The XT25SC90-04 got only 90dB, in a passive setup you won't get anywhere with a 15" in the bass.
You can use a WG for soft dome tweeters but it only boosts the level at the lower (mid) regions.
A large two way that goes flat from the thirties to past 20kHz seems hard to make without spending high dollar on drivers or eq-ing the hell out of it.
I live in Thailand so driver availability is less than stellar here. A lot of locally made pro drivers around. They just go loud and louder with questionable fidelity. Even quality 2nd hand speakers (Wharfedale, JBL, Diatone, Victor) are hard to find and typically cost 2 to 5 times from what they are worth overseas.
Tweeters I can have someone bring to me from the US but the bass/midbass are too heavy. The only good brand readily available and reasonably priced is Eminence. So the most practical thing for me would be to use a woofer and maybe a mid from eminence.
So I was playing around with this:
Kappa 15LFA crossed over at 360Hz to an Alpha 6a? I simulated with baffle step and some room gain. The woofer is a bit elevated compared to the mid. But if I put a 20 Ohm parallel resistance and 1.5 ohm series resistance on the woofer the simulation is ruler flat @85 dB 2.83V/1m. Normally I hear people put L-pad on tweeters...is it ok to do for woofers? If not I would need to use 2 alpha 6a's to bump midrange sensitivity by about 3dB.
......or use a Beta 8a instead which has 1.5 db more sensitivity....
The alpha or Beta mid will be crossed over at around 2000 Hz to maybe a Faital Pro compression driver and waveguide.
I live in Thailand so driver availability is less than stellar here. A lot of locally made pro drivers around. They just go loud and louder with questionable fidelity. Even quality 2nd hand speakers (Wharfedale, JBL, Diatone, Victor) are hard to find and typically cost 2 to 5 times from what they are worth overseas.
Tweeters I can have someone bring to me from the US but the bass/midbass are too heavy. The only good brand readily available and reasonably priced is Eminence. So the most practical thing for me would be to use a woofer and maybe a mid from eminence.
So I was playing around with this:
Kappa 15LFA crossed over at 360Hz to an Alpha 6a? I simulated with baffle step and some room gain. The woofer is a bit elevated compared to the mid. But if I put a 20 Ohm parallel resistance and 1.5 ohm series resistance on the woofer the simulation is ruler flat @85 dB 2.83V/1m. Normally I hear people put L-pad on tweeters...is it ok to do for woofers? If not I would need to use 2 alpha 6a's to bump midrange sensitivity by about 3dB.
......or use a Beta 8a instead which has 1.5 db more sensitivity....
The alpha or Beta mid will be crossed over at around 2000 Hz to maybe a Faital Pro compression driver and waveguide.
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Nice, thank you!
As the page notes, most adapters leave a gap. And that gap causes issues:
This Denovo Audio adapter that will allow you to properly mount your 1-3/8"-18 TPI driver perfectly flush to the back of a waveguide that requires a bolt on flange. Most adapters leave at least a 1/2" gap between your compression driver threads and the waveguide your mounting it to.
I did a lot of research and after dropping the idea of aiming at something like the JBL M2 but now I am back at it.
Here is what want to build:
A two way speaker EQed and crossed over digitally/active with a minidsp hd.
Eminence Kappa 15LFA. In the attached image you can see that the response is quite close to the JBL M2 woofer. The JBL has a slightly more extended response in the top and bottom frequencies. The eminence is the red line.
Faital Pro HF10AK. The faital is more sensitive and has greater extension up top. The low end is hard to compare since the M2 measurement has the high pass passive filter in place. The faital is the light blue line.
I read the M2 uses a 6th order crossover which is 36db/octave if i am correct.
My question is this: Would the Faital driver be happy with a crossover that low (800 or 900HZ)? Advised is 1300Hz with 12db/octave crossover. So would 800 with 36db/octave work?
I plan on using a Karlson K-pipe instead of a waveguide. They have a 120deg horizontal and 35deg vertical dispersion with low distortion. For the woofer I want to make a 120 to 150 L bass reflex or some kind of transmission line. Need to research that more.
Here is what want to build:
A two way speaker EQed and crossed over digitally/active with a minidsp hd.
Eminence Kappa 15LFA. In the attached image you can see that the response is quite close to the JBL M2 woofer. The JBL has a slightly more extended response in the top and bottom frequencies. The eminence is the red line.
Faital Pro HF10AK. The faital is more sensitive and has greater extension up top. The low end is hard to compare since the M2 measurement has the high pass passive filter in place. The faital is the light blue line.
I read the M2 uses a 6th order crossover which is 36db/octave if i am correct.
My question is this: Would the Faital driver be happy with a crossover that low (800 or 900HZ)? Advised is 1300Hz with 12db/octave crossover. So would 800 with 36db/octave work?
I plan on using a Karlson K-pipe instead of a waveguide. They have a 120deg horizontal and 35deg vertical dispersion with low distortion. For the woofer I want to make a 120 to 150 L bass reflex or some kind of transmission line. Need to research that more.
The measurements shown are quite close to the ones I did on my JBL D2 and my Faital HF10AK (on an Eighteensound XT1086).
How well the HF10AK would fare on a Karlson pipe with a x-over frequency of 800 Hz I can't say. They don't give a rating for lower crossover frequencies like the do for some of their larger drivers. I will use mine crossed at 1300 Hz from an 10".
Just keep in mind that the D2 is a driver originally developped for rough handling in PA situations. It can take 200 Watts continuously !
What works well crossed at 800 Hz are some 1.4" drivers with the proper horn/waveguide. Faital HF144 and HF 146 should be very nice (perosnally I have only used the HF146). They don't extend as high as a HF10AK but they go still high enough for my taste (but I am over 50 so maybe I don't count in this respect).
Regards
Charles
How well the HF10AK would fare on a Karlson pipe with a x-over frequency of 800 Hz I can't say. They don't give a rating for lower crossover frequencies like the do for some of their larger drivers. I will use mine crossed at 1300 Hz from an 10".
Just keep in mind that the D2 is a driver originally developped for rough handling in PA situations. It can take 200 Watts continuously !
What works well crossed at 800 Hz are some 1.4" drivers with the proper horn/waveguide. Faital HF144 and HF 146 should be very nice (perosnally I have only used the HF146). They don't extend as high as a HF10AK but they go still high enough for my taste (but I am over 50 so maybe I don't count in this respect).
Regards
Charles
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I doubt I will ever throw more than 60 watt at the speakers. My amp maxes out at 120 watt anyway.
They might not take 60 Watts at 800 Hz. OTOH, even 10 Watts would be b.....y loud in a home Environment. I just don't know what it looks like in terms of distortion down there.
I use my Faital HF146 on a 18S XT1464 also lower than the recommended crossover frequency. While I have been driving the woofer amp into clipping a few times during testing I have never even managed to get the 4 Watts LED on the tweeter amp lighting up.
Regards
Charles
I use my Faital HF146 on a 18S XT1464 also lower than the recommended crossover frequency. While I have been driving the woofer amp into clipping a few times during testing I have never even managed to get the 4 Watts LED on the tweeter amp lighting up.
Regards
Charles
Hello,
While not an M2, for the price you might want to look at the two way 4PI speakers. Very good design, documentation and testing info is posted. While still expensive, not nearly as much as M2's.
I have built these and am quite happy with them. Will do quiet to extremely loud with great accuracy. If want deep bass, then add a subwoofer and you are there.
Check out 4PI on this web site:
Pi Speakers - unmatched quality and state-of-the-art performance
Regards,
Greg
While not an M2, for the price you might want to look at the two way 4PI speakers. Very good design, documentation and testing info is posted. While still expensive, not nearly as much as M2's.
I have built these and am quite happy with them. Will do quiet to extremely loud with great accuracy. If want deep bass, then add a subwoofer and you are there.
Check out 4PI on this web site:
Pi Speakers - unmatched quality and state-of-the-art performance
Regards,
Greg
After reading up on K couplers it seems they do not handle crossovers that are too low very well. Apparently somewhere between 1200 and 1500 Hz distortion rises rapidly. So if I stick to the Faital pro HF10AK with 1" K pipe I should cross over at 1200 or 1300. The Eminence Kappa 15a is down 6dB at that point but eminence gives a maximum crossover of 2k7 at which point it is already 12dB down (in recommended enclosure). But I guess the miniDSP can smooth out that 6dB drop easily with such a sensitive driver.
Would the eminence still sound good up to 1k3Hz?
I really want to stick with a two way setup since I do not want to get into more expensive DSP's with more than four output channels.
Would the eminence still sound good up to 1k3Hz?
I really want to stick with a two way setup since I do not want to get into more expensive DSP's with more than four output channels.
I agree, I think the 4pi is a lot closer to a JBL M2 than a Karlson is.
Another option to consider are the QSC speakers. Their waveguides are a shameless copy of Gedde's oblate spheroidal waveguides, and they work pretty darn well. I've never measured a waveguide that's outperformed the HPR152F's waveguide.
And believe me, I've tried! I've penned half a dozen threads about copying the JBL M2. At the end of the day, the QSC HPR152F outperformed everything that I've tried.
It's not a small speaker by any means, but it performs well and it's affordable. (You can find them used for around $800ish.)
Plus, if you like to tinker like I do, you could always put them in a nicer cabinet. The parts themselves are quite good; QSC mostly uses Celestion and B&C. A bunch of my projects using Celestion and B&C drivers were actually purchased as OEM parts from QSC and Peavey. I used to live on the same street as Peavey and QSC is about 90 minutes from me.
Hi Patrick,
I think if you check the newest horn used on the 4PI speaker build that you will find it meets
Geddes criteria for a horns dispersion. While not round, works pretty good.
Anyway, not sure I remember the exact details as it has been a couple of years since looked into this and then built some. FWIW.
Regards,
Greg
I think if you check the newest horn used on the 4PI speaker build that you will find it meets
Geddes criteria for a horns dispersion. While not round, works pretty good.
Anyway, not sure I remember the exact details as it has been a couple of years since looked into this and then built some. FWIW.
Regards,
Greg
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