Anyone here familiar with speaker Crossovers?

spile

It’s quite common for capacitors to have to be replaced, so I would do that.

prowla

ThisIsWeird said:

prowla said:

What happens if you swap the speakers to opposite sides of the room.

The faulty one always has significantly less treble.

OK - just good to do diagnostics 101 before getting out the soldering iron!

One of my speakers has an annoying buzz/resonance and I've got to swap them over before I do anything else!

SurferDan

Well done on your analysis of the problem. Nothing I can add to what's already been said so far.
Try posting on this site:-

https://www.maverick-hifi.com/

It grew from the ashes of HiFi Wigwam and there are lots of experienced people on there who might be able to help.

ThisIsWeird

SurferDan said:

Well done on your analysis of the problem. Nothing I can add to what's already been said so far.
Try posting on this site:-

https://www.maverick-hifi.com/

It grew from the ashes of HiFi Wigwam and there are lots of experienced people on there who might be able to help.

Thanks, but I won't know until I replace the caps :-)

I need to work out what audible difference going for 36uF will make as opposed to the existing 35.3uF (based on the 32uF + 3.3uF in the original setup), but I suspect it'll be zero that can be detected by ear, especially since moving a speaker an inch will almost certainly make more difference. So, I plan to replace the two caps C2 & C4 with a couple of 18uF Polyester types.

What can possibly go wrong...

Heedtheadvice

Along as you get  a high enough voltage rating then really they willl be better.

More reliable and likely to be closer to the value you already should have. Electrolytic are wide tolerance (typically +/- 20%, those fitted might originally have been better).Polyester maybe 10% or better....so just go for it!

prowla

Heedtheadvice said:

Along as you get  a high enough voltage rating then really they willl be better.

More reliable and likely to be closer to the value you already should have. Electrolytic are wide tolerance (typically +/- 20%, those fitted might originally have been better).Polyester maybe 10% or better....so just go for it!

Whilst the tolerances are wide on these components, sometimes it's a matter of needing two similar ones rather than their precise value.

One of the workarounds is to select matched components for electronics: if you have (eg.) 1000 items, you can test them all and pair up ones of similar values.

This is common in building stereo amps.

I'm not sure what the requirements are for a speaker crossover, though.

ThisIsWeird

prowla said:

Heedtheadvice said:

Along as you get  a high enough voltage rating then really they willl be better.

More reliable and likely to be closer to the value you already should have. Electrolytic are wide tolerance (typically +/- 20%, those fitted might originally have been better).Polyester maybe 10% or better....so just go for it!

Whilst the tolerances are wide on these components, sometimes it's a matter of needing two similar ones rather than their precise value.

One of the workarounds is to select matched components for electronics: if you have (eg.) 1000 items, you can test them all and pair up ones of similar values.

This is common in building stereo amps.

I'm not sure what the requirements are for a speaker crossover, though.

For the Mission M66i, pretty basic :-)

Heedtheadvice

ThisIsWeird said:

prowla said:

Heedtheadvice said:

Along as you get  a high enough voltage rating then really they willl be better.

More reliable and likely to be closer to the value you already should have. Electrolytic are wide tolerance (typically +/- 20%, those fitted might originally have been better).Polyester maybe 10% or better....so just go for it!

Whilst the tolerances are wide on these components, sometimes it's a matter of needing two similar ones rather than their precise value.

One of the workarounds is to select matched components for electronics: if you have (eg.) 1000 items, you can test them all and pair up ones of similar values.

This is common in building stereo amps.

I'm not sure what the requirements are for a speaker crossover, though.

For the Mission M66i, pretty basic :-)

Yes all the above true. If concerned about the stereo image select the components. Could be, if you buy a few, they will be close anyway and not change much with age unlike many electrolytics.

I doubt you will be interested in the electronic/audio details of why matching can make a difference...or even notice it in most domestic useage?

ThisIsWeird

Heedtheadvice said:

For the Mission M66i, pretty basic :-)

Yes all the above true. If concerned about the stereo image select the components. Could be, if you buy a few, they will be close anyway and not change much with age unlike many electrolytics.

I doubt you will be interested in the electronic/audio details of why matching can make a difference...or even notice it in most domestic useage?

I'm going to buy enough caps to swap the other speaker too, should this fix the first one.

I try to be realistic about HiFi, and what can be achieved and why. For instance, although you clearly can go too thin on speaker wires, I do not accept that £30+ cables make a jot of extra difference. So I have replaced the HiFi-supplied speaker cables with ~2.5mm2 78-strand cable and gold-plated bananas, but that only cost me a £enner.

Also, these Missions and the B&Ws which preceded them (now regret selling...) can be bi-wired. Oookkkaaay, I haven't tried this, and I won't, but I do not 'believe' that running two sets of cables from the same amplifier source to the separate HF and LF inputs of these speakers will make any detectable difference whatsoever. If your amp has separate HF and LF speaker outputs, then fair enough, but if only one set, then no - I don't believe it.

(By not 'believing' it, I mean that I highly doubt it from a scientific view, but will obviously be persuaded by evidence to the contrary.)

So, even if the caps in each speaker are at the extremes of their tolerance - so that could be a good 4uF difference betwixt them - I also doubt that I'd notice any practical 'deterioration'. The output is stereo, so is different in any case. Sound stage relies on careful speaker positioning, and the listener bolted face-on in an equidistant chair. Never have done this, almost certainly never will.

But if you have info to the contrary, then I am - lit and met - all ears :-)

Heedtheadvice

Man ( or woman) after.my own heart.

I am keeping my B&W 701CDMs for the long haul !! ( I have similar cables with crimped ends)

You will know I am sure that B&W and many other good manufacturers go to length to ensure phase coherence between lower frequency units and tweeters  - just one of the things that makes them good.  Small changes in values in a crossover have a small affect on frequency respons at the Xover frequency but also affect the phase difference. Whilst total phase angle of fhe whole system has no affect on listening differences can sound awful when big enough. Best policy is keep the components to design value or do the maths!