Vifa xt25 tweeter

[ThomasW]

Hi

They're only in the raw stage (prototype baffle w/ drivers mounted)

Jon just had lumbar disc surgery and isn't able to 'lift' more than 10lbs, so the requesite measurements haven't been completed.

Basic design is to use a full passive XO. The woofers are 10" Titanics. Their natural roll-off characteristics make a fullrange passive XO possible.

Here's a link where he discusses some aspects of the project

 

[transducer]

Thanks Thomas. I just read through the whole thread you linked to, and it's exactly what I want to design as well. I've always been interested in Linkwitz' designs, but not the overly complex active crossover and the need for 6 channels of amplification. I'd much rather go passive all the way and throw a big amp like a bryston at it.

I have a pair of Titanic 1200 drivers that I've used successfully in an H frame dipole woofer, albiet with active eq., and I loved that. I'm now building a small panel with an 8" vifa and a Seas tweeter. I hope to test some alternate 8" woofers, a Vifa MG and a Peerless HDS. I can't say that the T1200 has any sort of rolloff like the 10" version seems to, at least not in the nearfield. Too bad because just last night I was trying to work out how to do a passive crossover that would have the dipole eq and then transition into a 4th LR, and I couldn't do it I'm using SoundEasy as my crossover optimizer and network design program. I've got IMP/M for FFT measurements.

Hope Jon gets better quickly, I've been in touch with him in the past over one thing or another, great guy.

 

[Per Nielsen]

Is it not a litle low to cross this tweeter at 1.25??

SvErD I yoused water based kontact glue to the phase plug, and heat ressistent glue to the voice coil perhaps tommorrow I will post pics when I get my cam.

 

[AKSA]

Nah, Per,

The ft is at 500Hz...........

Hugh

 

[transducer]

Nah, Per,

The ft is at 500Hz...........

Hugh

Actually, even though the Fs is 500Hz, that doesn't tell the whole story, this tweeter is more like a 3/4" dome than a 1" dome. It has very high second order distortion if driven low, and should be crossed over quite HIGH if you don't want to hear the distortion. I have several graphs from Siegfried Linkwitz, who tested this tweeter, and they clearly show the distortion at low frequencies. On the other hand, it is remarkably low in distortion higher up in freq. especially the higher harmonics, better than Seas or Scan top of the line models

So I would say that crossing anywhere BELOW 2.5kHz with a steep order filter is asking for trouble.

Regards,
RonS

 

[Irwin AR]

I hope this would add as an additional info on the variety of
implementation for the ring radiator unit.
This is the Alpine (Japanese) version of the Vifa with dual-voice
coil! Hell.. even the midbass kicked ***

http://translate.google.com/transla...ww.reqst.com/pro-features.html&hl=en&lr=&sa=G

 

[mikaljones21]

I have this tweeter and use an active crossover. I have mine crossed at 3300 with LR4 slope. I tried it at 2500 but it didn't sound as good. Stage was compromised. Thought I could hear distortion too?? Really nice driver though. I think anywhere between 3000 to 3500 will be fine.

 

[mikaljones21]

This guy uses the Vifa XT25 on this design too. Take a look. This was where I got the idea to use it.