November 2020
My speaker system needed some help. After all the work I performed on
the McIntosh and Eagle2 amps, the system didn't sound right at all.
The ribbon tweeter had very low and indistinct output.
The dome tweeters were bitey and did not reproduce the highs correctly.
The midranges were ill defined, muddy and had no "stage".
So after MUCH research on capacitors, (talk about audiophile crazyness),
I decided to go with the "Jantzen Superior Z-caps" pictured above.
They seemed to be the best caps I could afford that were also highly rated.
However, I was not realizing just how physically big they would be.
Anyway, I rolled the dice and bought 8 caps.
Original 1984 "SpeakerLab" 3-Way Crossover Shown Below
Check out these new caps. They are HUGE.
The CAPS in a cradle and a silver spoon,
little boy blue and the man in the moon
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Lesson learned: Don't use heatshrink. It rattles.
RESULTS:
(Tone controls set to flat. Music source is FLAC Files).
(Signal path is: Computer Toslink to DAC to Preamp to Pwr Amp).
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The improvement is amazing to say the least. I didn't think I would hear this
much of a change. I find no need to "pad down" any high or mid levels at all.
The ribbon tweeter's level came up to that of the dome tweeters. Very nice blend.
The dome tweeters are now smooth with no bite, and very distinct with full highs.
The midranges are way more defined and correct. Not muddy anymore.
The overall stage is now very present, accurate and attention getting.
The dynamic range also improved greatly. The "attacks" in
the music sound correct and concise.
I find myself listening to a much higher volume without any of the
distorting harmonics that used to cause me severe ear fatigue.
Even at low levels everything is sounding great.
What a HUGE difference !
Conclusion: The roll of the dice payed off. I like it!
NEXT PROJECTS:
Yamaha C2 pre-amp service, woofer output and cabinet tuning.
YAMAHA C2 SEVERCE: (See C2 Pre Amp page).
WOOFER OUTPUT: (Future).
I think I see a potential problem with the inductor that is in series with
the woofer. Its wire gauge is actually smaller than the leads on the big
Jantzen caps. It also feeds the woofer through the lands printed on the
circuit board. Overall it looks to me like these issues could be an impedance
to the instantaneous currents powering the woofer, which might be reducing the
woofers output level. Jantzen makes an inductor that is wound with 15 gauge
multi-strand wire. That + direct descrete wiring might give the woofer more output.
This will probably lead me to make a whole new crossover circuit mounted
on a new larger board. Maybe a 4-way crossover this time?
CABINET TUNING: (11-9-20)
For now I have decided to try and tune the ports in the cabinets. I built some
"press-in" cardboard port vents for experimentation. (See below).
They actually work and I am hearing lower frequencies that I did not hear before.
I think I will just paint them flat black and leave them in place for now.
What the hey, they seem to work.
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A Carnacism: Cardboard, a sharp box cutter and a glue gun.
I built these 8 cu ft cabinets back in 1968.
They were a 2-way system back then.
Now that's a long time project for sure.