Speaker question

[Dr Bunsen Honeydew]

I can't believe it was a Goodmans bodge. All those reading are very low, are you removing the wires from the terminals before measuring, you must do this.

[floydfan]

Didn't remove the wires before measuring as they are soldered on, but if I keep them I will redo the measurements. As for the "bodge" I can see a blob of solder on the other terminal so it looks like the wire has been removed and resoldered on to the other terminal (negative). So probably not Goodmans. Could a previous owner be trying to attenuate the bass?

[Dr Bunsen Honeydew]

You wont know which drivers are working correctly until you desolder them. At the moment the multimeter is reading the whole circuit, so the readings are meaningless.

[floydfan]

I have stripped down what I thought was the weak speaker and rechecked the drivers. All the bass drivers were 3.9 ohms, the 2 mids were 6.6 and 6.7 and the tweeters were 6.4 and 6.5. These figures seem ok to me so still don't know why one bass unit was shorted out. I will test the drivers in the other cabinet before I look at the crossovers.

Ps the vendor gave me a few quid back to help with the refurb.

[Dr Bunsen Honeydew]

4 ohms is very unusual for Goodmans bass drivers. It probably means they are series wired for 8 ohms.

[floydfan]

The wiring doesn't look as if they are series wired as each set of leads go back to the PCB. Maybe they are linked in the PCB. The nominal speaker impedance is 4 ohms so I should be able to use some arithmetic to work out if they are series or parallel.

Interesting anyway.

[floydfan]

It looks like the bass units are in series parallel and the mids and tweeters are in parallel. There are 2 10 uF, 1 30 uF and 1 60uF Elcap capacitors in the crossover and 1 Erie 4.7 uF. I was going to replace the Elcaps with Alcap capacitors but am not sure what to do with the Erie one. Any suggestions will be welcomed.

[Dr Bunsen Honeydew]

Bit drastic, but you did ask.

Take all the crossover components off the bass drivers and wire them in series. That would be my first choice, then listen and report.

[jammy395]

Hi All
Hopefully a simple speaker question (Floydfan)

Let this be a lesson - There is no such thing as "A simple speaker question" (See Ed Miliband).

[floydfan]

A question mainly for the doc but anyone can chip in.
I am working on my Goodmans Dimension 8 and so far I have removed all foam , checked all the drivers , replaced wiring and replaced the capacitors, as some seemed a bit leaky. I am going to put some steel plate on them and will connect the bass drivers in series after removing them from the crossover. I am undecided as to my next step.
The 2 tweeters are in parallel giving an impedance of 4ohms and the 2 mids are also in parallel giving 4 ohms.So if I connect this up via the crossover the amp will see 16 ohm bass, 4 ohm mids and tweeters. I think , correct me if I am wrong, that the mids and HF will draw more from the amp and sound louder.
I have thought of two possible solutions:-
connect a resistance on the feed to the mids and tweeters and vary it to get a balance
or connect the tweeters in series to get 16 ohms and do the same with the mids
There is a third possibility but I don't think I would survive the tweaking that it would require ie remove the crossover completely and put a capacitor and resistor on the tweeters and mess about doping the 6 bass and mid speakers and varying the resistor until I was happy.
Ps I will be using an A80 to drive the speakers
Please feel free to comment even if it is to suggest I lie down with a cold compress on my head.