I have a pair of Vifa P17WJ-00-08 woofers vintage late 80s that were gathering dust. They are dusted off, checked and have a 15 l box almost ready for them.
Anyone have recommendation for suitable tweeter and crossover design to use with them?
Regards,
Glenn
Anyone have recommendation for suitable tweeter and crossover design to use with them?
Regards,
Glenn
Lucky you. This might give you some ideas.
Project CS-12 | Current-Drive - The Natural Way of Loudspeaker Operation
ScanSpeak Classic P17WJ00 6.5" Woofer
Project CS-12 | Current-Drive - The Natural Way of Loudspeaker Operation
ScanSpeak Classic P17WJ00 6.5" Woofer
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Vifa 2-Way Loudspeaker System
The crossover for the CS-12 project looks dodgy to me,
a notch with 10mH on the tweeter? - must be joking
The crossover for the CS-12 project looks dodgy to me,
a notch with 10mH on the tweeter? - must be joking
another one:
Speaker Project - V-D Vifa-Dayton 2-Way Monitors -- 8/17/2011
and another:
http://oakleyspeakers.tripod.com/MAIN.html
Speaker Project - V-D Vifa-Dayton 2-Way Monitors -- 8/17/2011
and another:
http://oakleyspeakers.tripod.com/MAIN.html
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I've heard the speaker in post #3. Well implemented simple crossover plus sounds very good. I don't know how easy is is to find the tweeter.
I had earlier found the link to the Georgia Tech design (post 3). I was skeptical that the single 0.42 mH inductor in the woofer circuit would give enough attenuation to sound good. This design apparently relies greatly on the acoustic rolloff of the woofer.
I checked (10mH). It's a Resonant Circuit for ~550Hz (Fs tweeter) because they opted for a 1.order, what is not in my book for the best practices. Usually, I never use notches on tweeters, as far as I can remember.
Anyway, that project (post#2) uses a Vifa P17WJ-00-04 (4 Ohms), pay attention to impedance because woofers are not the same e.g., for their circuits, BSC and crossovers.
http://www.sea.vg/vifa/P17WJ-00-04_data.pdf
Other woofers in the circuit (post#3) are Vifa P17WJ-00-08 (8 Ohms) that works better in bigger enclosure than the half brother.
#2 - 0.42 cubic feet/12 liters sealed (4 Ohms) below,
#3 - 0.6 cubic feet/17 liters BR 39/40Hz (8 Ohms) also below.
Note for diy: ports presented in this project are not enough (surface area).
""Port, 3-7/8 inch length of PVC tubing, 1.5 inch internal diameter"" instruction from the project. (1x) 1.5" diam. port tuned to 39/40Hz. This small surface area open for the front baffle, is not enough surf. area for this woofer unless using minimal power.😀
Attachments
I found a 2008 diyAudio thread Vifa p17 D25 by John K that brought me to this link:
DIY speaker designs: Vifa P17WJ-00-08 - D25AG-35-06 System at audioDIYcentral
Just what I was looking for; it looks like a good design and includes a link to a built project complete with measurements. My old parts bin actually has a pair of the D25AG tweeters used in this design so I am on my way.
I will copy this crossover design; I intend to go vented rather than sealed. Thanks to Inductor for advice on vent size; I will go 2 inch diameter rather than just 1.5.
I'll let you know result.
DIY speaker designs: Vifa P17WJ-00-08 - D25AG-35-06 System at audioDIYcentral
Just what I was looking for; it looks like a good design and includes a link to a built project complete with measurements. My old parts bin actually has a pair of the D25AG tweeters used in this design so I am on my way.
I will copy this crossover design; I intend to go vented rather than sealed. Thanks to Inductor for advice on vent size; I will go 2 inch diameter rather than just 1.5.
I'll let you know result.
The woofer has smooth roll-off. There is nothing wrong with 0.42 mH. HF peak issue will come from the tweeter not the woofer.
The only and main issues with the woofer are that it doesn't have sufficient low end extension [it is basically a midrange] and that it is not sensitive. Your design should not make it worse. JohnK design imho will make it worse. You will not enjoy such speaker if you believe me.
The bigger inductor in JohnK design I believe is to include baffle step loss with his narrow baffle. The design in post 3 has wider baffle [that I like so much], combined with small inductor it will give good sense of low level reverberation [not a dead sound that this woofer tend to create].
Your box is 15L but you didn't mention the baffle width [I like it wide in this situation]. This may have affect to the baffle step compensation inductor.
Vented is a good decision regarding the woofer short LF extension, especially you already have the box at 15L. 80Hz alone is a big drawback.
P17WJ is really suitable for a 3-way design. But if I'm forced to build a two way out of it, I will look for something similar to the one in post 3.
I agree with Jay on the 0.42mH inductor. Due to the roll off behaviour of the P17, you don't need high order electrical filters.
When designing a crossover we are after an acoustic roll off which is a combination of the filter roll off + driver roll off.
When designing a crossover we are after an acoustic roll off which is a combination of the filter roll off + driver roll off.
...Or driver roll off only. hehe🙂 i.e., HP on tweeter. e.g., Mordaunt-Short, Dynaco, Seas. Pi Speakers also takes great advantage of that in their designs. The secret recipe for ""unmatched quality"" with the right amount of driver inductance and enclosure Qtc/tuning.
https://en.wikipedia.org/wiki/Mordaunt-Short
https://en.wikipedia.org/wiki/Dynaco
Dyna Company History
10" Seas A26RE4 (H1411) pdf
Pi Speakers - unmatched quality and state-of-the-art performance
The Leach design with 0.42 mH certainly has an advantage in low parts count. This one can be tried with minimal investment in money or time.
My box is in between the examples. I went with (outside dimensions):
width: 10 inch (254 mm)
height: 15.5 inch
depth: 9.25 inch
It will be another week or two to get the boxes finished, then give it a go.
Glenn
My box is in between the examples. I went with (outside dimensions):
width: 10 inch (254 mm)
height: 15.5 inch
depth: 9.25 inch
It will be another week or two to get the boxes finished, then give it a go.
Glenn
Fwiiw, I built a TL with the p17wj ten years ago. Still in daily use at my parents' house and still a very pleasant performer if you have room for it.
PMC used the P17WJ in their FB1 TL too.
I've built this, very nice sound for the money, at the time.
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signet sl260
Those drivers are very good. I got a chance to grab a pair of Signet SL260 that use those drivers..what a wonderful sound...it killed my B&W speakers.
Those drivers are very good. I got a chance to grab a pair of Signet SL260 that use those drivers..what a wonderful sound...it killed my B&W speakers.
I finished the project and have been enjoying the result for past month. I went with the John Kreskovsky crossover design exactly as published. I compared to Zaph SR71 - the Zaph design is preferred but the Vifas are in the same league.
I built a set of 2.5-way TL's based on Paul Spencer's design but I'm not overly happy with the upper bass - fairly weak. Otherwise the clarity and warmth of the sound is really impressive. It seems to produce really low end <35Hz really well however so I am thinking it's the tuning.
Anyway wife wants smaller speakers so I'm thinking of cutting up the boxes to make a vented/sealed 2.5-way with these (2xP17 + 1xD25AG). Anyone know of any good designs?
Anyway wife wants smaller speakers so I'm thinking of cutting up the boxes to make a vented/sealed 2.5-way with these (2xP17 + 1xD25AG). Anyone know of any good designs?
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