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In the Thread: A listening room for a domesticated Cat?
Post Subject: The last night looking…Posted by Romy the Cat on: 7/12/2017
The last night I put the kids d and wife and bed and desired
the spent some time with my playback like I use to: listening, thinking, experimenting,
thinking again, smoking a good Padron Family Reserve 50 cigar… OK, I lie to
you. I do not smoke in my listening room anymore but the rest was true…
Or new hour is relatedly big and the way how it made the
listening room is acoustically isolated from the rest of the house and I my
plays my music when the rest of the family sleeps… So I did for a few hours
after 9 PM. I was not too comfortable with the sound I am getting lately and I thought
to go to the bottom of it. This recent flash excitement that I got with the idea
of Khorn is good but it is not the way how I usually thinking about audio.
The very first I did was the recalibration of Macondo based
upon my initial check list.
http://www.goodsoundclub.com/Forums/ShowPost.aspx?PageIndex=14&postID=14994#14994
Then I discovered that one of the woofers in my midbass was disconnected.
I can blame Thomas the Son or the cleaning lady, who knows but as I connected
it the midbass certainly got to sound slower, as I wanted, and the imaging was
back how I expected to be. The fixing of the woofer and calibration of the playback
made Macondo to sound so distinctly recognizable. It has that unique very silky
and very not abusive sound that I so cherish…
I did not turn the ULF for a whole evening and did not moved
any speakers yet. I feel that connection the missing woofer made Macondo to
sound more compiled and more imaging-wise collected, so I hold moving to 8-8-1
for now. As the last midbass woofer went online the HF cleaned up and become
more prominent and they do not sink anymore in the right and left channels but
rather more organically presented from the space between the speakers. Or was only one woofer but it did give to me
that “space” filling effect that I felt should be there. So, I fixed the whole presentation
and lost some negative rage that developed during the last week.
Now about the bottom of the midbass. The faster then needed
decay is not there anymore. I think I was reacted to a missing woofer in my
right channel. The decay still has no right softness but I recognize that it is
not a hardness but rather some strange coloration,
almost like some crap that come from port but it is not as much tonal but more dynamic
+ tonal. I desired to focus on the problem and was trying to deal with it. First
I decided to test the QTS reasoning. I opened up the whole for the binding posts
on the midbass enclosure, creating a fake ports. There was no impact that I
heard. Then I unscrewed the woofers and put a good 1” stick between woofers and
baffle. To my HUGE surprised, even the sound change, but the hardness
that I was fighting with did not go away. That was very interesting as it looks
like the problem then was not acoustic but electric. I closed up the woofer and
begin to look at the electrical part. The woofers are driving by LF channel of
Milq, the 5.5R transformer, with 78Hz line level filter and additional 9mH coil at 150Hz at speaker level.
Something in there did not work well. I played the plate current on the output
stage and to my huge surprise the sound was changing very much. I mean as you drive the plate current from 250V
to 200V the sound should be changed but NOT in the way I was changing now. The midbass channel is very far away from any current
or voltage clipping and why the dropping of voltage made me to minimize my
woofer hardness I do not know yet. Dropping voltage will raise the output impedance
and very slightly drop the amp gain. If I defeat the hardness by dropping of
the output impedance then I would understand what is going on but I minimize the
hardness by raising the output impedance!!! This is very interesting and I need
to think about it more. It is possible that filter coil somehow talk with VC inductance
and opon a microscopic black hole where all be good sound goes? Anyhow, I need
to experiment with it more but the fact that my problem might be electrical
make me much happier.
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