If the cabs and drivers are shot, save your money, toss them, and buy working speakers.
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Jennings Research speakers 70s - info needed
- Thread starter cortico
- Start date
dogwan
Dogwan
I kind of have to agree. As much as I like saving things, especially vintage speakers, I didn't find these Jennings to be anything special other than the unique cabinets. I was in the same boat trying to find a compatible replacement for one of the woofers and I never did find anything contemporary that was compatible.
Also, I found the recessed grill section to look nice, but it created horrible diffraction issues with the tweeters. And the internal dimensions of a squared column cabinet with it's equal sets (front to back and side to side) of parallel inner surfaces seemed like an extremely poor design choice for standing wave issues. I didn't spend a whole lot of time trying solve these issues since there are so many great speakers from the same era that were designed properly. If only I knew then what I know now I don't think I would have wasted as much time on them.
PS, as a former professional cabinetmaker I can vouch for the fact that the pivot bases are shoddy particle board construction that was also doomed to failure.
In my opinion there's a reason these didn't last long on the market. Yet, I don't want to be discouraging, so really do wish anyone luck restoring a pair. They are neat looking.
Cheers!
JarredCrowe
AK's drunk troublemaker
It's a conflicting thing for me. Their condition is poor and they have suffered abuse. I also have more than one set of much better speakers.
However there is a family connection to them, that while not completely positive, I feel somewhat beholden to. Thats why I haven't been able to part with them, at least yet.
However there is a family connection to them, that while not completely positive, I feel somewhat beholden to. Thats why I haven't been able to part with them, at least yet.
superdog
AK Member
I found these for$20.Jennings Contrara Mk II In very good condition but one tweeter was dead then the other went.Decent sounding speakers.Im going to follow the recommendation of using a Kenwood 3500 amp since I have one.
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dogwan
Dogwan
HiFi in WYO
The universe is a big place, perhaps the biggest.
Well? It's been a few months - have you done anything with them?
JarredCrowe
AK's drunk troublemaker
I haven't done a thing with them. I lucked into a pair of revels locally and they have displaced my other speakers. I wish I had someone locally to give them too. Instead of hanging on for no reason.
Ziinda
Active Member
I like that "displaced" it sounds so much nicer than "makes my other speakers sound like ****! "
Giarcpnw
Active Member
Bringing this back, I just grabbed a pair of these Contrara pedestals. Missing the original peerless tweeters. I threw in the ADS tweets from my L520s to try these. Close enough. The speakers are ok but bright and lacking bass. Mids seems lifted. I did order the 8uf crossover caps so hoping that helps smooth the mids and highs.....but also a bit confused on the two woofers. The middle driver seems to be carrying the brunt of the frequency range. Bass and mids. The lower woofer is def limited to the lower frequencies but they aren't driving as hard as the middle one. Is it a passive woofer? I thought it would be carrying the kick and bass range more and it just seems muted vs the upper woofer.
Since the inductors are cutting the frequencies here there's now way to fix that is there?
C
Since the inductors are cutting the frequencies here there's now way to fix that is there?
C
It's not unusual to have two woofers with different crossovers frequencies in order to not have multiple sources for the midrange. I'd check to see that when the woofers are in phase, both speaker to speaker and woofer to woofer. I don't know if the surrounds are foam or butyl, but if foam, they will have been refoamed, perhaps several times, and who knows what happened to the wiring?
Giarcpnw
Active Member
Annnnnnnd…. Now I know why they sound weird.
This is not the oem crossover. Im guessing the crossover points are probably not that same either.
Sometimes when the price is too good there’s a reason.
Woofer surrounds are butyl.
I guess I could rebuild the original crossovers. Not sure these are going to be worth it though. The schematic is in this thread. But with the added cost of also buying peerless tweeters this may not make financial sense.
Wish I could hear what these were like stock to make that decision.
This is not the oem crossover. Im guessing the crossover points are probably not that same either.
Sometimes when the price is too good there’s a reason.
Woofer surrounds are butyl.
I guess I could rebuild the original crossovers. Not sure these are going to be worth it though. The schematic is in this thread. But with the added cost of also buying peerless tweeters this may not make financial sense.
Wish I could hear what these were like stock to make that decision.
Oof. Part them out.
dogwan
Dogwan
Geez, that sucks. Looks like a straight 3-way crossover, which as you are figuring out is not "right" for these speakers. They are 2-1/2 way design with one woofer covering mids down through bass with natural roll off. And the lower woofer re-enforcing the lower bass (probably also providing baffle step correction). So no wonder they are lacking bass.
If you're interested in restoring these I still have the air-core inductors I removed from the pair that I parted out. Send me a PM and I'll go dig them out of storage.
BTW, how are the cabinets? Pics?
The appeal of these speakers is largely due to the cabinets, but they were thought to sound quite good. So, to me, rebuilding them seems like a reasonable choice. Crossover components don't need to be expensive, especially if dogwan will provide the inductors (which can be expensive). You don't have to use fancy caps - the originals were probably electrolytics and using them will preserve the original voicing of the speaker - film caps typically have lower ESD so usually result in a brighter speaker, which, of course, some people like. If you use electrolytics and decide you would like to switch, you can always do so, and you won't be out much money, whereas going for the expensive caps and regretting it will be more costly.
Giarcpnw
Active Member
Ok, i'm about to rebuild my crossovers. Double checking that L1 inductors is in series on the tweeter correct? Bridging both positive and negative AFTER the capacitor?
The other two inductors are parallel to their respective drivers? What is the purpose of the tweeters inductor bridging like that?
ALSO..... Dogwan was so gracious enough to send me his remaining inductors, (thank you again) but had used one on another project so I had to replace one of the .53 inductors. (actually .52 on the actual inductors) I could not find .52mH so i had to settle for .50mH at 18awg vs 14 or 16awg on the originals.
My question is..... should I use this new inductor on the tweeter or the midrange? And will that .02mH make a diff anywhere in the crossovers that is better suited in one position over the other.
Thanks so much on the help. The cab refab is coming along nicely. Painting the bases tonight and have cleaned and sanded the main cabs for reoiling. Pics soon.