I know this is a Klipsch forum, but......Bozak FS in Illinois

[Thumpelstiltskin]

Here's a classified ad I found. The description suggests these could be the Bozak CS-410M Concert Grand speakers, worth more than $500.....a LOT more. The ad started on 6/03.

"8 BOSAC SPEAKER SYSTEMS, each has 8 tweeters & 4 woofers, $500 for all, will not seperate, 847-428-6893 Carpentersville, Ill."

Good luck, Rick.

[Colin]

Bozak, father of Bose, son of Ak...

[Thumpelstiltskin]

They are not the "father of Bose", but this could be a mother of a deal.

Retail

MSRP: $5,000.00

USED: $1,700.00

Wholesale

Mint: $1,150.00

Average: $780.00

That's for one pair.

Rick.

[edwinr]

They might be cheap, but do they sound any good?

[Thumpelstiltskin]

----------------

On 6/7/2005 5:23:36 PM edwinr wrote:

They might be cheap, but do they sound any good?

----------------

Who cares?

Buy low. Sell high. Buy more Klipsch with profit. Any questions?

Rick.

[D-MAN]

Bozak is legendary for their VERY large infinite baffle speakers. They take some serious juice to push them, but then LOOKOUT!

DM

[Thumpelstiltskin]

I found some cool info on Bozak Concert Grand speakers at highefficiencyloudspeakers.com. These things are huge, with four 12" woofers in each cabinet. They say a 50 watt amp is enough. The efficiency is listed as 4%.....what does that mean?

PAGE 1

PAGE 2

PAGE 3

PAGE 4

PAGE 5

[boom3]

4% efficiency is very good for non-horn speakers. A classic acoustic suspension system might be 1-2% efficient. I think Paul once said that Klipschorns were 25% efficient, but the memory is old. The big Bozak gets that efficiency from lots of cone area to move air and a large baffle to support radiation down to a relatively low frequency. I still would rather have my Corns, though!

[Thumpelstiltskin]

----------------

On 6/8/2005 5:33:00 AM boom3 wrote:

4% efficiency is very good for non-horn speakers. A classic acoustic suspension system might be 1-2% efficient. I think Paul once said that Klipschorns were 25% efficient, but the memory is old. The big Bozak gets that efficiency from lots of cone area to move air and a large baffle to support radiation down to a relatively low frequency. I still would rather have my Corns, though!

----------------

Thanks.....I'd never heard loudspeaker efficiency expressed that way.

Rick.

[DrWho]

4% translates to about 97dB if my memory serves me right. The percentage comes from the amount of electrical energy put in versus the total energy of acoustical output. The remaining 96% is basically being turned into heat. Most speakers are in the 1.5% range (or 90dB sensitivity). I think I remember reading in the Dope from Hope that the khorn was like 13% efficient...an order of 10 times more efficient than most other speakers, which is why they'd take like 1/10 the watts to reach the same volumes (which would translate to about a 10dB difference in sensitivity).

Anyways, I know my numbers are rough, but hopefully it gives you a good idea. Keep in mind that comparing the actual rated sensitivity versus the "no" (the % value) have different conversion factors based on the Znom rating of the speaker (8 ohms, 4 ohms, 16 ohm, etc etc...). The lower the ohms, the higher the no will be.

[CaptnBob]

I just talked to the guy. These are not Concert Grands. The model number is B-407, which, I think, is what Bozak called their "Monitor C." They have eight tweeters in a semi-circle array at the top, and four 8" aluminum cone woofers. One doesn't work and one seems to have come to grief in his truck - he was a bit unspecific in describing the damage, beyond saying it would require a trip to Home Depot. He also said the foam grills had decomposed - but that's to be expected.

As I recall - and again, this is mining a long abandoned shaft in my memory - these were Bozak's attempt to build a "rock & roll" speaker to compete with the JBL 200s and Altec 19s.