thanks dublin78, have emailed niel, in the meantime i got a response from toaster in wrong forum (me newby)
, but i thought it worth quoting him here - 'Hi boredsurfer, you'd be better putting this on the 'multi-way' forum, but I should think the obvious replacement would be the SEAS 27TBFCG aluminium dome tweeters. No doubt the crossover network would need to be modified to suit. The TDL tweeters are long discontinued of course. I suspect I was the first DIY user in the UK to buy a pair. I ended up using them in a couple of designs, one of which a friend of mine still uses- still sounds good too! Good luck with the repair. '
any comments or further info on this would be great, but i have one question, if i biwire the speakers will i need to modify the crossover network? as i said im a complete newby, lol
i am wondering if they hare the same tweeter as mc4's (mk1), i found some info on another forum about mc2 mk1 tweeters which sounds almost identical to mine he said - 'the label on the back of the (tweeter) unit is printed "MADE IN THE UK" and stamped 25DT 34 348 8Ohm'
mine have same label, with 25DT 34 398 9 Ohm, his MC2 mk1 have same tweeter housing as well, would they be a possible replacemnet for my mc4's?
i am wondering if they hare the same tweeter as mc4's (mk1), i found some info on another forum about mc2 mk1 tweeters which sounds almost identical to mine he said - 'the label on the back of the (tweeter) unit is printed "MADE IN THE UK" and stamped 25DT 34 348 8Ohm'
mine have same label, with 25DT 34 398 9 Ohm, his MC2 mk1 have same tweeter housing as well, would they be a possible replacemnet for my mc4's?
correction 8 Ohm, lol
Hi,
I see some MC4 with the SEAS H414 ?
SEAS still makes this dome
THE ART OF SOUND PERFECTION BY SEAS - H0414-08 19TAF/G
The 27TBCG is bigger and might need a bigger hole. A nice and useful tweak is to flush mount the new tweeter.
Hope this helps.
I see some MC4 with the SEAS H414 ?
SEAS still makes this dome
THE ART OF SOUND PERFECTION BY SEAS - H0414-08 19TAF/G
The 27TBCG is bigger and might need a bigger hole. A nice and useful tweak is to flush mount the new tweeter.
Hope this helps.
For future reference in this thread, I have a pair of MC4 mk 1 and the other day I bought some monitor audio R952/MDs and Monitor 9s (late 80s?) and the tweeters on these look just like the MC4's (except for the different company logo) and sound just like them so I suspect they are indeed the same!
MC4s too bright
Hi all, my MC4s (V1) are overly bright but the tweeters sound fine with no distortion.
So where is this brightness coming from ?
Have the woofers become lazy ? or is this all down to the crossover (caps) ?
Took a look inside and all is original and untouched.
Only took a close up of the xover caps for the bass, but the highs have the same capacitors again.
Date stamp in the cab says Sept 1987
Hi all, my MC4s (V1) are overly bright but the tweeters sound fine with no distortion.
So where is this brightness coming from ?
Have the woofers become lazy ? or is this all down to the crossover (caps) ?
Took a look inside and all is original and untouched.
Only took a close up of the xover caps for the bass, but the highs have the same capacitors again.
Date stamp in the cab says Sept 1987
Attachments
Possibly the metal tweeters are not set to your taste. There's a thing in the industry called showroom brightness that sells speakers, but they get on your nerves when you get home.
Looks like Musical Fidelity also used this similar common H0532-08 19TAFD/G tweeter.
I'd have to see the crossover schematic to say what you should do here precisely, but you'll probably add a tiny bit more resistance (maybe 2.2R) to the treble filter input and shunt a zobel (7.5R 7W wirewound resistor and 0.68uF polypropylene capacitor in series) across the tweeter to tame it. Very easy actually. You can get the bits at Maplin.
I take it you have the below model. Looks like polycone and metal tweet. It is common enough for ferrofluid, if applied here, to dry out and solidify. But that usually just stops the tweeters working at all.
Looks like Musical Fidelity also used this similar common H0532-08 19TAFD/G tweeter.
I'd have to see the crossover schematic to say what you should do here precisely, but you'll probably add a tiny bit more resistance (maybe 2.2R) to the treble filter input and shunt a zobel (7.5R 7W wirewound resistor and 0.68uF polypropylene capacitor in series) across the tweeter to tame it. Very easy actually. You can get the bits at Maplin.
I take it you have the below model. Looks like polycone and metal tweet. It is common enough for ferrofluid, if applied here, to dry out and solidify. But that usually just stops the tweeters working at all.
Attachments
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Hello Steve,
Yes that's the ones with the transparent woofer
From what I understand caps can go off tune with age. So replacing them might tame the treble or bring up the bass so they are even again.
Got no schematic, but there are 4 caps, 2x @3u and 2x @6u
That's the wrong tweeter, this one seems more like it:
Monacor DT-250
Yes that's the ones with the transparent woofer
From what I understand caps can go off tune with age. So replacing them might tame the treble or bring up the bass so they are even again.
Got no schematic, but there are 4 caps, 2x @3u and 2x @6u
That's the wrong tweeter, this one seems more like it:
Monacor DT-250
It's some sort of minimalistic design by Martin Colloms as I understand it. Uses the Rogers 8" bass AFAIK. Bit like some Epos designs.
The schematic is something you work out from observation. I'd expect a coil on the bass and maybe an RC shunt, and a capacitor and resistor to the tweeter at least. Perhaps a coil on the tweeter too. Bit like this maybe, but not too interested in coil values anyway. Resistor and capacitor values are readable.
Those plastic capacitors really shouldn't age. But some connectors and joints could be corroded or dry jointed. Crimp connectors to the drivers might be worth pulling off and reconnecting for fresh metal. It's worth noting polarity before you disassemble though. Otherwise you're scratching your head to get the phase right!
Bear in mind that frequency response IS slightly affected by amplification type too. Valves sound very different from solid state. They interact with speaker impedance more.
The schematic is something you work out from observation. I'd expect a coil on the bass and maybe an RC shunt, and a capacitor and resistor to the tweeter at least. Perhaps a coil on the tweeter too. Bit like this maybe, but not too interested in coil values anyway. Resistor and capacitor values are readable.
An externally hosted image should be here but it was not working when we last tested it.
Those plastic capacitors really shouldn't age. But some connectors and joints could be corroded or dry jointed. Crimp connectors to the drivers might be worth pulling off and reconnecting for fresh metal. It's worth noting polarity before you disassemble though. Otherwise you're scratching your head to get the phase right!
Bear in mind that frequency response IS slightly affected by amplification type too. Valves sound very different from solid state. They interact with speaker impedance more.
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ah ok so the bass was made by Rogers, interesting not heard of them doing anything but radios for a long time.
Yes my amp is valve, but got 4 pairs of speakers here and the MC4s are by far the brightest. They are known as being rather bass heavy by design !
I imagine some new ClarityCaps would blow the pants off of those installed here near thirty years ago anyway
Yes my amp is valve, but got 4 pairs of speakers here and the MC4s are by far the brightest. They are known as being rather bass heavy by design !
I imagine some new ClarityCaps would blow the pants off of those installed here near thirty years ago anyway
I never spend too much on capacitors these days. Good 250V polys are quite adequate. Get 400V types if you've got room.
Capacitors
Now come on. Work out the schematic. I can then tell you why they sound bright and how to fix it. Soggy bass is a given with valves. They don't drive reflex too well. Something to do with damping factor, or lack of it!
Capacitors
Now come on. Work out the schematic. I can then tell you why they sound bright and how to fix it. Soggy bass is a given with valves. They don't drive reflex too well. Something to do with damping factor, or lack of it!
At your leisure, my friend.
Ping me a PM when you do update here. Otherwise I might miss it.
FWIW, I think that bass was used in the Spendor BC1 too. Tweeters are tweeters though, IMO. All much the same.
Ferrite is perfectly stable. It's the old AlNiCo drivers that needed periodic remagnetising. No, that's not it...
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