Seas 27TDFC H1189 vs Seas 27TFFC H881

[karoly7603]

Thank you for your info. According to a lot reading, suggestions, etc. I settled down at the 27tdf. It is a good choice next to the Seas MCA15RCY midrange.
You are absolutely right, but I don't have any measuring stuff so my problem starts here.
So only textbook, ear, Xsim simulation and a lot listening test unfortunately.

 

[karoly7603]

Thank you the info. I read after today and it is a very good tweeter indeed with very linear FR. Somebody told that it is a bit bright but detailed. There isn't much project about it, I think the most popular is the 27TFFC or the 27TDFC. The TDFC is smoother indeed but the TFFC gives wider dispersion as I can see on the original FR curve. Can be heard this in real life?

I know it kind annoying to suggest something else, but I 29tff is a very strong contender

 

[YSDR]

Thank you the info. I read after today and it is a very good tweeter indeed with very linear FR. Somebody told that it is a bit bright but detailed. There isn't much project about it, I think the most popular is the 27TFFC or the 27TDFC. The TDFC is smoother indeed but the TFFC gives wider dispersion as I can see on the original FR curve. Can be heard this in real life?

Actually not much difference in the dispersion between the TDFC and TFFC. The measurements in the TFFC datasheet maybe very old, here is some newer measurement with identical conditions:

SEAS 27TDFC (Tweeter 1", 6 Ohm, 220 Wmax)

SEAS 27TFFC (Tweeter 1", 6 Ohm, 200 Wmax)

Anyway, I would consider the ferrofluidless 27TDC too.

SEAS 27TDC (Tweeter 1", 6 Ohm, 150 Wmax)

 

[karoly7603]

Wow very good info, thanks.
My friend again suggested the TFFC because some PMC use it and sounds fine.
Well, I cannot decide again, TFFC or TDFC.

Actually not much difference in the dispersion between the TDFC
and TFFC. The measurements in the TFFC datasheet maybe very old, here is some newer measurement with identical conditions:

SEAS 27TDFC (Tweeter 1", 6 Ohm, 220 Wmax)

SEAS 27TFFC (Tweeter 1", 6 Ohm, 200 Wmax)

Anyway, I would consider the ferrofluidless 27TDC too.

SEAS 27TDC (Tweeter 1", 6 Ohm, 150 Wmax)

 

[YSDR]

The TFFC waterfall response is the cleanest (and very clean in absolute terms too) of the linked 3 Seas tweeter, maybe that's why some call it boring or dull?? The TDFC have the worst waterfall response here.
Btw the TFFC have the highest sensitivity of them.

 

[karoly7603]

In that case my Monacor DT-254 is not so bad at all, also dispersion is better than the TDFC.
Monacor DT-254

 

[YSDR]

The DT-254 measurements have 1 off-axis response only instead of 2 like with the Seas units. Yes the Monacor dispersion at the top end seems wider but that doesn't mean it's better. Same dome size and almost same faceplate but wider top octave dispersion usually means that the dome are less likely pistonic which means it's working more in break-up mode.

The waterfall is clearly worse than all the three mentioned Seas unit. I bet the spectrogram would be even more revealing but that's missing with the Monacor unit.

 

[karoly7603]

Yes, indeed. Only question regarding the rotational L-Pad potentiometer - that is originally for 8 ohm - how could react with a 6 ohm tweeter?

 

[YSDR]

Yes, indeed. Only question regarding the rotational L-Pad potentiometer - that is originally for 8 ohm - how could react with a 6 ohm tweeter?

Well, it depends. A 8 Ohm tweeter rarely have 8 Ohm impedance, so then to which exact impedance the rotational L-pad was designed??
I would forget the rotary pad anyway, but that's just me.

 

[YSDR]

But of course the 6 Ohm impedance can be lifted to 8 Ohm with a series resistor after the L-pad. This way the 27TFFC's higher sensitivity can be an advantage and privides more flexibility.

 

[karoly7603]

I went to this page, downloaded the FRD and ZMA. Loaded to Xsim.

- Green Monacor DT-254
- Blue, Seas 27TFFC
- Red, Seas 27TDFC
The Monacor is very strong, even at 1Khz almost 90db!
Question is who measured, how and when?

But of course the 6 Ohm impedance can be lifted to 8 Ohm with a series resistor after the L-pad. This way the 27TFFC's higher sensitivity can be an advantage and privides more flexibility.

 

[diyiggy]

Does the 2 ohms resistor after the L-pad not contributing to more noise by thermal behavior ?



Not better to have a more difficult impedance curve/phase mismatch at these "high" frequencies vs the more Z to make the 6 ohm as 8 ohms?


Which of either is the best trade off if one want to use a 6 ohms tweeter in a 8 ohms design ?

 

[karoly7603]

Sorry for late response. I ended up going with the 27TFFC tweeter and we really like the sound so much, nothing complain. It is very listeneable indeed no matter how long time and quite relaxing with no aggressive tendencies. Has smooth, flat response and airy as well. Overall a very good tweeter, thanks for help.

 

[karoly7603]

For curiousity I would try a different tweeter than the 27tffc.

I have had the 27tffc till now. It is a really very good tweeter but after a lot experimenting/listening it is not the best.
Why? For me the rising top-end response is not natural, too much. At strong transient female voices it is like screaming/shouting at the upper tones and hurt the ears. I also tried the 27tdfc and here slightly missing the "airy" feeling that the 27tffc has. None of them is perfect for my ears.


Any recommendations? I would like to have smooth and natural sound without any edge, etc.

Thanks.

 

[celef]

both 27tffc and 27tdfc looks good and similar in many ways, 27tdfc looks to have a bit wider dispersion, what happens if you angle your speakers away from listening position so you are listen more to the off axis response?

 

[karoly7603]

I will try it. Overall the 27tdfc is calmer for the ears, but after 10Khz it can be heared the slightly rising top end. Not much, but it is there.

I am looking some Scanspeak models. Fx. the D2606/92000
Very simple, quite good frequency response and rolled-off top end.

 

[pliedtka]

I played with 27TDFC a little this week - clean but bright, comparing at least to 'my pair' of SB29RDNC. I put Zobel parallel with the tweeter, 3.0-3.3 uF and 2.4-3.0 ohm, the lower resistor value attenuates very top more. Zaph, J. Krutke used similar trick in his SR-71 Seas based kit.
BTW, how about the D2604/83300. Vance seems to like the tweeter and a few others, Heißmann Acoustics.

Ignore the peak-dip around 800 - 1.5kHz which is a surround/cone resonance, and MLS artifact.

 

[karoly7603]

Thank you for your info.
Yes, I also tried it with a 4.7ohm+2uF but the edgy spectrum is always there only dampened.

We have also another speaker an old japansese Pioneer CS-R500 from 1973 and the metal tweeter rediculously much better than either the 27TFFC or the TDFC. It has rich and thick charasteristic or how can I describe it and the instruments are very real. Very pleasant to listen to without any fatigue, I love the way it is even the crossover is original with full electrolyt capacitors. I am a bit disappointed in these Seas models.

 

[pliedtka]

Yeah it's even more with 2uF, actually 2uF with 4.7ohm did nothing to my ears, had to go more radical with 3.3uF-2.4ohm to cut the 'zing' - I get it why my friend complained, that 27TDFC is a horrible tweeter.
I'm still curious how SS D2604/83300 or SB offerings like SB29SDAC sound like. Tempting, but maybe it's better to go straight with Satori and forget the entry level tweeters.

 

[karoly7603]

How is the SB29RDC sound comparing with the 27tdfc?


I am thinking also the SS 2608/91300 version. Is it good?

Good idea, yes, probably I wil sell all of them and will go for a quality one.


I think metal dome tweeters are not always edgy or tiring. In our JBL HP-8B speaker the titanium dome tweeter has fantastic real and crisp presentation.