skyegreen424
brandon
Hi all,
Just recently got a hold of a pair of JSE Infinite Slope 1.2's. The exterior cabinets are in great condition, not even a scratch on the veneer :-] The binding posts are also in good shape and the jumper cables are still present. The drivers themselves, however, are strange. The tweeters were both pushed in, and from the advice of others I repaired them by removing the front plate of each tweeter and pushing them back out with a q-tip. I did notice however that both tweeters must have been punctured when initially pushed in. I don't know if this will affect the sound - I noticed after I got the shape back the tweeters sounded much clearer and less harsh but I'm a touch worried about the punctures. I found matching replacements on the auction site and money isn't too much of an issue so I wouldn't mind ordering replacements but if I really, really don't need to then I won't bother.
In addition, I noticed on one cabinet that its two bass drivers matched (removed to confirm) but the other cabinet had two different bass drivers, neither of which matched the first cabinet with the matching drivers. The drivers that match are Vifa M21WJ-49's. On the other cabinet, the first bass driver from the bottom is some sort of cheap "Precision Loudspeaker's INC." branded driver. The second bass driver from the bottom is, interestingly, a Vifa P21WO-10 driver. This was confusing me - why would the previous owner replace one driver with a non-matching Vifa driver, assuming that the M21WJ's were originally in here? Moreover, why only get one and spring for a cheaper brand for the second driver?? I did some reading about the "Bass Loading" feature on these loudspeakers and I have to guess that the uninformed careless choice of using two different driver's probably screws up the phasing part of this...
Anyways, it's clear that I need to acquire new woofers for these things. Originally I was going to look for two more M21WJ-49's to match the complete loudspeaker. Can't find them... a pair sold at some point in December but that's all I know. Then, I ended up looking up the P21WO's. They are available - used - but available nonetheless. I then remembered that someone else had posted in a thread about their JSE Infinite Slope 1.2's.... their cabinets each had two matching P21WO's (post #74) - NOT the M21WJ's that I thought would be the standard. Maybe I was wrong, perhaps the M21WJ's are aftermarket.... the plot thickens.........
I ended up looking at the spec sheet and learned that the M21WJ's are paper cones. This is the spec sheet for these:
I then learned that the P21WO's are polypropylene cones, and this is the spec sheet for these.
It seems like the P21WO's have a heavier magnet, and are a touch more sensitive. I know that you shouldn't just throw in any driver into the JSE Infinite Slopes I'm guessing due to the frequency response, so I compared the two. I think I read somewhere that the crossover point was like 150hz from bass to mid? When comparing from the bottom to here, they seem like an almost perfect match, at from the lowest rated for this loudspeaker 39hz to 150hz. (see below)
Here's what I'm thinking: I'll replace the other three drivers with P21WO drivers. The graphs seem to work out, and in addition the P21WO drivers have been noted to have been used on another example of JSE Infinite Slope 1.2's. In theory, the crossover should be able to do its job with both, but perhaps there's something subtle I'm missing between the two spec sheets and graphs which would make the M21WJ's the proper replacement, if the M21WJ's were the original drivers all along. See - I just don't know. There's really not enough info out there on which is the originals, I've seldom been able to find info on the Infinite Slope 1.2's.
Does anyone have experience with these speakers, and what route I should take with the woofer replacements?
Also, I read somewhere that I shouldn't mess with the crossovers because each component is super specifically chosen. I noticed a mixture of film and electrolytic caps on the crossover. I'm inclined to leave it be but if anyone thinks otherwise let me know.
Thanks for reading!!
TLDR: Should I replace the two bass drivers in each cabinet with P21WO's or M21WJ's? Signs point to the P21WO's being used in the Infinite Slope 1.2's, but I'm unsure if the M21WJ's are the original for my specific loudspeakers...
Just recently got a hold of a pair of JSE Infinite Slope 1.2's. The exterior cabinets are in great condition, not even a scratch on the veneer :-] The binding posts are also in good shape and the jumper cables are still present. The drivers themselves, however, are strange. The tweeters were both pushed in, and from the advice of others I repaired them by removing the front plate of each tweeter and pushing them back out with a q-tip. I did notice however that both tweeters must have been punctured when initially pushed in. I don't know if this will affect the sound - I noticed after I got the shape back the tweeters sounded much clearer and less harsh but I'm a touch worried about the punctures. I found matching replacements on the auction site and money isn't too much of an issue so I wouldn't mind ordering replacements but if I really, really don't need to then I won't bother.
In addition, I noticed on one cabinet that its two bass drivers matched (removed to confirm) but the other cabinet had two different bass drivers, neither of which matched the first cabinet with the matching drivers. The drivers that match are Vifa M21WJ-49's. On the other cabinet, the first bass driver from the bottom is some sort of cheap "Precision Loudspeaker's INC." branded driver. The second bass driver from the bottom is, interestingly, a Vifa P21WO-10 driver. This was confusing me - why would the previous owner replace one driver with a non-matching Vifa driver, assuming that the M21WJ's were originally in here? Moreover, why only get one and spring for a cheaper brand for the second driver?? I did some reading about the "Bass Loading" feature on these loudspeakers and I have to guess that the uninformed careless choice of using two different driver's probably screws up the phasing part of this...
Anyways, it's clear that I need to acquire new woofers for these things. Originally I was going to look for two more M21WJ-49's to match the complete loudspeaker. Can't find them... a pair sold at some point in December but that's all I know. Then, I ended up looking up the P21WO's. They are available - used - but available nonetheless. I then remembered that someone else had posted in a thread about their JSE Infinite Slope 1.2's.... their cabinets each had two matching P21WO's (post #74) - NOT the M21WJ's that I thought would be the standard. Maybe I was wrong, perhaps the M21WJ's are aftermarket.... the plot thickens.........
I ended up looking at the spec sheet and learned that the M21WJ's are paper cones. This is the spec sheet for these:
I then learned that the P21WO's are polypropylene cones, and this is the spec sheet for these.
It seems like the P21WO's have a heavier magnet, and are a touch more sensitive. I know that you shouldn't just throw in any driver into the JSE Infinite Slopes I'm guessing due to the frequency response, so I compared the two. I think I read somewhere that the crossover point was like 150hz from bass to mid? When comparing from the bottom to here, they seem like an almost perfect match, at from the lowest rated for this loudspeaker 39hz to 150hz. (see below)
Here's what I'm thinking: I'll replace the other three drivers with P21WO drivers. The graphs seem to work out, and in addition the P21WO drivers have been noted to have been used on another example of JSE Infinite Slope 1.2's. In theory, the crossover should be able to do its job with both, but perhaps there's something subtle I'm missing between the two spec sheets and graphs which would make the M21WJ's the proper replacement, if the M21WJ's were the original drivers all along. See - I just don't know. There's really not enough info out there on which is the originals, I've seldom been able to find info on the Infinite Slope 1.2's.
Does anyone have experience with these speakers, and what route I should take with the woofer replacements?
Also, I read somewhere that I shouldn't mess with the crossovers because each component is super specifically chosen. I noticed a mixture of film and electrolytic caps on the crossover. I'm inclined to leave it be but if anyone thinks otherwise let me know.
Thanks for reading!!
TLDR: Should I replace the two bass drivers in each cabinet with P21WO's or M21WJ's? Signs point to the P21WO's being used in the Infinite Slope 1.2's, but I'm unsure if the M21WJ's are the original for my specific loudspeakers...
I hope to find time to do a write up soon. If you have any questions about these speakers or their pairing with a freshly recapped Technics SA-R477, I will do my best to respond. For now here are some photos I have of them:
