system7, thanks for your work and insights.
Should I remove the 20ohm resistor?
As for complete crossover changes, the speaker sounds so excellent at low and medium volumes inevery region except low bass though, wouldn't a complete rework change the sound completely? Nothing I have previously heard beats the CS1.2 for mids and highs.
Like you say, though, during dense high volume stuff it doesn't really shine. It becomes congested.
What about the path of removing the tweeter, woofer, and crossover, and starting anew using the frankly awesome CS1.2 cabinet as a base and put in newer, more capable drivers and crossovers? The enclosure has lots of volume, so I think it could accomodate lots of different 6" woofers, taking away inteior volume and changing port dimensions as needed.
Thirdly, maybe I would acheive the same result by putting a high-order low-pass filter around 80hz or so and use helper stereo subs for the low bass, allowing higher volumes without the Thiels getting congested? Or is the congestion caused by the midbass getting into the tweeter, making this a moot point?
Should I remove the 20ohm resistor?
As for complete crossover changes, the speaker sounds so excellent at low and medium volumes inevery region except low bass though, wouldn't a complete rework change the sound completely? Nothing I have previously heard beats the CS1.2 for mids and highs.
Like you say, though, during dense high volume stuff it doesn't really shine. It becomes congested.
What about the path of removing the tweeter, woofer, and crossover, and starting anew using the frankly awesome CS1.2 cabinet as a base and put in newer, more capable drivers and crossovers? The enclosure has lots of volume, so I think it could accomodate lots of different 6" woofers, taking away inteior volume and changing port dimensions as needed.
Thirdly, maybe I would acheive the same result by putting a high-order low-pass filter around 80hz or so and use helper stereo subs for the low bass, allowing higher volumes without the Thiels getting congested? Or is the congestion caused by the midbass getting into the tweeter, making this a moot point?
moebuster, if you need a replacement woofer, you can buy them here:
Vifa P17WJ-00-08 Woofer
Vifa, P17WJ-00-08
Vifa P17WJ-00-08 Woofer
Vifa, P17WJ-00-08
Hmm.......
I'd try making from scratch.
The morel cat 378, using a single cap, would be a good start.
I'd try making from scratch.
The morel cat 378, using a single cap, would be a good start.
No. It's a lousy idea. You haven't done your homework here. This is a time-aligned sloped baffle design, why would you want a waveguided Morel CAT 278 tweeter? 😛
The best idea is to convert this first order LGWAG speaker to third-order butterworth. A considerable modelling project, but the Heybrook HB2 gives you a point of departure. Nice drivers.
12db, yuck.
Some of us really like a 6db time aligned speaker. Yes, distortion is high and dynamics are low, but voice and transients are good.
And the waveguide on the morel moves the acoustic tweeter center back. That tweeter seems rugged and has a low Fs (that would need to be notched). It may be the same tweet as in the Devore orangutan.
Norman
Some of us really like a 6db time aligned speaker. Yes, distortion is high and dynamics are low, but voice and transients are good.
And the waveguide on the morel moves the acoustic tweeter center back. That tweeter seems rugged and has a low Fs (that would need to be notched). It may be the same tweet as in the Devore orangutan.
Norman
Perhaps I should remove the passive crossovers and just control the Thiels with a miniDSP?
Which is not devoid of its own compromises. Nor are 3rd order Butterworth filters for that matter. It depends exactly what it is you are hoping to achieve.
Well, with all this talk of the problems with the CS1.2 stemming from power handling due to the 1st order tweeter crossover, it would be interesting to be able to increase the high volume capability of this speaker to see what it sounds like. Perhaps this experimentation should be done digitally with a miniDSP?
sure. It will sound different, but one person's "different" is another person's " better" or "worse" depnding on what they value or define sound quality as.
norman
norman
Hi....
Anyone knows why the Vifa woofer of my CS1.2 is a P17WJ-01 of 4 ohms??Seems thats the model fitted was 8 ohms...
Manuel
Anyone knows why the Vifa woofer of my CS1.2 is a P17WJ-01 of 4 ohms??Seems thats the model fitted was 8 ohms...
Manuel
It turns out that the Vifa P17WJ-00-08 theory is just a wrong assumption of System7 (http://www.diyaudio.com/forums/multi-way/265242-can-thiel-cs1-2s-upgraded.html#post4129984).
According to a german forum (Ersatz - Tieftöner für Tiehl 1.2CS, Lautsprecher und Subwoofer - HIFI-FORUM) the woofer of the Thiel CS 1.2 is labeled
Vifa P17WJ-01 601 4Ohm
4 Ohm is also mentioned here: Speaker Asylum
There's nothing wrong with your speaker. 🙂
According to a german forum (Ersatz - Tieftöner für Tiehl 1.2CS, Lautsprecher und Subwoofer - HIFI-FORUM) the woofer of the Thiel CS 1.2 is labeled
Vifa P17WJ-01 601 4Ohm
4 Ohm is also mentioned here: Speaker Asylum
There's nothing wrong with your speaker. 🙂
Hey cuckoo-clock man, it was EVERYBODY'S assumption. No need to be snarky! 😀
The Vifa P17WJ-00-04 data is here: http://www.sea.vg/vifa/P17WJ-00-04_data.pdf
We guess it was a robust SEAS 25TAC/GW with long tinsel leads.
http://www.seas.no/images/stories/vintage/pdfdataheet/h0417_25tacgw.pdf
Combine the electrical with the frequency response and it's quite well-behaved. But I'd still lose that 20R resistor on the tweeter, the effect of which is shown in the dotted line. Looks much better to me. And fitting the Vifa P17 8 ohm version, which is still available looks a reasonable fix for broken ones.
Attachments
Does anyone have a source for replacement tweeters for the CA1.2? I'm looking for the Seas dome tweeter or a replacement tweeter with similar specs.
marcmathieu
marcmathieu
I would think this one would do it:
H1212-06 27TBFC/G
104mm. Slim connection tags. Ability to go low. Ferrofluid never does much harm. Go for it.
H1212-06 27TBFC/G
104mm. Slim connection tags. Ability to go low. Ferrofluid never does much harm. Go for it.
Hi,
First post here. I have 1.2s as well and the fluid had dried out of the tweeters. I did replace them with H1212-06 after speaking to Madisound. I was assured by the salesman that they would not require any change to the crossover and have greater power handling. Just the ticket. I think they sound even better than the stock old tweeters. You will have to notch out space for the connection tags because they’re not in the same location as the original stock ones. I
Unfortunately, the woofer surrounds aren’t going to last much longer. The replacement woofers from Thiel are priced to be economically unreasonable. In all likelihood I’ll just have to buy something new when they do finally fail, so I was looking at the Zaph SR71 kit from Madisound. While researching the sr71 on Zaph’s website, I noticed the he had designed a speaker using this tweeter along with a metal cone woofer. I noticed in his description of his design process that he really wanted to use a 2nd order crossover, but that would require a slanted cabinet. Can you see where I’m going here? Would it be unlikely to replace the woofer with the seas l18 (I believe) and design or have designed a crossover that would work well? I would be a shame to throw out these 50 pound each cabinets.
First post here. I have 1.2s as well and the fluid had dried out of the tweeters. I did replace them with H1212-06 after speaking to Madisound. I was assured by the salesman that they would not require any change to the crossover and have greater power handling. Just the ticket. I think they sound even better than the stock old tweeters. You will have to notch out space for the connection tags because they’re not in the same location as the original stock ones. I
Unfortunately, the woofer surrounds aren’t going to last much longer. The replacement woofers from Thiel are priced to be economically unreasonable. In all likelihood I’ll just have to buy something new when they do finally fail, so I was looking at the Zaph SR71 kit from Madisound. While researching the sr71 on Zaph’s website, I noticed the he had designed a speaker using this tweeter along with a metal cone woofer. I noticed in his description of his design process that he really wanted to use a 2nd order crossover, but that would require a slanted cabinet. Can you see where I’m going here? Would it be unlikely to replace the woofer with the seas l18 (I believe) and design or have designed a crossover that would work well? I would be a shame to throw out these 50 pound each cabinets.
You can replace ferrofluid easily enough. Parts express sell it. I really don't see anything wrong with the idea of using the polycone Vifa P17WJ-00-08 here. It's still around. You might have to take the tweeter down a tidge.
There are quite a few 6" plus 1" designs around. DIY-Loudspeakers. This Michael Chua one impressed me: Seas ER18RNX with 27TDFC
I wouldn't have thought phase was a huge issue on sloped baffle. You usually flip tweeter polarity.
There are quite a few 6" plus 1" designs around. DIY-Loudspeakers. This Michael Chua one impressed me: Seas ER18RNX with 27TDFC
I wouldn't have thought phase was a huge issue on sloped baffle. You usually flip tweeter polarity.
Hi, I am helping a friend replace the woofers in his 1.2s.. Is the ScanSpeak Classic P17WJ00 suitable? It is 8ohm vs the 4ohm of the original; I am not sure how this will affect the sound, and any possible ill effects with the crossover.
If 4 ohm is preferred, does anyone have a recommendation?
If 4 ohm is preferred, does anyone have a recommendation?
You may be able to preserve the electrical topology as on the basis of a very quick look the basic response curves of the 4ohm & 8ohm models was similar. But you'll also need to change quite a few component values; the tweeter level padding will need changing to match the different unit, which in itself may require some adjustments elsewhere. And the low pass values & Zobel will all need to be altered to reflect the changed impedance. This doesn't necessarily have to be as difficult as it sounds; I'm on my laptop at the moment though & don't have time to check anything properly. Will have a look later; no doubt Steve will make some suggestions also.
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