3 way ultra high output

I am designing a speaker to play extremely loud, 120 dB realm, that gets good dispersion. Live sound apps. My current design is Eminence Kappa 15LF (I like it a lot, already have them, [Qts:.38, Vas:5 ft3, Fs: 46 Hz]) Reference efficiency is above 3%.(about 97dB at 1 w/m) Eminence rates them at 100dB at 1 w/m. I'm thinking about a 4 - 5 ft3 box tuned to resonance. The tweets are the eminece 2" tit horn drivers w/ 1" exit. Absurdly efficient. Already have both of these, so I cannot change them. Also have big huge horns. I think I can cross these as low as 1.5 kHz @ 12 dB/octave. These in a two way crossed at 1500 would lack in the mids. I want to make it a three way so I can get good dispersion and clear mids. I don't have a mid yet, but I'm looking at the eminence alpha 6 midrange as a possibility. I like how it won't take up very much room on the already very large baffle, and its frequency responce. Although it isn't as efficient as the woofer, maybe bandpass gain will make up for it? Any crossover advice, or any advice at all? (I've never done anything with 3 ways)
-andy
 
Since the Kappa will go up to 4K and the Compression driver down to 1.5 why do you want a mid? This stuff is made to take a beating so crossing at 3 to 3.5 aught to make it plenty easy on the drivers. If you still want a 3 way I would stay with the Eminence since all the cone drivers seem to be in the same ballpark as far as efficiency goes. I would personally use an L-pad on the compression driver, but that is just my tastes.
 
My buddy Chris used the Eminence 6 in a 3-way mod to a set of AMT-1s. It works well. If more quality and efficency is required the Audax PR17 (the paper is better than the aero gel) is even better (at more money). When i was doing proPA we used the Audax extensively.

I'd suggest using then from about 350-400 Hz up to 2k -- they will go higher but a horn is only designed to cover a certain range. I am somewhat surprised that the 2" compression driver & horn only goes down to 1.5k -- these are usually designed for working down to 500 or 800 k in which case a nice active 2-way system would be possible (big huge horn usually means goes low).

XO -- go active. Even if you have to build the amps yourself. The horns won't need much -- a 25 w chip amp would do the trick (<$100 if you DIY) but you need something like 200W to achieve your desired SPL in the bottom -- absolute best for the ap would be a Bryston 4B (when i was doing PA we used 2x4B and 1x3B on each side -- with a Quad 303 as back-up for the top).

dave
 
I like the audax's. I didn't know that they made pro stuff. The PR170M0 is $70 at madisound. Not bad. I'm willing to pay a little more for nice mids. Where can I find a pic of them, audax.com didn't have it.

Tell me more about active XO.

Built in amps are too complicated for this project. I want to make it bi-amp compatible.
thanks
-andy
 
I think the horn will go lower. haven't tried.

Although a 2 way with the drivers I have would work, I chose a 3 way design because a 15" cone loses off axis responce as frequency increases, and a little light cone would have better sounding and better dispersed. Mids than a big giant one.

Would passive eq defeat the benefits of biamping if I were to biamp?
-andy
 
bostarob said:
Built in amps are too complicated for this project. I want to make it bi-amp compatible.

Just run terminals out to the back from each speaker. Use the XO, active or passive, outside the box.

Tell me more about active XO.

More systems should be active.

Active XO is before the power amps, of which you have one for each speaker. It has some excellent benefits.

I have a set of Active XO links on my website. There are basic overviews, pictures, projects, kits...

dave
 
Dave,
I just got an Ashely XR2000. Going to get the XLR to RCA plugs next week. Can this be used as a preamp as well as an active cross? It can handle 4 2ways which with the SE amps I have I am looking at building 2 way TLs. Eminence Beta 12" 40 to 10K mid woofer and as yet to be decided tweeter. I have some great pairs but no quads. I don't like compression drivers except for the EV 35s and am not willing to pay the price for those. I am going to start hitting the auctions to try and come up with a quad of Heils out of old ESS speakers. Scrounging is good. The ESSs also have good open air chokes in them which is a big plus for building passive crosses. Foam rot does have the advantage of creating good scrounge for formally high priced speakers.
David the TL lover
 
Thatch_Ear said:
I just got an Ashely XR2000. Going to get the XLR to RCA plugs next week. Can this be used as a preamp as well as an active cross? It can handle 4 2ways which with the SE amps I have I am looking at building 2 way TLs. Eminence Beta 12" 40 to 10K mid woofer and as yet to be decided tweeter.

The Ashley has 4 2-way sections? (ie this would be used as a stereo 3-way XO in the field). Does it have a master gain control? If not you could just add a Harry Haller passive pre to the front end of the thing -- might be kinda cramped to put it inside. These benefit greatly by power supply tweaks, and possibly by op-amp upgrades. I wonder how easy it would be to retrofit the Class A biasing (somewhere in another thread here).

I am going to start hitting the auctions to try and come up with a quad of Heils out of old ESS speakers. Scrounging is good. The ESSs also have good open air chokes in them which is a big plus for building passive crosses. Foam rot does have the advantage of creating good scrounge for formally high priced speakers.

Some of those thrift stores don't seem to see foam rot as a problem. The Heils are great tweeters -- and efficient too.

David the TL lover

You need to post a TL project up on my website.

dave
 
You gave me an idea. I'll have a single set of inputs that go to a passive xo.
In addition, I will have pair of inputs, one leading to the woofer, the other leading to a 2way dividing the mid and tweet.
Simpler would be to just have 3 sets of inputs leading to their respective driver, but who wants 3 amplifiers?

I looked into active xo info, and I am impressed mostly at how simple it really is. I thought it would be much more complex! I've got some reading to do.

I am probably not going to use these very much, I am going to sell them. I am thinking about using active xo's in my "dorm room monitor" project. Two ways using hi vi F8 and audax D25AG. I am almost done tweaking passive xo's for them, and am planning to build esp's 3A amp to run them. Eventually this amp will run the high's and a big amp that I will build later will run the lows. The center of it all: Active xo.
As I said, I have a lot to learn and will probably change my mind many times. Maybe the 3A is big enough to run the lows. I could build a little teeny amp with a high slew rate and low hf distortion to run the highs. I don't know.
-andy
 
bostarob said:
Simpler would be to just have 3 sets of inputs leading to their respective driver, but who wants 3 amplifiers?

Me. Actually i'll need 6 stereo power amps once i get my system finished. (2 for the subs, 2 for the coupling woofers, 2 for the full-range sats (and then whatever i need for the surrounds)

dave
 
bostarob said:
i hope trapeze work pays well!:D

Pays well -- when it pays.

Trapeze is awesome Mac only spreadsheet SW last released in 1988 (10 years or more ahead of its time). I use it to produce world-class business financial models -- even on my 50/100 MHz 68040 Macs i can, with this software, do a job in an afternoon that would take a week in Excel on my G4.

dave
 
bostarob said:
Ohh, I thought you were joking in your profile about being a circus performer.

One of the reasons i use the title (instead of VP Technology) is because it makes people think twice.

im sure your system will sound delightful

Indeed it does and i know i can make it better. New cart in the Linn tomorrow, and i'm gonna make time to get the Alnicos into the pipes...

Question: how much do you think it would cost (if you were to make it) to make a 2 way active xo for one speaker?

Let's talk stereo -- a lot of the cost is in the power supply and you can share it... and i'll only cover off the least expensive approachs (for more $$$ check out the Marchand XM26 for an example).

Depends on how good a scronge you are. You can get John Pomann's Active XO Experimenters Kit for $75, you could get a couple Marchand XM1 boards for $25 each (kit) and the matching power supply for another $50, or you could scronge a bit and probably scare up parts & power supply and then do a dead bug wiring job for under $25 or less for the works. You could also pick drivers where you could get away with 1st order and do a Passive Line Level XO for pocket change (especially true for Canadians who have all those Loons & Dubloons [$1 & $2 coins -- CAD $ mind you]). If you need more than 1st order you can do a PLLXO with inductors & caps just as you would for a passive XO for a speaker except, given the much higher R of the amps you are crossing to, the Ls & Cs are small -- the perfect place for those single layer air coil inductors.

And don't forget eBay. for example here is a Biamp Systems 2-way with a Buy-it-Now for $60 -- that is just an example there is a lot of choice (i picked this one because we used 2 of these for our pro PA with the 6 Brystons). The pro ones can get way better with some tweaking too.

dave