Vifa P21 woofers

[KeithL]

Can anyone explain the differences between the Vifa P21wo-10 and P21wo-20?

[MGrant1957]

Re: Vifa P21 woofers

easy:
P21wo-20
-P21wo-10
____________
10

[DanP]

Re: Vifa P21 woofers

easy:
P21wo-20
-P21wo-10
____________
10

Well played sir.

[Pete Basel]

Re: Vifa P21 woofers

Why do you ask, what are you trying to accomplish?

I don't know the answer, but I believe that the -10 was OEM to Vandersteen and perhaps PSB.

[billcurrier]

Re: Vifa P21 woofers

If they were a buyout of old from madisound the magnet was smaller and one dB less efficient. My memory gets fuzzy going that far back.

[DDF]

Re: Vifa P21 woofers

If they were a buyout of old from madisound the magnet was smaller and one dB less efficient. My memory gets fuzzy going that far back.

[DDF]

Re: Vifa P21 woofers

Attached my on axis measure of it, in a JPW AP3 cabinet (http://www.canuckaudiomart.com/detai...images/179614/)

[KeithL]

Re: Vifa P21 woofers

Why do you ask, what are you trying to accomplish?

I don't know the answer, but I believe that the -10 was OEM to Vandersteen and perhaps PSB.

I have a pair of Vandersteen 2C speakers that need woofers. One of the cabinets had a P21wo-10-08 woofers, which is not the right driver as the frame is too big to fit in the hole. I have seen the 20 and 33 and wanted to see if they were the same driver with a different number because of who sold it.

[KeithL]

Re: Vifa P21 woofers

I may just sell them as is since I found another pair locally and don't really need another project at this point.

[Pete Basel]

Re: Vifa P21 woofers

I have a pair of Vandersteen 2C speakers that need woofers. One of the cabinets had a P21wo-10-08 woofers, which is not the right driver as the frame is too big to fit in the hole. I have seen the 20 and 33 and wanted to see if they were the same driver with a different number because of who sold it.

Are they 2C's without a suffix? I think those had a US stamped frame driver with a clear cone
and a foam edge. Are you sure that they are straight 2C's without any suffix?

Interesting, I reverse engineered the Vandersteen 2Ci and it used a Vifa woofer built on
the same frame as the -20 but with a slightly wider edge - by about 1/16", not much.
I did an approximate clone of them, with a few variations, and the -20 worked fine in
them, the Vandersteen version would give a bit more excursion but not by much. I measured
the Vandersteen version of the woofer but I'd have to really dig to find those numbers.
Do your's have a suffix? The letter designation is in the very small print at the bottom
of the input plate.
Do your's have the midrange with a plastic cone and edge of the same material? It is a Peerless.

I know of one report of the P21wo-10 being used in the Vandersteen model 1.

[Chris Roemer]

Re: Vifa P21 woofers

I was not 20 mi. from Mechanicsburg (I-76) a week or two ago.

P21WO-10-08: Qts 0.29, Vas 5.2cf, Fs 25, Re 5.8, 91dB, Sd 36.4 sq.in.
P21WO-20-08: Qts 0.33, Vas 4.0cf, Fs 28, Re 5.7, 91dB, same Sd (and cone dia.)
Should have nearly identical performance in a vented 2cf box (upper 30s).
The -20 was rated 80wRMS, the -10 was 70w.