Whats Your Favourite Passive OB Bass Driver

[DQ828]

I'd be very interested to hear what your favourite OB bass driver is for a passive setup. Wether used as singles or pairs or more. Also why you like them.

My favourites are Altec 416 8B, but thats because I'm very new at building speakers & it's the last one I used, oh and much bigger than the driver in my previous build.

 

[Pano]

The 416 may be my fav for a box, but not for OB.

Of what is currently on the market, this one - Goldwood GW-1858 - used 2 per side is quite good. Also quite large.
For a much more reasonable size, this Peerless - Peerless 830669 12" - is hard to beat. A really amazing driver.

 

[sreten]

Hi,

The Altec is probably a nice driver for a box but a dreadful choice for
a passive open baffle speaker due to its very low Qts of 0.23, and
TBH the Xmax is not that impressive either for the application.

Checkout MJK's articles on passive open baffle speakers :
Quarter Wavelength Loudspeaker Design

rgds, sreten.

The Eminence Alpha 15" is very popular.

 

[Helmuth]

Hi,

The Altec is probably a nice driver for a box but a dreadful choice for
a passive open baffle speaker due to its very low Qts of 0.23, and
TBH the Xmax is not that impressive either for the application.

Checkout MJK's articles on passive open baffle speakers :
Quarter Wavelength Loudspeaker Design

rgds, sreten.

The Eminence Alpha 15" is very popular.

Do not only look at the Q also Fs,Vas. The altec is very very good here simulation 2phi.

 

[Helmuth]

eminence alpha 15

 

[Helmuth]

I am afraid that the mid of the goldwood could be to poor qaulity.

The peerlees is nice qaulity.

 

[jerome69]

The SLS10 could be also a nice performer, dry bass and fast, not as low as the SLS12. Could be used as single or pair, easily down to [email protected]
Peerless 830668 10" Paper Cone SLS Subwoofer | Parts-Express.com

 

[Helmuth]

The SLS10 could be also a nice performer, dry bass and fast, not as low as the SLS12. Could be used as single or pair, easily down to [email protected]
Peerless 830668 10" Paper Cone SLS Subwoofer | Parts-Express.com

can do nice for a 10" limited spl around 100-105dB two. Is enough 10" is better for mid.

 

[Helmuth]

limited xmax monacor sph250ke keflar cone good spl for hifi. xmax at 8W or two 16W = spl102dB for two at xmax.

 

[Helmuth]

Low price dayton good xmax 6mm can compete with peerles 10" only dayton has steel basket.SD270.

 

[skorpion]

Helmuth, all your Hornresp simulations how are they done ?

Hornresp is not very suited to do OB simulations since the programme suppose a centric placement on the baffle. You can do simus of the naked driver which is interesting. But to get things right with OB simulations you have to take the combined SPL response to account for the bass loss.

/Erling

 

[skorpion]

Simulation of Eminence Alpha15 by itself (No Baffle) 2Pi 1 watt would look like this:

[IMGDEAD]http://img813.imageshack.us/img813/1482/nobafflealpha15.jpg[/IMGDEAD]

/Erling

 

[Helmuth]

Helmuth, all your Hornresp simulations how are they done ?

Hornresp is not very suited to do OB simulations since the programme suppose a centric placement on the baffle. You can do simus of the naked driver which is interesting. But to get things right with OB simulations you have to take the combined SPL response to account for the bass loss.

/Erling

Yes your right Erling, my simulations did not calculate combined response.

It doesn't really chance the indication about the woofer being suitable for OB.

The combined response depends on how far away the woofer is placed from the backwall. So it also not possible to give the exact response.

combined for sph250ke

 

[Helmuth]

Simulation of Eminence Alpha15 by itself (No Baffle) 2Pi 1 watt would look like this:

[IMGDEAD]http://img813.imageshack.us/img813/1482/nobafflealpha15.jpg[/IMGDEAD]

/Erling

witch distance for combined did you use Erling. Ok I can see 19cm sorry.


Do you really think this is a better simulation. Here is no floor or baffle that did help the low frequency it is ok for nude chassis placed near floor or wall.

 

[Pano]

Do not only look at the Q also Fs,Vas. The altec is very very good here simulation 2phi.

It's a great driver, but not for OB. Unless you use 4 per side. No matter what the plots say, it not really practical. I know, I own a few.

I am afraid that the mid of the goldwood could be to poor qaulity.

It's much better than you think. Used in a 3 way system, it's actually rather clean. Somewhere here I have measurements taken at LSAF. It does need a little trap circa 3Khz for best performance. It also has a nice bump at 16Hz for those organ pedal tones.

The Peerless is super clean. But it's a 12 and you'll need to throw a lot of power at it. It can take the power, but it will always be low efficiency on OB.

 

[sreten]

Do not only look at the Q also Fs,Vas. The altec is very very good here simulation 2phi.

Hi,

Fs is low but for OB Vas is irrelevant. Ideally for OB you want a Vas
completely impractical for boxes to mjke the the best of OB's.
Nevertheless for a passive OB Qts is far too low.

rgds, sreten.

 

[DQ828]

Simulation of Eminence Alpha15 by itself (No Baffle) 2Pi 1 watt would look like this:

/Erling

What does "2Pi 1 watt" mean?

 

[skorpion]

The Pi is used to illustrate speaker placement:

0.5 Pi is in room corner placement
1.0 Pi is in room wall placement
2.0 Pi is in room freestanding placement
4.0 Pi is free air placement

1 watt beeing fed to the speaker.

/Erling

 

[Helmuth]

The behaivour of the eminence alpha is quit rare.

It is easy to copy that behaivour by using two high Q drivers in series. And best types are high spl 4 Ohm car sub woofers/ or pa.

I simulate here a monacor car sub in series. So it stretches the low end with the bump at Fs in combined response.

Ad 3 dB to the spl. It is low efficient because they are in series it makes in passive low end configuration easier.

MONACOR INTERNATIONALroduct detail page

 

[Helmuth]

here two eminence alpha in series ad 3dB for serie config and then with four drivers the cut of is 35hz and spl will be 79dB 1wmtr.