Unidentified Speakers.....Can Anyone Shed Some Light?

[Atom Drop]

I notice the EQ on that receiver has the treble boosted quite a bit. Those old caps are probably eating up the treble with high ESR. New film caps almost always open up the top end on speakers this old.

Yeah that was the only way to get decent treble from them tweeters. Thanks for informing about it being due to the old caps on them tweeters. So how do you suggest I replace them? Do I remove the old caps and replace with the same rating caps? Or does the label on the back of the cabinet shed light on what I can do with those tweeters? The label said 8 ohms 34 watts rms max. Thanks for your advice and expertise. I greatly appreciate you toxcrusadr.

 

[Atom Drop]

I sold mine off, it was hissy too, and not enough watts for my speakers at the time. The eq section was also incredibly strange sounding, you can make the music wah like a guitar pedal, but JVC used inductors instead of transistors for the EQ section, so thats probably why.

It's an interesting receiver. I found that I had to turn the volume up to three quarters of the way up for sound. The four speakers I had connected to shouldn't have eaten up too much power. So the JVC is under powered just as you experienced with it. The 4 channel matrix speaker mode definitely produced some different sound effects with that S.E.A. equalizer. I think that it's pretty cool that you had this same receiver.

 

[slimecity]

Same rating ideally, get a specialised crossover speaker cap. IN this application I'd imagine generally a 3.3 or 4.7uF cap. Get a film cap, something like this:

https://www.parts-express.com/dayton-audio-dmpc-47-47uf-250v-polypropylene-capacitor--027-422

 

[Gazdatronik]

It's an interesting receiver. I found that I had to turn the volume up to three quarters of the way up for sound. The four speakers I had connected to shouldn't have eaten up too much power. So the JVC is under powered just as you experienced with it. The 4 channel matrix speaker mode definitely produced some different sound effects with that S.E.A. equalizer. I think that it's pretty cool that you had this same receiver.

Yes, i believe the unit only made about twentysomething watts per channel in quad and fortysomething in 2ch mode.
Unfortunately, those jvc's require speakers with ohmage that doesnt drop too low in 2ch mode, since it bridges the amplifiers internally, and you lose half of your low impedance stability that way. All bridged amps do this.

Since I run 6 ohm nominal transmission line speakers, which can dip down to 2 ohms or less, at some frequencies, I would have fried that amp in a short time.

 

[toxcrusadr]

Ditto on the Dayton caps from Parts Express. Remove the woofer (that's usually the way in) and see what you find. They may be on the input connector board or soldered onto the drivers. Match the uf rating as close as possible (you can get most any value but +/- 10% is OK if you can't - or you can parallel caps and add their uf ratings). The voltage rating doesn't matter as long as it's at least as high as the originals. The Daytons are 250V and most vintage speakers have caps rated 50V or 100V.

 

[faber12]

I slightly agree with nolasally, mostly because I have a basement room that is full of mediocre gear. I try to only buy now if it will be an upgrade from what I already have.

On the other hand, $20 is not much to spend to have some fun. There are much worse things you could be spending it on.

I would probably use the electrolytic capacitors from Parts-Express to recap those speakers.

Those look pretty decent, the tweeters look good, and the woofer magnets are reasonable. Some don't like the rolled off highs of a paper cone tweeter, I find them to be a little less fatiguing than many.

I got a chuckle from your speaker stacks. I only caution you about making sure they do not fall over due to pets/guests/family members. The speakers can be replaced, someone's foot, not so much.

 

[Atom Drop]

Same rating ideally, get a specialised crossover speaker cap. IN this application I'd imagine generally a 3.3 or 4.7uF cap. Get a film cap, something like this:

https://www.parts-express.com/dayton-audio-dmpc-47-47uf-250v-polypropylene-capacitor--027-422

Thank you, slimecity. I appreciate the information and the web link. Looks like parts express is the place to go for caps and other electronic needs. I also appreciate your simple advice. My employment supervisor went to school for electronic engineering. Anytime I ask him for advice, he goes into this huge explanation of information that leaves my head spinning and without any useful help. Especially the language and or terminology used by him makes no sense to me right now.

 

[Atom Drop]

Yes, i believe the unit only made about twentysomething watts per channel in quad and fortysomething in 2ch mode.
Unfortunately, those jvc's require speakers with ohmage that doesnt drop too low in 2ch mode, since it bridges the amplifiers internally, and you lose half of your low impedance stability that way. All bridged amps do this.

Since I run 6 ohm nominal transmission line speakers, which can dip down to 2 ohms or less, at some frequencies, I would have fried that amp in a short time.

I wander which speakers JVC designed for this particular amp. I am curious enough to peek through an old JVC catalog from the same year model as this receiver. It would have to be from 1973. Do you know if JVC made audiophile speakers at that time? Or at any time?

 

[Atom Drop]

Ditto on the Dayton caps from Parts Express. Remove the woofer (that's usually the way in) and see what you find. They may be on the input connector board or soldered onto the drivers. Match the uf rating as close as possible (you can get most any value but +/- 10% is OK if you can't - or you can parallel caps and add their uf ratings). The voltage rating doesn't matter as long as it's at least as high as the originals. The Daytons are 250V and most vintage speakers have caps rated 50V or 100V.

Okay thanks toxcrusadr. I will have to go deeper into the cabs very carefully and get my hands on the supplied caps. I would then love to learn on how to test the caps with a multimeter. I just purchased my first multimeter and am eager to perform a first test of some sort. Especially with speakers.

 

[Atom Drop]

I slightly agree with nolasally, mostly because I have a basement room that is full of mediocre gear. I try to only buy now if it will be an upgrade from what I already have.

On the other hand, $20 is not much to spend to have some fun. There are much worse things you could be spending it on.

I would probably use the electrolytic capacitors from Parts-Express to recap those speakers.

Those look pretty decent, the tweeters look good, and the woofer magnets are reasonable. Some don't like the rolled off highs of a paper cone tweeter, I find them to be a little less fatiguing than many.

I got a chuckle from your speaker stacks. I only caution you about making sure they do not fall over due to pets/guests/family members. The speakers can be replaced, someone's foot, not so much.

Haha on that speaker stack, faber12. I no longer have it like that. It was in my bedroom and no pets. Lol. I have since obtained some different speakers that I have stacked, but not so dangerously high. And the $20 for the speakers have been well worth the amount of knowledge I am getting since starting this thread. Because of these speaker I am now a member on here. It was meant to be. They're growing on me and I can't to recap them soon.

 

[Gazdatronik]

Maybe closer to mid-fi speakers, but they would have been fairly efficient to work well with very few watts. Most stereos were like that anyway. The monster reciever wars didn't happen until a few years later.

 

[toxcrusadr]

If your meter has a capacitance feature, you can measure both the old and new caps. Keep in mind they may not have drifted much in capacitance but there are other measurements like ESR that require a specialized meter.

You can also check the DC resistance of the speaker drivers. It will be lower than the AC impedance so a nominal 8 ohm driver will usually measure about 5 ohms. The exact value isn't so important but they should match rather close between speakers. Of course if you find one with infinite resistance it's got a burnt voice coil or a loose wire.

If the cap is below about 10-15 uf I would go with the metallized polyprop, higher values the nonpolar electrolytic (NPE) is much smaller and cheaper.