Audax HM130CO - How good are these in a 2 way speaker?

duanebro

I have a set of Audax HM130CO drivers I got at InDIYana a few years ago. Now I see that Charlie is selling another set. I have been wanting to "upgrade" my Tritrix TL speakers for a while now. The HornRESP model looks good with the Audax woofers. My question is are these a good fit in a 2 way speaker? Or are they better used as a mid? Would I be better off with the RS150 instead?

Thanks!

charlielaub

It's a 5.25" driver with limited Xmax, so keep that in mind for your expectations of LF extension. The driver has reasonable performance and good sensitivity for its size. One possiblity is a small 2-way system crossed over at 150Hz to a subwoofer, or as a midrange crossed over a little higher than that. The RS150 lineup might have slightly better distortion performance but I never compared the two directly. The HM130C0 is IMO one of the better drivers from the old Audax lineup and can still hold its own today despite the age of the design.

duanebro

Thank you for the reply Charlie. I modeled the Audax and RS150 against the 5" classic used in the TriTrix MTM. They all model exactly to same in the enclosure. As far as power handling/SPL the Audax gain 1db over the classics. While the RS150 gain 4db at double the power.

I am not sure that this matters much as I don't have any complaints with the spl of the Standard Tritrix...

DrewsBrews

Found this

https://ampslab-spk.com/2017/08/22/audax-hm130c0/
https://ampslab-spk.com/2019/02/04/audax-hm130c0-carbon/
https://ampslab-spk.com/2019/03/12/orion/
https://ampslab-spk.com/2019/06/28/orion2/
https://ampslab-spk.com/2021/02/24/orion-rt13/

Seems he liked it enough to mess around with quite a bit

charlielaub

The HM130C0 is a great driver and built like a tank. I think it looks very cool with an inverted surround and nice carbon fiber cone. It's probably at its best as a midrange and not as a mini-woofer. It has pretty high sensitivity and breakup is very well controlled. Some excerpts from AmpsLab writeup (second link):

My thoughts on the Audax HM130C0 and the Heil AMT

Having worked with the HM130C0 and the Heil AMT, I find you either love them or hate them. When they are good, they are excellent. Conversely, when they are bad, they are horrible.

Case in point, the Audax HM130C0 is totally deficient in bass. It only managed 70Hz (-3dB) in a bass reflex. So, unless you are listening to violins all the time, it’s useless.

Where the HM130C0 really shines is in the midrange. It exhibits a flat frequency response all the way up to 10kHz. Granted that the midrange extension from 6kHz~10kHz is derived from the cone ringing, it is not an issue when crossed at 3.8kHz (24dB/oct).

A huge plus in the HM130C0 that is not apparent is the speed. This midwoofer is fast. By that I mean the transient. I picked this up when I first listened to the HM130C0 without any crossover. This prompted me to measure the Step Response shown in Fig 19.

Some interesting and insightful comments there but OMFG if I hear another person talk about the "speed" of a driver that they listened to I am going to puke. The transient speed is 100% set by the upper frequency response limit of the driver. That's it! Don't believe me? Just put a lowpass filter on it and see how it "slows down". You can easily measure it. Where is the facepalm emoji when I need it! Also: it's not because of a high Qms either. The Qms of this driver is 3.6! But still "fast"...

OK, I am done hyperventilating now...

BTW there is still one pair available.

DrewsBrews

I bet it has tight bass.

charlielaub

Fast, high, and tight!