Hey all,
So I picked up a pair of TB2 clones for almost nothing on eBay a few years ago. While I don't generally agree with the cloning thing, especially with a smaller company like PMC, it was just someone's personal project and they were too cheap to resist. I already have another pair of real ones, and they measure perfectly against them so they've done a great job. I believe the crossover and drivers came out of an original, and it was just the box that was cloned.
I've had them as my living room system for a while, but one of the metal domes is caved in causing a 2k peak with a dip further up. I pulled it out with some tape, but there's still a little dip and it doesn't sound quite right. As they're kind of a donor set anyway, I was thinking of experimenting with them a little.
From what I've read the "TB2i" version uses a lower crossover point and the Seas 27tdfc soft dome. As I'm not too keen on metal domes anyway I thought it might be worth dropping a set of these in just to see how it sounds. As far as I can tell, the sensitivity and impedance are exactly the same as the originals, but is there anything else I should look out for that might cause an issue? Possibly a different phase response? As far as I can tell the originals were Tymphany D25AG-35.
Alternately I'd really like to try out a set of ribbon tweeters in them, but I can't find one with similar specs.
Would love to get some input from you guys.
All the best,
Blindmelon7
So I picked up a pair of TB2 clones for almost nothing on eBay a few years ago. While I don't generally agree with the cloning thing, especially with a smaller company like PMC, it was just someone's personal project and they were too cheap to resist. I already have another pair of real ones, and they measure perfectly against them so they've done a great job. I believe the crossover and drivers came out of an original, and it was just the box that was cloned.
I've had them as my living room system for a while, but one of the metal domes is caved in causing a 2k peak with a dip further up. I pulled it out with some tape, but there's still a little dip and it doesn't sound quite right. As they're kind of a donor set anyway, I was thinking of experimenting with them a little.
From what I've read the "TB2i" version uses a lower crossover point and the Seas 27tdfc soft dome. As I'm not too keen on metal domes anyway I thought it might be worth dropping a set of these in just to see how it sounds. As far as I can tell, the sensitivity and impedance are exactly the same as the originals, but is there anything else I should look out for that might cause an issue? Possibly a different phase response? As far as I can tell the originals were Tymphany D25AG-35.
Alternately I'd really like to try out a set of ribbon tweeters in them, but I can't find one with similar specs.
Would love to get some input from you guys.
All the best,
Blindmelon7
So you're saying the TB2i version has a lower cross (both ways), and different tweeters. You want to put in the tweeters but aren't sure about the cross.
I guess the easiest way would be to leave the woofer as it is and try to fit the new tweeter in to cover the same range as the previous one.
I guess the easiest way would be to leave the woofer as it is and try to fit the new tweeter in to cover the same range as the previous one.
Yeah that was the plan. I'm not so worried about the crossover point as they've moved it down by 1k, I assume because the new tweeter is capable of a lower frequency response. I was more worried about any other specs I should be looking at on the tweeter that might cause an issue. Also, it looks like the replacement tweeter is 1dB more sensitive - would an L-pad sort that out?
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Broadly speaking the sensitivity, the impedance interaction, and the individual characteristic of the tweeter response would be the main issues. An L-Pad could sort out the first, might have some effect on the second.
If you can't get a hold of the other crossover schematic, and you can't measure then you have some options. The first would be to simply put the other tweeter in and begin tweaking based on what you hear.
The second would be to attempt to reverse engineer through the difference between the two tweeters, using simulations to come up with a replacement crossover.
If you can't get a hold of the other crossover schematic, and you can't measure then you have some options. The first would be to simply put the other tweeter in and begin tweaking based on what you hear.
The second would be to attempt to reverse engineer through the difference between the two tweeters, using simulations to come up with a replacement crossover.