Electro-Voice mystery speaker?

[62vauxhall]

It is a gamble buying speakers at auction when the internals are unknow. Curiosity is the best influencer.

I threw a $10 bid on some large speakers once and won. Once home with them I learned they were Isophon G3037's. My optimism spiked. But after listening to them, they were without doubt, the worst sounding, intended as HiFi speakers that I have ever heard.

It took a year or more of repeated Craiglist ads before finding someone who wanted them. I should not have made the upgrades I did or refinished the cabinets but I wanted them gone.

Only a $10 flutter but with time and travel, I lost the bet.

 

[Puddintane]

Found this online when I searched for Electro-Voice L-pad, and that’s pretty much exactly what the knob looks like.

 

[Puddintane]

Decided to gamble a bit and buy them. Mystery no more: Electro-Voice 12TRXB and a very crustily corroded L pad(?). Or at least one, since I haven’t opened the other cabinet yet. I’ve never used 16 Ohm speakers before. Is there any special consideration to take into account before testing them on my Yamaha CR-2040 receiver? (Edit: added one additional image of the bottom part of the cabinet.)

 

[radioactive]

Decided to gamble a bit and buy them. Mystery no more: Electro-Voice 12TRXB and a very crustily corroded L pad(?). Or at least one, since I haven’t opened the other cabinet yet. I’ve never used 16 Ohm speakers before. Is there any special consideration to take into account before testing them on my Yamaha CR-2040 receiver?

View attachment 2938165View attachment 2938166View attachment 2938167

Congrats you got the more desirable 12trxb drivers
.

 

[Sitka]

My EV Aristocrats are all 16ohms. They are very efficient, about 96db/1w/1m. Don't know the specs on your EVs. Your cabinets look very well constructed! Well built with3/4" plywood. Braced and filled with baffle.

How do they sound??

 

[Puddintane]

My EV Aristocrats are all 16ohms. They are very efficient, about 96db/1w/1m. Don't know the specs on your EVs. Your cabinets look very well constructed! Well built with3/4" plywood. Braced and filled with baffle.

How do they sound??

Hi Sitka, just curious how you calculate that efficiency number (because I have no idea how it’s done). I found these specs from EV online.

 

[Puddintane]

My EV Aristocrats are all 16ohms. They are very efficient, about 96db/1w/1m. Don't know the specs on your EVs. Your cabinets look very well constructed! Well built with3/4" plywood. Braced and filled with baffle.

How do they sound??

I am quite impressed. I first listened to “Ella and Louis Again” (mono CD—seemed appropriate for these!) and am now listening to Brubeck’s “Time Out.” I think they sound great and look pretty cool too.

 

[doctorolds]

Some folks like full range / point source drivers, I am one of them! I'm happy to hear that you are enjoying your new acquisition!

 

[radioactive]

Some folks like full range / point source drivers, I am one of them! I'm happy to hear that you are enjoying your new acquisition!

Miss my old lt12's but i have enough orphan coaxials and triaxials from altec, university,jensen etc and even celestion but the celsetians i have in cabinets for a stereo pair.

 

[radioactive]

Hi Sitka, just curious how you calculate that efficiency number (because I have no idea how it’s done). I found these specs from EV online.
View attachment 2938427

Im pretty sure that is wrong and i dont think any speaker of that era had a a rating that low

 

[doctorolds]

Miss my old lt12's but i have enough orphan coaxials and triaxials from altec, university,jensen etc and even celestion but the celsetians i have in cabinets for a stereo pair.

I'm guessing that you have the pair of Celestians for a good reason!

I've also got a pair of University 312's in the original tiny-mite cabinets.
A pic of my LT-12 for those who care, lol.

 

[bowtie427ss]

Im pretty sure that is wrong and i dont think any speaker of that era had a a rating that low

EIA 426B standard uses 1mW @ 30ft.

JBL probably stuck with this standard longer than most, into the early 70's.

To convert to modern SPL@1W/1M add 30db to convert 1mW to 1W, and about 19.2db to convert 30ft to 1M.

So, about 100-101db @1W/1M for the OP's TRXB's

Specs from JBL 4311 manual:

 

[kevintomb]

EIA 426B standard uses 1mW @ 30ft.

JBL probably stuck with this standard longer than most, into the early 70's.

To convert to modern SPL@1W/1M add 30db to convert 1mW to 1W, and about 19.2db to convert 30ft to 1M.

So, about 100-101db @1W/1M for the OP's TRXB's

Specs from JBL 4311 manual:

View attachment 2938690

Agree!

 

[Puddintane]

EIA 426B standard uses 1mW @ 30ft.

JBL probably stuck with this standard longer than most, into the early 70's.

To convert to modern SPL@1W/1M add 30db to convert 1mW to 1W, and about 19.2db to convert 30ft to 1M.

So, about 100-101db @1W/1M for the OP's TRXB's

Specs from JBL 4311 manual:

View attachment 2938690

~100dB, eh?! Thanks for that info, I had no idea about how that works.