Hi,
I have just got hold of these speakers.
They have bass and treble but a whole range of mid-bass is missing. Noticed immediately when the oboe in King Crimson’s “I Talk to the Wind” was entirely absent!
What would cause this and how could it be fixed. I assume a crossover issue as I have bass and treble so the woofer and tweeter are functioning.
I have just got hold of these speakers.
They have bass and treble but a whole range of mid-bass is missing. Noticed immediately when the oboe in King Crimson’s “I Talk to the Wind” was entirely absent!
What would cause this and how could it be fixed. I assume a crossover issue as I have bass and treble so the woofer and tweeter are functioning.
Welcome to the forum!
Below, the Tannoy Mercury M 2.5 loudspeaker - it's always nice to see the whole picture!
I see these speakers date from 1998, so the two blue electrolytic capacitors (the only parts in the crossover that could be suspect) are still likely to be up to spec. However, you should examine them closely for leakage. What do you know of the past history of the speakers? I can see corrosion on the screws in your first image which suggests that the drivers may have deteriorated as a result of non-ideal storage conditions.
Before jumping to the conclusion that the problem lies with the crossover it would be best to test the operation of the mid/woofer. You can do this by disconnecting the mid/woofer wires from the crossover and connecting them directly to the amplifier, when you will be able to listen carefully to their midrange performance. A tweeter can be similarly tested, but you must include a bipolar crossover capacitor (2.2 uF to 4.7 uF) in series with its positive lead in order to protect it from bass frequencies. Test it at low volume.
Below, the Tannoy Mercury M 2.5 loudspeaker - it's always nice to see the whole picture!
I see these speakers date from 1998, so the two blue electrolytic capacitors (the only parts in the crossover that could be suspect) are still likely to be up to spec. However, you should examine them closely for leakage. What do you know of the past history of the speakers? I can see corrosion on the screws in your first image which suggests that the drivers may have deteriorated as a result of non-ideal storage conditions.
Before jumping to the conclusion that the problem lies with the crossover it would be best to test the operation of the mid/woofer. You can do this by disconnecting the mid/woofer wires from the crossover and connecting them directly to the amplifier, when you will be able to listen carefully to their midrange performance. A tweeter can be similarly tested, but you must include a bipolar crossover capacitor (2.2 uF to 4.7 uF) in series with its positive lead in order to protect it from bass frequencies. Test it at low volume.
Thank you. They were from a spurious eBay seller who claimed “many years” of happy listening.
However, when received the binding post plate wasn’t even attached 🤦🏻♂️. So they (or the previous owner) evidently had taken them apart to try and see the issue, decided it was too much and to just sell them on.
So I have no idea the genuine history.
There is a lot of surface corrosion on the screws - so probably kept in a shed gathering dust and getting damp.
But no evidence of internal corrosion and the caps don’t have any signs of leakage.
I’ve now had them going for a hour or so and after “warming up” I seem to be getting more mids now.
Almost like the drivers have freed themselves up or something. I’ve not experienced this before!(?)
However, when received the binding post plate wasn’t even attached 🤦🏻♂️. So they (or the previous owner) evidently had taken them apart to try and see the issue, decided it was too much and to just sell them on.
So I have no idea the genuine history.
There is a lot of surface corrosion on the screws - so probably kept in a shed gathering dust and getting damp.
But no evidence of internal corrosion and the caps don’t have any signs of leakage.
I’ve now had them going for a hour or so and after “warming up” I seem to be getting more mids now.
Almost like the drivers have freed themselves up or something. I’ve not experienced this before!(?)
Run them for several hours and hope that they improve further, in which case no further action would be required.
The only components that could have degraded in the crossover are the two bipolar electrolytic capacitors which could be replaced with fresh equivalents if you are confident with the desoldering/soldering process.
The capacitors fitted are radial types which are available from Mouser UK in selected uF and VDC values. Just ask if you need help with the selection.
https://www.mouser.co.uk/c/passive-...acitors-radial-leaded/?q=bipolar electrolytic
The only components that could have degraded in the crossover are the two bipolar electrolytic capacitors which could be replaced with fresh equivalents if you are confident with the desoldering/soldering process.
The capacitors fitted are radial types which are available from Mouser UK in selected uF and VDC values. Just ask if you need help with the selection.
https://www.mouser.co.uk/c/passive-...acitors-radial-leaded/?q=bipolar electrolytic
If the tweeter has ferrofluid, that could be an issue with age and sitting unused. Warming up might influence that as well, but could revert when temperatures decrease.
The carrier fluid in ferrofluid can dry up and leave behind a sticky paste that can mute a tweeter's high frequency output.
However, since we have "treble" and suffer from a lack of "mid-bass", dried out ferrofluid would appear not to be the problem.
I can say that the brief specs I've seen on the M series tweeter do no mention ferrofluid.
@TrampSkateboards Do you have an update that will hopefully close the thread?
However, since we have "treble" and suffer from a lack of "mid-bass", dried out ferrofluid would appear not to be the problem.
I can say that the brief specs I've seen on the M series tweeter do no mention ferrofluid.
@TrampSkateboards Do you have an update that will hopefully close the thread?
The OP wrote "Missing Mids" in the thread title so you thought correctly. It may just be a case of the OP "warming" to the sound of this speaker!
Hi i have the same speakers that were plugged into an Amp set to output 8 ohms
Soon after the speaker started to have a burning smell.
The two 5watt resisitors next to the bi-polar cap got VERY hot, burnt the PCB in that area to a crisp, and one of the resistors has disintegrated !
I plan to repair these rather than chuck them - as thats in my nature to do so!
I can read well, the 5W 2.7 Ohm J on one of the resisitors, but the other one on both speaker boards are burnt out, and the text is gone.
Can anyone please tell me the required value for that one?
Thanks
Simon
Soon after the speaker started to have a burning smell.
The two 5watt resisitors next to the bi-polar cap got VERY hot, burnt the PCB in that area to a crisp, and one of the resistors has disintegrated !
I plan to repair these rather than chuck them - as thats in my nature to do so!
I can read well, the 5W 2.7 Ohm J on one of the resisitors, but the other one on both speaker boards are burnt out, and the text is gone.
Can anyone please tell me the required value for that one?
Thanks
Simon
Hi Simon!
I can find no crossover schematic for the Mercury M 2.5, so that avenue is closed to us. Let's hope you can find another owner.
Is there an obvious reason why the resistors got fried? Excessive volume levels at a party perhaps?
To ascertain if it is worth pursuing a repair, you should first check the condition of the drivers (see post #2).
I can find no crossover schematic for the Mercury M 2.5, so that avenue is closed to us. Let's hope you can find another owner.
Is there an obvious reason why the resistors got fried? Excessive volume levels at a party perhaps?
To ascertain if it is worth pursuing a repair, you should first check the condition of the drivers (see post #2).
That's likely an error in the production. The tweeter should be in reverse polarity but the crossover doesn't indicate it. Aside from that, the 2-3W resistors should be replaced by 5-10W ones instead.
I'm sorry I've missed that one. The issue is, Tannoy preferred to burn the resistors instead of the drivers (which ..mostly.. worked), it was not just a thing of trying to reduce the costs. The drivers will take the power for an extended period of time but some things in the chain WILL break if driven too hard. Since get new drivers (or diaphragms) is pretty hard, it should be taken as a hint that burnt resistors indicate the speakers are WAY overdriven and not suitable for that kind of power and spl. If you need to go loud, get other speakers that can deliver on that.
Thanks for that info, ICG.
So if @simon_m74 is very lucky, his drivers may have survived!
Does your crossover expertise supply any clue as to the function of the pair of (side by side) 5 W resistors?
So if @simon_m74 is very lucky, his drivers may have survived!
Does your crossover expertise supply any clue as to the function of the pair of (side by side) 5 W resistors?
The first thing would be to swap the tweeters from one side to the other to see if they survived. A multimeter and Rdc measurement would provide that information too, of course. Anyway, better the resistors failed than the VCs.
Am I to take from your response that you think the pair of side by side resistors is associated with the tweeter?
If so, there are fried resistors in that side by side arrangement on both crossovers so swapping tweeters may not prove fruitful.
I've suggested to Simon a way he may test the drivers. If he has a multimeter he can go with your suggestion of looking for open circuit voice coils.
He didn't mention which, if any, drivers were still working, so we await further information.
If so, there are fried resistors in that side by side arrangement on both crossovers so swapping tweeters may not prove fruitful.
I've suggested to Simon a way he may test the drivers. If he has a multimeter he can go with your suggestion of looking for open circuit voice coils.
He didn't mention which, if any, drivers were still working, so we await further information.
No, that's from my experience from repairing blown speakers.
What's kicking the bucket is dependent on what music was played and the spl/power. Looking for VC resistance is ofc the first thing to do, that's right. But that should be done after disconnecting the XO. (Yes, I know you know that, but the TO possibly don't) And yes, you are ofc right, we have to wait for any replies, until then, everything is just guessing.
What's kicking the bucket is dependent on what music was played and the spl/power. Looking for VC resistance is ofc the first thing to do, that's right. But that should be done after disconnecting the XO. (Yes, I know you know that, but the TO possibly don't) And yes, you are ofc right, we have to wait for any replies, until then, everything is just guessing.
All,
The speakers were never driven very loud at all - well not by my (they are scond hand).
Used at the Retro computer Museum in Leicester.
The first use, was they were connected to a gaming setup (Wii, Xbox, PS3) via a sony Amp - used like this for a couple of years.
Then when we erlocated the museum. things changed.
We put the Sony Amp in the arcade, connected to a pair of Warfdale diamond`s. The input to the amp was from a PA system, on its
It worked for months like this - then speakers got moved, and the warfdales sounded very dull.
After investigation, diagnosing the problem, we found it to be the speakers - so we changed to our (at the time) spare Tannoy ones.
These worked for a few weeks (well the weekends asn the Museum is only opne Saturday and Sunday) - then last Friday, I was there working on stuff, I put the amp on so I could hear the music - shortly after I smelt the burning smell.
The Tannoys` crossovers .
As we never put them loud at all, and they worked fine for a coule of years on the same amp - any idea what could of caused this failure?
Could is be the 8ohm vs 4 ohm switch?
Could it be that the cables are run in the same conduit as power - but thats been the case for almost a year - and rthis is a recent problem.
The Tannoys are burnt resistors on the crossover - dont sound bad considering, but lacking high tones
The Warfdales
As for the repair of the Tannoys, I did look online for a schematic, and as said by @Galu , I cannot also find one online.
Hence I question on this thread - as per the photos at the start, I was hoping someone still has som Tannoy mercurt 2.5`s, and could remove the corssover to let me know the values of the resistors.
Thanks
Simon
The speakers were never driven very loud at all - well not by my (they are scond hand).
Used at the Retro computer Museum in Leicester.
The first use, was they were connected to a gaming setup (Wii, Xbox, PS3) via a sony Amp - used like this for a couple of years.
Then when we erlocated the museum. things changed.
We put the Sony Amp in the arcade, connected to a pair of Warfdale diamond`s. The input to the amp was from a PA system, on its
preamp outIt worked for months like this - then speakers got moved, and the warfdales sounded very dull.
After investigation, diagnosing the problem, we found it to be the speakers - so we changed to our (at the time) spare Tannoy ones.
These worked for a few weeks (well the weekends asn the Museum is only opne Saturday and Sunday) - then last Friday, I was there working on stuff, I put the amp on so I could hear the music - shortly after I smelt the burning smell.
The Tannoys` crossovers .
As we never put them loud at all, and they worked fine for a coule of years on the same amp - any idea what could of caused this failure?
Could is be the 8ohm vs 4 ohm switch?
Could it be that the cables are run in the same conduit as power - but thats been the case for almost a year - and rthis is a recent problem.
The Tannoys are burnt resistors on the crossover - dont sound bad considering, but lacking high tones
The Warfdales
look un affected - but no high tones, and bass is sounding muffled. As for the repair of the Tannoys, I did look online for a schematic, and as said by @Galu , I cannot also find one online.
Hence I question on this thread - as per the photos at the start, I was hoping someone still has som Tannoy mercurt 2.5`s, and could remove the corssover to let me know the values of the resistors.
Thanks
Simon
From your description it would appear that the Sony amplifier is faulty and that's why the high frequency sections of both the Diamonds and the Mercurys have been damaged. The solution here would be to replace the amplifier.
Regarding the Mercurys, it would appear that the mid/woofers are OK.
The first thing to do is find out if the tweeters have been fried along with the resistors.
Disconnect the tweeters from the crossover and measure the resistance across their terminals. Your ohmmeter should read in the region of 5 ohms.
Please report back on your findings and then we'll see if it's worth continuing with a discussion regarding replacement of the resistors.
I have the amp and speakers here at home and when I spotted the 4ohm-8ohm switch in 8hom pos, and the speakers are 4ohm (I think), I switched to 4 ohms and I tested the amp for about 6 hours the other day, on the tannoys, although not sounding brill, I wanted to see if the burning smell returned (this was done before I removed the crossovers)
No smell, and the sound, although muffled, was constant.
Due to this, I suspect tha Amp to be
I have measured the ohms on both tweeters, and they are both about 4.6ohms
Both drivers are about 3.4 ohms.
No smell, and the sound, although muffled, was constant.
Due to this, I suspect tha Amp to be
ok, but we do have others spare Amps at the Musuem - just no more spare speakers - hence this..I have measured the ohms on both tweeters, and they are both about 4.6ohms
Both drivers are about 3.4 ohms.