Shakey
New Head-Fier
- Joined
- Mar 28, 2004
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Like quite a few Head-fi members, I am a happy owner of a pair of Spica TC50's and have loved their sound and affordability. As most owners know, the Spica's have a fantastic midrange, but suffer from a rolled off bass and treble response (55Hz to 17KHz according to Spica). To make things worse, the Spica's Audax sourced tweeters (TW025A2) are no longer manufactured and NOS drivers are impossible to find.
The Audax tweeters are especially problematic because they roll off pretty steeply after 12KHz-14KHz and a lot of higher frequency "air" and transparency seems to be missing in action. Also, they have an extremely low power handling capability (55 watts) and loads of Audax tweeters have been fried from playing music at not-unreasonably high levels.
So, having fried one of my original Audax tweeters about 8 months ago, I had to find a replacement driver that fit the bill. Unfortunately it seems that most driver manufacturers have stopped making 4 ohm tweeters and the choice was pretty limited. I luckily found a very helpful person at www.madisound.com who recommended two choices, both made by Vifa:
1) MG27TG29-04 ($22.10)
2) DX25TG05-04 ($26.10)
I ended up choosing the MG27TG29-04 for a couple of reasons. The first was that it more closely matched the freq. curve of the original Audax tweeter (amazingly so, actually). Also, the Fs factor also more closely matched the Audax:
Audax Free Air Resonance (Fs): 1090.5 Hz
MG27TG29-04 (Fs) : 1050 Hz
DX25TG05-04 (Fs) : 650 Hz
In terms of physical dimensions, the DX25TG05-04 faceplate is a wee bit thicker than the MG27TG29-04 and their freq. curves and a few other specs. are also slightly different:
DX25TG05-04 at Madisound:
http://www.madisound.com/cgi-bin/ind...27857&pid=1365
MG27TG29-04 at Madisound:
http://www.madisound.com/cgi-bin/ind...29165&pid=1381
The MG27TG29-04 faceplate, at 104mm, is 4mm wider than the 100 mm wide Audax driver so you can either widen the cutout on the Spica or simply slide the Vifa in and let the faceplate sit on top of the Spica baffle, as opposed to flush with it. If you decide not to widen the front baffle, the Vifa driver will sit 4mm forward of the original tweeter position.
Finally, the sound quality:
I am pretty amazed by the difference in sound between the Audax drivers and the Vifa MG27TG29-04. The Vifa tweeter extends all the way out to 25KHz-30KHz and this extended range results in a much, much wider and open soundstage. The details and imaging are improved across the board and the Spica TC50 really compares favorably to my friends B&W Nautilus 805 from the lower midrange and up. Violins, voices, live concerts, etc., suddenly open up in a way that the original Spica was totally incapable of re-creating.
I was on the verge of pulling the trigger on a Nautilus 805 or a Dunaudio Contour but the Vifa modified Spica is such a revelation that I feel it's a completely different and vastly improved speaker that I can live with for a long, long time.
The Vifa's did take a long time to break in. It took about a month of playing before the Vifa's settled in. During this period, they sounded clinical and bright, but after they broke in, they mellowed to the classic Spica midrange, except with an incredibly open and transparent high end.
The Vifa's can handle up to 950 watts of peak power which means that you can crank the Spica's way up to 11 with no ill effects. What's not to like?
I think that every Spica TC50 owner should go out and try this. It's the most cost effective upgrade you'll make in a long time!
The Audax tweeters are especially problematic because they roll off pretty steeply after 12KHz-14KHz and a lot of higher frequency "air" and transparency seems to be missing in action. Also, they have an extremely low power handling capability (55 watts) and loads of Audax tweeters have been fried from playing music at not-unreasonably high levels.
So, having fried one of my original Audax tweeters about 8 months ago, I had to find a replacement driver that fit the bill. Unfortunately it seems that most driver manufacturers have stopped making 4 ohm tweeters and the choice was pretty limited. I luckily found a very helpful person at www.madisound.com who recommended two choices, both made by Vifa:
1) MG27TG29-04 ($22.10)
2) DX25TG05-04 ($26.10)
I ended up choosing the MG27TG29-04 for a couple of reasons. The first was that it more closely matched the freq. curve of the original Audax tweeter (amazingly so, actually). Also, the Fs factor also more closely matched the Audax:
Audax Free Air Resonance (Fs): 1090.5 Hz
MG27TG29-04 (Fs) : 1050 Hz
DX25TG05-04 (Fs) : 650 Hz
In terms of physical dimensions, the DX25TG05-04 faceplate is a wee bit thicker than the MG27TG29-04 and their freq. curves and a few other specs. are also slightly different:
DX25TG05-04 at Madisound:
http://www.madisound.com/cgi-bin/ind...27857&pid=1365
MG27TG29-04 at Madisound:
http://www.madisound.com/cgi-bin/ind...29165&pid=1381
The MG27TG29-04 faceplate, at 104mm, is 4mm wider than the 100 mm wide Audax driver so you can either widen the cutout on the Spica or simply slide the Vifa in and let the faceplate sit on top of the Spica baffle, as opposed to flush with it. If you decide not to widen the front baffle, the Vifa driver will sit 4mm forward of the original tweeter position.
Finally, the sound quality:
I am pretty amazed by the difference in sound between the Audax drivers and the Vifa MG27TG29-04. The Vifa tweeter extends all the way out to 25KHz-30KHz and this extended range results in a much, much wider and open soundstage. The details and imaging are improved across the board and the Spica TC50 really compares favorably to my friends B&W Nautilus 805 from the lower midrange and up. Violins, voices, live concerts, etc., suddenly open up in a way that the original Spica was totally incapable of re-creating.
I was on the verge of pulling the trigger on a Nautilus 805 or a Dunaudio Contour but the Vifa modified Spica is such a revelation that I feel it's a completely different and vastly improved speaker that I can live with for a long, long time.
The Vifa's did take a long time to break in. It took about a month of playing before the Vifa's settled in. During this period, they sounded clinical and bright, but after they broke in, they mellowed to the classic Spica midrange, except with an incredibly open and transparent high end.
The Vifa's can handle up to 950 watts of peak power which means that you can crank the Spica's way up to 11 with no ill effects. What's not to like?
I think that every Spica TC50 owner should go out and try this. It's the most cost effective upgrade you'll make in a long time!
