But I really don't know why you spoilt your effort by taking the crossover lower, Lojzek! This is not what we want to be doing with the Vifa XT25 here, which, FWIW, is almost IDENTICAL to the ScanSpeak R2604. Unsurprising since Tymphany own Vifa.
Danner, I won't spare your feelings here, because the engineering always wins, but your crossover is distinctly Mickey Mouse. You might as well have this Visaton HW2/70...
HW 2/70 NG - 8 Ohm
I thought this Troels CSM design was pretty darn similar to your setup:
Compact Studio MonitorKIT #
So I have lifted his R2604 2.8kHz High Pass filter almost exactly. Third order and the smaller coil should cure any Fs problems. "Window on the sound" be jiggered, that bass needs a bigger coil to ease design. I ended up with the below circuit.
I could do something a bit simpler with smaller component changes to your current 2nd. order filter, but my heart isn't in it really.
Attachments
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If I were you, I would give up on the XT 25-s. I suffered months with them, tried everything possible (shunting, parallel/series notch filters, reduce/change the rear cup size etc.) but they never really sounded right for some reason. I tried them with different 6 inchers from Scan, and SB Acoustics- no music enjoyment. It is difficult to admit - and cannot really pinpoint why- but they are a flawed design. Sorry Vifa, there are other excellent tweeters made by them, but not these... Finally I settled with the fabulous SB 29 RDC-s, oh boy.... I am not even trying to describe the difference. Even Vifa's own DX25 TG-s are so much better it is hard to believe. The XT-s are just plain not worth the time to fiddle with, switch to something better and live happily ever after.....
#Inductor
Yeah yeah we r not always all that fast xD
If the tweeter is the problem, I think I might discard the tweeter and the crossover. Replace the driver with this one:
30 mm diskant 4 Ohm XT Black - ScanSpeak Illuminator - FreQuence
Rebuild the crossover while using my own reciver for testing this time.
What are your thoughts of this driver ? I wan't to stay with Scanspeak.
And should i lover the crossover point while im at it? if so how much?
It all depends on weather or not it's the tweeter or not though
Yeah yeah we r not always all that fast xD
If the tweeter is the problem, I think I might discard the tweeter and the crossover. Replace the driver with this one:
30 mm diskant 4 Ohm XT Black - ScanSpeak Illuminator - FreQuence
Rebuild the crossover while using my own reciver for testing this time.
What are your thoughts of this driver ? I wan't to stay with Scanspeak.
And should i lover the crossover point while im at it? if so how much?
It all depends on weather or not it's the tweeter or not though
The Illuminator tweeter is a very good one, used in some hyper-expensive designs (Sonus faber, Magico), but IMO seriously overpriced. For a fraction of it you can have the above mentioned SB 29 RDC, which you must hear to believe how good it is. (Zaph|Audio). It is also an -easy to integrate- type of tweeter, not requiring complex crossover design. SB Acoustics is a company formed by ex-Scan-Speak designers, so it is "almost" Scan-Speak, but their prices are mush more realistic. Check out: Killer Tweeter - SB Acoustics SB29 Ring Radiator.
And- icing on the cake- its mounting size is the same as the Illuminator's.....
Also, for about 150 USD you can have its "super-duper" double faceplate version, which is still less than a half of the Illuminator's price
http://www.madisoundspeakerstore.com/sb-acoustics-soft-dome-tweeters/satori-tw29r-ring-dome-tweeter/
And- icing on the cake- its mounting size is the same as the Illuminator's.....
Also, for about 150 USD you can have its "super-duper" double faceplate version, which is still less than a half of the Illuminator's price
http://www.madisoundspeakerstore.com/sb-acoustics-soft-dome-tweeters/satori-tw29r-ring-dome-tweeter/
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If I had any doubts about Vifa XT 25, the only logical thing would be not
to buy XT's offspring called Scan Speak. I'd choose Classic range over
everything else anytime. Cheaper than Revelators and high quality.
I know SB, my sub is a SB. However the tweeters I have now where free, that's why I used them, if I'm gonna buy new tweeters I would really like to be satisfied of course on the sound and I won't buy anything I haven't heard. However the visual is not irrelevant to me, and if the sound is better or the same, I wouldn't mind paying that extra for the illuminator over a SB. At least not for this specific set of speakers besides I might get a good price
But I definitely will consider that SB for another build Thx.
I'we heard one of the more expensive XT's and I loved the sound of it, that's why I'll go for another XT..
But is there really no difference at all on a classic and a illuminator?
But I definitely will consider that SB for another build Thx.
I'we heard one of the more expensive XT's and I loved the sound of it, that's why I'll go for another XT..
But is there really no difference at all on a classic and a illuminator?
Danner, the problem with the XT25 ring radiator is that it's not ferrofluid damped, so the peaky Fs resonance can cause problems.
I don't see that as a big problem with correct design of the filter. It's how tweeters used to be.
SB Acoustics use a similar toroidal design, the centre is pinned, but I'd guess it's ferrofluid damped. Crossover design is then simpler.
There's good theoretical reasons why ring radiators might work better than soft domes. It's to do with eliminating the troublesome resonance at the centre of the spherical dome by pinning it.
I don't know if SB Acoustics or the Vifa/Scanspeak approach is better. I'm sure Vifa/Scanspeak would have added ferrofluid if they thought it helped though.
An externally hosted image should be here but it was not working when we last tested it.
I don't see that as a big problem with correct design of the filter. It's how tweeters used to be.
SB Acoustics use a similar toroidal design, the centre is pinned, but I'd guess it's ferrofluid damped. Crossover design is then simpler.
An externally hosted image should be here but it was not working when we last tested it.
There's good theoretical reasons why ring radiators might work better than soft domes. It's to do with eliminating the troublesome resonance at the centre of the spherical dome by pinning it.
I don't know if SB Acoustics or the Vifa/Scanspeak approach is better. I'm sure Vifa/Scanspeak would have added ferrofluid if they thought it helped though.
Neither the Vifa or SB ring radiators employ ferrofluid, but in the case of the SB-s the resonance peak is almost inaudible (the max impedance peak at Fs is only around 7 ohms, while the Vifa's is around 25 ohms!), so you can use those safely from about 1.5kHz with a 2nd order network.
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Okei, thx for the explanation!
I have now testet without the tweeter, and that def. removed the problem, so the problem was with the tweeter somehow.
So if i go with my old woofer and the tweeter
30 mm diskant 4 Ohm XT Black - ScanSpeak Illuminator - FreQuence
Where should the crossoverpoint then be? Should it be lover than Troels 2.5 kHz ? around 2 kHz maybe?
I have now testet without the tweeter, and that def. removed the problem, so the problem was with the tweeter somehow.
So if i go with my old woofer and the tweeter
30 mm diskant 4 Ohm XT Black - ScanSpeak Illuminator - FreQuence
Where should the crossoverpoint then be? Should it be lover than Troels 2.5 kHz ? around 2 kHz maybe?
I would take this one, but that's only my personal choice (in this thread for this post).
http://www.scan-speak.dk/datasheet/pdf/d3004-662000.pdf
http://www.scan-speak.dk/datasheet/pdf/d3004-662000.pdf
Since the Scan tweeters Fs is 520 Hz, you can cross it over as low as 1.8-2 kHz, but it is always the case of final "voicing" with the XO parts. HF dispersion, and off axis response will be better with lower crossing point, distortion, and the stress put on the tweeter will be better with higher XO frequency. Playing with parts values (+/-10-15% off from the calculated ones) sometimes can make a big difference in overall sound quality.
This is like repeatedly watching a car crash in slow motion.
I keep telling you the problem is your Mickey Mouse 3kHz tweeter filter is useless for the particular Vifa XT25 or Scanspeak R2604, which do have Fs resonance problems with poor shallow and low crossovers.
Now it seems you have ordered an expensive boutique tweeter in some vague hope that throwing a new ring radiator tweeter at it will fix a broken crossover, the ScanSpeak Illuminator R3004/6620-00. Well, read my lips, THAT one has even worse Fs problems. Fs impedance is 25 ohms. Troels found it necessary to apply a ca. 6dB 550Hz Fs notch on a 2.5kHz crossover: Ellam-FLEX-3W
My own opinion is that Fs notches sound horrible and are hard to implement, and you will do far better with a steep third order and some shunt resistance across the tweeter to reduce the Fs impedance peak. And crossing high is a particularly good thing with these tweeters. 3kHz XO is hardly stressing a 6" bass into cone breakup. But hey, time will tell.
I keep telling you the problem is your Mickey Mouse 3kHz tweeter filter is useless for the particular Vifa XT25 or Scanspeak R2604, which do have Fs resonance problems with poor shallow and low crossovers.
An externally hosted image should be here but it was not working when we last tested it.
Now it seems you have ordered an expensive boutique tweeter in some vague hope that throwing a new ring radiator tweeter at it will fix a broken crossover, the ScanSpeak Illuminator R3004/6620-00. Well, read my lips, THAT one has even worse Fs problems. Fs impedance is 25 ohms. Troels found it necessary to apply a ca. 6dB 550Hz Fs notch on a 2.5kHz crossover: Ellam-FLEX-3W
My own opinion is that Fs notches sound horrible and are hard to implement, and you will do far better with a steep third order and some shunt resistance across the tweeter to reduce the Fs impedance peak. And crossing high is a particularly good thing with these tweeters. 3kHz XO is hardly stressing a 6" bass into cone breakup. But hey, time will tell.
Attachments
Andrew,
post #2 shows the schematic of the filter Danner has right now
installed and the post #17 shows the simulation of XO parts of his
original filter and mine, which I made up playing around with it.
The values of the parts are written in the same manner as original
filter from post #2 with the addition of a 3rd order for the tweeter.
post #2 shows the schematic of the filter Danner has right now
installed and the post #17 shows the simulation of XO parts of his
original filter and mine, which I made up playing around with it.
The values of the parts are written in the same manner as original
filter from post #2 with the addition of a 3rd order for the tweeter.
Sometimes I think the OP's are not doing simulations. Just my guess.
Maybe only calculators, or tables. That's very bad. What would work for their first input in their first simulation design they are using as final. One design that doesn't fit all...
Then you have the others things to match, output level, phase, impedance, BSC, compensations...
Maybe only calculators, or tables. That's very bad. What would work for their first input in their first simulation design they are using as final. One design that doesn't fit all...
Then you have the others things to match, output level, phase, impedance, BSC, compensations...
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