Ah! Great!
Been looking forward to this actually.. 🙂
Couldn't open the JBL plot, but I could clearly see the differenve in 3d harmonic distortion!
The CT 62 seems quite good though, allthough compared to the JBL, it is evident that it could have been even better with a better motor-system?
Thinking about it.. that would have been quite a cool project, building a new magnet assembly with some copper in the right places, good soft iron and some crazy magnets..
Been looking forward to this actually.. 🙂
Couldn't open the JBL plot, but I could clearly see the differenve in 3d harmonic distortion!
The CT 62 seems quite good though, allthough compared to the JBL, it is evident that it could have been even better with a better motor-system?
Thinking about it.. that would have been quite a cool project, building a new magnet assembly with some copper in the right places, good soft iron and some crazy magnets..
I should mention that I have not applied any smoothing, resolution is 1/48 octave. The L26 puts out about 5dB more than C62 with the same input.
I could do more testing if there is some interest, for example with equal sound pressure for better comparison.
I could do more testing if there is some interest, for example with equal sound pressure for better comparison.
Anders,
Those plots were great, it really elevates the thread when a discussion like this is suddenly substantiated with proper measurements and data! 🙂
What would really be interesting would be to see a similar plot for an "ordinary" dome-tweeter.
Do you have any of those knocking about?
Those plots were great, it really elevates the thread when a discussion like this is suddenly substantiated with proper measurements and data! 🙂
What would really be interesting would be to see a similar plot for an "ordinary" dome-tweeter.
Do you have any of those knocking about?
Hi
Deleted the JBL post it must still be in the browser cache if still visible.
I have a Peerless dome-tweeter 811815 that could be measured.
I'll do a 30 degree offset measurement also and keeping level at about 96dB during all measurements (may not be able to do it this evening but its coming).
My place is right now not properly setup for speaker measurements. I'd like to do longer range measurements but I get to much reflections so all I could do for now is near field. Roof height is a problem, even with MLS it's hard to gate out information due to time (length) restrictions.
Some differences between Peerless C62 and JBL LE26. 😀
Deleted the JBL post it must still be in the browser cache if still visible.
I have a Peerless dome-tweeter 811815 that could be measured.
I'll do a 30 degree offset measurement also and keeping level at about 96dB during all measurements (may not be able to do it this evening but its coming).
My place is right now not properly setup for speaker measurements. I'd like to do longer range measurements but I get to much reflections so all I could do for now is near field. Roof height is a problem, even with MLS it's hard to gate out information due to time (length) restrictions.
Some differences between Peerless C62 and JBL LE26. 😀
An externally hosted image should be here but it was not working when we last tested it.
Woha!
Well, in terms of motor design, there is obviously MORE of it for the JBL tweeter! 🙂
Hmm.. can't help wondering how that CT 62 would perform with an optimized motor design...
since I have access to a lathe at work, it would be no problem to machine the components for a magnet system.
A T-shaped pole-piece with copper rings and a big neo-magnet.. hmm
Perhaps even adding a chassis machined from aluminium?
But the problem would of course be to transplant the cone-voicecoil assembly in one piece and center it poperly in the new motor/ chassis, not to mention getting hold of the right quality magnetic oil and adding the right quantity..
Well, in terms of motor design, there is obviously MORE of it for the JBL tweeter! 🙂
Hmm.. can't help wondering how that CT 62 would perform with an optimized motor design...
since I have access to a lathe at work, it would be no problem to machine the components for a magnet system.
A T-shaped pole-piece with copper rings and a big neo-magnet.. hmm
Perhaps even adding a chassis machined from aluminium?
But the problem would of course be to transplant the cone-voicecoil assembly in one piece and center it poperly in the new motor/ chassis, not to mention getting hold of the right quality magnetic oil and adding the right quantity..
I think the peerless C62 performs good as is. The fact that several highly regarded mfg has chosen it says something. It may look tiny and have limited SPL capabilities but in other regards I think it performs great.
Elbert, may I ask, in what kind of project do you plan to use a cone tweeter?
Elbert, may I ask, in what kind of project do you plan to use a cone tweeter?
You have a good point there Anders, just allowing my self to fantasise a bit there! 🙂
I am just about to finish a couple of 12L closed boxes which will used as stereo speakers together with a subwoofer, possibly two in the longer run.
For bass-midranges I have a pair of Access 6A (Focal) which I got from Zalytron at a reduced price of 35 $ each. These drivers have very light coated cones (Mms 6 g!) foam surround and a very high efficiency of 92 dB (IEC test baffle) The plan is to cross them over to a Tweeter at 4 Khz as this is where they start to roll off.
Speaking about SPL capability, do you have any idea of what the CT 62 is capable of tin this department?
The maximum SPL I expect to see with the 6A's in the stereo-speakers is around 110 dB...
I am just about to finish a couple of 12L closed boxes which will used as stereo speakers together with a subwoofer, possibly two in the longer run.
For bass-midranges I have a pair of Access 6A (Focal) which I got from Zalytron at a reduced price of 35 $ each. These drivers have very light coated cones (Mms 6 g!) foam surround and a very high efficiency of 92 dB (IEC test baffle) The plan is to cross them over to a Tweeter at 4 Khz as this is where they start to roll off.
Speaking about SPL capability, do you have any idea of what the CT 62 is capable of tin this department?
The maximum SPL I expect to see with the 6A's in the stereo-speakers is around 110 dB...
Ok, just looked at the Access 6 specs and to me it looked like a fine driver (just happen to like the combination of high Qm, light cones and foam surround).
Some domes do have good sensitivity, this Peerless tweeter is highly regarded, although somewhat expensive.
I have no experience in C62 SPL capabilities. I just noticed that they blow occasionally. Maybe distortion rise at high levels due to loss of saturation in the VC gap. I'm only speculating here so take it for what it is. Someone with experience of C62 may answer this better.
Some domes do have good sensitivity, this Peerless tweeter is highly regarded, although somewhat expensive.
I have no experience in C62 SPL capabilities. I just noticed that they blow occasionally. Maybe distortion rise at high levels due to loss of saturation in the VC gap. I'm only speculating here so take it for what it is. Someone with experience of C62 may answer this better.
Yes, I also thought the A6 driver looked interesting for much of the same reasons! 🙂
I'll soon find out if that interest was well founded or not!
The original plan was to use the SEAS DTX tweeter, but their sloping high end response means that additional correction and loss of efficiency is inevitable. Also, they are designed specifically for wide dispersion, which I'm (as stated earlier) not to sure about any longer..
I've heard others say nice things about that new Peerless dome tweeter, perhaps it is worth further consideration?
But back to cone tweeters, just found this loudspeaker on the web:
http://www.redwineaudio.com/wlm/la_scala.html
Looks like a serious piece of kit.. at least the price is serious!
Wonder what tweeter they have used?
Perhaps it's just a radio-shack replacement tweeter??😀
One of the points made is that it is easy to set up/ place.. could this have something to do with the directivity characteristics of the cone tweeter?
I can see that the CT 62 can be fragile due to its small voice coil, but I guess that allso depends on the X-over frequency?
I'll soon find out if that interest was well founded or not!
The original plan was to use the SEAS DTX tweeter, but their sloping high end response means that additional correction and loss of efficiency is inevitable. Also, they are designed specifically for wide dispersion, which I'm (as stated earlier) not to sure about any longer..
I've heard others say nice things about that new Peerless dome tweeter, perhaps it is worth further consideration?
But back to cone tweeters, just found this loudspeaker on the web:
http://www.redwineaudio.com/wlm/la_scala.html
Looks like a serious piece of kit.. at least the price is serious!
Wonder what tweeter they have used?
Perhaps it's just a radio-shack replacement tweeter??😀
One of the points made is that it is easy to set up/ place.. could this have something to do with the directivity characteristics of the cone tweeter?
I can see that the CT 62 can be fragile due to its small voice coil, but I guess that allso depends on the X-over frequency?
Hi,
Of course it depends on crossover frequency, after all its a matter of energy distribution.
Thinking about your tweeter choice, have you considered horn tweeters?
Sorry, have not had time for more measurements, it will come later. I'll do some off center measurements and throw i a horn tweeter as well. The Peerless dome-tweeter I mentioned seem to be broken, measures terribly, perhaps the VC rubs or some loose windings.
Of course it depends on crossover frequency, after all its a matter of energy distribution.
Thinking about your tweeter choice, have you considered horn tweeters?
Sorry, have not had time for more measurements, it will come later. I'll do some off center measurements and throw i a horn tweeter as well. The Peerless dome-tweeter I mentioned seem to be broken, measures terribly, perhaps the VC rubs or some loose windings.
No rush with the measurements Anders, this is hobby, not work! 🙂
Funny you should mention it Anders, using a horn tweeter has crossed my mind more than once..
The small Coral HT-40 horn used with my Flat 8 II's was very nice to listen to. Undoubtedly directive, but very clear and detailed.
Kind of regret getting rid of those now, but I don't think they would be happy with low X-over..
I see that fostex have some very nice looking ones, but they do cost, and I don't recall any of them being crossable as "low" as 4khz.
Seen plenty of cheap 'n cheerful horn tweeters out there, but like with so many "replacement" cone-tweeters, origin and performance is often obscure at best..
Shame about the blown tweeter, hope it wasn't destined for any ongoing project.. 🙁
A horn tweeter measurement would be very Interesting!
Perhaps you have some clever recommendations again? 🙂
Funny you should mention it Anders, using a horn tweeter has crossed my mind more than once..
The small Coral HT-40 horn used with my Flat 8 II's was very nice to listen to. Undoubtedly directive, but very clear and detailed.
Kind of regret getting rid of those now, but I don't think they would be happy with low X-over..
I see that fostex have some very nice looking ones, but they do cost, and I don't recall any of them being crossable as "low" as 4khz.
Seen plenty of cheap 'n cheerful horn tweeters out there, but like with so many "replacement" cone-tweeters, origin and performance is often obscure at best..
Shame about the blown tweeter, hope it wasn't destined for any ongoing project.. 🙁
A horn tweeter measurement would be very Interesting!
Perhaps you have some clever recommendations again? 🙂
Yes, most small horns require quite high crossover freq. In the Fostex line up the FT-17 is the one that probably could go lowest.
It's few tweeters in between if one want to avoid domes and in the same time want a small tweeter, physics put demands.
Ah..Coral Flats, most beautiful speaker units I can think of... 🙂
Several years ago I used the Foster 025N05 (alnico) similar to this in a three-way setup and I liked the sound very much.
Yeah, the blown one is not something that I miss, just some tweeter that have been laying around. 😉
It's few tweeters in between if one want to avoid domes and in the same time want a small tweeter, physics put demands.
Ah..Coral Flats, most beautiful speaker units I can think of... 🙂
Several years ago I used the Foster 025N05 (alnico) similar to this in a three-way setup and I liked the sound very much.
Yeah, the blown one is not something that I miss, just some tweeter that have been laying around. 😉
Yes, the Coral Flat's sure were an amusing aquaintance! 🙂
Very high efficiency and good dynamics, but distortion- and frequency-wise, I finally figured that it was time to move on as things have happened over the last 30 or so years...
Been looking at that Fostex FT-17..
Besides looking a bit cheap and plasticky, I found it very interesting, only problem is a recommended X-over at 5 Khz.. Then again, the cut-off is at around 4 Khz, wonder if it could work crossed over here with a steep slope?
Found this horn loaded tweeter from Ciare:
http://oem.ciare.com/en/294/313/prodotti.php
Looks rather interesting at first glance, and crossover-wise it should be OK.
response looks a bit ragged though..
Foster? Sounds like some sort of Fostex rip-off...
😀
Very high efficiency and good dynamics, but distortion- and frequency-wise, I finally figured that it was time to move on as things have happened over the last 30 or so years...
Been looking at that Fostex FT-17..
Besides looking a bit cheap and plasticky, I found it very interesting, only problem is a recommended X-over at 5 Khz.. Then again, the cut-off is at around 4 Khz, wonder if it could work crossed over here with a steep slope?
Found this horn loaded tweeter from Ciare:
http://oem.ciare.com/en/294/313/prodotti.php
Looks rather interesting at first glance, and crossover-wise it should be OK.
response looks a bit ragged though..
Foster? Sounds like some sort of Fostex rip-off...
😀
Read here 😉
The FT17H has 2.6Khz cutoff according to the datasheet.
P.Audio have a few smaller horns, maybe something to look up?
Perhaps moving up to a true compression driver/horn setup? Ok, ok size I know. There is however lots of info regarding good sounding combinations here on the forum. But maybe this is shooting over the target?
Ah, seems there was more to the Foster-Fostex link than just the similarity of the name!
😀
with a cut-off of 2,6 Khz, wonder why they recommend 5 Khz x-over??
well, as my boxes are already built, a full horn-driver job is out of the question due to the size restrictions...
A the end of the day, perhaps I'm better off with one of the many SEAS tweeters, at least that will fit with the cut-out I've made already! 🙂
Been looking at this one recently...
http://www.seas.no/index.php?option=com_content&task=view&id=79&Itemid=103
Apart from the too expensive and too large Davis tweeters and the discuntinued Peerles CT 62 tweeters, it turns out that the selection of "serious" hi-fi cone tweeters were more limited than I had thought..
Then there is the Fostex.. although promising.. it looks a bit cheap.. and yes, visuals is a concern..the overall design and finish of my speakers will be quite "high end"..
😀
with a cut-off of 2,6 Khz, wonder why they recommend 5 Khz x-over??
well, as my boxes are already built, a full horn-driver job is out of the question due to the size restrictions...
A the end of the day, perhaps I'm better off with one of the many SEAS tweeters, at least that will fit with the cut-out I've made already! 🙂
Been looking at this one recently...
http://www.seas.no/index.php?option=com_content&task=view&id=79&Itemid=103
Apart from the too expensive and too large Davis tweeters and the discuntinued Peerles CT 62 tweeters, it turns out that the selection of "serious" hi-fi cone tweeters were more limited than I had thought..
Then there is the Fostex.. although promising.. it looks a bit cheap.. and yes, visuals is a concern..the overall design and finish of my speakers will be quite "high end"..
When the driver unloads distortion skyrockets, some safety margin allowing filter to slope must exist. Of course a sharper filter allows one to move closer.
When...I put up horn (Foster) tweeter measurements it will be more than obvious.
Ah, Of course, thats just logical! 🙂
Well, since I'll eventually be using an active set up, a 24dB slope is well within reach! 🙂
Well, since I'll eventually be using an active set up, a 24dB slope is well within reach! 🙂
Hmm.. seems this thread is petering out..
But the conclusion so far is:
The selection of available "modern" Hi-fi cone tweeters is virtually nill, except for Davis units.
Peerless CT 62 looks nice, but hard to come by..
Anders will probably get a better price and generate more joy by selling his CT 62's to a Sonab or Carlson owner with blown tweeters
Tomorrow I'll be heading off to buy a pair of Peerless/ Scanspeak/ Ex-tymphany DTS tweeters!
But it was a very interesting journey so far! 🙂
But the conclusion so far is:
The selection of available "modern" Hi-fi cone tweeters is virtually nill, except for Davis units.
Peerless CT 62 looks nice, but hard to come by..
Anders will probably get a better price and generate more joy by selling his CT 62's to a Sonab or Carlson owner with blown tweeters
Tomorrow I'll be heading off to buy a pair of Peerless/ Scanspeak/ Ex-tymphany DTS tweeters!
But it was a very interesting journey so far! 🙂
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