Hi.
I've been sitting on repairing these Jensen LS 2b Loudspeakers for awhile & decided to make a start.
When they were given to me the foam on the woofers had turned to dust.
Also the speaker terminal bracket/spades was pulled off tearing the hair thin wires feeding the cone.
I successfully re foamed the woofers yesterday.
To do this I sliced off the dust caps so I could place strips in the voice coil gap to make sure the voice coil was centred.
Today I re glued the dust caps, and doped the cones with a thin coating of Mod Podge.
While apart I noticed these have 3.7μF electrolytic caps (fixed to the rear terminal pane) which service the tweeters.
Do you think I'll be able to get away with 2 x 2μF electrolytic caps in parallel per speaker?
What would an extra 0.3μF tend to do to the reproduction of a Tweeter?
Also, although these are sealed boxes (not ported), there is only a thin layer of acoustic material lining the rear of each box.
Should I fully stuff these boxes with material?
thanks
I've been sitting on repairing these Jensen LS 2b Loudspeakers for awhile & decided to make a start.
When they were given to me the foam on the woofers had turned to dust.
Also the speaker terminal bracket/spades was pulled off tearing the hair thin wires feeding the cone.
I successfully re foamed the woofers yesterday.
To do this I sliced off the dust caps so I could place strips in the voice coil gap to make sure the voice coil was centred.
Today I re glued the dust caps, and doped the cones with a thin coating of Mod Podge.
While apart I noticed these have 3.7μF electrolytic caps (fixed to the rear terminal pane) which service the tweeters.
Do you think I'll be able to get away with 2 x 2μF electrolytic caps in parallel per speaker?
What would an extra 0.3μF tend to do to the reproduction of a Tweeter?
Also, although these are sealed boxes (not ported), there is only a thin layer of acoustic material lining the rear of each box.
Should I fully stuff these boxes with material?
thanks
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The small difference will be ok, more interested in your opinion on tweeter level etc. Sometimes this is an opportunity for an inductor each for the woofer and tweeter.
First would be to try padding the tweeter with a resistor, unless it doesn't need it. If you then find the midrange troublesome you could try first order on the woofer and second on the tweeter.
Thanks Allen.
Technically, that's when it gets over my head.
Unfortunately I don't have the technical knowledge to assess and apply what you're describing.
Initially, why would a resistor assist?
What issue am I trying to correct by adding a resistor?
The ability to hear the tweeter as being a separate driver, harsh treble, an audible disconnect in the blend at the crossover. Any of the above.
Is another way of dealing with this "harsh treble, an audible disconnect in the blend at the crossover" , is to fit an electrolytic cap rather than a poly cap?
It was said earlier that upgrading electrolytic caps with poly caps in old speakers can result in overly bright reproduction.
It does effectively add resistance and that should be accounted for, however I don't approach things that way in this particular kind of circuit.. It doesn't make sense to change capacitors until you find one with the right amount of resistance. The right way is to adjust the resistor to work together with the capacitor.
An earlier attempt of mine in trying to tame harsh treble by using resistors resulted in the neutering of highs.
Particularly the highs of lead guitars.
The caps was audio grade poly and I had tried 2ohm & 1ohm sandcast resistors.
I think these are different things. I'm talking techniques and yet it still independently comes down to degrees.
Learning to cross by ear takes time. There's much you can hear but can't explain easily.
Learning to cross by ear takes time. There's much you can hear but can't explain easily.
I have a pair of Jensen LS-2 speakers too. They were made in 1977.
The LS-2s were given to me by my Dad 15 years ago. There was always something different about them. They make the high register sounds super believable! I am also a drummer so I know how live cymbals, rattles, tambourines and snare drums sound. These speakers produce such a clear sound with amazing texture and detail. I am in the process of trying to figure out WHY these sound so good. When people hear the name, they are instantly turned off. They think I'm crazy. I have found Danny Richie with GR-Research on YouTube. Everything Danny has said and recommended in videos and over emails is true. I am not drinking the cool aid. I would be honest if something didnt make a difference.
I own a new Rotel A11 tribute. I have upgraded to GR-Research 8 foot 16 strand braid speaker wires with GR tube connectors on the outside of the cabinet. On the inside, I rewired the speaker with GR high copper wire and replaced the Caps with 2.7mF Auracaps for the tweeters. The woofers have no crossover parts. I also added a sheet of GR no-rez to solidify the cabinets. I put the original yellow fiberglass insulation back in after the no-rez. The woofers have been refoamed as well.
Dude, these things sound amazing with an added subwoofer on channel B on the Rotel. The detail is AMAZING. I can provide a list of all of the songs I listen to and share the specific things I can hear with these speakers that I can't hear with others. I just got the Sony SS-CS5s that YouTube is raving about and they just dont even compare!
Putting in the new caps, wire, no-rez and connectors improved these speakers so much that I can't believe it. I wish I could invite everyone over for a listen to confirm what I am hearing.
If you have any questions about Jensen LS-2s let me know.
Dave
The LS-2s were given to me by my Dad 15 years ago. There was always something different about them. They make the high register sounds super believable! I am also a drummer so I know how live cymbals, rattles, tambourines and snare drums sound. These speakers produce such a clear sound with amazing texture and detail. I am in the process of trying to figure out WHY these sound so good. When people hear the name, they are instantly turned off. They think I'm crazy. I have found Danny Richie with GR-Research on YouTube. Everything Danny has said and recommended in videos and over emails is true. I am not drinking the cool aid. I would be honest if something didnt make a difference.
I own a new Rotel A11 tribute. I have upgraded to GR-Research 8 foot 16 strand braid speaker wires with GR tube connectors on the outside of the cabinet. On the inside, I rewired the speaker with GR high copper wire and replaced the Caps with 2.7mF Auracaps for the tweeters. The woofers have no crossover parts. I also added a sheet of GR no-rez to solidify the cabinets. I put the original yellow fiberglass insulation back in after the no-rez. The woofers have been refoamed as well.
Dude, these things sound amazing with an added subwoofer on channel B on the Rotel. The detail is AMAZING. I can provide a list of all of the songs I listen to and share the specific things I can hear with these speakers that I can't hear with others. I just got the Sony SS-CS5s that YouTube is raving about and they just dont even compare!
Putting in the new caps, wire, no-rez and connectors improved these speakers so much that I can't believe it. I wish I could invite everyone over for a listen to confirm what I am hearing.
If you have any questions about Jensen LS-2s let me know.
Dave