Open Baffle Suited Woofer Suggestions

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Pleeese help!

I have been mulling over a few speaker designs and my friend suggested something very cool. To make it work though I need a large woofer, ideally 10" but 12" will be okay. It needs to work well open baffle up to 1.5KHz and down to about 35Hz.

My knowledge of open baffle stuff is pretty limited.

I realise its hard to go that low open baffle, but I will be using digital EQ so it isn't all that hard. Ideally I need a FS of 39Hz and a Qts of 1.5. But, as I say, I will be using EQ so I can sort out the low end as long as the woofer can take the extra power and is not too far from that ideal.

I was really excited when I found the Fostex W300A2 simply because it seems so high quality. Sadly though it has a very low Qts so rolls off pretty early. It would need a boost of about 10dB at 35Hz. Anyone think if it could cope with that or not? It looks like it should have such good midrange (or maybe I am just looking at the price and going oOooh!).

Thanks peeps!
 
the fostex wouldn't make it at any decent spl that low in freq.. (not enough excursion).

Its also a bad idea for a number of reasons (..not the least of which is IMD).

The PHY 12" fits your description however..

If I were you I'd consider one driver for the midbass & midrange:

http://www.supravox.fr/haut_parleurs/285_GMF.htm

This driver has the lower midrange lift that is needed for a practical baffle size.

(note the mms of the driver.. seems a bit more like a midrange driver no?)

And 2+ filler drivers for the low freq.s (activly assisted/eq'ed):

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=295-464

There is also this driver, BUT distortion will be higher and eff. isn't that great:

http://www.hawthorneaudio.com/drivers.htm

(Silver Iris OB 15" Augie)

..or ditch the idea for extending the response with a dipole character and instead look to normal "subwoofer" solutions.
 
I was planning to use a boxed fill-in driver for the low bass (thinking Peerless XLS), but I still need the open baffle to get down to about 40 or 35Hz. I know the peerless goes much higher but I need the extension from the open baffle for other reasons. It is a little bit secrete-ish as I may take it commercial so before I protect the idea I don't want to give too much away. I hope the secrecy doesn't **** people off! Maybe it is obvious what I am thinking anyway.

Actually I just modelled the Fostex W300AII and it doesn't do too bad just running full range. It rolls off to soon but it too shallow a roll off. So If I boosted at 35Hz by 5dB which is what it would need I can roll it off more sharply which might help with IMD.

Can anyone say how the W300AII sounds?

I could run a separate midrange and mid-bass driver but I am trying to stay away from lots of crossovers and I think what I want can just about be pulled off. Hell it definitely could be if I had a custom driver made but you have to order at least 50 drivers and I don't know quite what its final sound quality would be like, only that it meets the T/S spec I stated!

That Silver Iris Augie looks very close to what I need in terms of T/S, only a little too big :( Any FR graphs for it?
 
Tenson said:
I was planning to use a boxed fill-in driver for the low bass (thinking Peerless XLS), but I still need the open baffle to get down to about 40 or 35Hz. I know the peerless goes much higher but I need the extension from the open baffle for other reasons. It is a little bit secrete-ish as I may take it commercial so before I protect the idea I don't want to give too much away. I hope the secrecy doesn't **** people off! Maybe it is obvious what I am thinking anyway.

Actually I just modelled the Fostex W300AII and it doesn't do too bad just running full range. It rolls off to soon but it too shallow a roll off. So If I boosted at 35Hz by 5dB which is what it would need I can roll it off more sharply which might help with IMD.

Can anyone say how the W300AII sounds?

I could run a separate midrange and mid-bass driver but I am trying to stay away from lots of crossovers and I think what I want can just about be pulled off. Hell it definitely could be if I had a custom driver made but you have to order at least 50 drivers and I don't know quite what its final sound quality would be like, only that it meets the T/S spec I stated!

That Silver Iris Augie looks very close to what I need in terms of T/S, only a little too big :( Any FR graphs for it?


(..its fine with me.)

Kloss on the High Eff. forum of the AudioAsylum has used them and the design was even reviewed on 6moons:

http://www.6moons.com/audioreviews/realitycheck2/kalinowksi.html

Ask on the fullrange part of this forum for more into on the silver iris..

To my knowledge only the PHY driver does what you want.

Good luck!
 
Hmm those PHY drivers do look good on the specs. A little bit too much variation in the FR but not too bad. VERY expensive though! Thats about the max I could spend.

Any reviews or thoughts on how these would do used up to 1.5KHz?

The Eminence Omega 12 looks good. It rolls-off pretty early but being 95dB efficient AND taking 700watts of power it could cope with a 5dB boost at 35Hz I think!

Thanks,

I think I am getting somewhere now!
 
Tenson said:

The Eminence Omega 12 looks good. It rolls-off pretty early but being 95dB efficient AND taking 700watts of power it could cope with a 5dB boost at 35Hz I think!

Hi,

The omega PRO12 needs a lot more boost than 5db for decent
bass at 35hz, and that is in a large sealed box, on an open baffle
it would needs loads more.

Anyone who thinks a 95dB efficient driver can handle 700 watts of
power at 35Hz doesn't really know much about loudspeaker design.

Power handling at 35 Hz open baffle is around 35 watts.

:)/sreten.
 
Hi

At www.usspeaker.com/homepage.htm
Under 15" woofers:
Kappa Pro-15LFA US$ 155 6 mm Xmax
18 Sound 15MB700 US$ 193 5.5 mm Xmax (better quality?)
B&C 15PS76 US$ 173 7.5 mm Xmax
Under 18" woofers:
Magnum Pro-18LF US$ 220 6.4 mm Xmax

Elsewhere:
Peerless 12 inch 830500 US$ 150 12 mm Xmax, used by Linkwitz in the Phoenix dipole www.linkwitzlab.com/woofer3.htm

P.Audio have a huge range – see LHS of
www.p-audio.co.uk/products/db_1_10.htm
eg
www.p-audio.co.uk/products/db_product_1_10_s15-64m.htm 8 mm Xmax
the C12-500 MB 4.8 mm Xmax
www.p-audio.co.uk/products/db_product_1_6_bm-15lf.htm 8 mm Xmax
 
sreten said:


Hi,

The omega PRO12 needs a lot more boost than 5db for decent
bass at 35hz, and that is in a large sealed box, on an open baffle
it would needs loads more.

Anyone who thinks a 95dB efficient driver can handle 700 watts of
power at 35Hz doesn't really know much about loudspeaker design.

Power handling at 35 Hz open baffle is around 35 watts.

:)/sreten.


I didn't mean to give the impression it could handle 700watts at 35Hz, only that it has a 700watts power rating. At 96dB efficient and in a home environment it is never going to get close to that so I think it can handle the bass boost.

The FR graph for it shows it at about 5dB down at 35Hz. So does my open baffle modelling from the T/S parameters. It does have a 20mm linear exertion you know.
 
That would be -5dB in an infinite baffle, so unless your commercial plans include instalation work, the response at 35Hz will be quite a bit lower. Especially with a Qts of .3. Really not to be negative but your going to have some trouble reaching very high SPL's at 35Hz with only a single woofer on an open baffle. The displacement requirements are really a bit much for a single 12" woofer I would think. I could be wrong though and I wish you luck. If you think you could work a 15", then maybe something like this would work well with minimum EQ'ing:
http://stores.channeladvisor.com/musicsupplycenter/Items/700-08-4506?
good luck
Joe
 
There is also a Peerless XLS 12" in a sealed sub per channel so the open baffle only has to do half the work where this kicks in. I still need it to go down to 35Hz though. So it would be all EQ'd down by about 6dB where the sub comes in and then at 35Hz the open baffle would need a little boost to keep even with the sub. Below 35Hz I want it to fall off.
 
Hi,

As stated open baffles are very different beasts to infinite baffles.

According to WinISDPRo (parameters from here) on an infinite baffle the
driver is 12dB down at 35Hz, to this you would have to add baffle loss.

Efficiency infinite baffle at 35Hz = 82dB/W.
Efficiency open baffle = 82dB/W - baffle loss.
Maximum SPL at 35Hz = 98dB - baffle loss.
Maximum power at 35Hz = 35W.

Linear Xmax is given as 4.8mm.

:)/sreten.
 
the OB crusader is here....

(background sound effects: Ker klop, ker klop...in the best possible Monty Python ,"In Search of the Holy Grial" onomatapic sense)..

crusader--yes, expert--No. Any instrument style driver intended for guitar, organ etc. can often accomplish the OB.. they're often designed for use in "open back" enclosures. The old guitar drivers I used seemed good for about 35 Hz (comparing to a Polk SW10, supposedly good for 35Hz). The bass was at least as deep but without the viceral 1mpact proper subs create. This can be a good or bad thing depending on your needs and point of view.I added a left over tweeter and a salvaged cross over.

Still as I have pointed out numerous times (in other threads), look at the JE Labs open baffles . Please do not alter the dimensions. If more bass is needed, make the "top" as wide as the "legs". and make a stabalizer to connect the legs at the bottom (a piece of left over ply from the consruction, about 6" high by the seperation width of the legs worked well for me.)

I have driven these using about 10 watts of power, and they are simply too loud to listen to for long periods of time (I listen at least 10' away in a room approximately 19' X 12'), no pain, just once done you'll know you've been listening to something that makes loud sounds..
 
Has anyone looked at the Morel MW1075?

It looks pretty ideal for open baffle use as far as I can see. Not great sensitivity, but it doesn't need any EQ to go nice and low and still handles a 'fair' amount of power.

Qts - 0.65
FS - 25Hz
SPL - 89
LE - 0.2
RE - 6.4
Coil Dia - 3"
Power - 180 Watts RMS

What do you think?

If I used this in my design I would actually need to apply reductive EQ in the bass!
 
I need -3dB from 35Hz or 40Hz to to about 100Hz at which point it goes up to 0dB.

I will have to do that with EQ I think, but I obviously need a driver that can go that low. This Morel MW 1075 goes that low with no EQ and also goes high enough for my crossover point. I just need to add EQ to bring the level DOWN to -3dB over teh 100Hz range.

It isn't as sensitive as I'd like and doesn't handle quite as much power as I'd like but I guess thats the trade-off for going low with a open baffle.

It seems ideal for open baffle so I just wondered if anyone had tried it.
 
Unless baffle size is big, you’ll almost certainly need EQ.

Have you read Linkwitz (heavy) write up on dipoles?

> -3dB from 35Hz

But at what SPL? 105 dB? 115 dB?

Low Q drivers with low distortion can be used with more a little more EQ. If SL used them (and I’ve heard them, and the bass is great), it’s a valid option . .
 
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