If it can be made to sound good on an OB over some portion of its BW, then I see no reason why it can't be done with a horn. whether it will perform the way you want it to is another matter altogether and why you ideally find the right driver for the app rather than 'make do' with something else and if a suitable driver can't be found, then it's probably not a practical alignment, what with the plethora of driver choices available today.
GM
That's because you didn't use the right horn for the job, though if the driver sounded like crap to start with, a horn isn't going to do anything but tonally balance its response over a wider BW than a simple baffle.
Hmm, unless the Azura was either designed for the TB or a driver with very close specs, then it's not up to the task. I guess I'm not understanding the situation. I mean either the Azura meets the needs of the app or it doesn't.
One thing though, to load down to cut-off either means some throat distortion/beaming or an incredibly large WG, especially if there's any directivity control (DI) to a low frequency. Anyway, based on published specs, this driver only needs loading to ~233 Hz, so if you're planning on a higher cut-off, then it will be strictly a WG.
GM
I suppose the weight-thing per se was a bit simplistic Greg, at least WRT transient response as the lighter unit, all other things being equal, is notionally only responding to higher frequency content better than the heavier one, & with greater efficiency, right? I assume you're refering back to the Fourier transform etc.? I was applying the above in relation to FR units with their v. wide BW rather than universally; shift to dedicated woofers with attendant XOs etc., where we've got a different approach on our hands & I take a different view. Although I'd still take a well designed HE woofer with less weight in the moving parts (& admittedly, a lower VC inductance as an ROT... 
) over an equally well designed lower efficiency woofer. Call it engineering efficiency; I see the latter as being inefficient in raw engineering terms as well as in its conversion ability.
) over an equally well designed lower efficiency woofer. Call it engineering efficiency; I see the latter as being inefficient in raw engineering terms as well as in its conversion ability.
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Though I can not be 100% sure, the combo should be very good.
I've had a period of experience with Lowther PM4 and Oris 150, that combo was very good. One of the best sounding home use speakers I've heard, within a certain SPL, of course. (oh, and you'll need something for the bass section... )
Any other low-Q, up-tilted response widerangers should also be similar.
Talking about Seas, I think of years ago I once played Oris 150 with Jordan Watt 6"er alu cone fullranger. That speaker looks like this:
http://audioart.audionet.com.tw/141/images/1/a.jpg
That Jordan Watt Flagon has a very warm sound, somewhat colored and thicken mid to midbass. This couldn't be a good candidate for horn loading, but I tried it just for fun.
The horn throat was for 8"er so didn't match the smaller Jordan very well. And lacking of any mating hardware (and also in a hurry), I just "put" them together. Horn mouth lip touched the floor, flagon and horn throat on a stool, they sang, beautifully! LOADS of details and so much improved dynamics. What a shock! And much to my surprise was that the range wasn't any narrower than the original speaker! I think it's the floor helping in the bass and nearfield listening helping in the high. Great fun!
The measured Q of the 1772 seemed lower than published. This would be my only concern.
Oh! I must correct the Q thing. It's the opposite, I meant the measured Q is higher than published data.
If it's the case of very very low Mms, thus the high fs couses high Qts, then it should be OK. If it has low fs and the motor is not powerful, then the response may be rough. I've tried Oris 150 with an 8"er with fs of 50Hz or so, Qts of 0.45, not good. The motor was not enough for the load.
If it's the case of very very low Mms, thus the high fs couses high Qts, then it should be OK. If it has low fs and the motor is not powerful, then the response may be rough. I've tried Oris 150 with an 8"er with fs of 50Hz or so, Qts of 0.45, not good. The motor was not enough for the load.
Three things:
1. Both Lambda and Adire are hawking low inductance woofers. This does not mean that the white papers are inherently wrong, but it does raise a red flag. Infomercials are infomercials.
2. I agree completely that the "speed" of a driver is directly related to bandwidth.
3. Do a dimensional analysis on BL/Mms. You wind up with
__ m __
s^2*A
or acceleration per Amp. Interesting in itself, no?
Bob
1) OK, I'll concede that in 'attacking' this issue, DW may have done it in such a way as to 'shine a light' on some of Avatar/Adire's products, but I'm of the opinion that the primary reason was to not basically quote Tom Danley's work that he published on the old basslist. I haven't really worked through it, but don't doubt either its technical veracity and for sure not its conclusion.
2) Well, there's 'speed' where it defines the driver's HF BW and then there's 'speed' that defines its acceleration below its HF mass corner, both of which interests us WRT the accurate reproduction of transients, i.e. a driver's ability to reproduce a square wave or some portion of it in a multi-way system. IMO, it's at this basic level so much 'failure to communicate' occurs with these types of discussions similar to 'TL', vented oversimplification.
3) Not sure what your point is, though if it's that since radiation impedance falls with increasing frequency, its BL requirement is reduced a proportional amount, ergo its acceleration is falling with increasing frequency, making mass a moot point except WRT efficiency and the extra power it implies.
GM
Right, the way to make an 'accurate' wide BW driver is to make a huge tweeter. The pioneers of audio understood this and why up to nominally 18" drivers had as small as 1" VCs. Power handling sucked, but then they only had up to ~8 W/amp available with the majority of apps having < 1 W, so efficiency was the prime performance goal. Since a 'tweeter' requires a thin/rigid diaphragm to reproduce the acoustically weak HF BW with good radiation efficiency, an incredibly high compliance (Vas) was required to get a low Fs, i.e. a Fs/2 reduction = 4x Vas increase and one reason why vintage drivers typically have a high Vas. I read somewhere that a particular '30s era 12" WE driver had a usable 40-12,500 kHz BW, but the trade-off was a 40+ ft^3 Vas! Talk about flimsy!
Later, they developed variable thickness diaphragms among a number of other ways to allow a high mass to lower Fs and a reasonably wide BW in a smaller net loading bulk.
GM
I noticed today the 8" TB full rangers are out of stock at PE... both versions. To those who have heard it, would you say they're more, less or about equal in efficiency to the 8" Fostex drivers? They are rated a little lower but just wondered about subjective experience since i've had drivers rated at 95 and 90db sound practically identical in this respect.
TIA,
Godzilla
TIA,
Godzilla
Damn..
Thankfully im considering the 1772 version which is due 7/10, if they dont change it. The 1808 is due 22/1/10....!Oh well, I didn't mean to bring up the Mms/BL things again. What I wanted to say was the concern of motor strength.
I was saying that the motor strength could be misled by the Q number. Qts can be tuned low by very soft suspension and the low fs it causes. Another driver with this particular motor comes with stiffer suspensions yields higher fs, thus higher Q.
So, it's possible that a driver with higher Q has a stronger motor than a driver with lower Q.
In some horn related articles, we can read the same driver recommendation -- low Q + high fs. This more or less guarentee a strong motor. There should be an equation or something, but I don't remember.
I was saying that the motor strength could be misled by the Q number. Qts can be tuned low by very soft suspension and the low fs it causes. Another driver with this particular motor comes with stiffer suspensions yields higher fs, thus higher Q.
So, it's possible that a driver with higher Q has a stronger motor than a driver with lower Q.
In some horn related articles, we can read the same driver recommendation -- low Q + high fs. This more or less guarentee a strong motor. There should be an equation or something, but I don't remember.
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