A couple of days ago I was given a pair of Panasonic SB-CH7cabs, one water damaged - drivers OK. The cabs were bi-amped (no xover inside), and 9L, some odd bandpass arrangement inside. The 10Cm woofer (Matsushita EAS-14PL74C) is interesting, FR good up to ~6KHz, but very Low Qts, ~.28. LIMP measurements give me Vas 5.4L, Qe .29, Qm 6.0, Re 4.7 Sd 78.5 The driver has a huge magnet, eff ~92dB.
The only prob is that there are some glitches in the impedance curve between 1-2KHz.
WINISD sims give best results in an EBS alignment in a small cab ~4.5L, maybe best to use it as a mid driver?
The only prob is that there are some glitches in the impedance curve between 1-2KHz.
WINISD sims give best results in an EBS alignment in a small cab ~4.5L, maybe best to use it as a mid driver?
Attachments
Nice looking cone, I think it's poly, but not sure.
I guess my question is how would you guys use this driver?
(came with a cone tweeter that has a very smooth FR from 2kHz up). I'm thinking an EBS mini monitor in 6L cab tuned to ~50Hz???
Obviously I need to do some listening to see if there are intrusive peaks in the HF...
I guess my question is how would you guys use this driver?
(came with a cone tweeter that has a very smooth FR from 2kHz up). I'm thinking an EBS mini monitor in 6L cab tuned to ~50Hz???
Obviously I need to do some listening to see if there are intrusive peaks in the HF...
Attachments
Hi,
5L/40Hz looks about right for line level EQ.
FWIW cone tweeters can be not that bad, I've always liked the
Peerless 2" paper cone tweeters, they are a victim of fashion.
A simple first order series c/o could work well but the whole
speaker would need some 10dB or so of level passive EQ
to balance it out, down to ~ 100Hz, slow roll off after that.
Getting the small box volumes correct for sealed / vented does not
look easy, shown also is 4th and 6th order bandpass, again they
need tiny box volumes and port tuning is critical, not easy.
/sreten.
5L/40Hz looks about right for line level EQ.
FWIW cone tweeters can be not that bad, I've always liked the
Peerless 2" paper cone tweeters, they are a victim of fashion.
A simple first order series c/o could work well but the whole
speaker would need some 10dB or so of level passive EQ
to balance it out, down to ~ 100Hz, slow roll off after that.
Getting the small box volumes correct for sealed / vented does not
look easy, shown also is 4th and 6th order bandpass, again they
need tiny box volumes and port tuning is critical, not easy.
/sreten.Attachments
after listening, with just a 4u7 cap for the tweeter, I've decided to keep them in their original cabs for now, & make a 2nd order xover at ~ 4KHz.
With a little eq, they do bass pretty well, and although a bit rough high up, a good xover should fix that. Add a touch of gap sealer to fix up the water damage where the seams have split, and I should have a nice pair of computer speakers....which can be cannibalized later
With a little eq, they do bass pretty well, and although a bit rough high up, a good xover should fix that. Add a touch of gap sealer to fix up the water damage where the seams have split, and I should have a nice pair of computer speakers....which can be cannibalized later
PeteMcK said:
Hard to tell with that impedance curve because you have the top of the peak chopped off. Most of the things you're seeing though are from the driver moving during the testing. It is very important for the driver not to move if you want clean, repeatable impedance peaks. Without a clean curve I wouldn't trust the T/S parameters derived from it. Here's some info I wrote on our experiences of testing parameters.
http://www.aespeakers.com/phpbb2/viewtopic.php?f=4&t=927
John
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