Electro-Voice Marquis

Jstas

OK, so, hoping the brain trust here can help me out on this.

I have a set of Electro-Voice Marquis speakers and they have in them a couple EV 12TRXB full-range drivers. Well, they are coaxial full range. Probably one of the earliest examples. They're dirty and a bit beat up from being in storage but they can be cleaned up.

Problem is, I'm not sure if they work. Mainly because I'm not sure how to hook them up to an amplifier.

I have manuals and schematics for them but none of it gives any clue on how to attach them to the outputs of an amplifier. So I'm hoping someone here might have seen this before and can offer some insight 'cause it's a new one on me. Pictures below.

Any ideas?

SeleniumFalcon

Here's a link to the original owner's manual:

https://products.electrovoice.com/binary/12TRX and 12TRXB EDS.pdf

SeleniumFalcon

SeleniumFalcon

I'm sure @mhardy6647 will have plenty of experience with the EV.

mhardy6647

Yeah, but the 12TRXB can be a little abstruse.
The crossover is built in (under the magnet's bell cover); the EV symbol can be encouraged off with a little heat (hair-dryer kind of thing, IIRC) to loosen the glue and give access. Simple first order on both drivers, again, IIRC.

There is normally an L-pad wired to the tweeter. It looks like @Jstas has the L-pad (or at least the wiring). If the two "hot" terminals are tied together in the manner described by the manual text @SeleniumFalcon reproduced above, feeding the amp signal to one red terminal (+) and connecting the amp's (-) to the black terminal, the loudspeaker should work -- just as EV's doc says

Some caveats.

* That is a very sensitive driver and not built to handle much power. I believe the spec was 25 watts music power, so be quite careful.
* The T35B tweeters in those are pretty fragile; it is pretty common to find them with nonfuctioning tweeters. EV no longer provides diaphragms for them. There are plenty of cheap aftermarket diaphragms -- I've yet to have the chutzpah to try any, though.
* The L-pads can be oxidized and interfere with tweeter function, too. Fiddle with the L-pad and see if the tweeter will show
* some life if it's initially dormant.
* The tweeter can be hard to hear against the "fullrange" driver any way. Using something like a paper towel roll (former) as a stethoscope can help.

The 12TRXB came a decade or more after the Altec Duplex coaxial fullrange driver -- Coaxials were quite popular in even the early 1950s, although the Duplex dates to ca. 1943.

There are... a few... 12TRXBs (both morphs) here Several of those have dead tweeters. So it goes.

Jstas

OK, so where's the "L pad" then? Is it on the speaker or is it that RCA dongle thing? 'Cause that's wired to the positive side as the other RCA port is labeled C for common ground.

Any idea what that RCA dongle is for? Because it doesn't look like it's wired to anything specific.

SeleniumFalcon

The wire with the RCA plug appears to be a jumper of some kind, kind of like the jumper plates on the back of some speakers. What's on the other side of the RCA jacks? What wires are connected to them?

Jstas

There wasn't much. I'll get better pictures today.

I grab these last week when I was unburying stuff in the barn loft. But now the "Bench of Healing" in the "Empire of Dirt" is cleared off and I can get one of these up there and in a better position to get better shots of it.

BTW, last I knew for these, they worked, no issues. They've been in storage for a while, not climate controlled but in a garage, collecting dust and cobwebs. It'd be cool to resurrect them but if they don't want to play fair, I'll at least do something with the cabinets if I can't find another pair of 12TRX drivers. And by do something with the cabinets I mean get new, modern drivers and a crossover system and make a working set of speakers in a nice vintage cabinet.

Oh and also, I was going to use my 11BM8 tube amp to power them. 8Wx2 is perfect for these.

mhardy6647

The 11BM8 amp should do quite nicely with those indeed.
I have one of those here, too (imagine that) and 1) I like the sound of it and 2) it is one of the quieter (in terms of hum/noise) vacuum tube amps in the house.

So, heres' what led me to speculate that you had the L-pad:

That twisted cable looks like the umbilicus that connects the L-pad (tweeter level control) to the speaker.
What's at the other end of it?

I'd ignore that little RCA plug thingy completely.

Jstas

I did not get better pictures yesterday, got tied up with work. Will get them today.

mhardy6647

any updates?
Does the speaker work? woofer and/or tweeter section?

Jstas

Sorry, got tied up with work BS last night. I'll get pictures up later today.

mhardy6647

Not a problem,
Render unto Caesar and all...

Jstas

Look!

Pixchurs!

pitdogg2

A very interesting piece there. I take it the speaker it was made for were the RCA type? My very first stereo was like that. Crazy thing going to Radio Shack or Musicland and buying 25' of speaker cable extensions.
Fun times!

mhardy6647

Well, the L-pad for the tweeter ("Brilliance") is clearly shown in the second photo.


As to the connections to the outside world...



Based on this, the hot (?) connector of each RCA jack is used for one side of the (fullrange) speaker wire; one +, the other - Presumably the one labeld "G" is the negative wire.



No idea what that male RCA terminated jumper is there for, though. I'd just disconnect all that cr@p and put a dual nanner in its place. You can trace the + and - leads back to the 12TRXB when you install the new terminal plate.


The two with red gaskets are "hot" (+); the other one's G (-).
Note that the two hot terminals (one for woofer, the other for tweeter) are tied together with a jumper.
You could biamp if you prefer

pitdogg2

pitdogg2 wrote: »

A very interesting piece there. I take it the speaker wire it was made for was the RCA type? My very first stereo was like that. (RCA speaker wire) Crazy thing going to Radio Shack or Musicland and buying 25' of speaker cable extensions.
Fun times!

Fixed it.

TennMan

pitdogg2 wrote: »

A very interesting piece there. I take it the speaker it was made for were the RCA type? My very first stereo was like that. Crazy thing going to Radio Shack or Musicland and buying 25' of speaker cable extensions.
Fun times!

My first stereo system was like that too. It had a turntable built into the top of the amp/receiver and it was connected to 2 small speakers with RCA plugs. I think it might have be a Sears brand. I thought it sounded great until I went to a store called HiFi House and heard what a real stereo system was supposed to sound like.

mhardy6647

Good ol' Radio Shack, for many years, would put both screw terminals and an RCA jack on the back of even some of their "better" (it's all relative, right?) loudspeakers.

The cabinets that @Jstas is asking about, though -- are just weird in their application of a dual RCA jack panel. By appearances, I am wondering if Cap't Halfa$$ was involved in wiring those Marquis cabinets?

The jumper on there is completely incomprehensible to me, too.

Jstas

Nah, these came from Mr. Grand who was equally as baffled. He had them up for sale for a period of time and no bites. Probably because nobody knew what they were or what the stupid dongle is for.

But these Marquis are pretty old. Like late 50s to mid-60s old. They were cutting edge at the time and like many high end speakers back then they could be had as a kit and we surmised that may have been the case with these.

Given that the rear panels are vented over the entirety, the speaker are pretty much operating open air because I doubt they have enough oomph to pressurize the cabinets to make tuning vis the vents possible.

Either way, I probably going to do exactly what Doc said and nanner plug them. Maybe even terminal cup them for bi-wiring potential.

If they still work. Will hopefully get that tested soon.

mhardy6647

They weren't exactly SOTA, but the folded corner horn (licensed from Col. Klipsch and his little eponymous company in Arkansas) was (still) the leader in good bass and efficiency in a (relatively) small enclosure. The 12TRX was their top 12 inch coax of the era; the 12TRXB is similar but built to a more modest price point, with smaller magnets and a less massive frame. As an aside, EV did, IMO/IME, get better sound out of the T35 tweeter family in their own coaxes than did many other loudspeaker manufacturers (lookin' at you, Klipsch!) using those same tweeters.

FWIW, EV's statement loudspeaker enclosure back then (and for many years afterwards) was the Patrician in its various incarnations.


http://www.hifilit.com/Electro-Voice/Electro-Voice.htm

As an aside, if'n any of you boys in the northeast stumble across a pair of EV Aristocrat enclosures in decent/restoreable condition... umm... let me know, 'K?


source: https://worldradiohistory.com/Archive-Catalogs/Allied-Catalogs/Allied-Catalog-1960.pdf

Jstas

I said cutting edge, not state of the art.

Coaxial style drivers were pretty new when these came out and this series of EV speakers was the first to use them. They weren't the most innovative use and they weren't the first or even only ones to use them. They just did like Polk and put fancy, new driver tech in an affordable package.

Jstas

Also, I saw a pair of Patricians on eBay when I was looking for pictures and I go on the Marquis. They were listed on Massachusetts although I don't remember what town. They might be still up. Just gotta search eBay for electro-voice patrician

pitdogg2

Here ya go.
Nothing cheap about these.

https://www.ebay.com/sch/i.html?_nkw=electro-voice+patrician+&_trksid=m5467.l1311

mhardy6647

Jstas wrote: »

I said cutting edge, not state of the art.

Coaxial style drivers were pretty new when these came out and this series of EV speakers was the first to use them. They weren't the most innovative use and they weren't the first or even only ones to use them. They just did like Polk and put fancy, new driver tech in an affordable package.

The EV coaxes weren't even close to cutting edge in their time, but I totally agree with your last statement. That they did. That they did.

"Coax technology" was about 15 years old at the time the EV coaxes debuted.
EDIT; 13 Years old, per the 1956 Radio Shack catalog. The Duplex debuted in 1943.
Note the price of the 15 incher! The Altec 604C Duplex in the same catalog was $156.


https://www.radioshackcatalogs.com/flipbook/1956_radioshack_catalog.html

FWIW, the EV "Wolverine" line was even a bigger bargain, and - other than a bit of sensitivity and some LF response, gave up very, very little to the SP and TRX and SP-B and TRXB series of drivers and coaxes. The later "Michigan" line were quite decent for their extremely modest cost.

Jensen, University, and Utah were also playing in the same space(s) at the same time -- Jensen's array of coaxial drivers from the 1950s into the 1970s is astonishingly deep and broad.

Jstas wrote: »

Also, I saw a pair of Patricians on eBay when I was looking for pictures and I go on the Marquis. They were listed on Massachusetts although I don't remember what town. They might be still up. Just gotta search eBay for electro-voice patrician

Don't tell me that!

Fortunately, there's no way I could physically get them into this house, which is probably for the best.

PS
Don't buy a Patrician! Gather up the components piecemeal and build your own!
https://www.ebay.com/itm/223643940245?hash=item341237b595:g:CXQAAOSwcGhdaSk5

Jstas

Ok, so, update.

They work.

Replaced the wires with 16 gauge speaker wire 'cause that's what I had sitting around. Pretty scientific, huh?

I tinned the wires and jammed them in to the posts on the drivers like Ken's documents said to.

Then I hooked them up to a NAD 902 because it's low power and gave it a signal from an oinker pre-amp using a cellphone as a source.

Color me impressed!

A bit weak on the low end but I was reluctant to give them the beans on the first trot out of the gate what with being dormant for so long.

So Imma hook up the 11BM8 tube amp later on and see what comes of it.

They are stupid sensitive though. Didn't get past 25% throttle on the Oinker before they started getting shouty.

But this is good as they are totally worth cleaning up as is.

Might replace the batting inside, though. Smells pretty strong of cigarettes and mustiness.

mhardy6647

They are very sensitive indeed.
Do be easy with the throttle.
They should work pretty nicely with the 11BM8 amp -- if it's the same one I have (and probably if it isn't, the same one, too!).

Jstas

Well, I changed sources and the bass response improved dramatically. I'm thinking that set of RCA cables from previous testing was bad.

But they were rocking pretty hard at 35% throttle. They were loud enough that the kids working on their Camaro were complaining it was too loud.

I'll mess with the 11BM8 amp tomorrow. Didn't get much time today stuffing a 350/350 combo into the Camaro.

And the 11BM8 is a kit I got many years ago now from Antique Electronics Supply, IIRC.

I'll have another update tomorrow and I'll probably be hitting up AES because they had the grille cloth for these. Hopefully they still do.

Jstas

I will say this.

I have an old RCA console stereo that needs restoring and if these EV 12TRXB drivers are that good, it's be worth finding another pair for the console stereo repair. 'Cause the RCA drivers in them weren't all that impressive. But with the modern compact electronics, I could build a Bluetooth based stereo that would power those 12TRXB drivers with 15 watts each in a space no bigger than a couple packs of cards. That leaves the rest of the space taken up by the current busted turntable and the busted receiver for other stuff...like a booze cabinet.

mhardy6647

The lesser (albeit less common) EV LT12 coax is a worthy 'plan B' for 12TRXBs if you can find 'em. They're usually considerably cheaper, and as far as I am concerned, not very inferior.

Of course, the non-B morph (12TRX) is a pretty serious choice -- not all that out of the leage of an Altec Duplex. Not common, though, and not cheap. Maybe cheap compared to classic Duplexes in this day and age, though. I don't think I have a single 12TRX, and I know I don't have a pair.

Jstas

So I hooked them up to my trust K502 model amplifier, the 11BM8 tube deal. I call it "The Bomb" because people always ask "What the hell is that?!?!" I casually say "My bomb." and they look at me like "Oh sh

---

, is he serious??"

Anyway, they were a bit flat at first and then the tubes warmed up sufficiently.

There was ample low end with the 11BM8 on most tracks, even the ones I was lamenting the other day.

These are not for near-field listening. Testing on the workbench, the drivers are firing at my stomach and off-axis response is good on anything below like 10K Hz but above that it's a sharp drop off.

However, point them at your face and there's all the highs! So you either have to angle them to the listening position or sit a significant distance from them. That's not a big deal though because even at 8 watts per channel, these things have a presence. I don't know how well they will pressurize a room but they had no problem duplicating a symphony or a bass drum. Just not going to get the low-end rumbling extension like you would with a sub.

Anyway, I ran through a bunch of material and as they loosened up and the amp warmed up, they smoothed out and got less shouty. They really liked the Oinker's tone controls though so maybe I try a different pre-amp later.

Either way, for speakers that are like 65 years old, they're pretty impressive.

Also, if you want to find out how good a horn is, play this track:

https://www.youtube.com/watch?v=KDurza1o2dA

It's going to expose all the harshness or lack thereoff with ease.

These Marquis on tube power are bright but honestly, pleasant to listen to.