P17wj-00-08

[davethomp]

Hello everyone:
I have 4 X Vifa P17WJ-00-08 and Vifa Tweeters: 2 X D25AG-35-07, and 2 X D27TG-36-06..(amongst others) and was wondering whether anyone has a good plan for cabinets and crossover networks for a good 2 &1/2 way, (3 way?) using these drivers and tweeters? I was planning on building a version of the 'Etude' however, have started to re-think Transmissionline (due to other projects/experiments with 8 inch Vifa P21 WO-20 amongst others) and headed back towards Bass Reflex. Thanks and kind Regards:
Dave

[davethomp]

Hi whoever reads this.....
I know that these little 6&1/2 inch Vifa drivers were once thought to be pretty good by the DIY scene. But that was some years ago. I am surprised that there have been so few responses??!! Then again, my choices of stuff to experiment with could be a bit off the track???
Regards

[Andy G]

Here is my offering
ARGOS loudspeakers

If you are interested and have trouble downloading the plans, email me by private mail.

A build of these is/was shown in Parts Express project showcase, under the name Pipes iirc
(for some reason I can't get to showcase to get the url at the moment, sorry)

[davethomp]

Hey Andy:
How you going? I built a pair of your "pipes" and all went really well! Mine are painted a sort of medit. suede blue! Anyway, the kids chose the paint! I've just lent them out to a mate. Ah yes, another seperation/divorce! The 'pipes' can put out some music and they are enjoyable. I ended up pulling the vifa drivers and tweeters out and replacing with AAD drivers from a pair of new bookshelf speakers I bought. These came with little info, but by the time I had adjusted the resistor on the corssover I was blown away! Anyway, I bought another pair of the Vifa P17WJ's and planned on building a more traditional TL with the 4 drivers in an MTM arrangement like Essential/LSK whatever it is....but a little larger. But recently I got scared off about the design. The 'Etude' on google is very nice but many knock the MTM set-up in a TL with 6 & 1/2 inch drivers. There is so much conflicting advice it makes it hard for us lesser mortals to make a choice!

Thanks for responding. I am getting a bit paranoid about this great site and its' contributers because, no-one responds to me. The answer couldn't be that therefore my projects must be crap! Surely ..no! I got a bit of a hammering from the Full Range side...man, it is complex to get the best out of them. I have a pair of Audio Nirvana Super cast 10inch I was tring to get the best design for. Phew! I was totalled mate. The math and theory and considerations are beyond me. I should have simply bought a pair of SEAS Exotic and left it at that.

I've also build a pair of "Bigger is Better" with Fostex Fe167e with a Fostex horn tweeter...these sound great: a friend was so inspired he built a pair of Humble Home made Hifi/Tony Gees 'Optimos'. My BiB rock the house. I'm not sure how accurate they are, but they really, really fill the house...and I use 12 watts per channel to drive them!

I have LOTS of other projects on the go, but have stalled. I can't figure out the math! I've begged for help from some of the 'gods' and capable of this site...but to no avail, and yes, I've even offered to pay! No-one has yet chosen to help me. I cannot afford many more projects and want to stop at these next few. (Well actually, do you know of a 'ripper' 3 way? I have even been looking at Adelaide Speakers/Ascension..he has some great options..if you can believe the figures!) Then I would stop!

I almost decided on a pair of your Argos windswept design as I also have a pair of Vifa 8 inch P21wo-20's. However I want something to look a little more 'trad' after the 'pipes', "the BiB" and few other funny looking things...I was trying to work out the math for a TL cabinet for these Vifa 8 inch as well..but can't seem to get it right, far less build a crossover.!!! I've sort of given up...my study is full of drivers and not one great idea of how to use them!
Good luck and keep the ideas coming....you do help the DIY people you know!
All the best.
Regards: dave
Thanks again Andy.

[Andy G]

If can find a nice 10" bass driver (or 12") something with an open back mid using the P17's in a MTM would be VERY workable withn a simple 3-way linked series x-0 (see my web site), so long as you can get 3-4 foot behnd the speaker .. whoops sorry, a metre or so.
I hope Rabbitz chimes in, because he has heard what can be done.

Maybe a P21Wo below (although a 10" would be preferable, the P21 is no slouch in a 40-50 litre vented cab) with a P17/D25 or 27 mtm open back on top.. again look at some of the OB MTM+W on my web site for ideas. ARGOS loudspeakers

[Inductor]

What do you want to do? I would use the Vifa P17WJ-00-08 (2x) woofers as is, maybe with some BSC later, and the super nice D27TG-36-06 tweeters (Scan Speak D2606/9220) with a 1.order cap at ~4K (6 Ohm). Now, about attenuation on tweeter. You probably don't need, but if starting introducing BSC inductors on the woofer then you need the attenuation in the same amount at the xover frequency band. I think that will give you a very nice sweet type of monitor at ~92dBSPL or less (with just one cap).
Post your results if you'd like.

[rabbitz]

Originally Posted by Andy G

If can find a nice 10" bass driver (or 12") something with an open back mid using the P17's in a MTM would be VERY workable withn a simple 3-way linked series x-0 (see my web site), so long as you can get 3-4 foot behnd the speaker .. whoops sorry, a metre or so.
I hope Rabbitz chimes in, because he has heard what can be done.

Maybe a P21Wo below (although a 10" would be preferable, the P21 is no slouch in a 40-50 litre vented cab) with a P17/D25 or 27 mtm open back on top.. again look at some of the OB MTM+W on my web site for ideas. ARGOS loudspeakers

Dave

I can vouch for Andy's MTM OB + W speakers as I've heard most of them. They are reasonably easy to build, flexible in appearance (let your imagination wander) and use very simple crossovers with around 3 resistors, 2 caps and 2 inductors. The sound is impressive and give an incredible presentation. They do however need a largish room and some space behind the speaker to work at their best.

You have all the drivers to do a build with the 25AG, P17 and P21 so would not be very expensive to pursue as a trial. A 10"-12" woofer of course would be better and would suggest something like the SB29NRX but another pair of P21 to give 2 per side could be a cheap option. I'm sure Andy would have a good starting point crossover for this and these are not hard to tweak.

[Andy G]

Originally Posted by rabbitz

Dave
but another pair of P21 to give 2 per side could be a cheap option. I'm sure Andy would have a good starting point crossover for this and these are not hard to tweak.

Ta Muchly, Rabbitz

The major issue with using 2 x P21's is the required volume.. ie BIG !.
It is not like an M22.
Depending on the room size, a single P21 in a 40-50 litre vented cab would probably be close to what would be required to match an MTM OB top section., But hey, you can always pad the mids and top down a bit further to get the right balance in room, sacrificing a bit of efficiency.

[rabbitz]

Yeah, I found the P21 needed over 50 litres vented. With 2, what's 100 litres between friends?

Another option with only 1 P21 is to use only 1 P17 to give TM OB + W.

A sneaky method is to do a MTM OB + W with the lower M crossed over lower to fill in the loss (downward slope) between Fe and Fp. In a series xo would the addition of an inductor prior to the lower M achieve this or does it need a 4-way? I'll have to model it and see. I've seen this method used to great effect on a OB speaker in the 80's.

[davethomp]

Hi Andy, Rabbitz and Inductor:
Yep, thanks so much guys! Inductor, yep, if I knew exactly what it was that I wanted to do......well, I have not an answer for that! I will know it when I hear it! Hence the experiements. I have changed plans quite a lot, as I learn more, engage in discussion more I then refine my search and ideas. These drivers reflect an earlier part of that experience. I don't NOT want to use them, and/or, I can still use them in the original ideas/plans. However I have learnt more since I bought them and have other ideas now that don't require these drivers. It's funny how quickly your original ideas change isn't it? I also have many friends who are building frantically. This continues to influence my learning. I hear what they have tried and then these outcomes inform different ideas and directions? So yes, I can still build the original MTM 'Etude' TL with the 4 X PW17WJ-00-08, and whatever I planned for the P21's which was either a plan developed by 'Danmarx' or a TL based upon Troels! But that's why I asked this forum? Before I start with these designs, does anyone have a really good plan that has worked well and could be considered a bit more advanced or developed, or might get more out of the drivers than what I had planned? If there isn't, hey that's fine also! Andy and Rabbitz, I like the idea of the OB...this has sparked off further considerations and discussions with my friends as some have started down this road........I'll check it out. I may not use the Vifa P21's....I'll look for 10 inch or killer 12 inch just to give the project some might!
Thanks again guys.
Kind Rgards: Dave