Vintage NEAR Boom-4 Subwoofer

[Gwho]

Any help would be appreciated. I recently picked up a subwoofer from the 1990s that I would like to restore and improve if possible. I cannot seem to find any information on the subwoofer. The subwoofer was built by NEAR (New England Audio Resource). It is a passive subwoofer requiring amplification. It is a ported design that has 4 8" woofers. It appears that each side (2 8") are independent from each other as they are side firing with each side having a separate port. Does anybody know anything about this device (frequency response, efficiency, power requirements etc.). Is it only good for HT or could it be used for a two channel system?

Thanks for any input you may have.

Best Regards,
gwho

 

[chris661]

If there's two sets of inputs, that suggests to me it was intended to be run in parallel with main speakers, in a 2-ch set-up.

An impedance sweep would be rather useful:
the dip between two impedance peaks is the port tuning. Above and at port tuning, power handling is very large. I'd expect 4x8"s to go rather loud, so long as you don't go below port tuning.

Photos would help, too

Chris

 

[Gwho]

I will try to get some pictures up if I can figure it out.. The speaker measures 3' x 2' and is about 20" high. I do not know much about speaker building (I'm better at electronics). Is an impedance sweep a measurement of the speaker output over frequency?

Thanks
Gary

 

[weltersys]

Is an impedance sweep a measurement of the speaker output over frequency?

Gary,

An impedance sweep is a measurement of the speaker impedance, measured in ohms, over frequency.

Speaker output level is measured in decibels, (dB) dB SPL (Sound Pressure Level) using a dB meter or more advanced RTA or FFT devices.

You can determine the Fb (tuning frequency of the box) visually using swept sine waves (available for free on the web), the speaker movement (as well as impedance) will be at minimum at Fb.

Below Fb, ported boxes tend to drop in level at around 24 dB per octave.

 

[Gwho]

I got a couple articles on doing an impedance sweep. I will read them and attempt a measurement.

Thanks
Gary

 

[Gwho]

Here are some pictures of the subwoofer. It has two drivers on each side.

 

[Gwho]

I was told that the woofer cone is metal.

 

[BP1Fanatic]

Since you didn't provide the model number, try here.

Bogen Document Index

 

[djk]

Boom 4-FG
Manufacturer: NEAR-New England Audio Resource

 

[BP1Fanatic]

About Bogen, Location, Other web sites, Board of Directors

 

[Audio Baja]

Way overdue, but probably the best resource for NEAR speakers would be Terra - Terra Speakers | All Weather Indoor & Outdoor Speakers as they are building speakers based on these driver designs. The woofers are, indeed, aluminum with a coating of ceramic to dampen resonance. I just stumbled into this as I'm building a small powered sub based on two of these woofers.

 

[jackmetro]

Better way late than never

I too own a Boom 4 sub-woofer and have had it for over 20 years, powered by one channel (100w) of my Kenwood KM-X1 amp. I have always LOVED this sub for it's efficiency and extreme low end (I'd guess in the 15-20 hz range).
The metal cones and magnetic fluid suspension make the drivers smooth long throw pistons with zero distortion.
I also have four Mast speakers and one 20MV center channel to go along with the sub.
The original designer is still around now with Near/Bogen doing what he does very well, designing high quality speakers. I expect that Bill would love to hear of your experiences with "one of his babies". Here's a link to the history:
HISTORY - NEAR Outdoor Speakers