best 15'' driver's for the job(0-300hz)

miguel42 · « **on:** 12 Mar 2009, 04:39 pm »

hi
on reading various threads the opinion of the Eminence alpha 15'' seems to be preferred choice,but while visiting their web site i found a complete range of 15'' drivers,ie beta,delta etc.
what is the main reason for the alpha's choice,is it spec & sound quality ,or has the cost had any influence.
i am really looking for the best performace i can achieve within reason,are the alpha's still top choice
thanks mike

gainphile2 · « **Reply #1 on:** 12 Mar 2009, 10:33 pm »

I would think that the Alpha is an excellent all-rounder. Emerald physics must think so too otherwise they woould use other woofers.

My only complaint would be the Fs is not low enough and there is significant peak at 2kHz.

ultrachrome · « **Reply #2 on:** 12 Mar 2009, 11:29 pm »

Nelson Pass made a comment on diyaudio.com that he preferred the stronger magnet of the Beta, however, to my knowledge he did not elaborate.

MJK compared all three Eminence 15" woofers here: http://www.quarter-wave.com/OBs/OB_Design.pdf Simply, the Alpha worked better with his crossover and baffle.

Of course, MJK is pioneering all passive designs. If active EQ is used on the woofers, you can likely bend the response to your liking assuming you manage xmax.

On the high-end side, aespeakers.com will build you Lambda Dipole12 or 15 woofers. But the cost difference is substantial. John usually gives a discount if you buy two woofers but my four Dipole12's where in the $800 neighborhood when I bought them in 2005.

Not having heard Alpha's I don't know if the Lambda's are worth it. Probably depends on a number of factors. I didn't know about the Alpha's or MJK's work when I bought them back in 2005. I was looking at Linkwitz who uses woofers that I believe have a pretty low Qts and a bunch of active EQ.

If I was doing it again today, I'd start with the Eminence or Goldwood. In fact I'm thinking of buying a pair to use for future OB experiments.

MJK · « **Reply #3 on:** 13 Mar 2009, 12:25 am »

Quote

If I was doing it again today, I'd start with the Eminence or Goldwood. In fact I'm thinking of buying a pair to use for future OB experiments.

A Eminence or Goldwood 15" driver with a Qts of ~1.0 is the simple, least expensive, and still a very high performance entry into OB bass drivers. Because of the high Qts, the design and build is less complicated by not requiring any additional EQ. An Eminence driver is probably a little higher quality at a little higher cost compared to a Goldwood driver. You can spend more money and get a driver with a higher pedigree, high tech design and materials, and with a more robust build but I am not convinced that it will provide that much better performance to justify 4 or 5 times the cost.

nullspace · « **Reply #4 on:** 13 Mar 2009, 02:35 pm »

Quote from: ultrachrome on 12 Mar 2009, 11:29 pm

On the high-end side, aespeakers.com will build you Lambda Dipole12 or 15 woofers. But the cost difference is substantial. John usually gives a discount if you buy two woofers but my four Dipole12's where in the $800 neighborhood when I bought them in 2005.

AE also has the less-pricey IB15 and OB15 -- four for $400. Here are their specs: AE open baffle 15"s.

Regards,
John

MJK · « **Reply #5 on:** 13 Mar 2009, 04:48 pm »

Quote from: nullspace on 13 Mar 2009, 02:35 pm

Quote from: ultrachrome on 12 Mar 2009, 11:29 pm
On the high-end side, aespeakers.com will build you Lambda Dipole12 or 15 woofers. But the cost difference is substantial. John usually gives a discount if you buy two woofers but my four Dipole12's where in the $800 neighborhood when I bought them in 2005.

AE also has the less-pricey IB15 and OB15 -- four for $400. Here are their specs: AE open baffle 15"s.

I see many drivers from AE quoted with interesting specs and a wide range of prices. But when I go to the website and look at the "Products" all that is shows is the IB15. There is nothing with a "OB" or "Dipole" designation. The posted specs that have appeared on the AC forum look interesting, the price is unknown, and the availability and ordering info is not shown on the AE site. So I move on and stick with what I can find on PE's site.

nullspace · « **Reply #6 on:** 13 Mar 2009, 08:22 pm »

I happen to have a quad of the OB15, so they do exist. AE like a lot of businesses I patronize are little more than a 1- or 2-man shop -- Magnequest is another. An email to get info & pricing is hardly burdensome, and I might add that the dudes at AE are a pleasure to deal with.

If a tricked-out website is the minimum benchmark for your purchasing $$$, then there's plenty you're missing.

Regards,
John

MJK · « **Reply #7 on:** 13 Mar 2009, 08:40 pm »

Quote from: nullspace on 13 Mar 2009, 08:22 pm

I happen to have a quad of the OB15, so they do exist. AE like a lot of businesses I patronize are little more than a 1- or 2-man shop -- Magnequest is another. An email to get info & pricing is hardly burdensome, and I might add that the dudes at AE are a pleasure to deal with.

If a tricked-out website is the minimum benchmark for your purchasing $$$, then there's plenty you're missing.

Any product that is not on the website with specs and a price as far as I am concerned is not available. It does not take much to keep your website up to date. I am not chasing a manufacturer for verbal information over the phone. How many other people pass over AE because they cannot find what they are looking for on the products listing on the website? I passed over Oddysey a few years ago for a similar reason, I bought three amps and a preamp from somebody else. How much are some small manufacturer's missing in sales because the website is out of date? Maybe business is so good that the website is not a priority. There are plenty of other people with accurate websites and competing products that will gladly take my money.

nullspace · « **Reply #8 on:** 13 Mar 2009, 09:01 pm »

Fair enough, Martin. I suppose that building my own amps has dulled my senses to the effort it takes to get parts. If I held the same opinion as you, I'd be stuck building with Hammond (eeek!) rather than getting custom power transformers from Heyboer and plate chokes & output transformers from Magnequest.

I ordered a spare set of cones from Fertin a couple of years ago -- to me, that's the standard for onereous. 66 emails and 4 months, start to finish.

Regards,
John

ultrachrome · « **Reply #9 on:** 13 Mar 2009, 10:16 pm »

Quote from: MJK on 13 Mar 2009, 04:48 pm

I see many drivers from AE quoted with interesting specs and a wide range of prices. But when I go to the website and look at the "Products" all that is shows is the IB15. There is nothing with a "OB" or "Dipole" designation. The posted specs that have appeared on the AC forum look interesting, the price is unknown, and the availability and ordering info is not shown on the AE site. So I move on and stick with what I can find on PE's site.

John seems to be able to build any of the old Lambda woofers although he doesn't actively advertise them on his site but for lambda specs the best place to go is to the old lambdacoustics.com site cached at web.archive.org. You can find some data in his forums. He sounds like a busy guy in dire need of staff.

I payed $269 + $169 for each woofer pair.

My Dipole12 specs:

Quote

These are the actual Lambda dipoles. Underhung motor, 12+mm Xmax, copper faraday so Le is only .0375mH with the dual 8ohm coils in series.

Here are parameters for coils in series:
Fs: 25.9Hz
Qms: 11
Vas: 273L
Cms: .7mm/N
Rms: .81kg/s
Xmax 12mm
Xmech: 18mm
Sd: 530sqcm
Qes: .73
Re: 3.075ohm
Le: .0375mH
Z: 4ohm
Bl: 6.1Tm
PE: 100W
Qts:.68

miguel42 · « **Reply #10 on:** 13 Mar 2009, 10:38 pm »

hi
i have e-mailed ae about his drive units,''dont forget i am in england'' but this was a couple of days ago and he has not even managed a reply !!!,from what i understand the new ob drivers are very popular but still a reply would be good..waiting in anticipation

dmiller · « **Reply #11 on:** 16 Mar 2009, 09:22 pm »

Sometimes it worth chasing a hard to get product. I've done that, but not with something like a pro driver with the vast number of choices.

To the OP, I'm sure you've read the forum and can see your question is on many people's mind. The fact that Martin was able to build a system with a $60 15inch driver is a testament to his modeling skills and the potential of OB. The answers you've received are good. If your doing active crossover, there are likely more expensive drivers that have better sonic characteristics than the Alpha. You'll still want to do the math to get an idea of the levels it will take to get bass. The two "gotchas" are adequate bass without distortion, and all drivers exhibiting good characteristics at the crossover points. There's all kinds of thoughts of where the bass to mid xover should be.

If you're going to do a mockup, one way to choose drivers is based upon their potential use in other projects. One reason I would not use the Alpha is that I would always wonder about a expensive driver. But the logical reason to use the alpha is that it's proven and a terrific bargain. I do this for fun and do not want to be logical in that way. I would rather learn from mistakes. "I was sure the 31" woofer would match with the Feastrex........"

Edit: I didn't notice the 0-300 hz. The best 15" driver for 0-300hz is a 18" driver

. My concern with an inexpensive drive like the alpha is it's "voice" as it gets above 300 hz. The high efficiency of alpha and the fact no one complains about it running out of xmax make it a good choice. I would chose to put extra money in the midrange rather than a more expensive deep bass. I assume you know your not getting a flat line to 20hz in 15" OB no matter what you spend on the driver.

miguel42 · « **Reply #12 on:** 16 Mar 2009, 10:28 pm »

thanks for the comment,i am already running atc sm75-150 mid units which i re-guard as the best money can buy,one thing i have started doing is taking measurements in more 'actual' listening position ie in my rather odd shaped triangle extension with some really nasty corners to the room
at the moment i am experimenting with a volt 3143 unit in a ported reflex enclosure and the same driver in a plain flat ob panel, almost no matter where i place the reflex enclosure i am getting high & low db readings all over the place,and cant find a comfortable location anyware apart from in the middle of the room(not popular with the wife but does make a good table for the beer).however the ob design is giving an extremely flat responce almost everyware ,some 5-6 db higher than the mid to high frequency's already being produced by the rest of the design.
unfortunately the bass still sounds a bit light even though much cleaner ?.
after reading the theory on 1/4 wave enclosures i am going to try the H style enclosure to see if i can extend the bass frequency's while having a few extra db to loose on the gain.
I'm still not sure if the light bass sound is due to the lack of db or bass extension or even too many years of hearing the booming undertones which i have thought to be the norm.
i can only apologise to save the word as yet another piece or 8x4 will be going under the jig saw this weekend.will post my results!!!

miguel42 · « **Reply #13 on:** 17 Mar 2009, 06:18 pm »

even though I'm still playing with my volt units i haven't ruled out the AE ob/ib 15's i just haven't had any reply yet,its been a week now
while still checking the net i came across Hawthorne audio and their silver Iris ob 15'' Augie...has anybody had any dealings with Hawthorne and more importantly the iris 15'' driver....
thanks mike

mcgsxr · « **Reply #14 on:** 17 Mar 2009, 06:41 pm »

Try Bob in St Louis here on AC, he has plenty of Hawthorne experience...

Bob in St. Louis · « **Reply #15 on:** 17 Mar 2009, 06:48 pm »

Yea, I got a few of them.

I can't speak of the drivers mentioned previously in the thread, but I can speak about the Augies.
As far as the taughtness of the bass they produce, I'd call it "Tighter than a bulls ass on rodeo day".
No sloppy mud here. No Sirree.
The extra bonus is you can't hurt them, I've tried.

Give me half a chance and I'll rant about them for hours. You'd be hard pressed to find a higher recommendation for Augies than from me.

Bob

ebag4 · « **Reply #16 on:** 17 Mar 2009, 06:58 pm »

Quote from: Bob in St. Louis on 17 Mar 2009, 06:48 pm

Yea, I got a few of them.

I can't speak of the drivers mentioned previously in the thread, but I can speak about the Augies.
As far as the taughtness of the bass they produce, I'd call it "Tighter than a bulls ass on rodeo day".
No sloppy mud here. No Sirree.
The extra bonus is you can't hurt them, I've tried.

Give me half a chance and I'll rant about them for hours. You'd be hard pressed to find a higher recommendation for Augies than from me.

Bob

x2 for the Hawthorne Augies, very nice drivers. I use them in my DIY OBs in my 2 channel room:

I am also using the AE IB15 (older generation than what is currently available) in my HT, they are very nice as well:

I have never tried to compare them, they serve different functions. The AE IB15s are used in an infinite baffle from 80 Hz down, my Augies are used from 200 Hz down.

Best,
Ed

Bob in St. Louis · « **Reply #17 on:** 17 Mar 2009, 07:01 pm »

I was thinking about your DIY speakers Ed. I still think they're sexy.

Bob

dmiller · « **Reply #18 on:** 17 Mar 2009, 07:48 pm »

I really like Ed's design. I may be "borrowing" the concept.

nicksgem10s · « **Reply #19 on:** 17 Mar 2009, 09:01 pm »

I have been using the Hawthorne Audio 15" Augie for bass duty in my system for the past year and cannot say enough good things about them.

The Augies provide very lifelike bass reproduction and sound more like music and not like boomy subs. I have a pair that I run as OB subs and will most likely be adding an additional pair at some point in the future.

I have never used them as high are you are so I am not sure if someone who owns Augies can chime in about using them up to 300hz.

I have to also mention that the support provided by Darrel & Diana Hawthorne on their website forum is nothing short of world class just like their products.