From Newsgroup: uk.rec.audio
In article <
9bbf521d-4b8f-4be2-bbe4-b71fbc3a06een@googlegroups.com>,
Phil Allison <
pallison49@gmail.com> wrote:
Don Pearce wrote:
----------------------------------
RJH wrote:
I've gone as far as I want to go on the audio hardware front,
and tend to arrange living spaces for comfort rather than
optimal audio. With that in mind, something got my attention
the other day:
https://www.dirac.com/live/home-audio-for-audio-lovers/
Some amplifiers have it built in. Any opinions?
You can't compensate a room.
** Ever since the arrival of graphic equalisers with 20 or 30
bands, a whole industry has sprung up with the opposite idea.
Firstly just to sell such units and later also various ways to
"calibrate" the settings.
You have to treat it to make it as good as possible.
** However, effective room acoustic treatment is quite expensive
and runs counter to modern room styling and construction methods.
While snake oil devices are ( as usual ) far cheaper and quite
unobtrusive.
Modes see to it that the frequency response at various points in
the room varies wildly.
** Particularly with bass frequencies - from about 200Hz down. Box
speakers radiate low frequency sound pressure omni-directionally so
are the worst for exciting room nodes, while types radiating back
and front ( eg full range ESLs ) the the least likely. Reason
being that reflected, low frequency sound pressure waves arrive
back in the room " in phase" in the case of box speakers - so
reinforcing the SPL - while being largely out of phase in the
other case.
This effect plus also much narrower dispersion of mid and high
frequencies makes the audible difference quite stark.
FYI : the best way to eliminate negative effects rooms have on
reproduced sound is getting rid of the room. Do you own a pair of
ES headphones ??
Whilst I don't dispute anything you've said I do have another POV.
I'm going to regret posting this I know, tin hat on....
I own Kef R105 mk1 loudspeakers. In our first house they sounded (to
my ears in 1977) fantastic. In 1982, moved to new house and big bass
problems. After 6 months we built an extension on the listening room
to give more space and hopefully fix the bass. It didn't.
For decades we tried everything we could afford and even experimented
with a suspended ceiling because the extension led to an RSJ across
the room. It helped a lot but not a fix.
In 2014 I purchased a music streamer. I'd not had it long and it got
a firmware update giving room correction. I had to try it didn't I?
This system does not use microphones instead you enter into a
computer room dimensions, speaker positions, surface information etc.
etc.
Switched it on... No bass at all !!
The filter had 3 very sharp notch filters at 27.92, 64.18 and 78.83
Hz. The filter at 27Hz was at -38dB the other two were much less
severe.
More reading followed and it explained how it had set up what it
thought were correct filters but they needed to be adjusted by ear.
I have reduced all the filters depth by ear with the big one being
reduced to -7dB .
Okay shoot me down I don't care. It stopped all of the problem, it
was just gone and I had (to me) good bass but best of all was the
opening of the mid range, it gained a lot of detail after mud removed.
Obviously it can't really correct the room but it seems here to
seriously reduce the amount of energy put into the room at the
critical frequencies and for me it really works.
I'd had an Arcam AV8 since about 2005. It doesn't have HDMI inputs
and I wanted them. In 2021 I purchased a second hand AV860. It also
has Dirac.
Eventually and with much hope, I got around to trying it but first I
purchased a microphone with known response and a mike stand.
This was a major faff and then some. Multiple readings have to be
taken with the mike in multiple positions, it takes ages and ages.
The software doesn't work the same and for me it was less pleasing,
it displayed the mess that was reality and what it was going to end
up as when treated.
I did not like this system to be honest. It did have one strong item
though and that was with my sub woofer. I have a BK monolith sub but
unlike my Kefs I'm unable to place it in the room well away from the
walls, it is against a wall. What it did for the sub when playing a
music video was astounding to my ears. Bass so clean and yet so
powerful a real punch in the guts. Didn't particularly like what it
did for the Kefs though.
What I wanted to do was transfer the known good (for me) filter
settings used in my streamer to the AV860 but I couldn't see any way
to do that.
I should say, the sub is only used when watching video films etc. in
5.1 mode and the kefs are then treated as "small speakers" I didn't
want my old kefs handling earthquakes.
So yes, I'm sure you cannot correct a room in this manner but you can
make a system cope more pleasingly with a bad situation.
I rest my case.
Bob.
--- Synchronet 3.21d-Linux NewsLink 1.2