Pimp my JVC SX-911. Good thing or blasphemy?

[Amilius One]

Hi! I'm new to the scene! I have a beautiful pair of these monstrous (30Kg piece) speakers from the early 80's that I'm thinking of customizing just a little. They're flawless in looks but the bass is a little dry and the mid-range is a bit "canned up" (as in "sounds trapped, like in a can"). Would it be a good idea to clothe it internally with some dampening material and mount a bass reflex pipe to the back - also - replace the old connectors with new gold plated speaker connectors for use with banana plugs?? Or should i just try to punch it up with an EQ instead, not to ruin the vintageality of the set? Also, I haven't found any posts or threads on these speakers on the forum. Am I the only one who has them? Image is not mine.

 

[pauldrewry]

How old are they? Your problems could be from old caps in the crossover.

 

[Amilius One]

Thank you for the info. I'd say the speakers are at least +20 years old. What's meant by the "crossover" and what is fixed by replacing the caps? Thx.

 

[aidynphoenix]

the crossover is most likley a small board inside the box with a component or two on it.. most likley there is a capacitor or two, and there may be a inductor..
capacitors look like a tiny beercan and the inductor might look like a coil of wire (might be shrinkwrapped)

now what i would do is inspect the crossover and read all the ratings of the capicators,
might be something like 3.3UF 100v or something.. they might be rated in MDF which is the same thing.

anyways usually caps are used to filter out sounds so they dont reach the speakers that shouldent be making it. the caps are most likley responsible for the tweeter and midrange sound.. and the inductor is what filters the high sounds from reaching your woofer..
however a cap can still be used to filter highs from a woofer. but i dont think it is as common..


i would definetly not port your speakers doing so can destroy your woofer by making it bottom out or break your spider or surround. if they are shy on the low end, i would add another pair of speakers that you could use to give that extra thump or warmness to your sound.. equalizing the sound might do the trick too, but it may be more dangerious to play your speakers at high volumes like that.

something else you might want to consider, if all the wireing inside your speakers is really thin and crappy or if the wire ends look green or like they have any corosion on them. i would replace all the internal wireing to something you like better.

 

[MunkeyQ]

Don't port it without doing any calculations - playing with the cabinet tuning without planning will certainly result in them sounding worse. If you know the T/S parameters of the woofers and have measured the internal cabinet volume, you can plug the numbers into a box modelling program and run some simulations with a port to see if it improves the bass response.

However, those look like a fairly well-made pair of speakers so the woofers probably play best in a sealed box as they are.

As the others said, replacing the capacitors in the crossover is a good idea. The crossover is the electronic circuit which filters the frequencies going to each driver to ensure they only get the correct range. In that circuit, there will be capacitors and if they aren't the film sort, they degrade with age, affecting the sound. Replacing the capacitors often improves the midrange and treble a lot.

 

[geiman]

Those sure look good! The cosmetics are great for 20 years old.
You might do a google search on that JVC model number and see what comes up.
Chances are someone else may have some improvements that have worked for this speaker.
My guess that the mid range "canniness" may have to do with the crossover capacitors.
Change them out or have someone do it if you lack the tools ect. If there are level controls for mid and tweeter you might clean them with electronic spray cleaner, (AKA Deoxit D-5).
Do a thread search on this forum for your model, From what I've found these are high quality speakers, carbon fibre woofer cones cast frames machined mounting rings ect. Sold in the Japanese home market under the Victor brand. Forum member Suzuki might be able to give you his input.
I wouldn't hack these up. they're too good!
BTW don't mod this speaker until it is operating correctly first, then evaluate and make improvements/changes. They might be very good to start with!

 

[michiganpat]

when you open them up, check out the stuffing that's in it..if it's foam or poly-fill (like stuffing in a pillow), you could play around with amount of stuffing, or replacing it with fiberglass insulation, playing the the amount.

 

[Amilius One]

Thanks for the feedback all of you! I will definetly check out the capacitors and wiring to see if improvements can be made. Should I go for the same specs on the caps or would it be preferable to have a lower or higher value to brighten up the mids? I've done some soldering before so hopefully it shouldn't be that much of a fuzz. Also, should i replace the back connectors to banana-plug types? I'll get in touch with Suzuki as well to see if he's got some info. Thanks again!

 

[aidynphoenix]

i would go with the same UF rating as the origional caps. or as close as possible.
inorder to know what those caps are used for we need a drawing or schmatic of the crossover..
its likley that if you recap, replace internal wiring, than maybe play with the internal dampening material possibly adding more you might be able to get them to sound better..
if the hookups on the back are of poor quality i would consider replacing them.
if they are push or spring type i would replace them. you want to get good contact there.

 

[aidynphoenix]

SX-911:
Super Digifine speaker system
— 12" cloth carbon woofer
— 4-1/2" fine cloth carbon midrange
— 1" amorphous diamond coated tweeter
— 150 watts power handling 300 max
— Weight: 62.8 lbs
— Width: 15" Height: 26 3/16" Depth: 13 7/8"

-Sealed enclosure
-91dB sensitivity
-6ohm
-40Hz-50 000Hz
X-over 500Hz and 4kHz
-Alnico magnets
-Ellipse front baffle

 

[VINTAGEO]

Old thread revival alert!!
Do you still have these speakers?
I'd like to buy some, but not many available, I have the digifine system, Amp, tuner, cd player, and cassette deck

 

[Ds2000]

There was a set for sale in bartertown a little while back.

 

[VINTAGEO]

I searched, nothing..

 

[Ds2000]

I just did too, they sold. Sorry about the false hope.

 

[VINTAGEO]

No worries, thanks

 

[GD70]

These are a very nice set of speakers. Hope you find some in the U.S of A. More common in Japan.
If you check out jauce.com, Yahoo Japan, type in Victor speakers. Often model numbers are different in Japan for the same speaker sold in the U.S. market.

http://www.jauce.com/auction/b224230755

 

[SaturationPt]

Mine were the ones in Bartertown, they sat there for a month or two and I ended up selling them on evilbay. Great speakers, but not easy to find.

 

[AudioSoul]

Thank you for the info. I'd say the speakers are at least +20 years old. What's meant by the "crossover" and what is fixed by replacing the caps? Thx.

If they are from the eighties they are a lot older than 20 yrs. Many of the mainstream audio companies made some pretty bad equipment. They were trying to appeal to the average consumer. So they built average equipment now that they had established a name for themselves. People were buying this crap based on the name alone. Now, I am not saying this applies to you situation but something to consider when things don't sound right....

 

[GD70]

^^ Not the case with these speakers. Hi end and desirable.

 

[SaturationPt]

Built 1991, they were some very well designed and built speakers, cabinets, etc.

Alnico magnets, cast aluminum baskets, amophous-diamond coated titanium tweeters, carbon-fiber woofers, 1" thick HD particle board, 3 separate crossovers, ... pretty hard to compare to the cheap stuff of the era.