which components to replace for better audio quality?

[AndrewT]

He's provided the schematic - its obvious to me (having designed active speakers commercially in a former life) that design has problems. Maybe the paralleled amp matching problem will cause failure of one or more of the chips over time.

Do you have a view on the peak SPL capability of each of the different frequency drivers?

I have and continue to contend that the peak SPL of all the actively driven drivers should be roughly similar.
Many here contend that the treble driver need only achieve peak SPL at a much lower level (they typically claim -6dB to -10dB ref mid frequency level) because average signal levels to a treble driver are significantly lower.

 

[jacco vermeulen]

Amp chips only go 'bad' when abused.

(50V power supply electrolytics does make one wonder what the rail voltages for the quartet are)

 

[abraxalito]

Do you have a view on the peak SPL capability of each of the different frequency drivers?

I concur with you - the peak capability should be similar. Of course the average power for the tweeter is considerably less but it should still handle the same peak power, roughly, assuming similar sensitivities (which isn't normally the case - typically the tweeter has a padding resistor in a passive XO indicating its more sensitive).

 

[johnr66]

Use an oscilloscope or make an audio test probe to find out where the scratchy sounds enters the chain. Seems odd that the output ICs would be to blame.

 

[sreten]

Hi,

Peak single sine wave SPL is just a mindless misunderstanding of the real
facts, when it comes to the power spectrum of real peaks on recordings.

Even if you have a fancy 60 band 1/6 octave peak analyser indicating
all bands hitting peak levels, the power for each amplifier in an active
system is very related to the number of bands the amplifier covers.

rgds, sreten.

 

[nexus77]

Thanks again, everyone! I really appreciate all your input. I will see what I can manage. Maybe I should built new amps from scratch as well. That would be a pretty big learning experience for me. Is there a better design or chip amp kit that would take into consideration the appropriate crossover points for this particular application?

 

[sreten]

Thanks again, everyone! I really appreciate all your input. I will see what I can manage. Maybe I should built new amps from scratch as well. That would be a pretty big learning experience for me. Is there a better design or chip amp kit that would take into consideration the appropriate crossover points for this particular application?

Hi,

You will learn a lot more by being pragmatic than going for excess.

Say you gave them to me to fix, and instead of saying I'll see
what I can do, I said you need new amplifiers costing more
than the retail cost of the speakers, you wouldn't be happy.

If you can't fix them, don't think about rebuilding them.

rgds, sreten.