Is it possible to cover the whole spectrum, high SPL, low distortion with a 2-way?

Really? I said I don't think it's large enough to load and hold directivity that low.

The way I took it was you implying that it couldn't play down to 300hz. Its rated to be able to play to 500hz where as, I implied using it at, 600hz. Can you clear that up for me?
The comments I was referring to, were on the reviews parts-express, from people who used the product, not anything said here.

Brett you seem passionate enough, if you have any suggestions on the materials, please share. In particular, is there even a waveguide of reasonable price that can play down to 300hz?
 
The way I took it was you implying that it couldn't play down to 300hz. Its rated to be able to play to 500hz where as, I implied using it at, 600hz. Can you clear that up for me?
I generally ignore ratings and measure myself based on hard won experience. Whilst I haven't used that unit, I don't believe it will load well to 600Hz, nor hold pattern control till there. Happy to be shown to be wrong.

Brett you seem passionate enough, if you have any suggestions on the materials, please share. In particular, is there even a waveguide of reasonable price that can play down to 300hz?
First tell me which CD will do high SPL into a horn/WG at 300Hz. CDs have Xmax limitations like all other drivers.

If you really want a quality horn loaded source to do 300Hz to ~20k, build a Synergy.
 
I generally ignore ratings and measure myself based on hard won experience. Whilst I haven't used that unit, I don't believe it will load well to 600Hz, nor hold pattern control till there. Happy to be shown to be wrong.

First tell me which CD will do high SPL into a horn/WG at 300Hz. CDs have Xmax limitations like all other drivers.

If you really want a quality horn loaded source to do 300Hz to ~20k, build a Synergy.

+1, just doing a quickie 'ballpark' assessment assuming wall angles are actually 90x40, then using 10^6/[angle*width], ~740 Hz x 2841 Hz with a mouth cutoff = ~246 Hz, axial length = ~372 Hz, so meets its stated 500 Hz cut-off: GM-450PB - goldwoodsound.com

Pretty typical of vintage spec horns once the mouth end correction is factored in, lowering the pattern a bit.

In short, no pattern control to 600 Hz and in its pattern flip BW only averaging ~1400 Hz.

Vintage spec Altec/GPA 1.4" exit series/311-90 expo does 300 Hz, though only to ~12.5 kHz at high SPL/SQ.

+1 Synergy concepts are currently where it's at for high SPL super wide BW at high SQ in a typical HIFI/HT app.

GM
 
Hmm. Sounds like I need to build a synergy. Is there a particular synergy design that you guys can recommend?

On your other design, Brett brings up a good point about pattern control. You had better know if the woofer beams at all at the xo frequency so you make sure the directivity matches the horn ok. To explain, at say 30 degrees off axis you don't want the frequency response curve to have a sudden change at the cross over frequency. My horn's directivity falls off pretty smoothly at 500-700 hz, so by 500, it matches the woofer which has no directivity at 500hz. Since your woofer is a 15", it probably will beam a little at 500hz though.

As badman pointed out, it is fair to say that my speakers don't necessarily qualify as "high spl" compared to the output capabilities of most horn systems. I would argue that in any reasonable size domestic room, you don't need that capability. I'm only sending 2 watts max to the horns, but at 110dB/1w/1m, that's enough to make it more than loud enough.
 
I was able to audition some altec horns today, and I can't go back now. Being that I can't cross lower than 500hz I don't see a need for a coaxial CD, which brings the Radian 950PB up to the front, being that the name came recommended and it covers the intended frequency range. The chosen horn seems to be able to load to 500hz (according to GM's calculations), though lacking directivity at that lower note, its still about the best I'll do for a decent price. The Acoustic Elegance was chosen for its specs not its name, so no reason to change. I think I've finally reached a conclusion, The only thing I want to study now is construction philosophy. I might do something weird and use a microphone stand to mount the horn to make it easily adjustable for the listener, who knows....
 
I was able to audition some altec horns today, and I can't go back now. Being that I can't cross lower than 500hz I don't see a need for a coaxial CD, which brings the Radian 950PB up to the front, being that the name came recommended and it covers the intended frequency range. The chosen horn seems to be able to load to 500hz (according to GM's calculations), though lacking directivity at that lower note, its still about the best I'll do for a decent price. The Acoustic Elegance was chosen for its specs not its name, so no reason to change. I think I've finally reached a conclusion, The only thing I want to study now is construction philosophy. I might do something weird and use a microphone stand to mount the horn to make it easily adjustable for the listener, who knows....

It's great you were able to hear the "horn sound" before committing. I think you have a very promising design started. Congrats!
 
I have a two way with 2x15" and a 1.4" CD that I regularily listen to. I don't claim it to be the last word in resolution but it is definitely fun to listen to this speaker that definitely doesn't break a sweat even with bass-heavy music at increased listening levels.
The quality of the drivers chosen by you is above the ones used in mine.

Regards

Charles
 
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I was able to audition some altec horns today, and I can't go back now. Being that I can't cross lower than 500hz I don't see a need for a coaxial CD,...

You are missing the point of a concentrically mounted tweeter and the integration that it brings to playback with a dramatic increase in focus and dimensionality of the music. I would recommend that you listen to an Altec 604 or better yet a Tannoy fifteen inch dual concentric which has a true dual concentric mounted tweeter system. These systems will show you what a compact wide band two way can do. They are impressive.
 
Since your woofer is a 15", it probably will beam a little at 500hz though.

According to Altec measurements of their deep cone drivers Vs JBL's shallow cones, a 15" 'sets' on the baffle [normally listed as 180 deg, but actually ~160 deg] till around 900 Hz and 90 deg around 1.25 kHz. Above this point, they basically track the cone's curve vs the theoretical straight line out to 40 deg/2.5 kHz with the JBL staying flat to 3.15 kHz whereas the Altec opens back up to ~50 deg.

In short, two very different cone designs 'close enough' follow piston theory out to the highest acceptable XO points for a 15", so confident it's good enough for other brands/models.

GM
 
As a general rule I take 13,550/(drivers active diameter) So to ball park it 13550/15=903hz which is a KA=1, kind of like, the point of no return with almost no directivity, according to the charts I seen and then for good measure divided that by 2 which would be 450hz, which gets past the range with absolutely no directivty, at all, so 500hz seems perfectly fine to me, for a 15" driver.

Moray James - I hear what you are saying but there isn't a system that stays completely co-axial that is going to get me into a sub range. So a two-way or FAST speaker is the only option. If you are addressing my comment regarding a coaxial CD.....I'm almost certain that a coaxial CD running from 500hz-20khz has no benefit over another qualified, no coaxial CD, that can cover 500hz-20khz....actually the extra crossover is a disadvantage and the coaxial design is to allow for a deeper driver capability that I do not care to invest in the equipment to utilize it properly, so instead of being able to cross at 300hz, or 200hz as advertised by some coaxial compression drivers, 500hz seems to be just fine for a non co-axial CD....unless someone knows something that I don't, now would be the time to speak up. I can't get a CD to run to say 150hz, to create a true FASt or WAW setup, but this is the next next thing if I want to stay the course of a CD powered system. If coaxial CD's offer a lowered intermodulation distortion, I'd definitely be all ears, to that.

Phase_accurate - Don't you think CD offer something in the terms of resolution that you cannot get from any other type of driver, because thats how I feel.
 
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I think your newfound love for CD's is a result of the high sensitivity.

Some big CD's work down to 600hz, and sound impressive, but those drivers sometimes need help up top.
There are some 1.4" exit drivers that can work well to 900hz.

Either way you'd be relying on some form of DSP to get sharp enough xo, to smooth out the squiggly bits, and both of the above would require a proper horn in the majority of cases. Not to mention that if you're chasing for a point source system you'd be better off looking at the various synergy designs.

In most cases involving CD's you'd end up with a 3way solution to cover the whole spectrum, pending on how low in frequency and how loud you want to go.
 
I agree. Also the directivity creates a stereo imagine that is weird good, like unexpectedly good, like 3d. I don’t think people understand that the directivity also places the source closer to your ears (seemingly) via projection kinda like wearing headphones but not? I think 500hz is a fair xover for the horn. I’m just wondering what I’d have to gain by using a coaxial CD since there plenty of single voice coil CD’s that cover 500hz to 20khz. Intermodulation distortion vs adding another crossover? I was told a quality CD can handle the range specified without breaking a sweat. Can any one concur?
 
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