billy said:
Stupid Not Likely (or you woundn't be here) -- inexperienced maybe, we all start out as newbies sometime, somewhere.
The vifa P13WH-00-08 has a very smooth response at roll-off and in my experience sounds best run full-range with no XO. Then, if the tweeter can hack it, you just bring the T in 1st order with a single cap -- or a single cap + an impedance compensation network. There are a couple Vifas where this works admiraly, the seas i'll have to go do some research on.
dave
Fossil said:
The TLb uses a 10uF cap on a nominal 4 ohm T (2 Vifas in parallel) for a nominal XO of just under 5k.
I'm not sure what size Chris is using on his Dalines (the project page hasn't been updated with the new Vifa Tweeter & XO odessy), but i can check.
dave
I simulated my crossovers in Pspice using the values for the speakers DC resistance and the voice coil inductance to simulate the behavour of the speaker. When doing this I could (among other things) see if the tweeter impedance needed to be compensated for.
This was over 5 years ago. I don't know if there is any newer software out there dedicated to simulating xovers. Could be worth a check.
BTW, can't you just use the formula f = 1/(2*pi*R*C), where R is the speakers nominal impedance and C is the filter cap, for a rough value?
/Marcus
This was over 5 years ago. I don't know if there is any newer software out there dedicated to simulating xovers. Could be worth a check.
BTW, can't you just use the formula f = 1/(2*pi*R*C), where R is the speakers nominal impedance and C is the filter cap, for a rough value?
/Marcus
planet10 said:
Just wondering, doesn't the woofer need impedance compensation at higher freq (Zobel type filter) and impedance correction at resonance, in order to present a near resistive load to the amp? This is based on the freq response curve that I am asking.
And also some say that the manuf. spec curves are not that accurate. If so, how do we measure these specs ourselves.
prash said:
It is nice to give the amp as flat an impedance as possible, especially if you are using an SE tube amp, but in this case the added complexity is probably not worthwhile. You can get a good crack at the resonance peak in a TL or aperiodic enclosure.
Impedance correction is used more so that a complex XO in front of it sees a flat impedance.
dave
I have built a TLb using a single North Creek Music Crescendo 10uf Cap on the tweeter only, the woofer runs full range, and the tweeter does not need to be lowered in dB. It works just fine.
As for the bass, being a Transmission Line, it does extend the bass from the manufacter's figures, but this speaker was designed for transient responce and it has that in spades. Every commercial speaker I have listen to since building the TLb, does not come close. (Tannoy, NHT, Sonique and others). I use them with a Phoenix Diploe woofer for the low stuff.
My technical knowledge is limmited, but I do know what sounds good, and the TLb is one of the best "Hi"-Fi speakers in existance!
As for the bass, being a Transmission Line, it does extend the bass from the manufacter's figures, but this speaker was designed for transient responce and it has that in spades. Every commercial speaker I have listen to since building the TLb, does not come close. (Tannoy, NHT, Sonique and others). I use them with a Phoenix Diploe woofer for the low stuff.
My technical knowledge is limmited, but I do know what sounds good, and the TLb is one of the best "Hi"-Fi speakers in existance!
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