Big @ss subwoofer in Wisconsin / Kef B-139 driver

[Ohighway]

One of you fine Wisconsin folks needs to step up to the plate and grab this thing....

 

[chard306]

I have contacted the seller, and trying to work out a deal. $300 for something I cannot test is a huge leap of faith...how would you even hook this thing up?

 

[eddantes]

Hook it up? Who cares! You will be a legend!

 

[Ohighway]

I won't swear to it, but I believe there's merely a pair of KEF b139 bass drivers in there, so verifying the function of those shouldn't be difficult. I don't believe there's any internal crossover, etc.

For real world use I suspect you'd need an electronic crossover and amps to properly utilize it.

 

[Ohighway]

Just looked on ebay.... and it's still there......

Doesn't anybody need a nice big 'coffin' for Halloween ?

 

[chard306]

I have worked out a price we can both live with, now I have to wait to sell some stuff in my garage, I have someone coming on Monday. If I sell my stuff it is mine, unless someone else grabs it first, then it was not ment to be....He did find the cables for it.

 

[Ohighway]

I like your style. Hope you get it.

also...Hope it doesn't cause the foundation on your house to crumble....

 

[fitzwaddle]

Seems like a reasonable size for a subwoofer to me :thmbsp:

(building the second one now)

 

[Arkay]

Glad someone has claimed it first. I was trying to work out what the car's gas consumption would be to drive it from Wisconsin to Hong Kong...

Making (DIYing) one of those things would be fun. I wish I had the space these days for such things... If I got one, I COULD make it a coffee table in front of the sofa, in the middle of the living room. Just imagine the nice wave patterns in the drinks glasses set atop such a nice "coffee table" when the explosions started occurring in the HT system...

 

[SaSi]

I enjoy the mis-information provided in that auction.

"Can't do high SPL but can go really low"
And then
sensitivity 95dBWm, max SPL 113dB.

Boy, if that coffin did 10Hz ~ 200Hz at 100+dB (anywhere in that range), it should be the holly grail of subs.

 

[chard306]

Here is what is on the Perfectionist Audio Web Site, where you can still get the info to build your own.
SPECIFICATIONS

FREQUENCY RESPONSE: (4 pi measurement)

10 Hz to 240 Hz +/- .8 dB

TOTAL HARMONIC DISTORTION:

Less than .9% from 10 Hz to 240 Hz @ 95 dB SPL

FREQUENCY RESPONSE VERSUS DISTORTION: (worst case)

0 dB = 95 dB SPL @ l meter (4 pi measurement)
Even Order Harmonic Distortion: Less than .9%
Odd Order Harmonic Distortion: Always less than Even Order

EFFICIENCY :

l watt R.M.S. = 95 dB SPL
64 watts R.M.S. = 113 dB SPL

MAXIMUM SOUND PRESSURE LEVEL:

113 dB SPL @ 1 meter on axis

POWER HANDLING CAPABILITY:

72 watts R.M.S. per channel

DIMENSIONS :

26" x 72" x 24"

 

[mech986]

The input connection shown on the pics is a typical 3 pin XLR so not hard to figure out which two pins go to positive and negative on each woofer.

The KEF B139 is a fairly stout woofer but it was designed and built before the era of big power amps so it can't take super power nor hit really high SPL as noted. In TL and long line cabinets though, it can play pretty low. Would suggest using a low pass filter around 100 hz or lower, some might suggest a high pass around 20 hz to protect against infrasonic signals if you are playing stuff that really goes low.

 

[Ohighway]

Wow, this thing is still available. Now at $200 buy it now , plus has a "make offer" option....

 

[MrGlobe]

What would be the cheapest way to power as well as wire this thing? You'd have to re-wire the speaker connections, but how much power would it need? Would a modern day AVR/Receiver have a good enough low freq filter to use the sub pre-out?

 

[mech986]

What would be the cheapest way to power as well as wire this thing? You'd have to re-wire the speaker connections, but how much power would it need? Would a modern day AVR/Receiver have a good enough low freq filter to use the sub pre-out?

Not sure how one will be able to get inside the panels but here goes. Rewiring is very simple - Unscrew and pull out the XLR jack. There will be two wires, one to the positive and one to the negative wire on the woofer. Test it to the correct woofer. You would then have to fashion a plate to fit over the original XLR jack - you can use a double banana jack, gold plated or not, and corresponding double or single banana plugs for the wire. Parts Express and Orange County Speaker are good sources for those.

A suitable plate is just a piece of wood or decorative plates can be used. Or really simply, buy the common prebuilt terminal cup, round, square or rectangular, that already has double binding posts and drill/cut the panel to accept the cutout needed. Rewire the XLR wires to the correct polarity on the binding posts, solder, gasket the cup, then screw back in. Repeat for the other XLR, Done!

Power wise - if the unit can run about 75W continuous power, I'd suggest running with about amp that can give you at least 100 watts. You want an amp that is loafing along and putting out clean power, rather than an amp that runs out at 50-75 watts and then clips, which could send some problem signals or DC to your woofers. While the B139 woofers are common, they are not always cheap to purchase or ship due to weight. So important to try not to blow them if possible.

Whether an AV receiver has a good low pass filter depends on the specs. If it can give you something like 120hz or lower filter, should be good to go.

These are some pretty good subwoofers if you have the space and the ability to transport them to your home (and get them in!).

Good luck! No affiliation, yada, yada.

 

[audiomagnate]

That is a work of art! Why hasn't anybody snagged it? Extra points for the planking.Seriously, it would cost thousands to make one of those.

 

[Ohighway]

That is a work of art! Why hasn't anybody snagged it? Extra points for the planking.Seriously, it would cost thousands to make one of those.

I just don't think a lot of folks realize what this is. That and a lot of people cannot handle or do not want anything that large.

It's gotten to the point where this thing is going for the price of the drivers alone.

 

[colinsouney]

I am not very smart so I need some help understanding this. Frequency response is as low as 10hz. Speakers are only good down to 20hz, per kef specifications on the link below. How do you get 10hz out of a driver that is only capable of producing 20hz? Unless there is a complex device that splits the phase of each and makes it work half duty (I am an idiot arent I). Or does this transmision line reduce the resonant frequencyof the driver by altering the air that passes? I am confused and need to be set straight (

 

[colinsouney]

UH I forgot link
http://homepage.mac.com/planet10/TLS/drivers/images/B139small.GIF

 

[chard306]

Well I made an offer and he jumped at it, waiting to see how much he will charge to deliver, or I will have to borrow a van.
Now I wait...