Jensen System B Can they really sound as good as they do?

[happy]

I bought a pair of Jensen System C from a guy in a parking lot in 1982 at college, and they have been my main speakers, teamed with a Pioneer SX-3900 since then. I toasted a few parts, since although rated at 125 watts, the SX-3900 was rated at 120, and the Pioneer won a few times. I had them fixed under warranty at least twice, and I still listen to them practically every day. I want to recap them, and probably have to replace a L-pad or two, and I know I put in some junk rear facing tweeter at some time.

if you find any information about the System C, I would really like to see it.

 

[soundmotor]

You've got a lot of re-capping to do.

Those may be film caps in there already and not electrolytics. They are all marked with AC voltage ratings. I believe they are motor-start or switch snubber types. Just sayin......

 

[shrinkboy]

hey, i'd be tickled pink if i found those...

 

[ARRAY]

AAAHAHH Jfzea Thank you.. That is the first I've seen.

And to be honest Array, I dont know if I would actually call them "Warm".

Usually when I think "Warm" I tend to think slightly rolled off although not quite enough to complain.. And these definitely arent. Though far from bright (which I have some Polks that are a bit-bright and these arent arent anywhere near bright)

But if you turn down the mid and tweet controls then the do become "Warm",.. but set to "0" or neutral,.. I wouldnt accuse them of being warm.. Though I guess to be fair, if you had to chose either Perfectly Flat, toward Bright, or toward Warm,. then yeah,.. I could see making the call toward Warm rather than Bright.

And Musical is always a term I found kind of confusing as (like most things people use it differently and subjectively) I will say what does suprise me about these that they may have called "musical" is the fact that the strange resin/plastic? casing actually has a very nice ressonance or tone to it. That might have been very intentional. I dont know. I cant imagine any other reason you would use plastic or resin on a speaker you meant to compete with the top of the lines..

Warm and Musical? I dont know. But so far I like them.

I'll find out about the drivers soon.

Thanks all for helping me figure them out.

Hi Fau, I agree that these adjectives are confusing, subjective
and way overused & misused which is why I don't use them. As a designer and listener, instead I use descriptors such as transient response, frequency response, extension, smoothness, dispersion etc to objectively describe sonics with respect to realism of loudspeakers and other equipment when applicable. I'm interested in how exacting the playback performance of the source material is no matter how good or bad the original recording is (and hopefully it's good!). I agree with Gordon Holt in his assessment of the original audio "purist" goal for the most part and in any case I'm glad he felt the same about losing sight of the aim.

But, I'm sidetracking this thread... I was wondering if it was easy for you to yank a tweeter and post up a snapshot of the front and back. If not, no problemo. Four scews should be a snap unless they're glued in there (heaven forbid).

 

[fau5tu5]

I'll try to grab a pic Array.

Film Capacitors???
Why does that just sound like another way of saying "Expensive and hard to find"?

Dont mind the layman here,. But I would LOVE to hear that the Film Capacitors, last longer and fail less, and likely arent the problem.. and that it's likely just a short or busted solder or something.. Leaving me only needing to refoam and enjoy..

?? ?? any chance ?? ?? (I'm not looking forward to the idea of having to hunt down and then replace all of those, especially if they are rare and pricey)

 

[ARRAY]

I'll try to grab a pic Array.

Film Capacitors???
Why does that just sound like another way of saying "Expensive and hard to find"?

Dont mind the layman here,. But I would LOVE to hear that the Film Capacitors, last longer and fail less, and likely arent the problem.. and that it's likely just a short or busted solder or something.. Leaving me only needing to refoam and enjoy..

?? ?? any chance ?? ?? (I'm not looking forward to the idea of having to hunt down and then replace all of those, especially if they are rare and pricey)

Hello Fau, sounds good. Whenever's convenient.

 

[fau5tu5]

Thanks again Array.. Thats what I wanted to hear ..

I'll have your answer about the tweeter/mid drivers soon.

And happy, let me know what exactly you would like to know, so I can know what to find out while on my hunt.

 

[jfzea]

Though I guess to be fair, if you had to chose either Perfectly Flat, toward Bright, or toward Warm,. then yeah,.. I could see making the call toward Warm rather than Bright.

Warm and Musical? I dont know. But so far I like them.

About the high frequency I think It's not a bright speaker, to me this is better because you can hear them more time with no fatigue.

As I told before the bass and midrange are good and I'd say "balanced" in one word. Probably not to hear effects coming from a movie but to hear music it's OK. And the price you payed is better. I remember some years ago, not more than 2 or 3, the price was higher than $500.

I was checking some old "Stereo Review" publications and I found a test for the model 400 or 500 of the same series. I'll try to scan it and put it here is someone is interested.

 

[fau5tu5]

You callin my speaker dumb jfzea???

j/k. Couldnt pass that one up.

 

[fau5tu5]

found this on ebay.. .. Now ladies and gentlemen.. THAT is some HAIR.

 

[Trower]

Hmmm they sound like winners warm smooth, I like those words

 

[jfzea]

You callin my speaker dumb jfzea???

j/k. Couldnt pass that one up.

Not at all, it's a very good speaker to my taste. Call it dumd is like call dumb to the Dynaco A25s.

How do you feel it at high levels, specially the bass and midrange ?

 

[jfzea]

I found a quick test in the Stereo Review magazine. It's about the model 400. Anyway it'll give more idea of the sound of this series.
In the comments you'll read that this is a smooth and uncolored sounding speaker.

 

[fau5tu5]

Well,.. To my amazement, and thanks to "a little bird who wispered in my ear" who I wont mention I was put in contact with the original designer of the speakers. How often does that happen???

Anyway he is going to scan me what info he has and answer any issues. ( I dont know.. thats kinda like a transferred 30 year tech support warranty)

So to answer a few questions that have come up:
1. Upper Mid, and Tweeter are indeed Audax.
MunkyQ you win that one.

2. The Woofer and lower mid were specifically designed for the speakers by the designer and produced by Rola

3. The Capacitors are "A" rated Film. ( which was explained as being smooth rather than rippled, of which the rippling increased surface area and required less film and a smaller size for a given capacitance.) That explains something, thought I'll admit, I'm not sure what.. But I think.. uh.. good?

I'll get more data soon, and need to refoam, and figure out the Mid-Bass issue in one. Also considering swapping out the terminals with more significant binding posts.

I didnt expect this much fun from a $25.00 garage find.

 

[ARRAY]

Ah ok, thank you for taking out the time to determine the identity of those Tweeters.

 

[fau5tu5]

I have actually been in contact with the original designer of these speakers..

He got me some more info and I asked more questions.. He mentioned that in fact one of the tweeter or mid "May actually be" Panasonic (as Array thought) I guess they used a variety of different units in the "System" line..I guess I will need to go ahead and pull them all to be sure.

He also gave me these...

That end to that next to last sentence in the "High Fidelity" review was a bit surprising,.. Though reviews always tend to go extremely favorable, neutral or negative... I didnt expect them to say "to our ears, the best speaker the company has ever made" .

Thats pretty bold, even for a HiFi review...

$25.00??? (not counting whatever repairs cost) and direct communication with the original designer.... I think I ended up doing ok on this deal

 

[ARRAY]

I have actually been in contact with the original designer of these speakers..

He got me some more info and I asked more questions.. He mentioned that in fact one of the tweeter or mid "May actually be" Panasonic (as Array thought) I guess they used a variety of different units in the "System" line..I guess I will need to go ahead and pull them all to be sure.

Ok Fau, we simply must get to the bottom of this tweeter mystery. Pull a tweeter without disconnecting it (if you don't want) and see if it's possible to take a snapshot of the rear.

 

[happy]

fau5tu5

Can you ask the designer if he has any information about the System C?

 

[fau5tu5]

What would you like me to ask him? I believe he was the designer for that whole line, I know he was also the designer of the System C.. In fact he still uses a pair of those he says.

 

[fau5tu5]

All right.. Definitives.. on some drivers.

Ok if everyone is right???

The Woofer is a Unique and custom build for that speaker (System B) and I'll quote the response when asking if there was anything I needed to be aware of if I was going to have the drivers rebuilt " PRETTY STANDARD CONSTRUCTION AND PARTS, ALTHOUGH CONE MASS IS QUITE HIGH IN ORDER TO ACHIEVE REQUIRED MOVING MASS FOR THIS BASS ALIGNMENT. VOICE COIL IN WOOFER IS UNUSUAL – 2” DIAMETER, 1” WINDING LENGTH FOR HIGH POWER HANDLING, LOW DISTORTION."

The strange "Plasic/Resin/ PVC like material" that the a 3/4 the cabinet is made of is unique "Structural Foam". Supposedly was thought to be a wonder material and the wave of the future. But too pricey, and they went back to particle board for everything else.

Ok.. Now for the mystery Mid/Tweeters.. Pix below.. The Tweeter looks to be made in Japan (havent looked it up,) but the MID, is a French made Polydax/Audax.

So I guess everyone was right...

So there you have it.. With Audax mid, Custom woofer/mid bass drivers, (yet to be determined tweet, let me know if you know what it is) unique structural foam casing, and smooth film capacitors in a rather complex crossover configuration.. the Jensen System B, seems to be a strange but enjoyable bird indeed. Thanks for ALL the help and fun AKers... Wouldnt be 1/5th the fun without you.

Now just find me a couple more pairs for the same price.. (as well as some System C's )