Vifa P22WP-01 8" woofer?

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On a lark I bought four of the Vifa P22WP-01 8" woofers offered by Apex Jr. Anyone here use these before? If so what size of box? I'm thinking of a two way system, something trapezoidal just for kicks.

Here are the specs from www.apexjr.com

TS: Fs 29.5Hz,
QMS 2.20,
QES 0.31,
QTS 0.27,
Vas 77 l,
Re 5.8 ohms,
Sd 235 cm2,
Rm 2.5,
Bl 10.2,
Md 29.5 g,
Xmax 6 mm

Michael
 
Hi Michael

You should be able to get a nice 2-way, in a compact 20L (F3=52Hz) vented box at that. For 40Hz @-3dB, 40L. With a EBP of 95, you will get a well controlled bass. Actually, it looks very good on paper.

Cheers
 

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Vifa P22

Michael,
I received some of these drivers recently. Measured them with my
Woofertester (added mass). Here's the ave of two samples
Fs 35
Qms 2.42
Vas 1.76 cu ft
Cms .59 mm/N
Mms 35 g
Rms 3.185 kg/s
Sd 248 sq cm
Vd .141 liter
Qes .291
Re 3 Ohm
Le .8 mH
Z 4 ohm
BL 9 Tm
Qts 0.26
SPL 90 1W 1 M alt 91.5 2.8V
given the above your best box would be about 23 liters,
eg about 500mm high, 337 wide and 212 deep
ported with a 50mm X 140 tube this would give a F10 in the mid thirties.
Note this is definitely a 4 Ohm speaker , be careful in your
Xover design or low impedance may be a problem... but the positive also with good sensitivity on hand ...one can properly account for the baffle step in the design.

I suggest you cross low in a 2 way design.........tweeter candidates may be Usher, Scan 9500, Morel MDT30, Vifa PL27 0r similar
Have fun and post your design !!
Brian
 
Re: Vifa P22

Brian Bester said:
Note this is definitely a 4 Ohm speaker , be careful in your
Xover design or low impedance may be a problem... but the positive also with good sensitivity on hand ...one can properly account for the baffle step in the design.

I suggest you cross low in a 2 way design.........tweeter candidates may be Usher, Scan 9500, Morel MDT30, Vifa PL27 0r similar
Have fun and post your design !!
Brian [/B]

Brian,

Actually, I've mated these to the bi-amped Alesis M1 modules also from Apex Jr so they are actively crossed over around 1.6k. I have some of Steve's dome tweeters as well since they were cheap, but may eventually go for a Vifa tweeter.

I hope to make the boxes this weekend. Pix next week if I'm satisfied.

Michael
 
Using P22WP-01-04 in Folded Horns

I'm using the Vifa P22WP-01-04 driver in folded horn speakers, with two per cabinet in series (8ohm load), and actively crossed over (Marchand XM9L, 24db Linkwitz-Riley) and bi-amped with Vifa D27TG-45-06 tweeters. The Vifa D27TG-35-06 costs a nickel less and has a slightly different faceplate, with otherwise identical specs.

I would really like to get a full set of reliable specs and response curves for the P22WP-01-04, but am only confused by the inconsitent ones provided by the resellers carrying this driver. I contacted Mackie's Tech Support, and they were only willing to verify the following information:
* 16mm cone excursion (not a typo!)
* 8.75-inch (222mm) die-cast magnesium frame
* mineral-filled polypropylene cone
* oversized magnet structure
* Rated power output: 150 watts, 4 ohm load
* Burst power output: 350 watts

For some reason I don't understand, the resellers claim 5-6mm excursion, not the whopping 16mm that Mackie claims. It would be nice for someone to verify this. In addition, I don't understand why resellers only claim power output of 100-125 watts, when Mackie claims 150 watts. Why do the resellers substantially downgrade the specs?

At any rate, in my tinkering, they appear to sound pretty good.
 
How did you Alesis/Mackie hybrid clone come along? I'm planning on making exactly that! However, my concern is that the P22 isn't shielded. Coffee can? Bucking magnet? I hope that will solve the problem. Will it? Other than that, I was thinking of using the Mackie box design (minus the passive radiator and horn guide) and adding a port to the back. Any of this sound ok? Alternatively, I could build the 20" tall boxes as suggested and place them on the 24" stands I already have.

If you have any tips from your own project, it'd be greatly appreciated!
 
My basic subwoofer idea was to throw a Vifa P22 into a 1cubic foot box - qtc of .5 or so - with an apex jr. amp crossed roughly around 50hz for stereo subs to integrate with my NHT Pro A-10 monitors which supposedly have an F3 around 50-55hz in a sealed enclosure. The pure numbers on this design tell me that my F3 on this sub is at about 80hz, which is way too high. However, considering I will be dialing the crossover to roughly 50-60 hz, I expect to be able up the gain and maintain a relatively flat curve from 50 down to around 38-40 or so. Now...this seems like a whole lot of money for 10 hz. Am I doing something wrong? All I want is a F1 or F2 of about 40hz and I would be immensely satisfied. Quick and fast bass response, matching with my monitors are priority. The 1cubic foot box is pushing me already - it's getting too big to mount on stands. Am I inherently looking in the wrong place? I wanted to keep my budget under $250. Well under. I can't justify a penny more. Technically, this project will push $300 already.
 
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