[Telstar]

For bass driver (25-150 hz).

I was set on the Augies when a friend pointed me to the acoustic elegance driver.
Opinions?

[D OB G]

Lynn Olson has had John Janowitz of AESpeakers make a new variant of the Dipole15. It's called the LO15.
Here are the measured parameters of the new drivers:

Fs: 33hz
Qms: 31.28
Vas: 325L
Cms: 0.31
Mms: 75g
Rms: 0.49
Xmax: 9mm
Xsus: 10mm
Sd: 855 sq. cm.
Qes: 0.98
Re: 3.1ohm (parallel)
Le: 0.058mH
Bl: 7Tm
Qts: 0.95
1W SPL: 92.75dB

It's in an utterly different quality league to the Augie (reflected in the price), with a very sophisticated magnet design.

AESpeakers would, I understand, recommend this model over their IB15.

David

[Telstar]

Lynn Olson has had John Janowitz of AESpeakers make a new variant of the Dipole15. It's called the LO15.
Here are the measured parameters of the new drivers:

Fs: 33hz
Qms: 31.28
Vas: 325L
Cms: 0.31
Mms: 75g
Rms: 0.49
Xmax: 9mm
Xsus: 10mm
Sd: 855 sq. cm.
Qes: 0.98
Re: 3.1ohm (parallel)
Le: 0.058mH
Bl: 7Tm
Qts: 0.95
1W SPL: 92.75dB

It's in an utterly different quality league to the Augie (reflected in the price), with a very sophisticated magnet design.

AESpeakers would, I understand, recommend this model over their IB15.

David

Very interestingm thanks. I'm still reading Lynn thread over diyaudio.

Which would be the price of the LO15? I plan to use only one per speaker for size reasons (read WAF). And I plan to cut it quite low (around 100hz), so extreme quality shouldnt be needed.

I may pm Lynn to get more info.

[JoshK]

The LO15 is the same as other lambda drivers (iirc $289 ea in pairs).  From the looks of it, one per side would be sufficient unless you want to play really loud.

[nullspace]

If you're planning on lowpass'ing the driver at 100hz, I would think that the LO15 is a bit more driver than you need. If my reading of the BtheA thread is correct, he's looking for a driver to run from ~50hz up to ~200hz. The IB15 w/ heavier cone and less advanced motor, at $129 per, would suffice for your purposes as would the OB15.

I have a quad of OB15 heading my way, so hopefully I'll have a listening impression before the New Year.

Regards,
John

[Telstar]

If you're planning on lowpass'ing the driver at 100hz, I would think that the LO15 is a bit more driver than you need. If my reading of the BtheA thread is correct, he's looking for a driver to run from ~50hz up to ~200hz. The IB15 w/ heavier cone and less advanced motor, at $129 per, would suffice for your purposes as would the OB15.

I have a quad of OB15 heading my way, so hopefully I'll have a listening impression before the New Year.

Regards,
John

I'm not sure, I will try to lowpass it as low as possible. The Bastanis usually suggest between 80 and 150hz. For my room 100-120 is probably more appropriate.

Cost is not an issue, as shipping would account for a good 20-40% of it. So, I can certainly affort $300 per driver. And I do not want to experiment changing it after a while. If I were in the States, it would be a different matter.

Essential requirements:
1) bass driver per speaker (space issue)
2) Being able to go as low as possible with narrow baffle (MAX width 42cm) - the Augies like is bigger.
3) Clean, linear response (I wont EQ)

4) I'm gonna mail Lynn anyway

[MJK]

Essential requirements:
1) bass driver per speaker (space issue)
2) Being able to go as low as possible with narrow baffle (MAX width 42cm) - the Augies like is bigger.
3) Clean, linear response (I wont EQ)

I think you are wasting your time and money, the narrow width of the baffle is going to determine the low frequency response. Getting a driver with a lower fs is not going to add any significant additional low frequency response. Also, having one driver is going to limit your SPL/W/m so you will need to significantly pad down your mid range or full range driver, you will need a lot of power. If you are not going to use EQ, I would recommend a driver with a Qts of 1.0 to 1.2 and an fs of 40 to 50 Hz and as efficient as you can find.

Not trying to rain on your parade but I am not optimistic about your plans, in my opinion you are going to spend extra money and not get any additional or optimized performance.

Martin

[Telstar]

I think you are wasting your time and money, the narrow width of the baffle is going to determine the low frequency response. Getting a driver with a lower fs is not going to add any significant additional low frequency response. Also, having one driver is going to limit your SPL/W/m so you will need to significantly pad down your mid range or full range driver, you will need a lot of power. If you are not going to use EQ, I would recommend a driver with a Qts of 1.0 to 1.2 and an fs of 40 to 50 Hz and as efficient as you can find.

Not trying to rain on your parade but I am not optimistic about your plans, in my opinion you are going to spend extra money and not get any additional or optimized performance.

Martin

Hmm... I know people using successfully Augies with baffles from 42 to 50cm. I'm not sure how much i can stretch more, maybe 45cm, and only with a curved design (smaller on top).

Now, about the drivers, I wont EQ, but i'll use dedicated plate amps, so power is not an issue, they can be 4ohm even.
For the size of my room (3,5x5x3.3m), I have already evaluated that one 15" woofer per speaker is enough, SPL-wise.

Augie specs are the following:

    *      2.5" voice coil
    *      Power handling: 225 watts RMS.
    *      Impedance: 8 Ohms
    *      SPL: 88.7 dB 1w/1m
    *      Le:   0.81
    *      Re:   5.69 Ohms
    *      Qt:   0.92
    *      Vas: 250.3 liters
    *      Xmax: 7.15 mm
    *      Fs: 27.0 Hz
    *      Magnet weight: 67ounces

Which are the specs of the IB15?
Do you have suggestions for a different driver, possibly engineered for OB setup?

[Telstar]

PS: I could use back wings to improve bass response, but not H shape.

[panomaniac]

I have a quad of OB15 heading my way,

Gosh John.  Can I come over to your house to play? 

[nullspace]

Only if you bring these...

[MJK]

Do you have suggestions for a different driver, possibly engineered for OB setup?

OK, a plate amp will help you since you now have a volume control on the bass driver. I am really not a fan of plate amps and prefer an active system with multiple amps, it is more flexible. What is your low frequency goal and what type of SPL are you looking for to match the next driver in the system?

[Telstar]

Do you have suggestions for a different driver, possibly engineered for OB setup?

OK, a plate amp will help you since you now have a volume control on the bass driver. I am really not a fan of plate amps and prefer an active system with multiple amps, it is more flexible. What is your low frequency goal and what type of SPL are you looking for to match the next driver in the system?

A plate amp will also help driving the woofers better than my F3
I'm looking for a pre to send directly to the plate amps with silver wires (always preferred for tight clean bass to copper).
My low frequency goal is 30hz. I'm not looking for high SPL, I think no higher than 100dB.

[MJK]

My low frequency goal is 30hz. I'm not looking for high SPL, I think no higher than 100dB.

If you said you wanted 50 to 60 hz bass I can see that being possible. But 30 Hz, I think it is out of reach with the baffle width and crossover you want to use. I think you should do some basic sizing calculations to get a handle on what you can expect for bass performance from an OB design of this size using the Augie driver.

[panomaniac]

Only if you bring these...

Ouch, John - you really know how to hurt a guy.   My dear old Lounge Lizards....   I still have the drivers but the baffles are buried in the Maui landfill.  sniff....  (But I did make a new pair of fuzzy Obees today)

Back on topic.  There a few fun tricks you can try with the plate amp and the bass drivers.  Try turning the palte amp x-over way down low, like 45~60Hz, then bring the gain up.  The low x-over will kill the rising response of the woofer on OB, and you'll need the gain to make up for all the stuff you're cutting out.

I think a number of Augie users are doing this and are happy with it.  It worked well for me on the Lounge Lizards.

[markC]

As an experiment, I moved my pair of IB15's from the intended installation of Infinite Baffle to Open Baffle. There are 2 drivers mounted on an approximate 17" x 38", (43cm x 97cm), baffle. I measured and more importantly listened to the two set-ups. Trust me, on this size baffle, with the IB15 drivers, Infinite Baffle is the Only way to go.
I am running the 15's in parallel, (4 ohms), with a  350 rated watt plate amp.

[nullspace]

My dear old Lounge Lizards....   I still have the drivers but the baffles are buried in the Maui landfill.  sniff....

Noooooooooo!!!!!!!!!!!!!!!! I had no idea, otherwise I would have never dug up such sad memories...

On topic, 30hz @ 100db with just one driver on a baffle that narrow will be asking an awful lot of both the driver and the plate amp. Applying EQ, boost, whatever you want to call it will have to be pretty heavy handed. And, a highpass at 30hz I would think is mandatory.

FWIW, I'm planning on 2xAE OB15 per side on a 24"x40" baffle with similar goals to yours. And, it will certainly require some EQ -- most likely some sort of a 6db/octave shelving filter plus a high Q highpass at driver Fs. BTW, MJK's MathCad worksheets have been of invaluable assistance in figuring out what's what.

Regards,
John

[dewar]

Hi Telstar, got your pm over at stereonet and thought I'd reply here for the benefit of anyone else looking to mate Augies with Bastanis widebanders.

I've got one Augie each side, mounted fairly low on a 44cm (just over 17") wide baffle. Small wings on the bottom half only, starting 12cm deep at the base and tapering to 4cm half way up, mainly just to stiffen the baffle.

XO in done with Behringer DEQ2496, as is some room correction. The DEQ has a 2nd order XO, but I use the GEQ and PEQ to roll it off pretty sharply(over 24db/octave I'm guessing) at about 200hz. This is higher that most Bastanis users opt for, but I have what I think is room induced roll off of the widebander starting pretty high up. Dont think there is any problem running the Augie this high if you can chop it off pretty steeply, better than running the Bastanis box subs that high. Seemless integration to my ears, I'm very happy with it. Though I'm curious as to other bass driver options - you can always do better.

The DEQ feeds a 120W NAD C370 integrated amp.
The Augies get down to the high 20's. I have a large room node at 30hz which I flatten with the DEQ, but reckon this is still letting me get a bit lower that most Augie users get. Though 30hz seems to be about the norm on similarly narrow baffles.

Really happy with my setup, can only snow dream of a bigger room and perhaps doubling up on the Bastanis widebanders and another pair of Augies.

Cheers
B.

[Telstar]

Hello and thanks for the reply.

Hi Telstar, got your pm over at stereonet and thought I'd reply here for the benefit of anyone else looking to mate Augies with Bastanis widebanders.

I've got one Augie each side, mounted fairly low on a 44cm (just over 17") wide baffle. Small wings on the bottom half only, starting 12cm deep at the base and tapering to 4cm half way up, mainly just to stiffen the baffle.

12cm are enough to hold the baffles stable? AFAIK Bastani recommends a bit larger. Larger wings can help with lower frequencies.

XO in done with Behringer DEQ2496, as is some room correction. The DEQ has a 2nd order XO, but I use the GEQ and PEQ to roll it off pretty sharply(over 24db/octave I'm guessing) at about 200hz. This is higher that most Bastanis users opt for, but I have what I think is room induced roll off of the widebander starting pretty high up.

Instead I have several bumps scattered from 40 to 110hz. More than the behringer could handle and at different freqs. So I'm not sure if i'll use it, maybe just to boost 30hz.

Dont think there is any problem running the Augie this high if you can chop it off pretty steeply, better than running the Bastanis box subs that high. Seemless integration to my ears, I'm very happy with it. Though I'm curious as to other bass driver options - you can always do better.

A friend of mine uses the 12" powered subs with his Atlas and lowpass pretty high as well and I didnt notice integration problems. I want a pure dipole setup instead, like yours and if possible lowpass lower, to use as much of the beautiful mids of the Atlas as I can. They will be powered by a Firstwatt F3, while I'll be using plate amps for the augies.

The DEQ feeds a 120W NAD C370 integrated amp.
The Augies get down to the high 20's. I have a large room node at 30hz which I flatten with the DEQ, but reckon this is still letting me get a bit lower that most Augie users get. Though 30hz seems to be about the norm on similarly narrow baffles.

Thanks, 30hz is definitely my goal. And IIRC Darrel told me that with about 20" baffle width I would for sure. But your baffle is narrower, and would fit perfectly MY needs So this is really helpful.

Really happy with my setup, can only snow dream of a bigger room and perhaps doubling up on the Bastanis widebanders and another pair of Augies.

Yes, I plan to get the atlas, which have 2x widebands. Not sure if i'll ever fit a second pair of 15" woofers, though
Are you putting any kind of damping behind the Augies? Seems like not. I've read of something like this on diyaudio related to AE Dipole15 drivers, that go lower that way.
I'm looking for the easiest setup, keeping the baffles small and room-friendly. I'm dreaming of a bigger and better room also.

[panomaniac]

....otherwise I would have never dug up such sad memories...

It did make me a bit sad. Even my wife was sad to see them go. She helped me build them.

MarkC, did you do any EQ or crossover tricks when you went from IB to OB?  The loss of low end would be severe. 17x35" is just about the size of my defunt Lounge Lizard OBs.  I had to use massive FR tailoring to get the balance right.  Nature of the OB beast, I'm afraid. 

Dewar.  Using the DEQ as a crossover?  I didn't know it would do that.  Thought it had only 2 outputs.  So maybe you can use a HP or LP function on those outputs - is that it?  Cool idea.