Try http://zalytron.com/. They have high efficiency kits section with crossovers and boxes designs.
Audax has made a few different versions of that driver; I've tried the TPX and it sounded fine until the TPX cracked (as it tends to do). So far, I've lost about half my Audax TPX drivers to cracking, even one that had never left its original box.
You might also think "multiple drivers." A pair of Audax Aerogel 4 or 5 inchers in parallel will give you the sensitivity you're looking for. And I haven't cracked any of them yet.
You might also think "multiple drivers." A pair of Audax Aerogel 4 or 5 inchers in parallel will give you the sensitivity you're looking for. And I haven't cracked any of them yet.
"cracking"??? That makes me nervous. These cabs are going to be my PA cabinets for a good long while, I hope... (I'm being ambitious! a 3-way full-range design with built-in TRIAMPING so all it needs is a signal and an IEC power cable and it's ready to go) so I don't want to be replacing drivers all the time. I guess I should've stipulated that from the beginning, but does that change anyone's suggestions?
Addendum: I'm looking now at the Audax PM170MO in the Madisound catalog, and I have but two concerns:
1. the rolloff at the bottom end starts a bit above my intended crossover point, and I'm worried that might cause a dip in the response right there. Can I overcome that with the design of the box?
2. Right at the upper xover point I see what looks like combing artifacts, and while I presume that's just diffraction crap from the baffle they used, I want the "Pro DIYer" opinion on this... will the combing go away if I shape the baffle differently or do something else to it? (Right now I'm thinking of putting a layer of open-cell foam on the front baffle and shaping it like a violin, to kill diffraction patterns... My woodworking may suck, but my foam working is fantastic!
)
Thanks for all the imput you guys; you're awesome.
1. the rolloff at the bottom end starts a bit above my intended crossover point, and I'm worried that might cause a dip in the response right there. Can I overcome that with the design of the box?
2. Right at the upper xover point I see what looks like combing artifacts, and while I presume that's just diffraction crap from the baffle they used, I want the "Pro DIYer" opinion on this... will the combing go away if I shape the baffle differently or do something else to it? (Right now I'm thinking of putting a layer of open-cell foam on the front baffle and shaping it like a violin, to kill diffraction patterns... My woodworking may suck, but my foam working is fantastic!
)Thanks for all the imput you guys; you're awesome.
I used the PR17 (as pictured) in horns (of my own design) from 300 Hz up to 1.5 kHz. Each pr of drivers was driven with a Bryston 4B. I don't recall ever loosing a midrange driver (the pr i have were spares for that set-up). I treated the paper cones with puzzlecoat (as i am want to do with almost any paper cone driver).
dave
dave
Nappylady said:Addendum: I'm looking now at the Audax PM170MO in the Madisound catalog, and I have but two concerns:
1. the rolloff at the bottom end starts a bit above my intended crossover point, and I'm worried that might cause a dip in the response right there. Can I overcome that with the design of the box?
2. Right at the upper xover point I see what looks like combing artifacts, and while I presume that's just diffraction crap from the baffle they used, I want the "Pro DIYer" opinion on this... will the combing go away if I shape the baffle differently or do something else to it? (Right now I'm thinking of putting a layer of open-cell foam on the front baffle and shaping it like a violin, to kill diffraction patterns... My woodworking may suck, but my foam working is fantastic!
.
1. Probably not, though some playing around with baffles might help (see my next point). Is it possible for you to move the xover frequency up slightly?
2. It won't go away, it will be different. You can use a program like BDS to model what ripples your baffle will cause. ALL baffles modify frequency response, none are perfect. The trick is to play with baffle size and shape and with driver position until you get the most of what you want and the least of what you don't want. Don't be afraid of EQ, and whatever you do, never forget that you need to pay a LOT of attention to the off-axis stuff when looking at your optimization. And thank the various deities that you can do this playing around in software these days, rather than cutting a lot of wood.
Foam will not "kill" diffraction, only (sometimes) reduce it and (always) change it.
Ordinarily I would be concerned about wattage, but since the speaker will be actively amplified, the only thing I'm really worried about is maximum SPL, and as I see it, efficiency is probably a good indicator of that.
The voice coil may be able to handle 100 watts, but if the excursion at my crossover frequency is all used up at just 1 watt, then it's no good for me.
How loud do I want the speakers? I'm not actually sure; that will probably fall out once I've got the drivers in a box with amplifiers; I'll get everything balanced, then find out how high they'll go, and cap the volume at that level.
Someone explain (or give pictures) of this "cracking" phenomenon--this is something I think I'd like to avoid. I'd like to use these PA speakers for a LONG time...
if I could ask a completely different question... I've read someplace that a 12 dB/octabe highpass filter keeps excursion constant as frequency goes down, assuming that the driver has flat response below the filter point... so, for the woofer of these cabinets, I'm thinking of adding a 12 dB/oct highpass filter at the resonance frequency of the woofer, (31 hz, I believe) so I can be sure that the excursion never gets out of hand... is this a good idea, or will it just kill my low bass response?
The voice coil may be able to handle 100 watts, but if the excursion at my crossover frequency is all used up at just 1 watt, then it's no good for me.
How loud do I want the speakers? I'm not actually sure; that will probably fall out once I've got the drivers in a box with amplifiers; I'll get everything balanced, then find out how high they'll go, and cap the volume at that level.
Someone explain (or give pictures
) of this "cracking" phenomenon--this is something I think I'd like to avoid. I'd like to use these PA speakers for a LONG time...if I could ask a completely different question... I've read someplace that a 12 dB/octabe highpass filter keeps excursion constant as frequency goes down, assuming that the driver has flat response below the filter point... so, for the woofer of these cabinets, I'm thinking of adding a 12 dB/oct highpass filter at the resonance frequency of the woofer, (31 hz, I believe) so I can be sure that the excursion never gets out of hand... is this a good idea, or will it just kill my low bass response?
diypole, no, those are two different materials. TPX is indeed polymethylpentene. It's a bear to anneal properly, thus the cracking problems. I've talked with one of the suppliers of this material to Audax and they told me that my problem is not that unusual.
OTOH, I am an unabashed fan of their HDA Aerogel cones.
When I get home tonight, I'll snap a picture of a cracked cone for Nappylady.
OTOH, I am an unabashed fan of their HDA Aerogel cones.
When I get home tonight, I'll snap a picture of a cracked cone for Nappylady.
TPX was very popular made so by DO of Sterophile with his Dahlia speaker in the 80s. or was it 90s. decreasing brain cell count affects me esp on fridays.
It is quite dead esp along with the Norosex surround Audax used. However at that time my exp with Audax was their published specs were quite a bit off.
They are better with the Aerogel series. I am happy with the HM170 between 200Hz and 3k.
The PR170 dave mentions is also a very good PA mid. can recomend that too.
another unrealted thing. many super flat drivers used high loss rubber surrounds. Vifa's P13s for example. Try and avoind them they soud nice but not exicting. Music must give me goose bumps. All else is incidental.
It is quite dead esp along with the Norosex surround Audax used. However at that time my exp with Audax was their published specs were quite a bit off.
They are better with the Aerogel series. I am happy with the HM170 between 200Hz and 3k.
The PR170 dave mentions is also a very good PA mid. can recomend that too.
another unrealted thing. many super flat drivers used high loss rubber surrounds. Vifa's P13s for example. Try and avoind them they soud nice but not exicting. Music must give me goose bumps. All else is incidental.
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