I've read quite a few threads on the Vifa P13 which got me thinking...
A 3-way, passive, with Vifa D27TG-35-06 tweeter, P13WH-00-08 mid, and Dayton 15" woofer.
The single 5 uF cap HP crossover which planet10 recommends (I assume that the -35- tweeter is a drop-in for the -45- tweeter) on the tweeter.
No LP (or HP) crossover on the mid because it will be built into 1.5L sealed chamber to get 150 Hz rolloff per Vifa spec sheet.
150 Hz LP (4th order?) on the woofer, in a vented box.
Comments?
(Yes, I thought of this because of the *great* rock speaker thread).
A 3-way, passive, with Vifa D27TG-35-06 tweeter, P13WH-00-08 mid, and Dayton 15" woofer.
The single 5 uF cap HP crossover which planet10 recommends (I assume that the -35- tweeter is a drop-in for the -45- tweeter) on the tweeter.
No LP (or HP) crossover on the mid because it will be built into 1.5L sealed chamber to get 150 Hz rolloff per Vifa spec sheet.
150 Hz LP (4th order?) on the woofer, in a vented box.
Comments?
(Yes, I thought of this because of the *great* rock speaker thread).
My Opinion
Hi leadbelly,
What do you mean that the mid (P13) has no high pass filter?
I don't really know what planet10 had suggested, but I think you would
feed full range frequency to the mid and filter the signal with 5uF for
the tweeter.
1. With P13 as a mid you need a tweeter that is working well at very high
frequencies, and it doesn't have to be a wide bandwidth. D27 is not that
good in that respect (IMO), but another cheaper Vifa type is better (the
bandwidth is much narrower than D27)
2. With the mid producing full range, the tweeter need to be crossed very
high in order to avoid the negative effect from overlapping in the upper
frequencies. 5uF is not high enough. I think it should be 2uF or something,
but like I said before, D27 won't produce good sound.
3. You cannot apply the same scenario to different tweeter-mid pairs. And
I believe that the result of this scenario is worse if you drive the speaker in high
volume.
Hi leadbelly,
What do you mean that the mid (P13) has no high pass filter?
I don't really know what planet10 had suggested, but I think you would
feed full range frequency to the mid and filter the signal with 5uF for
the tweeter.
1. With P13 as a mid you need a tweeter that is working well at very high
frequencies, and it doesn't have to be a wide bandwidth. D27 is not that
good in that respect (IMO), but another cheaper Vifa type is better (the
bandwidth is much narrower than D27)
2. With the mid producing full range, the tweeter need to be crossed very
high in order to avoid the negative effect from overlapping in the upper
frequencies. 5uF is not high enough. I think it should be 2uF or something,
but like I said before, D27 won't produce good sound.
3. You cannot apply the same scenario to different tweeter-mid pairs. And
I believe that the result of this scenario is worse if you drive the speaker in high
volume.
I've got a pair of Ariels (Lynn Olson), which use the P13WH-00-08 mid/bass drivers with Scan-Speak D2905/9000 tweeters. I think the system is super, and so do a couple of audiophile friends. Check out this web site: http://www.aloha-audio.com/Ariel.html The crossover I use is like the one on the web page, but with an additional notch filter. I've heard the notch filter is not strictly necessary, particularly with the D2905/9500 substituted for the 9000.
If you sub-woof a system based on those drivers, I'll be very interested to see how it goes.
If you sub-woof a system based on those drivers, I'll be very interested to see how it goes.
Which is what I said and it means there is no HP on the mid!
Jay, there have been many reports of good performance of the D27, good reports on DIY designs using it, good reports of it matching with the P13. And 5 uF is not a figure picked out of the air, it is what the TLb design is based on.
What would you recommend instead, since you think otherwise?
Hmm, I'm no Vifa fan, but just to 'stir up the pot' a bit, the D19 has better off axis response due to its smaller size and a peaking on axis response. The D27 is very smooth on axis, but its large size has it rolling off fairly low off axis. If still available, I propose the alum/ferrofluid damped D25AG-05-06 as a smooth sounding, and IMO more natural sounding, compromise.
GM
GM
My current-system's 7 litre satellites are made of P13 and D25AG35 (aluminum dome) and I also had tested D27 and 19mm Seas in the design process. I like the sound when P13 is paired with D25AG35 the most. However, my xover is not the simple single cap and I had tuned it for a few days before I got the one that I prefer.
OK, you guys have swayed me, D25AG-35 it is. Tough choice, as there are numerous examples on the LDSG pairing the P13 with both the D27 and the D25.
So, anything else amiss? This is what I'm thinking now:
tweeter = D25 with 5 kHz 2nd order crossover
mid = P13 in 1.5 L chamber, no HP or LP crossover
woofer = Swan 305, 150 Hz 2nd order crossover
Any opinions on the best alignment for the Swan?
Vas=166.5L, Fs=22.7, Qts=0.385
So, anything else amiss? This is what I'm thinking now:
tweeter = D25 with 5 kHz 2nd order crossover
mid = P13 in 1.5 L chamber, no HP or LP crossover
woofer = Swan 305, 150 Hz 2nd order crossover
Any opinions on the best alignment for the Swan?
Vas=166.5L, Fs=22.7, Qts=0.385
andrew01 said:
I changed my mind and never built it.
The idea of using a small enclosure to roll off the bass response of a driver isn't novel. I got the idea of not bothering with a LP filter from a project on Planet 10's site. IMHO one of the reasons that the P13 is pricey for its size is its HP and LP roll off, the other of course that it is used in the Ariel.
If I remember correctly, I removed the backing cup and removed (I think) a pad of felt or cotton waste. I replaced it with some dacron, lightly applying it to the transmission channel behind the dome. Later, I used them open backed into a 0.5 litre enclosure.
IIRC, I preferred the benefit of rearranging the damping material most.
PS, beware of chipping the magnet when removing the cup.
IIRC, I preferred the benefit of rearranging the damping material most.
PS, beware of chipping the magnet when removing the cup.
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