SBAcoustics, SBA-761, built by Andreas, Germany
Copyright 2020 © Troels Gravesen
Dear Troels
I finished the SBA761, my personal choice after years of joyfull
following your site. Perfect size + simplicity in concept and crossover
+ good price + attractive drivers. I changed the internal design a bit
and used a laminated stack of boards to build the top and tweeter front.
Very solid result.
Some surfaces use olive-ash veener, i like it for its change of color. I
was not able to enjoy all hours of work, to often i was concerned to do
a fault, but everything went right. Patience and trials are the secret i
guess, it was not my first speaker also.
For the veneer a small saw worked better than a cutter knife, to offer
one hint.
The sound is really good. I always wanted more bass than my old monitor
(SS 15W8531) could offer. And I got more, but was not prepared that I
was used to the old sound.
So I perceive this as too much bass, especially the upper bass leaves me
with a suspicion of to less precision. Also moving the speak could not
cure this, as it is still in the corner. Crossover is modified now with
a LCR circuit in parallel to the MW19 (nn mH-nn µF-n Ohm).
Jantzen Air Core Coil xx with its internal nn Ohm is perfect and
affordable. The difference is larger than expected with -2dB predicted
from simulation. It's better for my personal taste, less pressure in the
chest, but more precision in the brain.
Also the deep bass gets more pronounced, or less masked to explain the
reason.
Later i also stuffed one port for the speaker in the corner and
used R1 nn Ohm before both MW19. Did not expect bass response to be so
difficult, maybe the problem is also a matter of taste.
Two things i noticed, despite higher efficiency i still use a similar
position at the volume control, resulting in a higher playback level,
but without feeling disturbed. The speaker is easy and relaxed for the
ear, you can forget it if you like and stay with the music. I think a
6db design is my cup of tea.
Second, testing the speaker with different recordings ends quickly in
testing these recordings not the speaker anymore. So obvious are the
differences, most clear to notice at stereo panorama. Better records
sound better, we all know, but here this is very easy to evaluate.
Thank you very much for your precise and steady work, i learned so much
from all of your projects.
Kind Regards
Andreas
