Audax PR170M0 –100 dB or just *94 dB??

[AudioLapDance]

Zombie Tread! OMG zombies!!

I've worked extensively with PR170M0s and variants (PR17HR70, PR17HR100).

I too, would limit low end extension to no lower than 400 Hz, 18 dB/oct, or 500 Hz, 12 dB/oct. IME, for a more "public address" application (which is where these drivers see their most usage, ie, in several EAW and Peavey high-end cabinets... Audax OEM supplied the PR17 to these manufacturers, among others), a range of 500-5000 Hz is QUITE usable... I tend to use these drivers in a small enclosure (Qtc of about .8 to 1.0), with a silght overlap between the woofer and midrange, and a slight "underlap" (gap) between the midrange and tweeter. Also, using a slightly lower-Q low-pass (ie, larger inductor and smaller cap) on the top end of the PR170, will also benefit the response greatly. For the most part, if you use the tricks specified, the response will wind up pretty much ruler-flat. .. the "rising response" will be very well compensated for. Exemplary dynamic range and control...

For a "hi-fi" application, using them in the range of about 400-3200 Hz (three octave spread) would be quite nice. Avoids most of the breakup, and what you do get, does not color the sound to any detectable amount. GREAT driver. My first choice for high-efficiency 3-way systems, even to this day...

Regards,
Gordon.

Hey Gordon, do you have any values for this 500 18dB - 5000 ?dB xover?

 

[phivates]

I used a pair of the older model, MHD 17 HR 37 TSM etc in a MTM with an EV T-35 above a D-130 once upon a time decades ago. It went loud and clear as you could want thanks to Mike Hardwick's active filter and amp tweaks. No horn honk thank you very much, just a big easy presentation of the music. Audax claimed 70 watts power handling at 400 hz, third order. We went 4th order around 300 I think...it worked big time. Headroom is good.

 

[AudioLapDance]

Hey phivates, thanks for the info!

I should have specified that this is for home use (although I may occasionally crank it ~50W for this driver)

So I'm looking for values or perameters for:

GordonW:
For a "hi-fi" application, using them in the range of about 400-3200 Hz (three octave spread) would be quite nice. Avoids most of the breakup, and what you do get, does not color the sound to any detectable amount. GREAT driver. My first choice for high-efficiency 3-way systems, even to this day...


View attachment PR170MO.pdf

Wow, the waterfall looks a bit nasty! Sounds like GordonW was saying that the first few resonances sound benign and just watch out for the one around 6.5kHz.

As well, this:

Also, using a slightly lower-Q low-pass (ie, larger inductor and smaller cap) on the top end of the PR170, will also benefit the response greatly. For the most part, if you use the tricks specified, the response will wind up pretty much ruler-flat. .. the "rising response" will be very well compensated for.

Referenced to pro 500-5000 Hz, sounds like HP: 2nd order at 5k (15ohm@5k) with lower Q and LP: 2nd order at 500 (with a bit of boost from higher Q cab)

Hmmm ... sound right?

And then I would apply this to the 400-3.2k he recommends for home use.

Cheers,
Jeff

 

[AudioLapDance]

Found these in the archives:




Recommended 600 Hz crossover (R = 1ohm so that's not just dcR of the coil ... hmmmm):



And this from the web:

PR170MO et TW025A12


And an interesting idea from Thorsten:

http://www.diyaudio.com/forums/multi-way/55299-pr170m0-appreciation-club-new-member-questions.html

Quote:
Originally posted by ultrachrome
crossover: ESP 4th order LR 2-way active @ 500Hz

Thorsten
Bad choice. X-Over point is too high. Consider using a lower X-Over point (< 250Hz), a suitably large baffle and a low order X-Over. If you do your homework you can combine driver, baffle and a 1st HPF into a combination that offers a 4th order acoustical slope.

The Driver has a resonance aorund 120Hz and a Qt of 0.5, in other words without baffle rolloff you will have 120Hz/-6db. Make the baffle large enough and add a suitable 1st Order HPF and you can aim at 250Hz -6db and make the Woofer system to match. The woofer system needs to not go excessively low if you have a sub.

 

[murphythecat8]

Thy,

Thanks for your comments. Line arrays are not really what I'm looking for...

I looked at my DCX settings and it turns out I'm crossing them at 225hz LR8 slopes.. Sounds pretty good to me.. I'm listening to Genesis: Invisible Touch on LP right now as I type this message..

However I've been want to try crossing to my H-frames lower than the current 22 so I started looking at some of the 8" PHLs and thinkin about running them 125 to 3K.. I know its pretty demanding to play such a wide range but the 2460 looks pretty good ... QTS 0.44, FS 81 and +/- 5mm xmax

--Chris

hi, I doubt youll see this, but how can you acheive 225 hz flat with the pr17? I manage in a 35 L sealed box, 350hz, then it starts to roll off and its -3db at 300hz, -5 db at 200hz...

 

[Max Martin]

AUDAX PR170M0 (Mid-range 6", 8 Ohm, 200 Wmax)