Compression driver horn as "full range"?

[Racket Scientist]

Just looking over specs on some compression driver horns and realized that with the 2" drivers some apparently go as low as 400 Hz. Anybody use one of these as an "assisted full range speaker" with a constant directivity waveguide? I'm thinking maybe with a low woofer crossed over around 500 Hz? How well does it compare to, say, a Lowther 4" driver in a backhorn or open baffle for home stereo use? I'm thinking that could be the answer for someone who wants a stereo for metal at concert level or large orchestral works and also needs a PA sometimes.

In a related question, in broad strokes, are there any specific wrinkles that the Econowave crossover uses that are different from "standard" crossovers that allow the horn to mate well with the woofer that you could explain in brief non-techie jargon for me? Is a schematic for the Econowave crossover buried somewhere in that mega-thread (over on the AudioKarma forum)? Thanks!

[Racket Scientist]

Just to add one more comment - in my experiments with full range speakers so far I've been using an active crossover between the full range and low woofer; that would probably be my approach to this as well, especially as that would allow boosting the lows to compensate for the high efficiency horn. I'm hoping if there is something more to it with mating a horn to a woofer you can clue me in.

[LineArray]

Hornspeaker System LaCampanella MK III


This one has no compression chamber AFAIK. But the
design seems to meet your direction ...

[bear]

I am not sure exactly what you are asking...

But, fwiw, I use a single 1.4" exit compression driver down to ~250Hz. The response is very flat without EQ. Having said that, most compression drivers will not do this.

The WE555 compression driver could be used down to 75Hz.

Of course the max SPL is limited as you go lower, but that is still quite high compared to a dynamic driver typically, since ur starting with ~109dB SPL/1w/1m with a good compression driver... power handling typically around 40 watts... and that power rating is for use in a PA application where high SPL is the main goal (with a higher frequency xover than I use, of course).

In terms of mating a woofer to a horn what starts to matter is the time relationship on an impulse between the woofer and the horn...

The larger the exit size on a compression driver the lower the maximum high frequency will be.

In general but not always it is very difficult to use the same speaker system for home use and PA/SR use...

_-_-bear

[zobsky]

Originally Posted by bear

I am not sure exactly what you are asking...

But, fwiw, I use a single 1.4" exit compression driver down to ~250Hz. The response is very flat without EQ. Having said that, most compression drivers will not do this.

The WE555 compression driver could be used down to 75Hz.

Of course the max SPL is limited as you go lower, but that is still quite high compared to a dynamic driver typically, since ur starting with ~109dB SPL/1w/1m with a good compression driver... power handling typically around 40 watts... and that power rating is for use in a PA application where high SPL is the main goal (with a higher frequency xover than I use, of course).

In terms of mating a woofer to a horn what starts to matter is the time relationship on an impulse between the woofer and the horn...

The larger the exit size on a compression driver the lower the maximum high frequency will be.

In general but not always it is very difficult to use the same speaker system for home use and PA/SR use...

_-_-bear

Details please?
Which 1.4" compression driver do you use to go as low as 250 Hz, with what type of horn, and what's the upper usable bandwidth?

Impressions, pros / cons ?
Thanks

[bear]

I apologize that I am not going to state which unit I use. That is because they are relatively hard to find, not in production and the last thing I want is a stampede with a sucking sound...

But, for example the older RCA units, afaik do go that low, and as I said the WE555 is rated as low as 75Hz.

The higher frequency limit tends to typically be related to the diameter of the throat exit, which in a 1.4" driver ends up being ~14kHz. best case.

One of my philosophies is to try to get as much bandwidth as possible either side of say 750Hz... in this case the 109db/1w/1m obtained is very nice to have. I also have ESLs and other systems that embody this design philosophy, but the horns have the most "jump factor" yet. The horn I am presently using is less than optimum. If asked I'd suggest looking at the JMMC horn thread here, and buying or making one of them... it's on my "to do" list.

My impression is that I like it, it is my present reference speaker.

_-_-bear

[fakamada]

Big Bang, Standbox in K+T 4/2010

100db/w coaxial horn with 2x15" bass reflex per side. FULLY PASSIVE !!!

[Godzilla]

>>> are there any specific wrinkles that the Econowave crossover uses that are different from "standard" crossovers...

I don't think so but they have found components that work well together to make a tweeter meet a larger diameter woofer than usual in a two way speaker. I LOVE the idea of the Econowave because it simplifies the speaker by not having to use a midrange driver. It also offers efficiency for low powered amps many of us enjoy. The Econowave works by using a one inch compression driver that can handle power lower down in frequency than most and pairs it with a horn that loads to that frequency... i believe it's around 1200khz but not sure, it may go lower but probably not by much. This works in home environments bc power required to fill your listening room is much lower than filling a bar room, concert hall or stadium. The compression driver used would blow crossed that low in those situations. What's neat is how a pro sound compression driver sounds smooth enough to use in a home system.

Considering the larger compression tweeters, yes, they go lower in frequency (say 500 or 700hz) but they do not extend higher up in frequency so a tweeter or super tweeter of some kind is needed. Now you have a three way to design.

I really like the sound of the pro drivers i've listened to. I think they are worthy of consideration and bet the Econowave based systems sound really good bc it was developed by people interested in good sound. But i can also say i have heard terrible sounding pro drivers that are wired for maximum output without regard to sound. These systems are typically equallized heavily in order to provide a balanced sound. Far from the purist approach many of us take.

[tomtt]

There is a post, by GM, or Tom Brennen, here, or on the altec forum,

that says that the driver/horn theory will allow fullrange response,

with a single driver.



which made sense to me, as described.


not shure where that post is.


the western electric model 16 horn is 'mostly fullrange'.


p.s.

the word 'waveguide', should most likely be in this post as well -

[bear]

Sure, if you own some WE 555 drivers!

But it falls off dramatically on the high side... we could call it "wide range" for certain.

Larger than most people will want though...

_-_-bear