I recently aquired a pair of 32 ohm Stevens Tru-sonic woofers in good condition. I was told they were used in the early Klipschorns. Is this correct?

Thanks,
Jeff

Some time ago I posted the Vacuum Tube Valley article on the K-Horn.  Now it is difficult to find old posts because of the new search function.  But the webmaster is working on that.

In any event, the article has a side box listing the drivers used over the years.  It lists "1940s - 50s 103LX2 Stevens".  There is no info on impedance

Gil

DFH V12 No5 says thay used Stephens P52LX2 and Stephens 103LX2 early on...

I'm running the stock pair of 103-LX, that came in my '57 Khorns.

They sound great.

Of course, they were implemented in a mono configured cabinet.
That might say something about the design application, but I really can't comment on the specs.

I don't have the particular "dope from Hope", in front of me, but I do recall that PWK had suggested that it be retained for continued use after the 1958/60 modification period.

IMO they are really well made drivers.
Though, i'm biased in the fact that i'm a Stevens/Tru-Sonic fan.
Heh.
Even if they couldn't keep their building(s) from burning down....they still made some serious drivers.

Regards,
John.

Thanks everyone for all your great input...

John,
    The way I read your post, are there two of these drivers in a single K-horn?


Thanks,
Jeff

Jeff, one woofer for each speaker.

John, do you have a way to test the DCR of your 103 LX? I have a pair in '59 Shorthorns that are 16 Ohm.

Chris

All, would the 103 LX2 be used with the smaller 3 x 13 throat, while the 103 LX would be with the larger 6 x 13 throat? Curious.

I'm measuring 3.2 Ohms at the terminal block on the outside of the doghouse.

Strange....
Can that be right?

I really don't want to break the seal I made on the doghouses to get a more acurate measurement.

Can't comment on the differences between the two drivers types.
I'm not familiar with the other.

My 57s' have the 6 inch slot. FWIW.

Regards,
John.

on my  51,58 and 59 khorns the stevens drivers are all 16 ohm. as well as the Jensen drivers used early on.
I think with a 32 ohm driver you would have to change the crossover setting.

I don't think 3.2 ohms would be a strange DC resistance for the 16 ohm 103LX2.  The 16 ohm ElectroVoice  15WK also used in the Klipschorn has 3.2 ohms DC resistance., too.

Malcolm, doesn't 3.2 DCR come from an 8 Ohm driver? I got a reading of close to 11 DCR for the 16 Ohm drivers, using a Ratshack analog multimeter.

Chris

Great information! Thanks

Do you think these Tru-sonic speakers would be a good fit for a set of the university classics?

I have a marantz tube amp with 16 ohm taps so I would be running them at half power since they are 32 ohms...

Thanks,
Jeff

You are correct that most 16 ohm woofers have DCR in the 11 to 12 ohm range.  But that doesn't have to be the case.  The Stephens 103LX2 and ElectroVoice 15WK were designed to PWKs specs for use in a horn loaded enclosure, at least as far as the voice coil DCR was concerned.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5855217904&ssPageName=ADME:B:EF:US:1


Here is an old Khorn with a Stephens Woofer for anyone interested.


mike