice from anyone who has worked with this driver in a similar fashion. What has worked for you..Karl

Hi Karl71,

I wouldn't use this driver in a net. 12L ported box but in a TQWT = offset TL instead in order to avoid a sagged FR. In case a ported box is the absolute preference, I would use a volume of no more than 2 L and pass over to an overlapping sub at about 80-120 Hz to achieve a full grown sound stage.

I would use a Paradigm PDR8 sub to bring up the bottom end.

Why not instead invest $ 20 for 2 Bravox WFR-06BV-04B 6-1/2" drivers too and build a 34 L (~1.2 cu. ft.) BW-max= ~34-120Hz T-TQWT (Tapped Tapered Quarter Wave Tube) folded on or two times for maximum compactness?

b

[Karl71]

bjorno -

Sorry for the long dalay in replying. I've been very busy lately.

I do appreciate your response to my query and the work you did in simulating a TL. Unfortunately, I cannot read the screen image of the simulation; it comes up 'too small." Would you be able to enlarge it and then resend it as an attachment as you did before?

You also suggested a 2L sealed enclosure. Would that work well given that the driver has a Qts of .21? I prefer sealed enclosures due to their transient response. My Paradigm sub has a variable crossover range, I believe, of between 50 and 150Hz.

Thanks for your help.

Karl

[Karl71]

bjorno -

I just noticed my mistake regarding the last post. I was mistaken regarding the 2L enclosure. I should have realized that it could not be sealed.

BTW, how would the transient response of a TL compare to that of a sealed or vented enclosure for this driver?

Regards,

Karl

[bjorno]

Originally Posted by Karl71

bjorno -

I just noticed my mistake regarding the last post. I was mistaken regarding the 2L enclosure. I should have realized that it could not be sealed.

BTW, how would the transient response of a TL compare to that of a sealed or vented enclosure for this driver?

Regards,

Karl

Hi Karl,

The simulated impulse responses looks IMO good for both the TL and the Ported Aperiodic Box. See the pictures:

b

[Karl71]

bjorno -

I was able to enlarge the first thumbnail and take a look at the information. Again, thanks.

That's going to make a pretty small cabinet. I assume that this is for a mass-loaded TL. Should I allow extra volume for the Audax and a tweeter? If so, how much? I would mount the crossover externally.

Regards,

Karl

[Karl71]

bjorno -

Which enclosure would you recommend? The height and size of the TL would be no problem. Are there any sonic advantages of one over the other?

Regarding the TL, I believe Sd is the diameter of the driver. Is this correct? If so, how critical is the measurement of the cone? Some manufactures do not accurately measure a driver's diameter (there are some "8 Inch" drivers that are much closer to six or seven inches). In other words, should I measure out to the flange, to the surround, or just the cone itself?

I am going to check out Martin King's papers again (it's been a long time) to learn the terminology and his derivations.

Regards,

Karl

[jonnyq]

bump - looking 2 build a 2 way with this mid range unit...