I'm planning tu build a three way around the design of the Jansen CA from TG :
Jenzen CA
One of the recomemended tweeter is the seas T25CF001 wich cost around 100 € :
E0006-06 T25CF001
Fabric dome, magnetic fluid, rear chamber
One other well known tweeter is the seas 27TDFC cost about 45 € :
H1189-06 27TDFC
Has anyone heard those tweeters and do you think the T25CF001 has an extra value from the seas 27TDFC ?
From the datasheet I find no real differences exept the bigger faceplace 🙄 Both have Fabric dome, magnetic fluid, rear chamber.
The 27TDFC has -1 db sensitivity than the other and a slightly rinsing response in the last octave.
Jenzen CA
One of the recomemended tweeter is the seas T25CF001 wich cost around 100 € :
E0006-06 T25CF001
Fabric dome, magnetic fluid, rear chamber
One other well known tweeter is the seas 27TDFC cost about 45 € :
H1189-06 27TDFC
Has anyone heard those tweeters and do you think the T25CF001 has an extra value from the seas 27TDFC ?
From the datasheet I find no real differences exept the bigger faceplace 🙄 Both have Fabric dome, magnetic fluid, rear chamber.
The 27TDFC has -1 db sensitivity than the other and a slightly rinsing response in the last octave.
Well for a start, I wouldn't advise second guessing Troels. If you want to build one of his designs, it's presumably because you like it, and trust him and the way he does things. Trying to save $110 on a mid-high price design by stuffing a cheaper tweeter into it doesn't make much sense to me.
That aside, it's a fair comment that relative to the 27TDFC (probably still the best budget soft-dome on the market and one of the all-time great tweeter designs given the price / performance ratio), the Excel tweeter doesn't look great value. It isn't. But spec. and behaviour are not the same, so they're not drop-in replacements; the crossover will need to be redesigned. Impedance, frequency response on & off axis, SPL, LF rolloff profile, distortion behaviour etc. are all somewhat different -not necessarily vast differences, but sufficient. FWIW, the Excel, when crossed > 2KHz, is an improvement over the TDFC in most regards. Not night and day, since the TDFC sets the bar quite high, despite the low price, but reasonable. Distortion products (especially high order) are lower, the small waveguide is well designed so behaviour is consistent off-axis & it holds up well, on-axis FR is slightly flatter so you don't need to EQ this in the XO etc. if it bothers you (it's easy to flatten, but it does mean a couple more components). The TDFC does score over the Excel in one respect (other than price) -like the Millennium it can hang on in there down to very low frequencies for a 1in dome tweeter owing to a dip in higher order distortion between 1KHz - 2KHz (3rd order is a bit high, but acceptable). I've crossed it < 1.5KHz before now but that depends what you're doing. In the case of Troels's 3-way, that doesn't apply of course. IIRC, Troels doesn't actually like the TDFC & TDC -he prefers the older TFF and TFFC; if memory serves he thinks the newer models sound a bit dry / scratchy. To be honest, I disagree with him on that particular point, but YMMV as ever. Either way though, my advice is do yourself a favour and stick with the Excel tweeter. That's what it was designed for, and it's a higher performer in applications like this, if a little over-priced.
That aside, it's a fair comment that relative to the 27TDFC (probably still the best budget soft-dome on the market and one of the all-time great tweeter designs given the price / performance ratio), the Excel tweeter doesn't look great value. It isn't. But spec. and behaviour are not the same, so they're not drop-in replacements; the crossover will need to be redesigned. Impedance, frequency response on & off axis, SPL, LF rolloff profile, distortion behaviour etc. are all somewhat different -not necessarily vast differences, but sufficient. FWIW, the Excel, when crossed > 2KHz, is an improvement over the TDFC in most regards. Not night and day, since the TDFC sets the bar quite high, despite the low price, but reasonable. Distortion products (especially high order) are lower, the small waveguide is well designed so behaviour is consistent off-axis & it holds up well, on-axis FR is slightly flatter so you don't need to EQ this in the XO etc. if it bothers you (it's easy to flatten, but it does mean a couple more components). The TDFC does score over the Excel in one respect (other than price) -like the Millennium it can hang on in there down to very low frequencies for a 1in dome tweeter owing to a dip in higher order distortion between 1KHz - 2KHz (3rd order is a bit high, but acceptable). I've crossed it < 1.5KHz before now but that depends what you're doing. In the case of Troels's 3-way, that doesn't apply of course. IIRC, Troels doesn't actually like the TDFC & TDC -he prefers the older TFF and TFFC; if memory serves he thinks the newer models sound a bit dry / scratchy. To be honest, I disagree with him on that particular point, but YMMV as ever. Either way though, my advice is do yourself a favour and stick with the Excel tweeter. That's what it was designed for, and it's a higher performer in applications like this, if a little over-priced.
I owned the two tweeters (also the 27TFFC), the 27TDFC is the best value to my ears. The T25 is a good tweeter, with refinement but too expensive for the performance, not very at ease below 2kHz.
The 27TDC can be married with excel woofers without any complex. I used it too with the ER18NX and the marriage works well (see also : Zaph|Audio - ZA-SR71).
I don't think you need to change the crossover of the Jensen CA with a 27TDFC, perhaps the level of attenuation
Note I also disagree with Troëls about the 27TFFC vs 27TDFC 😉
The 27TDC can be married with excel woofers without any complex. I used it too with the ER18NX and the marriage works well (see also : Zaph|Audio - ZA-SR71).
I don't think you need to change the crossover of the Jensen CA with a 27TDFC, perhaps the level of attenuation
Note I also disagree with Troëls about the 27TFFC vs 27TDFC 😉
@Scottmoose : thanks very much for your long and detailled anwer, answer including both technical and subjective aspects.
I'm planning to do mysel a favour 😉.
@jerome69 : also thank you 🙂.
I'm planning to do mysel a favour 😉.
@jerome69 : also thank you 🙂.
I would shy away from tweeters using ferro-fluid. This material is usually employed to remedie shortcomings that shouldn't be there in the first place.
I wouldn't. Many excellent tweeters employ ferrofluid, in the same way that there are many excellent tweeters that do not.
Ferrofluid is good for voice coil's longer life, dampens the impedance peak too.
I have come to a conclusion that Seas cheaper domes are good sounding fabrics.
I have come to a conclusion that Seas cheaper domes are good sounding fabrics.
Don't overlook the 27TDC....I've used several generations of the Excel's and the TDFC, TFFC etc...regular series. The 27TDC holds a special place in my heart for Seas tweeters for flat out performance...not performance for the dollar, but overall sound.
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