W15CY & W15CH interchangable?

[tktran]

If I wanted a build a design which called for the W15CH and I wanted to use the W15CY (or vice versa), could it be done?

I can't for the life of me see any differences.
If there are, its close enough to be within sample-to-sample variation.

[Hdale85]

Variation's in the look of the drivers? Or the FR? Obviously the later is the important part.

[tktran]

amplitude response, impedance response, TS parameters etc, all very similar! :roll:

[Hdale85]

Just making sure I'm no expert though.

[jkrutke]

Yes, they are interchangeable, at least if they are of similar age. I have some of both here. Sensitivity, response and impedance are almost identical. Most have the breakup at about 8.3kHz.

I just looked up the current prices, USD:

W15CH-001 $219
W15CY-001 $162
Ouch. :E 8O

Not exactly value leaders. The W15CY used to cost about $120. I'd never buy the CH at the price it sells for. The 15W/8530K-00 5" Revelator is both cheaper and a better performer.

[Hdale85]

Yes all the Seas drivers went up like 50+ bucks. Really sucks as I've been thinking about using the W15CY's for a new speaker I want to build. An MTMWW so I need 4 of them not to mention a center and surrounds it really adds up. Been keeping an eye out for people selling them on forums and what not

[tktran]

Thanks John,

Your measurements was what prompted my query in the first place.

There are plenty of old designs floating about, including those with the popular and evergreen P17WJ, 8545, W18 etc, but I figure the main concern, (from the point of view of a builder without measurement gear) should be when the design was finalised/the vintage of the drivers used in the design vs when the builder decides to build the speaker/the date of the drivers purchased.

Driver drift is probably natural phenomena, from subtle changes in FR to wandering breakup nodes.

I suspect that most published designs are valid for only a year or two, any longer and without measurement equipment a builder can never know if their purchased drivers are to spec with the design...

Apart from the neo magnets was it possible to tell if the W15CY and W15H used the same cone, basket, spider, surround etc?


best regards,
Thanh

[Hdale85]

tktran, Being that your in Australia are the Seas drivers cheaper over there then here? I'm guessing not but just curious

[tktran]

Nope.

We've had a couple of price drops since 2005, but still they cost more here.

Currently equivalent to ~US $235-280 for W12-W22EX.

[jkrutke]

Apart from the neo magnets was it possible to tell if the W15CY and W15H used the same cone, basket, spider, surround etc?

Yes, I'll post this here for prosperity. To make sure you have a similar vintage, look at the area where the cone connects to the voice coil former. If there's a lip there, the chances are you have the newer version with the 8.3kHz breakup node. If it's a straight glued connection, chances are the breakup is at 6kHz and slightly more damped. The change was somewhere between 2003-2005.

I've seen this on a few, but not enough to say with 100% certainty however. From the cone side, I've noted no differences in the look over the years between any versions or models.

[jkrutke]

I suspect that most published designs are valid for only a year or two, any longer and without measurement equipment a builder can never know if their purchased drivers are to spec with the design...

Yes, very true. With my posted designs, I generally retest with new drivers now and then to be sure they haven't changed. I've had several designs I've had to pull or hold back posting because of driver changes - Including a W15 Excel design which was posted for a total of 24 hours before I pulled it.

[---k---]

John,
I wish you wouldn't totally pull your designs down. I always enjoy reading your very thorough write ups. Usually I learn something. You should consider just pulling the values off the crossover.

[Dave Bullet]

John,
I wish you wouldn't totally pull your designs down. I always enjoy reading your very thorough write ups. Usually I learn something. You should consider just pulling the values off the crossover.

I agree. I've learned just as much from his writeups as a bunch of books I've read. In fact I've read all of his designs for that very fact. He explains why he makes the choices he does. Books often miss the "why" out! or miss complete topics out (eg, vertical lobing to name but one).

I'm guessing why John doesn't leave designs like that up (ie.stripping values from the xo, putting cavaets in bold etc... ). This is because some newbie will build it, guess the values (or not remeasure wandering drivers) and when it sucks will blame the "Zaph design". I've seen John cop enough flack from his proven designs, let alone those where values were omitted.

Sorry OP for the off topic.

David.