Hi guys, wonderered if I could pick your brains on where I may have gone wrong and what I should be looking at to rectify the issue.
So I replaced all the components on the crossover with as like for like as i could reasonably find for the most has worked out great, massive improvement apart from now they sound super bright something is out of whack with the tweeter. I thought about just putting an LPad on the tweeter but Im not sure the issue is quite as simple as just the level. Listed the components I used below. Ive attached some pics from an old thread on here of a schematic which is for a Celeste 3 but its the same.
Jantzen Zcaps 4.7uf and 6.8uf in place of the 5uf's and 7uf caps
Jantzen air coils - 2.7mf 1mm DCR 0.9 and 0.2mf 0.5mm DCR 0.6
Any advice will be greatly appreciated.
So I replaced all the components on the crossover with as like for like as i could reasonably find for the most has worked out great, massive improvement apart from now they sound super bright something is out of whack with the tweeter. I thought about just putting an LPad on the tweeter but Im not sure the issue is quite as simple as just the level. Listed the components I used below. Ive attached some pics from an old thread on here of a schematic which is for a Celeste 3 but its the same.
Jantzen Zcaps 4.7uf and 6.8uf in place of the 5uf's and 7uf caps
Jantzen air coils - 2.7mf 1mm DCR 0.9 and 0.2mf 0.5mm DCR 0.6
Any advice will be greatly appreciated.
Attachments
Probally this crossover had elco's before that have a higher ESR, so they did attenuate the tweeter more than the filmcaps you have now. That's why just replacing caps does not work out like it should. You should compensate with an resistor for that lost ESR. That could be an Lpad also. How much depends on the ESR of the old caps. If you don't know that you will have to measure the drivers without crossover and sim from there.
That old chestnut:
Paper bass and T33 soft dome tweeter.
You've got to wonder if the grille cloth is important. Tames the top end a bit.
What Galu is talking about is simple level adjustment. The 2.2R which can be as small as a 3W ceramic. The 7.5R/0.68uF Zobel rolls the top off quite a lot too. This sort of circuit works too.
Those old Elcaps did reduce level a bit compared to modern film types.
Paper bass and T33 soft dome tweeter.
You've got to wonder if the grille cloth is important. Tames the top end a bit.
What Galu is talking about is simple level adjustment. The 2.2R which can be as small as a 3W ceramic. The 7.5R/0.68uF Zobel rolls the top off quite a lot too. This sort of circuit works too.
Those old Elcaps did reduce level a bit compared to modern film types.
Thanks for the quick replies 🙂
The og caps reducing the level is not something I had considered to be honest.. So thanks for that info.
Steve is that your own design? Very nice, unfortunately it’s too late for these to get a complete overhaul as I’ve invested in the components already but having said that I do have another pair of these that I may give your design a try on 😉
I’ll put a resistor before in the meantime and see how I go..
The og caps reducing the level is not something I had considered to be honest.. So thanks for that info.
Steve is that your own design? Very nice, unfortunately it’s too late for these to get a complete overhaul as I’ve invested in the components already but having said that I do have another pair of these that I may give your design a try on 😉
I’ll put a resistor before in the meantime and see how I go..
Sorry Steve just realised think I miss understood what you were saying, I can add the 2.2R and the zobel to my existing circuit.. doh, ill give that a go instead!
You can do different things beyond a 7.5R/0.68uF Zobel. Some people prefer a 22R. 3-5W again.
I often use 15R/0.33uF. Does a bit less. But does something to the very top.
I don't fancy replacing the ferrofluid on the KEF T33:
KEF T33 Tweeter Ferrofluid Replacement - YouTube
Looks a bit fiddly, especially if it ain't broke. But you can buy ferrofluid at Blue Aran for £5.
I often use 15R/0.33uF. Does a bit less. But does something to the very top.
I don't fancy replacing the ferrofluid on the KEF T33:
KEF T33 Tweeter Ferrofluid Replacement - YouTube
Looks a bit fiddly, especially if it ain't broke. But you can buy ferrofluid at Blue Aran for £5.
Oh I see, ah well I'm going with your first suggestion for now and see how it sounds, and go from there.. I should really spend some time learning about these things if I'm going to keep messing around with them lol.
See this is the strange thing about these being listed as having T33's, both my pairs have the Audax HD100D25 fitted?
See this is the strange thing about these being listed as having T33's, both my pairs have the Audax HD100D25 fitted?
This bit of modelling might help you get a vague idea how your speakers work:
Software | Visaton
I have reason to think the unzipped BPJ file will work when put in the projekte folder in Boxsim 2.0 (Eng). The program will offer the latest 2.0 driver files, but I would ignore that option. I used a G20SC because it is compatible with 2.0.
The 2.2R in the bass circuit is just a modelling adjustment for the different (high-inductance) W200S-8 bass I used. You don't need it. Notice the tweeter is psychologically bright on energy/power due to its better dispersion than the woofer. This is why adjusting tweeter level is a matter of taste.
Software | Visaton
I have reason to think the unzipped BPJ file will work when put in the projekte folder in Boxsim 2.0 (Eng). The program will offer the latest 2.0 driver files, but I would ignore that option. I used a G20SC because it is compatible with 2.0.
The 2.2R in the bass circuit is just a modelling adjustment for the different (high-inductance) W200S-8 bass I used. You don't need it. Notice the tweeter is psychologically bright on energy/power due to its better dispersion than the woofer. This is why adjusting tweeter level is a matter of taste.
Attachments
You say you used Jantzen Z caps.
Which ones ?
cross, standard, superior, silver, alumen, amber ??????
Which ones ?
cross, standard, superior, silver, alumen, amber ??????
Cheers Steve, way more info than I expected to get ill have a play around with it..
Out of interest was there much difference changing to W200S-8 over the kef driver?
@Userabuser used standards.
Out of interest was there much difference changing to W200S-8 over the kef driver?
@Userabuser used standards.
My opinion is they all sound the same... but you may disagree.
If I was an honest marketing man at Jantzen, I would call them Cheap and small enough, Not so Cheap, Quite expensive and ridiculously huge, more exorbitant but Gold-plated. Don't know if the Jantzen Boss would like it. And Troels Gravesen would lose his 10% cut on boutique capacitors. All his children starving. 😱
This is my standard forum circuit for all things 8" plus tweeter. Coil plus a bit of impedance correction to fix a small bump at crossover. Works with most stuff:
Usually just tweek treble level to taste. Saves me time. Your KEF driver is probably lower inductance, so more ambitious second-order things can be tried.
My current old clunker that I really ought to fix (It has fried tweeters...), a completely unknown Wharfedale Super Linton I picked up for nothing. How hard can it be?
I have purchased some MarkAudio CHN-50 fullrangers on fullranger fanatic planet10's advice because they look a bit like the old tweeters.
A few technicalities like low crossover and an enclosure to wade through, but how hard can it be? 😎