Help Redo My Room

[tkot]

i just caught up to this thread, but if anyone is looking for masonite call the lunber yard and ask for MDO (medium density overlay) its the same stuff

my wife works for a lumber yard

jay

[dbflash]

jay,

Thanks for the heads up.

Danny

[artto]

So glad to see a few folks are now taking this seriously. IMO it is indeed the most important aspect of "the system". And, it doesn't have to cost an arm and leg.

[dbflash]

Well things changed.

I couldn't handle my Cornwalls only being 80" apart and I had to sit back 10 feet, so I did the following:

The room I was trying to tame was long and narrow. Between the Cornwalls was a French Door. This was going to be a tempo room until I redid my other den, which I am using for HT.

Last week I thought about it and decided I never watch movies and mainly watch TV. I would watch CNN in 5 channel stereo. I sold my HT speakers (KLF20's and 3 KLFC7's). I moved the TV in to the other den and moved my 2 Cannel system into the HT den.

The Cornwalls are now 11 feet apart, 2 feet from the wall. I am sitting back at least 11 feet. Life is good.

On the wall where the speakers are is a window.

Here is my new question:

I liked what the panel did in the other room so before I setup my system I hung the panel horizontal covering the window starting about 2 feet above the speaker. I am going to make another panel and continue going horizontal across the wall between the speakers. I am also making a panel that will go behind the couch (horizontal betwwen a window and a door).

Is this helping or hurting my room. I know the answer is going to be take it down and see if it sounds any better or worse, but I have to take my system apart. Every post I have seem about the panels have always been showing them vertical. Is placing the panels horizontal a bad thing?

My system sounds great, but I'm wondering am I killing some of the sound?

Thanks,

Danny

[michael hurd]

Placing the curved panels horizontal is quite fine, as you can see from the picture, even PWK used them horizontally. He advised that 10-20% of the wall surface should be covered with them, and that the amount of bow and the physical size, be different. IE: 2 x 3 feet, with 6" bow, 3 x 6 feet, with 8" bow, etc.

[artto]

Actually, ideally, the curved panels should be of various sizes AND orientation. Personally, I havent really noticed any better performance with the orientation being one way or another, and Ive been using these in various configurations for more than 20 years. However, what is important, is where you place them, and this is obviously going to be different for everyone depending on your room, equipment set up, listening position, etc.

The one thing I can tell you (and Ive done much experimentation regarding this) is that you will most likely be better off with more absorption (than diffusion) behind you, especially if you are sitting closer to the rear wall than the front. Even with polycylindrical diffusers you can be getting too much reflection from the rear wall which can basically still form near-term early reflections which can play havoc with imaging and detail and focus.

[michael hurd]

There are 3 concepts that we need to re-iterate, absorption, diffusion and diffraction. Doing just one will help out, but by balancing all 3, you are getting somewhere. Low frequencies tend to pile up in the corners, because the wavelengths are long compared to rood dimentions. ( 50 hz is a 22 foot wavelength ) This energy is reflected back from the corner, and creates a null near the center of the room.

Turning up the bass control on a preamp if you have one, will just increase the amount of cancellation ( out of phase low frequncies cancelling each others out )

Adding just broadband absorption in the corners is a good start, then adding cylindrical diffusers. You should try an experiment, by playing a bass heavy track, and just walk around the room. Stand in one corner, and compare the amount of bass to the listening position. I measured 9 db difference in one corner vs. the listening position, that is like going from a 100 watt amplifier to a 1000 watt amplifier.

[michael hurd]

I see that musician's friend has taken another $ 20.00 off it's package price for the studio foam designer kit, it is only $79.99 now, with FREE shipping! Studiofoam_kit

[michael hurd]

The free shipping only applies if you add more items to your purchase to over $ 199.99.

[artto]

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On 2/4/2005 11:31:22 AM michael hurd wrote:

There are 3 concepts that we need to re-iterate, absorption, diffusion and diffraction. Doing just one will help out, but by balancing all 3, you are getting somewhere. Low frequencies tend to pile up in the corners, because the wavelengths are long compared to rood dimentions. ( 50 hz is a 22 foot wavelength ) This energy is reflected back from the corner, and creates a null near the center of the room.

Turning up the bass control on a preamp if you have one, will just increase the amount of cancellation ( out of phase low frequncies cancelling each others out )

Adding just broadband absorption in the corners is a good start, then adding cylindrical diffusers. You should try an experiment, by playing a bass heavy track, and just walk around the room. Stand in one corner, and compare the amount of bass to the listening position. I measured 9 db difference in one corner vs. the listening position, that is like going from a 100 watt amplifier to a 1000 watt amplifier.

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Actually there are eight basic (acoustical) concepts (not 3), absorption, diffusion, diffraction, reflection and refraction, reverberation (related to the previous five) and control of interfering noise, and modal resonances.

Turning up the bass control does not increase the amount of cancellation. The canecellations occur because of certain combinations of room dimensions, in simple (shaped) rooms of relatively smaller dimensions. You cannot increase the cancellation of something which has already been cancelled (ie: the "null" set, = zero).

While most everyone knows that I'm an advocate of "broadband" acoustic techniques, I think this concept is often misunderstood. Large polycylinders of type being discussed and asked about by Danny are also "broadband" devices, they in fact, absorb more bass than treble, even when open-ended and empty of absorption material behind/inside them. The larger ones are also effective at breaking up low frequency standing waves by other means than just absorption, such as reflection and diffusion.

[dbflash]

Thanks you guys.

This makes me feel better that to this point I am not wasting my time.

I will make another panel for the front wall.

I will get some accoustic foam panels and place them behind me. I will attach the foam to pegboard and hang it like a picture.

This room is going to be gutted later this summer and rebuilt so I have 2 corners for Khorns.

I will be able to reuse the hardboard panels, even if it means cutting one of the panels to make it shorter (3'x6') with a 7" bow.

Thanks again.

danny

[michael hurd]

I bow down to the artto! I was trying to generalize the info.

[artto]

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On 2/4/2005 2:21:40 PM michael hurd wrote:

I bow down to the artto!

I was trying to generalize the info.

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Yeah, well just keep on bowing.

BTW, that Roxul stuff is great! I got some free samples. Can't wait to get it installed behind all the polycylinders.