M21WO-39-08 VIFA vs. CA21REX(/DD) SEAS

[ermes]

hi!,
does somebody tried this woofers?
i would know the main sound differences between vifa and seas.
if nobody never tried they,i would know the differences in general between vifa and seas woofers.
thanks

[nikonguy]

The drivers are very similar in their capabilities. In a 40 L box tuned to 38Hz, the curves for both practically overlay each other. The Vifa has better Xmax, so it will provide an ultimately higher SPL if that's important. The frequency response also looks smoother (but Vifa may have just smoothed theres, while Seas did not). That said, I'm not bad-mouthing the CA21REX at all. They both look like good drivers.

If you haven't picked a tweeter yet, Dennis Murphy has a nice little tower speaker using the M21 and the Vifa D25 tweeter. I would think that any number of Seas 27mm tweeters would sound great also.

his site is at http://www.murphyblaster.com

I think they used the CA21REX in the Njord kit, so there is an XO out there, but I doubt that it is as good as the one Dennis came up with for the M21/D25.

Best,

Steve

[ermes]

thank you.
i posted to dennis my question,but he never tried the seas ca21rex.
can anyone help me please?

[5th element]

Although this isnt going to seem like much help. We all seem to get caught up in driver selection, this is a good thing because it means we dont consider drviers which are bad. But at the same time it can create problems such as these, "should I use this driver or the other one". If you really cannot decide then chances are theres not much between the two.

Both of the drivers are most likely pretty much as good as each other, just pick one (id go for the vifa because it looks marginally better on paper) and build something. DM design should be a good one.

[nikonguy]

If you want to go with the CA21REX, the kitbook for the Seas Njord is here, the box design looks reasonable and the crossover is at least a starting point. I have heard good things about the 25TFFC, I actually prefer silk domes to aluminum myself, but that is probably my own bias....

http://www.clofis.nl/nl/seas/Njord.pdf

[5th element]

Erm the 25tffc is silk....

[navin]

which would mate better with the Fostex FF85K? I was thinking of using a smaller woofer like this in say 22-25L to cover 40-400Hz and let the FF85K cover the rest.

[nikonguy]

Dennis' design with the M21/D25 uses the Vifa D25 tweeter, which is an aluminum dome. The 25TFFC is silk. Sorry if I wasn't clear.

[ermes]

however i asked about woofer comparison between vifa and seas.

[5th element]

OK I thought the question had kinda been answered as they are both OK but its up to you. However I will go thru the differences I can see now.

As stated before they both have a similar bass response so thats sorted.

The seas is more sensative by 3dB which is one point for the seas.

The vifa has twice the linear excursion which means more bass or less distortion.

Both have cone break up around the same point (about 1khz).

The vifa has a smooth frequency response which means its will be easier to work with. If you have software this is a moot point because both will be easily workable.

Both have designs already available. If you are considering building either the SEAS kit or DM kit then your preference on tweeter type might come into it. Do you prefer metal or fabric domes.

But the bottom line is I think the vifa is the better driver. I have also used another vifa paper cone and really like its sound too.