15" Bass Driver for OB (40-200Hz)

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OTMOPO3OK

Member
Joined 2004
I'm building B200 OBs so i need to augment it with 15" OB woofer (doing 40-200Hz duty). It will either be just a plain small baffle or a stuffed U baffle.
My room is 16'x11'x9' with speakers along a longer wall (1-2' off the back wall) so I'm wondering if i should buy 1 or 2 woofers per side? I'm a bit of a "fast+clean bass" head but i don't listen too loud, i just want doublebass to sound like it should. I'm SO tired of boomy bass with my room modes and TL sub. I have active XO + EQ so matching SPL is not a problem.
Music preferences are mostly Jazz, Prog. Rock.
Here are my options:

Eminence Alpha-15A $59
*Frequency range: 46-3,500 Hz
*Magnet weight: 25 oz.
*Fs: 41 Hz
*SPL: 97 dB 1W/1m
*Vas: 9.2 cu. ft.
*Qts: 1.26
*Xmax: 3.8 mm
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=290-407&ctab=2#Tabs

Eminence Delta-15LFA $96
*Frequency range: 42-3,200 Hz
*Magnet weight: 56 oz.
*Fs: 41 Hz
*SPL: 96 dB 1W/1m
*Vas: 6.6 cu. ft.
*Qts: 0.58
*Xmax: 4.8 mm
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=290-417&ctab=2#Tabs

Knight-15 $50
Frequency Response: 35 to 4500hz
FS 35 hz
VAS 4.48
Qts 1.006
Xmax 4.5mm
Magnet weight: 50 oz.
http://www.musicsupplycenter.com/ProductDetails.asp?ProductCode=813-013

Warrior-15 $35
Frequency Response: 35 to 4600hz
FS 36 hz
VAS 8.29
SD 143.13
Qts 0.826
Xmax 4.5mm
Magnet weight: 50 oz.
http://www.musicsupplycenter.com/ProductDetails.asp?ProductCode=813-021

Mach MAW-15 $79
Fs = 26 Hz
Qts = 0.32 (Using only 1 VC increases Q)
VAS = 129 litres
Xmax = 13 mm
http://www.mach5audio.com/index-2.html

And of course:
Silver Iris Augie $150
Fs: 27.0 Hz
SPL: 88.7 dB 1w/1m
Qt: 0.92
Vas: 250.3 liters
Xmax: 7.15 mm
Magnet weight: 67ounces
http://www.hawthorneaudio.com/drivers.htm

Can Qts be too high?
Visaton BGS 40 has Qts 0.4
http://www.visaton.de/en/chassis_zubehoer/musiker/bgs40_8.html
and people reported it sounding very good in OB while at the same time MJK really liked Alpha15A for their high Qts=1.26.
http://www.quarter-wave.com/Project07/Project07.html

I chose drivers with accordion surrounds since I believe low excursion sounds more accurate but will 3.8mm Xmas be enough? (Alpha15)

And finally the $300 question should i bother with all these cheap drivers of just get 2 Augies and a peace of mind? But then maybe at such price i should be looking at better drivers than Augie?

I wanted to save money with Alpha15 but if I need 2 of them to match the capability of 1 Augie then i'd rather get Augie ?!?

Suggestions?

Thank you.
 
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OTMOPO3OK

Member
Joined 2004
Thanks everyone for your input,
Ciares seem fishy and even more expensive than Augie. Augies to me right now seem like perfect OB drivers so if I were to splurge $300 i'd get them, anything more expensive is not necessary.
However the main point of this post is to get my feet wet with OB bass so i highly desire to get some *excellent* drivers in $50 range.
I'm sure if i really like what i hear i'll buy Augies in couple of months and use the less expensive drivers to make a ripole sub, so they won't go to waste.
However Knights and Warriors seem to 'scream' BAD QUALITY (glue on 50% of drivers' surrounds) and most specs lie.
Right now it seems i have 3 major contenders based on different recommendations i read:

GOLDWOOD GW-1558 $45 Qts:0.67
Pyle PPA15 $47 Qts:0.67
Eminence Alpha-15A $59 Qts:1.26

I always felt that Alphas had a weak motor and weak surround and Dick Olsher confirmed my suspision when he said that Q factor was just too high -> less control, all in a race for lower extension. I don't want that. So I think i'm ruling out Alphas due to their 'too high' Qts and weak damping. He also mentioned that Q factor should be closer to 0.6 (he even damped Augies with 25Oohm resistor Surprised).
http://www.enjoythemusic.com/magazine/equipment/0107/diy_loudspeaker_project.htm

I've seen PPA15 being used for U,H dipole, ripole sub (<80Hz) duty by several people over the years on different boards but i just have a 'gut feeling' they ain't good in midbass region. (from someone's comment of their rising, bumpy response higher).Plus i just feel a driver with cheesy picture on the front can't sound good up higher.Smile

Brad convinced me from his 'extreme' testing that Goldwoods can take a beating and sound great (and he is hard to please he says) :
http://www.hawthorneaudio.com/forum/viewtopic.php?t=634&highlight=poor+mans+augie
So at least I'm not worried about Xmax there. I don't know anything else about these drivers (manufacturer doesn't even provide freq. plot) but for some reason i'm still drawn to them. I've heard about the other 2 drivers but i learned about Goldwoods just today and yet after Brad's review i feel they deserve a chance. I' falling for them right now the most. Embarassed
PS: Both PPA15 and 1558 have Qts:0.67 just like Dick Olsher recommended.
BTW i've read that Eminence posts it's Xmas peak values so Alphas 3.8mm is in fact 7.2mm total.
I suspect that PPA15's 6mm is total while i'm not sure about Goldwood's 3.9mm.(i hope it's only one way) But from the review it seems that's more than enough for them.

What do you think?
 
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tinitus

Ex-Moderator R.I.P.
Joined 2005
If I should choose one of the two Emminence, my pick would be DELTA-15LF(A)

KAPPA-18 looks better with low Fs=28hz, allthough a bit expencive it would be my choice rather than double 15" with higher Fs

"Augie" has lost a lot of sensitivity, and they must calculate with plenty of room gain
 
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tinitus

Ex-Moderator R.I.P.
Joined 2005
About "Augie" - it might be worth to mention that its intended to be used only below 100hz with a plateamp and another 15"(IRIS), and a quite different setup

My guess is that you will use the woofer passive and a bit higher with your B200 (or Hemp ?) - so it would be nice to have some exstra SPL to take care of BSC :)
 
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rick57

Member
Joined 2002
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OTMOPO3OK

Member
Joined 2004
Tinitus, my setup is fully active computer controlled XO + EQ so cranking up low SPL driver is not a big deal.
As a matter of fact i've seen Augie being used with B200 as high as 300Hz with what appears to be good results. Who knows?!!

Rick, thanks for very informative links.
While the physics of this is unknown to me yet that makes driver selection even more confusing.:boggled:
And transient response is very important, almost on to of my list.
 
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tinitus

Ex-Moderator R.I.P.
Joined 2005
How I evaluate it, and "narrow" it down...

Fore efficiency, NO EQ and good transient response a big 18" woofer, the KAPPA-18, but thats just me

The more "modern" and less efficient alternative - in this respect I find the Augie a bit "vintage" and outdated (sorry), and an alternative could be the cheaper DAYTON 15" IB SUB, Qts=0.65, Fs=20.8,
Very interesting OB driver with nice low Fs that could be exspected to go very deep

just tell me if I talk rubbish

:)
 
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OTMOPO3OK

Member
Joined 2004
18" would be way too big for my room but i get what you are saying about efficiency.

From what i know Dayton 15IB has a sharp drop off at 700Hz so it's not really suitable for XO at 150-200Hz. It's a purely a sub driver.

Regarding the Sub:
I thought that dipole bass can't go lower than my room supports?!?!
My room is 16ft so the lowest note is 35Hz, i figured any driver with Fs<35Hz is good enough. Do i really need Fs=20Hz?
 
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tinitus

Ex-Moderator R.I.P.
Joined 2005
OK, but a 35hz woofer rolls off much ealier than a 20hz woofer, low Fs is very important - its also about phase, meaning that any early rolloff will cause phase problems

Of PA drivers I wont choose nothing less than 18", to get low Fs and better bass response

That your room cant hold anything below 35hz, doesnt mean that it shuts down completely below that, it will just be at lower level

If I remember correct, you have said that you dont play very loud but want the best of refinement and definition - then it could be of advantage to let the fullrange driver roll off by itself, and in that case you might just need the sub driver

But I know, its not that easy

BTW... why do you think that 18" is too big fore your room ... it will match your fullrange very well, and used in OB you should have no problem with ressonanses, and it wouldnt need much baffle either, and with the size and medium Qts=41 you will have well controlled bass

I wont argue any more, but will be interested in your progress

Oh, yes, if you want it small you could just make a small closed sub and mount the fullrange in a small OB, but it will not have the well defined bass like a pure OB
 
Pano

Pano

Administrator
Joined 2004
Paid Member
OTMOPO3OK said:
How is the extension on that Selenium?
Click to expand...

I think it is 3mm, but I rarely even see it move. Just on electronic stuff, like Brian Eno, then it really pumps.

The Selenuim has a progressive spider, so it will pretty much keep you out of trouble. It's meant to take a beating. With 100WPC behind it playing very, very loud I never heard it compress or distort, but that's partly the OB thing.

Really I should be running 2 per side, like Martin does with his Alphas. But that would be mighty big in my little living room. The friend who sold me this pair runs 2x18" per side. Whatever works!
 
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Poindexter

Member
Joined 2004
AudioTropic.net
I would not neglect the Dayton IB385.

Catalog Page

It's specifically designed for almost this exact duty, and I get some fantastic results in WinISD in the infinite baffle (several thousand litre sealed box). Reasonable price, too.

I have a 'dream rig' going on in me tiny brain right now, that uses a line array of 4 JXR6s on each side, and a pair of IB385s in a manifold in each upper corner, backing into the attic space. +0, -3dB at 23Hz.

Aloha,

Poinz
 
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