“Let our rigorous testing and reviews be your guidelines to A/V equipment – not marketing slogans”
Facebook Youtube Twitter instagram pinterest

JBL Vintage Speaker Restoration Continued

By

When my speakers arrived back, they also included an itemized list of services performed in the bill of receipt.

AudioholicsQuote.jpg

So for under $90, I got my pair of vintage JBL speakers fully restored to factory brand new condition, perhaps a little bit better. They definitely looked much cleaner and newer thanks to the courtesy cleaning of the cabinets they performed prior to shipping them back to me. Before I brought my speakers to Simply Speakers for restoration, I pulled a nearfield measurement. I wanted to compare the before and after response which is illustrated below.

JBL-Pro3-measurement.JPG

JBL Pro III before (purple trace) /after (brown trace) Frequency response
(mic 6” from acoustics center, 1/6th octave smoothing)

Granted this wasn’t a very precise measurement as I couldn’t assure the mic was in the exact same position both times but it does show a clear improvement in bass response below 100Hz after the fix. The high frequency response looks slightly elevated which could be a result of the lower ESR capacitor that is now used in the tweeters HPF.

Wrap Up

JBL Pro III Completed.JPGIt was time to hook these babies back up and hear the end results. I did the listening evaluation prior to my measurements so I could eliminate any bias based on the before and after results. I pulled up my favorite artists on Pandora and let it rip. I immediately noticed the much tighter and cleaner bass response the JBL Pro III’s were reproducing. The speakers played loud and clear and I heard no hint of woofer buzz or distress like I had before. I subjectively felt the top end may have been somewhat more lively but without doing a direct A/B comparison there was no way of telling.

Overall I was very pleased with the results. Restoring my JBL Pro III’s gave me a new appreciation for how good these little speakers really are. We tend to get so caught up in upgrading our A/V gear to the latest and greatest, but sometimes it pays to hang on to something that was well engineered. Simply Speakers did a first rate job from start to finish. They treated me with utmost respect and courtesy despite this was a low wage job for them. They proved to me that it’s hip to be vintage. If you’ve got some old speakers lying around that you’re fond of in need of a little TLC, I highly recommend Simply Speakers as your #1 choice for the task.

About Simply Speakers
Simply Speakers was formed in 1992 as a result of a need in our area of Florida for a factory authorized loudspeaker service center. We saw potential to gather a national and worldwide audience with advertising in national magazines like Stereo Review, Audio and Popular Science. Over time, we have built a loyal following for our customers who wish to maintain their vintage audio speakers. We offer services to electronic repair centers and consumers from our area and around the world. Our specialties include speaker refoaming (edge replacement), speaker reconing (full rebuild, including voice coil, spider, cone, surround and dust cap), replacement woofers, midranges, tweeters, horns, and diaphragms. Finally, we sell a line of replacement foam edge kits, recone kits, grill fabrics, and accessories.

 

Confused about what AV Gear to buy or how to set it up? Join our Exclusive Audioholics E-Book Membership Program!

Recent Forum Posts:

tintasbarnes posts on November 09, 2011 05:13
Jbl

Thanks for replies, I think I will sacrifice $50-$80 for a pair of swap speakers…just to feed my curiosity.
sawzalot posts on November 08, 2011 18:32
mattsk8, post: 840069
This is a 2 year old thread BTW !

Old Thread - Old Speakers, All Vintage and as always- All Good

I too regret parting out/ tossing out older vintage speakers in my early HT days but I had no Idea :o.
Pyrrho posts on November 08, 2011 12:47
mattsk8, post: 840069
I've never had good luck w/ rebuilt woofers. It always seems like they loose bass responce after they're rebuilt. I've had 3 pair done. Some MA Pro 8“ woofers (just had the foam surround replaced), some Cerwin Vega 8” woofers (blew one and had it rebuilt), and some Kickers. To me they never sounded as good after they were rebuilt. Could this just be a poor job or wrong material? I kinda gave up on speaker repair but maybe I just need a better shop??

This is a 2 year old thread BTW !

I have had excellent luck with repairs; I have used Millersound.

If the wrong materials are used (e.g., improper size of surround, etc.), or if they do it wrong, then it could adversely affect the performance of a speaker. Done right, it restores them to like new performance.
mattsk8 posts on November 07, 2011 14:34
I've never had good luck w/ rebuilt woofers. It always seems like they loose bass responce after they're rebuilt. I've had 3 pair done. Some MA Pro 8“ woofers (just had the foam surround replaced), some Cerwin Vega 8” woofers (blew one and had it rebuilt), and some Kickers. To me they never sounded as good after they were rebuilt. Could this just be a poor job or wrong material? I kinda gave up on speaker repair but maybe I just need a better shop??

This is a 2 year old thread BTW !
tintasbarnes posts on November 07, 2011 04:56
Great article! I also have some of these sweet boxes. Sadly one of my speakers has his paper pretty much worn out.

Question: where can I buy some swap speakers?

On ebay I didn't find any. I was searching after similarities and I've found this:

GW5028S Shielded Magnet Woofer
T/S Parameters

Z:8 ohms
Re:7.1 Ohms
Fs:80.1 Hz
Qms:3.9
Qes:1.2
Qts:0.9
Vas:4.2 Ltr
Sens:85 dB

Do you think it will do it?

(I'm not allowed to paste the link of the speaker since I'm new to this forum)

Thanks!
Post Reply