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

Agree with badman and mark100. The 2 way JBL 4722's I use are wide bandwidth, high output and low distortion. The double 15's have solid output to 40 Hz, but I ended up getting dual subs anyway to cover the bottom octave. I cross them between a room mode at 45 Hz: Official Rythmik Audio Subwoofer thread - Page 1223 - AVS Forum | Home Theater Discussions And Reviews

Like badman says, had I known this when I started out looking for a wide bandwidth two way, and what the compromises are, I would have gone with the subs first. Then I would have probably gone with a different two way as a higher XO opens up considerably more possibilities...
 
Badman, I have to agree.
For me, a 2-way can't give the SPL and extension I enjoy...particularly with some of today's bass enhanced music.
I've just accepted that, and every design I build incorporates subs...

My two way pulls it off. It does low and loud. The only way I could make it happen was with a horn on top of a subwoofer 12". Crossed at 500hz. I was very surprised that not only was the 100-500hz range acceptable from the sub driver, it actually sounded better than the other woofers that were designed to play that range. Check out the measurements. I think one of the reasons people are skeptical of the approach is that it does not honor crossover recommendations from compression driver manufacturer. When we're in a domestic setting and we only need a couple of watts, you can stretch it down without risk of blowing the driver. The quality of the bass is also better than I've been able to achieve with separate subs, although room correction is needed since bass will not be as balanced as placement of multiple separate subs.
 
My two way pulls it off. It does low and loud. The only way I could make it happen was with a horn on top of a subwoofer 12". Crossed at 500hz. I was very surprised that not only was the 100-500hz range acceptable from the sub driver, it actually sounded better than the other woofers that were designed to play that range. Check out the measurements. I think one of the reasons people are skeptical of the approach is that it does not honor crossover recommendations from compression driver manufacturer. When we're in a domestic setting and we only need a couple of watts, you can stretch it down without risk of blowing the driver. The quality of the bass is also better than I've been able to achieve with separate subs, although room correction is needed since bass will not be as balanced as placement of multiple separate subs.

It's good work, very attractive and nice performance and you should be proud of it, but your midrange SPL is severely limited relative to most other 2 way horn solutions, and requires an active biamp setup. You essentially have a small direct radiating midrange at the crossover point, sort of like a 12" and a 1.75". That doesn't fly for "high spl". By my calculation, you'd need around 3mm of excursion from the CD acting as a direct radiator at 550hz or so to achieve the 105dB your graph's showing on the distortion test, at 1M. The absolute SPL on your graph almost certainly is too high.
 
All of the above. My design quest started out with a mindset to create the "hydrid" that we know as a FAST speaker or, on this forum, a WAW, using a coaxial top. Which is a 2-way, 3-way.....I'm sure you know what I mean. Then I found out there weren't very many coaxials that fit the bill. Eventually I did the 5CX200ND, which isn't exactly out of the picture. Everything looks pretty good on paper. It has high sens and power handling, flat response, nice off axis response. I'd be able to cross at 150hz If I chose to run it. Thanks to this thread I learned about compression drivers, and noticed a lot of the horns had better off-axis performance than coaxials dynamic drivers. While researching this option I came across, the BMS 4590. Though I wouldn't be able to cross as low as I wanted, crossing over near 300hz, isn't very much higher, is do able for a 15", and quite common among 3 ways. On the top end the crossover can be near 6300hz....creating a much wider, naked range of frequency. Finding the right woofer was a journey, and I actually looked at it, earlier but was in denial of the specs, since they are pretty much better than the rest of the woofers in the same price range....I'm still skeptical but I noticed that some other semi-famous designers have chosen to use this brand so, at this moment I'm, semi-committed. Acoustic Elegance TD15H seems the choice woofer, supposedly being able to be crossed above 1000hz, should be fine crossed at~300hz, has great BL, super low inductance, actually so low its likely a lie, high sens and xmax, pulling off 114db at 30hz no prob, with nice group delay, in a ported ~5ft3 box . At this point, I am going to start studying the construction of some the enclosures I've seen on the board that involve horns. I think I like the horn outside of the woofer enclosure. So yeah, a FAST speaker with a coaxial compression driver. Sounds good to me. I'm looking to pick up a CTS 4200 to run the tops, a CTS 1200 to run the woofers. I plan on splitting the input signal from a Focusrite scarlet to, two, balanced minidsp's for crossovers and eq. If I can keep it all under 2500 hundred, thats fair.
What do YOU guys think about the parts chosen?

Cspieker - I'd love to take a gander at your design...where is it?
 
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While researching this option I came across, the BMS 4590. Though I wouldn't be able to cross as low as I wanted, crossing over near 300hz, isn't very much higher, is do able for a 15", and quite common among 3 ways. On the top end the crossover can be near 6300hz....creating a much wider, naked range of frequency. Finding the right woofer was a journey, and I actually looked at it, earlier but was in denial of the specs, since they are pretty much better than the rest of the woofers in the same price range....I'm still skeptical but I noticed that some other semi-famous designers have chosen to use this brand so, at this moment I'm, semi-committed. Acoustic Elegance TD15H seems the choice woofer, supposedly being able to be crossed above 1000hz, should be fine crossed at~300hz, has great BL, super low inductance, actually so low its likely a lie, high sens and xmax, pulling off 114db at 30hz no prob, with nice group delay, in a ported ~5ft3 box . At this point, I am going to start studying the construction of some the enclosures I've seen on the board that involve horns. I think I like the horn outside of the woofer enclosure. So yeah, a FAST speaker with a coaxial compression driver. Sounds good to me. I'm looking to pick up a CTS 4200 to run the tops, a CTS 1200 to run the woofers. I plan on splitting the input signal from a Focusrite scarlet to, two, balanced minidsp's for crossovers and eq. If I can keep it all under 2500 hundred, thats fair.
What do YOU guys think about the parts chosen?

Cspieker - I'd love to take a gander at your design...where is it?

300hz in a BIG horn. Accusing AE of lying about inductance is trashy. They achieve it with small voicecoils and a thick shorting sleeve, other shorting sleeve motors can achieve similarly low inductance.

Cspieker's thread: the "SPIEKER" my almost 20 year prototype finally done
 
Here's a link.

the "SPIEKER" my almost 20 year prototype finally done

Badman and Mark100. Thank you very much for the critique! Exactly what I was hoping for, I knew it must have disadvantages. I'll run some spl calibrated distortion measurements at higher output. I'm sure we'll see 500-1k distortion elevate some. I'll post them back on my thread so as not to hijack yours. One quick question badman: it's a 375hz Tractrix, what makes you think that it's not loading the driver down to 500? Thanks again, Craig

It will take me a couple of weeks, I'm nursing a broken leg.
 
Here's a link.

the "SPIEKER" my almost 20 year prototype finally done

Badman and Mark100. Thank you very much for the critique! Exactly what I was hoping for, I knew it must have disadvantages. I'll run some spl calibrated distortion measurements at higher output. I'm sure we'll see 500-1k distortion elevate some. I'll post them back on my thread so as not to hijack yours. One quick question badman: it's a 375hz Tractrix, what makes you think that it's not loading the driver down to 500? Thanks again, Craig

It will take me a couple of weeks, I'm nursing a broken leg.

I'm basing that impression upon the polars- I expect to see some directionality in any "loaded" frequencies. Others may look at it differently with respect to what constitutes loading, I guess the only way to be sure is to test free air vs. horn efficiency for those frequencies. Sorry to hear about your leg! As mentioned, it's quite impressive and if you're not having any output issues then the compromises on midrange output capability are well-chosen. Those RSS subs are great drivers for sure. Some people feel that you get "snappier" performance from more efficient drivers, but that's potentially related to driver bandwidth which is not really an issue with steep XOs like yours, or potentially with the often-higher Qms of those drivers. We could get pretty deep on subjective stuff if we're not careful!

They really do look gorgeous though, and great measurements!
 
300hz in a BIG horn. Accusing AE of lying about inductance is trashy. They achieve it with small voicecoils and a thick shorting sleeve, other shorting sleeve motors can achieve similarly low inductance.

Cspieker's thread: the "SPIEKER" my almost 20 year prototype finally done

If the specs are accurate, then more power to them! They seem like the best bang for the buck and so far I'm sold.

As far as horn's and horn sizes, I am completely ignorant to the topic. Do you have some reading to which I can educated myself out of my state of trashiness?
 
I've learned that a horn is not a waveguide. A waveguide is more likely something I'd be interested in at this time.
My question is, regardless of the angles portrayed in a waveguide...does the surface area of the opening play a large role on dispersion? Does it not, still operate like a dynamic driver, where the surface area, of the effective piston, directly affects dispersion, basically resulting in higher frequency dispersion, the smaller the opening on the wave guide. If not, could someone give some insight into why not.
Also - parts-express is the only collection of waveguides I've found. Can someone provide more sources please.
 
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You've probably already discovered these, but they are a good place to start :

https://www.google.com/url?sa=t&sou...Vaw2aCmaMMu3E6mWwvzUjTmPF&cshid=1552045000018

https://www.google.com/url?sa=t&sou...FjAAegQIAhAB&usg=AOvVaw2w9SFJXhe7Li3VAlsWtewE

You've got the dispersion understood right. A large opening produces beaming lower in frequency because of cancelation of the waves as you move off axis, the same way a line array limits vertical dispersion.

In general, a waveguide will require more eq than a horn because the frequencies are not all loaded as well, but a waveguide has the advantage of often having more constant directivity over the frequencies than a horn. I personally couldn't get an OS waveguide to sound right, my theory is that it has something to do with the fact that almost all speakers used for mastering a recording have narrowing directivity as frequency gets higher. A Tractrix horn keeps that trend somewhat. More beaming at higher frequencies but also providing some beaming lower in frequency. If you are after the highest sensitivity possible, which allows SET amps to be used, you are probably better served by a horn. Opinions will vary and someone else will give the other side I'm sure.
 
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One of the key things about an OSWG is the consistency across listening positions. The increased HF power response can make them sound brighter than "horns" for a given axial response, requiring different room treatment and/or fr shaping. For a single listener in a lower reflection environment, horns are almost certainly better, particularly something like a LeCleach profile with its optimized diaphragm loading, but the narrow treble dispersion of horns compared to waveguides is an issue if you're not in a very focused listening spot.