Room treatment??

[Hornblower]

Hi Guys,

I am starting to think on a new line now, I have today installed (LOL) some super easy basstraps and would like to know what you "the pro's" are using to extract that last nuance from your gear?

I am interested mainly in DIY methods as the comercial stuff is way overpriced based on what its made from.

Any particular thread that is specifically dedicated to this?

regards
Gareth.:applaud:

[baldrick]

Do you have any pictures/description of your basstraps? How good do they work? "Can they perform miracles"? I've BIG problems with my room, if you haven't read "my thread", read here: http://audioheritage.org/vbulletin/showthread.php?t=9583

Do you think basstraps could help me with my problem?

[Rolf]

Do you think basstraps could help me with my problem?

Hi baldrick. Bass traps removes unwanted bass at a specific frequency. I do not believe this is your problem. OR::: has something happen recently???

EDIT: I need help to remove some peaks at low freq. I will try to post a curve.

[B&KMan]

Hi Guys,

I am starting to think on a new line now, I have today installed (LOL) some super easy basstraps and would like to know what you "the pro's" are using to extract that last nuance from your gear?

I am interested mainly in DIY methods as the comercial stuff is way overpriced based on what its made from.

Any particular thread that is specifically dedicated to this?

regards
Gareth.:applaud:

Hello,

Your wish is impossible

any room is particular and the complete rule is complexe and need a specialise instruments who rarely person buy or rent.

but maybe hint is help you... the principe of bass trap is :

-- permit to bass freq to go inside and disipade energy by absortion or by or resonnance at inversion of phase for cancel energy.

and .

-- reflex any other medium and high freq.

more low freq more biggest trap size... at very low frq the treatment of entire back wall is necessary.

of course the bass is amplifie by the junction of 2 plane surface (room) so the higher efficience treatement is corner :D


anyway I send pict where the principe is visual expose.

I hope this you help.

:cheers:

[Hoerninger]

Many years ago TEAC/TASCAM has published "The Multitrack Primer" written by Dick Rosmini (Google) - it was 1978. Rosmini describes how to prepare the room for good recordings and has a view on cheap solutions. And he comments as follows: "Every little bit helps, and the last bit may be do the trick". Some of his ideas you can find here and they may inspire you for your living room:
http://www.wtc.mb.ca/mp/2004/aaron/web/cheapwav/started/index.htm
http://www.wtc.mb.ca/mp/2004/aaron/web/cheapwav/sndrm/tent.htm
http://www.wtc.mb.ca/mp/2004/aaron/web/cheapwav/sndrm/curtains.htm
http://www.wtc.mb.ca/mp/2004/aaron/web/cheapwav/sndrm/roomtun.htm

If you want to use tube absorbers, they probably will have a distance of 1 to 2 meters to the walls (I wouldn't like to have trees in my living room ;-) )
Concerning bass reproduction it is best to sit close to a wall, but that is not always possible.

If you have a longish room you can cover one of the small walls with glasfiber wool about 1 meter thick ( - don't forget to tighten fairly with a foil sheet because of the glasfiber dust). You may cover the construction with a curtain. If you place the two speakers, - I'm talking about stereo and not about quadro - at the other small wall symmetric to the middle preferably not in the corners, then you have a clean sound probagation with a minimum of standing waves in that direction. Resonances in other directions will hardly be generated.

If you want to minimize reveberation effects between the left and right wall (echo) when you are sitting in your proper place, it would be fine when the surfaces are not parallel. In studios they sometimes install a second non parallel wall within the room. It may be removable, but what an effort.

I have choosen none of these suggestions. It's a normal living room, but we could plan the house from scratch.

Regards
Peter

[jblfreeek]

What do you guys think about using EQ/RTA and trying to obtain flatness instead of acoustic treatments?
Former seems like a more dynamic solution to me, on the other hand the latter is fixed with room/system (leave aside cost/ugliness/hassle/anti WAF etc).

What are the drawbacks of using EQ/RTA vis a vis acoustic solutions?

[johnaec]

What are the drawbacks of using EQ/RTA vis a vis acoustic solutions?An EQ won't get rid of undesirable room nodes, so if you compensate for them at one location with EQ, you'll have an unwanted effect at other locations. Acoustically treating these nodes in a room generally is aimed at fixing the bad spots without having an effect on the good spots, so you end up with a better overall setting to start with. That's why recording studios are always physically optimized first. If it didn't make a difference, people would just leave all the walls hard, etc., and just fix it with EQ. It doesn't work that way... :no:

John

[boputnam]

What are the drawbacks of using EQ/RTA vis a vis acoustic solutions?John makes some points. However, IMO there is much that can be done with EQ.

With proper EQ you can lessen the frequencies that are more easily excited in the particular room you are in. This is what we have to do constantly in the world of live sound. Most often the results can be quite pleasing. In the home, this can avoid the need to install anything that doesn't fit with the decor.

Try some proper EQ first - by proper, I mean collect some good measurements of what is going on (Pink Noise, and use a FFT like SmaartLIVE if you can), and make some subtle cuts. Try not to boost anything, but bring down peaks to affect a flatter MEASURED response. See if the results are satisfactory enough - you might not need a lot of acoustic treatment afterall.

[johnaec]

However, IMO there is much that can be done with EQ.:p I definitely should have qualified my statement - I myself am an ardent believer/user of EQ in most cases. I was just trying to clarify that an EQ can't compensate for room problems in all cases...

John

[jblfreeek]

An EQ won't get rid of undesirable room nodes, so if you compensate for them at one location with EQ, you'll have an unwanted effect at other locations. Acoustically treating these nodes in a room generally is aimed at fixing the bad spots without having an effect on the good spots, so you end up with a better overall setting to start with. That's why recording studios are always physically optimized first. If it didn't make a difference, people would just leave all the walls hard, etc., and just fix it with EQ. It doesn't work that way...
Good point indeed.
I was mainly aiming to compensate for acoustic anormalies specifically for my own chair in my room. This is the chair on which I mostly listen to music.
But I see your point.


Try some proper EQ first - by proper, I mean collect some good measurements of what is going on (Pink Noise, and use a FFT like SmaartLIVE if you can), and make some subtle cuts. Try not to boost anything, but bring down peaks to affect a flatter MEASURED response. See if the results are satisfactory enough - you might not need a lot of acoustic treatment afterall.
Thanks boputnam for the encouragement. :)
This was actually something I wanted to do for a long time.
I'm kind of a math guy and analog sound and its related issues is something both interesting and challenging for me. I always wanted to measure sound. :p

So far I was gathering stuff I thought necessary like a decent 33band EQ with hard bypass with both graphic and parametric functions to make finer adjustments, software (SmaartLIVE, Room EQ Wizard,Smaart Acoustic Tools etc.), and an SPL meter.
I'm looking for a decent mic after that I assume I'm good to go for start.
So far I'm reading and reading. Quite interesting stuff actually.

If you think there is something I should add to the reading/equipment list, or points I should be aware of, I'm open to all suggestions.

[Zilch]

JBL provides good theoretical exposition and general advice in the manual for its LSR RMC room correction device, which I borrowed from Johnaec and copied. Of course, I cannot find it, now. Perhaps he will offer up a synopsis.

Basically, it was EQ out the peaks, and move your chair forward or back for the nulls.

Or, vice-versa, maybe. :p

I'll look for it online, too, now....

Edit: Here 'tis:

http://www.jblpro.com/LSR6300/PDF/RMCUserGuide.pdf

The devices themselves occasionally show up on eBay. The width template is an interesting graphic approach to "Q".

[boputnam]

...or points I should be aware of...You "sound" like you're off to a solid start.

The most important things to remember are:

Collect meangingful, repeatable measurements. Make sure you understand what you are looking at.
When applying EQ, the less you apply, the better - for ALL sorts of reasons (phasing, power consumption, interferences, etc).
When applying EQ, try to not boost. Cut, only. Look at the response curve and try and gently bring down the "excited" frequencies. You won't be able to get "flat", but anything close will sound darn nice.If you get stuck, post a question here - there's many that can help! :yes:

[Mr. Widget]

I think John was headed down the right path... do as much with the room as possible and then follow Bo's advice and carefully tune your system with EQ if necessary.

Think of it as room treatments attempt to cure a disease and the EQ is there to help lessen the symptoms of the disease.

In any event, in my far from optimum room, I lined three of the walls floor to ceiling with moderately heavy drapes... it made a dramatic improvement. Luckily the room is quite large so I moved my system and listening position around a fair amount to find the best location to minimize room modes.


Widget

[baldrick]

Hi baldrick. Bass traps removes unwanted bass at a specific frequency. I do not believe this is your problem. OR::: has something happen recently???


Hmm, I've heard basstraps should be placed where you have "too much bass" normally in corners. And when you've done this the bass will be "moved" (hopefully) to your sweetspot. Maybe this is totally wrong, but that's the simple explantion I've been told by those who sell basstraps and that's why I was hopeing they could work for my problem :)

[Rolf]

Hmm, I've heard basstraps should be placed where you have "too much bass" normally in corners. And when you've done this the bass will be "moved" (hopefully) to your sweetspot. Maybe this is totally wrong, but that's the simple explantion I've been told by those who sell basstraps and that's why I was hopeing they could work for my problem :)

I am no expert on basstraps, but as far as I know they remove to much unwanted bass in the room, such as the well known room resonance. I need to do something myself, but have no space for basstraps. Se the graph below for my room.

Rolf

[Hornblower]

Hi guys, thanks for the effort going into this its well appreciated, I dont profess to be extremly knowledgable on this subject , but the little I have read on the subject suggests that bass traps are quite effective, while concur with the earlier statement that traps get huge once you start to look for real "deep bass" treatment (this is because of the physical size of the wave that we try to treat, I.E many feet long) , the simple method that i used really helped me in my situation and I have to say that I was more than a little skeptical but thought id give it a try as it was well within my budget and hey, at the end of the day, I was considering spending quite a bit of my hard earned on "better equipment", not that the stuff I have is trash , just one does get the old "upgrade-itis" LOL.

As they say every little helps and I definately can hear the difference, If there is anybody in Mexico reading this thread I cordially invite you to come and prove it for yourself! We can do a/b comparsons with traps and without, and if you cannot hear the difference Ill refund you your travel money!

There is an excellent site I found regarding this subject and its from a well respected gentleman by the name of Mr. Jon Risch, the traps i have so far I admit are not high on the WAF/SAF scale, but its a dedicated room and I am KING in there! HEHE.

If anybody wants the link etc send me a p.m and ill be happy to pass it along, ive just assembled 2 more and these are so simple its rediculous.

Eq can be usefull, but what one must remember is that most eq's are wide band and you really dont want to be boosting frequencies as youll be effecting more than just the desired frequency, not to say that I dont advocate the use of, but one must excersise a modicum of restraint!:) For you could make worse the problem already there.

Anyhooo, my best regards and sincere thanks to all that have contributed so far your input is very valid and im enjoying it very much.

Kind regards
Gareth.:bouncy:

[Zilch]

http://www.bobgolds.com

[Steve Schell]

Lately I have been experimenting with room treatment. I have always preferred a heavily damped room, to maximize the ratio of direct to reflected sound. Rooms are basically evil sonically, especially small ones with parallel walls. Many years ago I upholstered the entire listening room in my apartment with R19 fiberglass. It freaked out visitors, but I sure liked the sound of my Quads in there.

A few years ago I built seven big 'n ugly absorbers from sound deadening board (compressed wood fiber), carpet padding and pieces of R19. They are 8" high by 30" wide and about 6" deep. More recently I added 24 panels of 1 1/2" compressed fiberglass, 2' by 6', built to use in demo rooms at trade shows. The room has been quite dead recently, helping the system to sound good.

Recently I did some recearch, printing out a couple of articles and a few patent papers. Particularly intriguing was a US Patent from 1982 by Per A. Hellstrom, "Arrangement for Damping and Absorption of Sound in Rooms." He describes the arrangement of panels spanning the corners at a 45 degree angle and methods of providing adjustment of them for different uses in a room such as a church. I decided to try this yesterday, and placed four of the big 'n uglies across the room corners. Wow, what a difference! The room is now even more dead, and bass from 80 to 150Hz. increased so much that I had to rebalance the system. The system sounds quite a bit better now, without changing the number of panels, only their placement.

From the reading I've done, it seems desirable to bring the reverberation time of bass frequencies down to that of the mid and high frequencies, or as close to this as possible. Placing the material across the corner gives the most bang for the buck from the panels, as low frequencies concentrate at room boundaries, and especially so in the corners. I also spaced the other panels out from the walls, which increases their effectiveness at lower frequencies.

[jblfreeek]

You "sound" like you're off to a solid start.

The most important things to remember are:
Collect meangingful, repeatable measurements. Make sure you understand what you are looking at.
When applying EQ, the less you apply, the better - for ALL sorts of reasons (phasing, power consumption, interferences, etc).
When applying EQ, try to not boost. Cut, only. Look at the response curve and try and gently bring down the "excited" frequencies. You won't be able to get "flat", but anything close will sound darn nice.If you get stuck, post a question here - there's many that can help! :yes:

Thanks boputnam, will sure do! :yes:

[hapy._.face]

I recently was given the nod to put together a dedicated listening room in my house. I don't know much about the subject of room treatment, nor do I have any software. I did, however, make MAJOR improvements using an imperical "trial and error" approach. I also saved a huge amount of money by squeezing performance from my system. Here's what I did:

The house is a circa 1938 EOG townhome with granite/brick/plaster/hardwood and has been largely modded out. The room is (technically) our formal living room. You know, that odd room with the furniture no one ever sits on? Now, it's mine! It's dimensions are generous, but the floorplan is an acoustical nightmare (unless you prefer a natural reverb all the time). It has 3 large windows and it is joined with 2 stairwells (one up and one down), an open french door and a standard open 35" door-. Neither door openings have doors on them (there is also a third entry door). The stairwell is also open with only treads and a handrail. The french door opening is joined by nearly 600 square feet of wide open kitchen and dining room space (we took out a couple of walls and added load bearing beams). It is not the ideal space- but it's what I had to work with.

I started off by clapping my hands all around the room to see how it echoed. The room was totally empty at the time. I noticed that the echoing sort of "canceled out" in the very center of the space. It was immediately decided that my chair would go there. :D
Next, I put a big rug down. That helped!
I'm an aesthetics junkie, so I typically hate anything on the windows. I'd rather walk naked in front of my neighbors than have curtains, but I knew something had to be done about the glass. I put up celluolose shades- triple insulated. This proved to be a major sonic improvement. I leave them up and out of sight until listening time. I threw in a small armless loveseat- and some throw pillows. I clapped some more. I hung the artwork back up. I stuck a cut panel of compressed fiberglass behind the canvas piece and mounted it slightly off the wall (about a 1/4"). I put a coatrack on the wall by the main door and put heavy winter coats up on the hooks. I made a piece of fabric wrapped panel board- very much like the ones in the Acoustical Solutions catalog- and placed it behind the speakers.

I clapped a lot, listened a lot, and learned a lot. I also saved a lot. I'm not done yet. My simple "upgrades"- put in the right places- have been more rewarding (sonically) than ...say...a better source component.

People overlook the room so much. What a shame. You really need some sort of benchmark or point of reference before you make system changes. It doesn't seem very scientific to swap stuff out without first addressing the room and making it better. I'm glad I did!

[allen mueller]

I saw a link to one of the white papers from Harman.com in another thread. The other night I read all the white papers and downloaded the room mode calculator. There is some good information on room setup in all of them. In the papers they discuss how to address many issues economically. I learned allot about how the room affects the sound from reading them all.

Link:
http://www.harman.com/about_harman/technology_leadership.aspx (http://www.harman.com/about_harman/technology_leadership.aspx)

Allen