I'm a DIY Audio newbie after buying a pair of JPW ML-310 speakers on eBay. I've had them apart to check out the drive units and crossovers and and now thinking about what to upgrade. See attached photos.
The crossover is pretty straightforward and I think I will definitely replace those electrolytics for polypropylenes . They've got to be 20 years old apart from anything else!
I am also wondering about making some improvements to the crossover to reduce the baffle step in the response but don't want to do anything until I've got datasheets on the drivers.
The bass-mid appears to be a Peerless unit, KO-100 PL. I can't find a datasheet other than for the KO-100 WFR which has a different frame so not sure it's Thiele parameters and response/impedance curves will the same. Anyone know where I might get a datasheet for the KO-100 PL?
The tweeter looks to be a variant of the Peerless SR-19 DT, which I do have a datasheet for, but the marking on the back (T - 19) isn't what I expect when I compare it to other images of the SR-19 DT on the web. Can anyone definitively identify it?
The cabinets appear well built out of chipboard with the front baffle strengthened with an MDF skin. Isn't that what Wharfedale are shouting about in their latest Diamond range? 😉 There is a decent amount of wadding in there too as well as a rear-facing reflex port. Haven't worked out what it's tuned to yet. Will measure the internal dimensions and port dimensions and plug the numbers into WinISD or Speaker Box Lite to find out!
They sound only just about OK at the moment; the midrange and treble sound a bit congested to me. I'm hoping changing the caps will sort that out. I may also experiment with the value of the tweeter series resistor and/or change it to be an impedance-matching L-pad configuration instead.
Grateful for any thoughts or comments!
The crossover is pretty straightforward and I think I will definitely replace those electrolytics for polypropylenes . They've got to be 20 years old apart from anything else!
I am also wondering about making some improvements to the crossover to reduce the baffle step in the response but don't want to do anything until I've got datasheets on the drivers.
The bass-mid appears to be a Peerless unit, KO-100 PL. I can't find a datasheet other than for the KO-100 WFR which has a different frame so not sure it's Thiele parameters and response/impedance curves will the same. Anyone know where I might get a datasheet for the KO-100 PL?
The tweeter looks to be a variant of the Peerless SR-19 DT, which I do have a datasheet for, but the marking on the back (T - 19) isn't what I expect when I compare it to other images of the SR-19 DT on the web. Can anyone definitively identify it?
The cabinets appear well built out of chipboard with the front baffle strengthened with an MDF skin. Isn't that what Wharfedale are shouting about in their latest Diamond range? 😉 There is a decent amount of wadding in there too as well as a rear-facing reflex port. Haven't worked out what it's tuned to yet. Will measure the internal dimensions and port dimensions and plug the numbers into WinISD or Speaker Box Lite to find out!
They sound only just about OK at the moment; the midrange and treble sound a bit congested to me. I'm hoping changing the caps will sort that out. I may also experiment with the value of the tweeter series resistor and/or change it to be an impedance-matching L-pad configuration instead.
Grateful for any thoughts or comments!
Attachments
Hello,
I have the same set of speakers (not modified, yet). They were a What HiFi 5 star speaker back in the day.
One thing you could try is an active crossover. If you want to build something, then ESP's Project 09 might be worth a try:
Linkwitz-Riley Electronic Crossover
Alternatively, this 4 channel amp with built in DSP could do the job:
ZOUDIO AIO4CH: 4-channel amplifier with DSP and Bluetooth
That's what I have planned for mine...
I have the same set of speakers (not modified, yet). They were a What HiFi 5 star speaker back in the day.
One thing you could try is an active crossover. If you want to build something, then ESP's Project 09 might be worth a try:
Linkwitz-Riley Electronic Crossover
Alternatively, this 4 channel amp with built in DSP could do the job:
ZOUDIO AIO4CH: 4-channel amplifier with DSP and Bluetooth
That's what I have planned for mine...
Cool. Your approach sounds fun. My application will remain a passive crossover, but I haven't had time to do any work on it yet.
Do you happen to have reverse-engineered the crossover? I could do with knowing the inductor values. And what I really want to do at some point is measure the drivers direct in the cabinets, but I've got another project on the go at the moment to revitalise a pair of Heybrook HB2 cabinets.
Do you happen to have reverse-engineered the crossover? I could do with knowing the inductor values. And what I really want to do at some point is measure the drivers direct in the cabinets, but I've got another project on the go at the moment to revitalise a pair of Heybrook HB2 cabinets.
I haven't even got to the stage of opening them up yet, unfortunately. I am also planning to measure the response of each drive unit.
I'll let you know if I find out!
I'll let you know if I find out!