I have a pair of vintage speakers that I built in the early 80s that I am trying to restore , they had originally a pair of Philips Ad 10100w8 drivers and
Ad 0141 t6 tweeters they always had an amazing sound but a couple of years ago one of the tweeters blew and that is probably were the problem started .
I replaced the tweeters with a cheap pair of 4ohm tweeters and replaced the crossover capacitors and they worked fine for a while until the tweeters blew again , I searched the internet to find out the impedance of the original tweeters and was told they were 6 ohm so bought some 6ohm scanspeak classics as replacements.
The problem is that I have a slightly muffled sound in the mid range and definite lack of punch from the base the tweeters sound great .
I have put a meter on the drivers and they register 6.2 ohms Philips rate them @ 8 ohms .
I am thinking there must be a problem with the crossovers there is no information on the crossovers but they are pretty simple looking I have attached a picture .
Any advice would be appreciated
Ad 0141 t6 tweeters they always had an amazing sound but a couple of years ago one of the tweeters blew and that is probably were the problem started .
I replaced the tweeters with a cheap pair of 4ohm tweeters and replaced the crossover capacitors and they worked fine for a while until the tweeters blew again , I searched the internet to find out the impedance of the original tweeters and was told they were 6 ohm so bought some 6ohm scanspeak classics as replacements.
The problem is that I have a slightly muffled sound in the mid range and definite lack of punch from the base the tweeters sound great .
I have put a meter on the drivers and they register 6.2 ohms Philips rate them @ 8 ohms .
I am thinking there must be a problem with the crossovers there is no information on the crossovers but they are pretty simple looking I have attached a picture .
Any advice would be appreciated
Attachments
Maybe your tweeters are more quiet than before (less sensitive). Could you show the other side of the board, and are there any resistors?
Is one of the blue wires just hanging onto the connector by molecular attraction?
Xover could be inductor for 1st order on bass, and inductor and capacitor for second order on tweeter.
If you trace the circuit through I am sure you will figure it out.
Xover could be inductor for 1st order on bass, and inductor and capacitor for second order on tweeter.
If you trace the circuit through I am sure you will figure it out.
I was in the process of replacing all the cables with better quality when I took the picture so it was partly disconnected but well spotted ��
I have attached a picture of the other side of the board I was wondering if it was because the tweeters were a lower impedance that they were louder is it possible to use a resistor across the tweeters to balance them to the drivers ?
The tweeters test @ 5.2 and drivers @ 6.2 ��
Last edited:
You originally said the tweeters sound great, but you have a slightly muffled mid range and lack of punch in the bass.
You now saying that the Scanspeak replacements are too loud - correct?
Note that your multimeter does not measure the nominal impedance (opposition to AC) of your drivers, but only their DC resistance.
If the tweeters are too loud, this is not down to them having a slightly lower DC resistance than the woofers, but due to them having a higher sensitivity.
To reduce the output of a tweeter, you do not put a resistor 'across it', as you said, but in series with (in line with) one of the wires going to the tweeter.
You could experiment, initially, by putting a 1.5 or 2.2 ohm 10W ceramic resistor in series with the tweeter.
You now saying that the Scanspeak replacements are too loud - correct?
Note that your multimeter does not measure the nominal impedance (opposition to AC) of your drivers, but only their DC resistance.
If the tweeters are too loud, this is not down to them having a slightly lower DC resistance than the woofers, but due to them having a higher sensitivity.
To reduce the output of a tweeter, you do not put a resistor 'across it', as you said, but in series with (in line with) one of the wires going to the tweeter.
You could experiment, initially, by putting a 1.5 or 2.2 ohm 10W ceramic resistor in series with the tweeter.
Thanks for the advice I have ordered 2 x 1.5 capacitors and 2x 1.8 I couldn’t get 2.0 I will try them and let you know how it goes .
I hope you made a typo there, and in fact ordered resistors rather than capacitors! 😉
And, yes, do please let us know how it goes.
And, yes, do please let us know how it goes.
Have you considered trying to obtain the correct model replacement tweeters? Replacing them with anything else will be a complete gamble as to how it sounds, not because the crossover has anything 'wrong' but because its design is not necessarily appropriate to match the new tweeters.
You could redesign the crossover from scratch, but this is far more involved than anyone can accomplish just by looking at pictures of the existing speakers.
You could redesign the crossover from scratch, but this is far more involved than anyone can accomplish just by looking at pictures of the existing speakers.
Although pictures of the speakers and the drivers might help people make informed guesses instead of WAGs
I received the resistors today and have fitted a 1.8 ohm resistor to one cabinet on the tweeter it worked as far as backing off the tweeter a bit unfortunately this just made the driver more noticeably dull ,it was a good experiment that has lead me to believe either my drivers are both past their prime or it’s the crossovers.
Looking at the crossover pcb there only seems to be one component between the input and the driver (the inductor) mine have nothing written on them so I’m guessing would be hard to replace .
I have a couple of questions can inductors deteriorate through old age (40 years? )And is it possible to work out what to replace them with?
I am not sure what to do next I have also considered buying some cheap crossovers off eBay just to see if there is any improvement.
Any ideas ?
Looking at the crossover pcb there only seems to be one component between the input and the driver (the inductor) mine have nothing written on them so I’m guessing would be hard to replace .
I have a couple of questions can inductors deteriorate through old age (40 years? )And is it possible to work out what to replace them with?
I am not sure what to do next I have also considered buying some cheap crossovers off eBay just to see if there is any improvement.
Any ideas ?
