Need help with room acoustics!!!

[Shan2nu]

So, we finally picked up the Jamo S406 5.1 Surround system with a Yamaha Amp. Total cost (2 Towers + 2 Sats + Center Speaker + Sub + Amp + 35mtrs of cable) came up to Rs. 47,895.



Buying a good system is one thing, but getting the best out of it is a completely diff ball-game. Room acoustics/dimensions play a major role in providing desired music quality.

Our music room is yet to be built, that gives me the chance to plan everything before hand.

Dimensions : I've heard that a room should ideally be built in such a way that the width is 1.14 times and the length is 1.39 times the height of the room.

EG : If height is 10ft, width should be 11.4ft and lenght should be 13.9ft.

Acoustics : By covering the wall, corners, floor and ceiling with sound dampening material, reverberation and other distortions can be avoided.

I'm planning on having corner bass traps, wall bass traps, rear wall scatter boxes, first reflection traps, floor carpet, thick wall curtains etc made for the room.

What sort of dampening material (for the traps) would be ideal, at a reasonable price?

Speaker Placement : This is one area thats got me scrathing my head (especially wrt to the surround speakers). Any information on this front would be appreciated.

Shan2nu

[Nos007]

For room acoustics:
plywood is used for the floor to reduce the resonance frequency and increase low frequency absorption. Floor joists are spaced at random intervals through the room to vary the resonance frequencies. Closer spacing is used under higher traffic areas to firm up the floor. Sound absorbing material is used in between the floor joists.

To reduce high frequency absorption from the carpet, vinyl sheeting is placed between the carpet and the pad on the rear shelf.
The walls and ceiling are built using 5/8" drywall on framing which provides excellent acoustic properties (although some surface-applied acoustic treatment is still required for the best sound).

For Speaker Placements:



Ideally, your front speakers, high-frequency drivers, or tweeters should be positioned at ear level (when you're seated). Our recommended height for the surrounds is above ear level, as soundtracks are likely to be optimized for that location.
Beyond keeping it on the floor, there's no specific rule for placing the subwoofer, as bass sound is non-directional. However, the amount of bass may vary depending on room location. You might want to try a few different places to determine what's best for you (sometimes moving the speaker even a few inches can change the sound)
If possible, center your seating area between the surround speakers.

The closer you place a speaker to intersecting room surfaces (corners, wall and ceiling, wall and floor), the stronger the bass output. This can help bass-shy speakers, but it can also add too much bass. Again, just moving a speaker a few inches can often make a big difference in sound.

[navin]

Originally Posted by Shan2nu

Our music room is yet to be built,
Dimensions : I've heard that a room should ideally be built in such a way that the width is 1.14 times and the length is 1.39 times the height of the room. EG : If height is 10ft, width should be 11.4ft and lenght should be 13.9ft.

I'm planning on having corner bass traps, wall bass traps, rear wall scatter boxes, first reflection traps, floor carpet, thick wall curtains etc made for the room. What sort of dampening material (for the traps) would be ideal, at a reasonable price?

Speaker Placement : This is one area thats got me scrathing my head (especially wrt to the surround speakers).

Room dimesions should be such that the wavelengths for each boundary are different. In fact if you can make the room so that there are no parallel surfaces it would be great. Have you seen how in many theaters the stage end is narrower with a lower ceiling than the audience end?

So keep as many boundaries non parallel as possible.

You could study the construction of Tube trabs and Room diffusors to get ideas on where to place them and how to make them.

For sound absrobtion and diffusion fiberglass (used as insulation) is a good option. Other options are wavy or pin hole foam, egg crates, etc..

However none of these options have a high WAF. Hence carpets (silk carpets hung on walls), book cases (the books should be of different sizes), curtains, etc.. are often used in most houses.

Avoid early reflections. So keep sound absorbing material on he walls and flloor near the main speakers and subwoofer (and if possible near near the rear speakers as well).

Since you wer building the room from scratch wire the room for 8.1 inase you want to upgrade later. 8.1 would include 3 rear speakers in addition to your front and side speakers. Also 8.1 wiring allows you the optionof using a 6.1 system as well.

[Shan2nu]

Thanks a lot guys. I wanna get everything right the first time, so i'm gonna go easy with the room design. Will give yo'l an update as the project progresses.

Shan2nu

[mithun]

I had bought a Altec Lansing 5.1 system for my PC. Please help me to position the speakers for better sound quality ?

And where should I position the sub-woofer ? Should I place it below the monitor OR place it at the ear level ?

[navin]

mithun those speakers dont come with very long wires. place them as far apart as the wires will allow.

[headers]

Originally Posted by mithun

I had bought a Altec Lansing 5.1 system for my PC. Please help me to position the speakers for better sound quality ?

And where should I position the sub-woofer ? Should I place it below the monitor OR place it at the ear level ?

Placing the SUB at a lower level gives the illusion of better BASE..hence If i were you, i'd place it on the floor or as close to it as possible..preferably at a corner around 1.5 ft away from the wall.

[santosh.s]

I had come across an interesting way to determine subwoofer location:

1. put the sub under your favorite seat which you want to make "the sweet spot"
2. play some bass heavy music, preferably with bass notes in quick succession.
3. crawl all over the place like an infant. At some places bass will become suppressed or loud but unclear/boomy while at certain locations it will be the best.
4. Locations where you find the best sound are actually optimum locations for sub placement in your environment!

Not to mention, if the best location turns out to be ridiculously odd- like right in front of a door, then obviously look for next best option!

[Bass&Trouble]

Originally Posted by santosh.s

I had come across an interesting way to determine subwoofer location:

1. put the sub under your favorite seat which you want to make "the sweet spot"
2. play some bass heavy music, preferably with bass notes in quick succession.
3. crawl all over the place like an infant. At some places bass will become suppressed or loud but unclear/boomy while at certain locations it will be the best.
4. Locations where you find the best sound are actually optimum locations for sub placement in your environment!

Not to mention, if the best location turns out to be ridiculously odd- like right in front of a door, then obviously look for next best option!

err, santosh, thats almost like the only way to determine subwoofer placement/ avoiding null points without using any test equipment. You have come across it a bit late.

[santosh.s]

Originally Posted by Bass&Trouble

You have come across it a bit late.

may be because I am not into audio retailing

[Nikhilb2008]

The layout of my room is shown below.



My mom and sister whose rooms are below mine have been complaining a lot.

So, my main aim is soundproofing, but in the process, I would like to know if I can improve the acoustics too.

I am planning to get thermocol and cover my windows with it.

The windows facing my neighbour's house are anyway closed 24x7 with the curtains drawn and so, the thermocol will be placed there and forgotten abt.

On the other set of windows, I will be constantly placing the thermocol when I want to listen to music at high volume and watch movies and removing it at other times.

I also plan to buy a mat (the bathrooom mat type ) and place it under my subwoofer. Chaos had done that to his Floorstanders and I want to know if it will help my cause.

BTW, the 5th speaker is placed on my monitor.

There are two older threads...

How to sound-proof my room ??? - TechEnclave

neighbours threatening to call police - TechEnclave

I dont plan on going for any heavy duty solutions....

[n_aditya]

Check out this linky :

http://www.team-bhp.com/forum/diy-do...acoustics.html (Need help with room acoustics!!!)

[Nikhilb2008]

Thank you.

But that isnt exactly my problem. I cant afford to do everything mentioned in that thread.

I just want to soundproof my room. First and foremost.

After that, if I can, I would like to improve the acoustics. I may not be using this room for too long and so investing in heavy curtains and carpets is not feasible.

I am still looking only at thermocol as the option.