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 Restoration Road

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Posts : 2227
Join date : 2009-09-18

PostSubject: Re: Restoration Road   Tue Aug 14, 2012 12:19 pm

Hi Robert and Michael

Robert: your description of an echo that follows me wherever I turn describes the situation better that I ever could. The BOO! is pervasive all round and if I face a wall, the BOO! is behind me.

Michael: the seam voicer sounds like a tool that might be the medicine my room needs.

Of course for new Tunees reading this, Sonic is not talking about using things like bales of fibreglass or those moulded foam panels and plastering them on the walls and ceiling.

Actually Sonic finds they make a room even more unbalanced than before. They kill off some waves but not others and in the process the remaining ones go out of equilibrium and the problem worsens. So the audiophile piles on more and then the room goes dead.

Once here, the audiophile thinks the problem is solved but his problems have just been replaced by something else -- the music is dry and dead, the amp seems weak, the soundstage is compromised, so a Bigger Amp....this may lead to mew speakers, then they have a sound signature that needs tubes, then a brighter cartridge, then cables with boxes attached, then isolate the.....

"Round and round and round we spin to build the walls that hem us in.." (Neil Young).

Sonic is planning my attack on the BOO! but will be employing only Michael's gear which keep the Sound Equilibrium -- and my equilibrium is already at the edge with a drop curtain. The path to removing the BOO! starts with a test programme that I will carry out the later part of this week and write about and ask Michael for his views each step of the way.

Michael, you ready for this? Quick turn around if you please!

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Join date : 2009-09-18

PostSubject: Re: Restoration Road   Wed Aug 15, 2012 12:29 pm

Hi Zonees

Caught the source of the BOO! problem. Think I got the solution too. Very Happy

Testing it now to make that I've got to the bottom of things. If it is right (and it looks like it), I'll describe how the problem was located and my solution in this Friday/Saturday's post.

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PostSubject: Re: Restoration Road   Fri Aug 17, 2012 12:00 pm

Hi Michael and Zonees

Here is the first result of Sonic’s full throttle attack on the Boo!

The Cause:
It turns out that the Boo! is a complex reflected sound that is made up of a low fundamental and at least two overtones, one of which is pitched at “f”. While they sound together, they do not emanate with the same spectral balance from different parts of the room (some parts of the room reflect more low Boo!, other reflect more of the overtones.

Sonic then did the Boo! test while slowly moving about the room and I found that the lower note of the Boo! came more from the length of the seams of the side wall/ceiling joints while the overtones came from the seam of the front wall.

This seems to show that sounds generated in the room runs up the side and front walls and radiate back into the room through the wall/ceiling joint like horns. There is a strong side to side component and a strong lengthwise flow that is leading to the different resonant frequencies that make up the Boo!

Subjectively, the Boo! resonance always seems to appear in the middle of the volume of the room because there will be at least two wall/ceiling seams funneling out the resonance down the length and width of the room whichever way the source of Boo! is delivered by a source.

Up till now, Sonic had an EchoTune mounted at the mid points of the front, left and right wall/ceiling seams – each ET is mounted 45 degrees across the ceiling/wall joint. Although Michael’s directions for his RoomTune products say a single EchoTunes at the midpoint of the front and one side wall is adequate, in my room they are swamped by the resonances coming off the length of the ceiling/wall seams making them inadequate. My room is more live and requires more than the textbook RoomTune application.

Now for the cure…
I brought out all the EchoTunes from my closet and added them to what was already mounted to the side and front wall seams. Effectively, Sonic is making up TuneStrips mounted along the front and sidewall seams.

What Sonic was not prepared for was how many ETs it took to bring the room into some form of control.

For each sidewall, I had to add two more ETs to the centrally mounted ET – making three ETs per side wall.

Then the front wall – that is where the upper overtones come from and it took five ETs to bring the resonance under any semblance of control. With this setting, the “f” note is finally damped and there is now much less overhang. CDs of unaccompanied vocals (Airs and Graces -- June Tabor, Track 2: Plains of Waterloo) that used to activate the “f” note are finally listenable and I can hear the release of the note instead of a resonant wash from the overhang.

Along the way Sonic found that adding more ETs do not deaden the sound more. After a point, the sound goes from controlled to thin, bright and echoy again (this time at a different frequency) which created new colorations of its own.

At the end of this test, just to bring the Boo! under control took eight more EchoTunes – so that makes 5 EchoTunes on the front wall and 3 EchoTunes on the Left and Right walls (that’s 11 EchoTunes in all).

The battle against the Boo! is not over. There is still overhang but it looks like we have the way to win the fight.


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