Room Treatment Advice

[sound_cycle]

Hi


I've been reading a lot on room treatment and found a lot of useful information on hfv. I think I have kind of understood what I need.

I was thinking of going the DIY route but there is that ready to use solution from here

I am not quite ready with a plan but a discount offer on bajao.com for corner bass traps has spurred me into action a little ahead of schedule

The room is 23.5 x 10.5 x 10 H. There a number of doors and one window. There is a small alcove. A portion of the room is not available for audio, but might need treatment ?

The goal is to rid the room of its worst modes and flutter echoes on a budget.

I have made a room plan and shown the treatments I plan and shown it on the figure below. Could you please let me know what you think of the plan.

Should I get the bass traps or will the broad band absorbers suffice ?

ciao
gr

 

[Nikhil]

Sound cycle,

That is a neat schematic! What kind of problems are you facing?
Is there some kind of partition between your listening area and the non-audio part?

Can you consider moving the setup to another wall/location?
Placing your speakers along the (dotted) division line would be fantastic if you can do it.

What kind of speakers are you using at the moment?
You can limit bass frequencies by closing the bass reflex port of a floor stander with a simple rolled up hand towel.
Very effective and vfm solution.

 

[koushik]

No commercial acoustic foams are as effective and cheaper than building one yourself using Glasswool. It make perfect sense to DIY acoustic panels.

 

[sound_cycle]

Thanks Nikhil and Koushik.

Is there some kind of partition between your listening area and the non-audio part?

Can you consider moving the setup to another wall/location?
Placing your speakers along the (dotted) division line would be fantastic if you can do it.

There is no partition, it is one of those living/ dining type rooms, one long tube. Audio was not in my list of important parameters while searching and buying the house . No alternate position for audio equipment is possible.

In my assessment the primary problems are flutter echos and that the L speaker is three times as far from the side wall as the R speaker. And then the room modes

I have yet to find out how the new speakers (Dali Zensor 5) fare in the room. I do expect a bit of boom. Should know by Saturday when they are delivered

It make perfect sense to DIY acoustic panels.

DIY it has to be.

I read on hfv that the aurica bass traps I linked to were not effective below 150 Hz and let that pass.

For the rest of it, in addition to a very compelling case for DIY - custom shapes, containing costs etc the cost of shipping the finished panels is very high (about 20%). The next step to my audio project has to be finding a source for rigid fiberglass/ Rockwool in Hyd.

ciao
gr

 

[koushik]

Great that I got another FM in Hyderabad as I am moving to Hyderabad next week with new job. I would also need the info of rigid fiberglass dealers over there.

 

[Fantastic]

......I have yet to find out how (Dali Zensor 5) fare in the room. I do expect a bit of boom. Should know by Saturday when they are delivered.....

Aren't you getting a bit worked up too early ?
Get your speakers , listen to them for a few weeks ! They need to break in too.
Then see if there is anything that is really a problem and address it. You need to remember the KISS principle. It works most of the time.

It's possible that you might not need most of the stuff you mentioned. Start experimenting with cotton/silk cotton/ fiber fill for pillows etc. before shelling out large amounts of money. Acoustic grade fiber glass is great but difficult to handle. Most companies use plastic fiber fill similar to what you get in pillows nowadays like BAF ( Bonded acetate fiber ). You can make decorative panels like the ones you buy. May not have identical properties but might solve your problem at low cost. Try them first.

 

[ranjeetrain]

sound_cycle,

It is easy to get lost in to room treatment maze without knowing what you are doing. That is - you try things without knowing if that's what you need.

Strictly my personal opinion: you don't need room treatment. You need room correction. Get a room correction device you will be happy you didn't waste money on experiments.

However, if you want to stick to this methodology, I'd suggest, before indulging in room treatment rotate your setup by 90 degree clockwise. Place your speakers one and half feet away from all walls. Then put wide-band absorbers on FRPs on either side. IMO, that's best approach in the given room.

 

[Fantastic]

May help in working with BAF...pillow stuffing.
Pillow Personality with Fairfield Processing: Pillow Stuffing Tips & Tricks | Sew4Home

 

[sound_cycle]

Aren't you getting a bit worked up too early

Yes, and no. The Sonodynes needed quite a bit of toe in, to get one cramped listening spot. The Dalis apparently have a wide dispersion pattern and do not like toe in.

I've been reading that it is the density that counts and therefore was ambivalent about polyfibre thing. (I have remind myself from time to time I am not trying to set up a recording studio ) edit: thanks also for that linky on pillow stuffing.

Strictly my personal opinion: you don't need room treatment. You need room correction. Get a room correction device you will be happy you didn't waste money on experiments.

However, if you want to stick to this methodology, I'd suggest, before indulging in room treatment rotate your setup by 90 degree clockwise. Place your speakers one and half feet away from all walls. Then put wide-band absorbers on FRPs on either side. IMO, that's best approach in the given room.

I asked on the treatment vs correction thread and learnt that

A good Digital Room Correction will correct for frequency and impulse response to make the response of both speakers the same... it will also delay one of them if one is farther than the other.

I figured that with my kit, the room treatment should be cheaper [1] but you make an interesting point with respect to the solution and the arrangement in the room.

Thanks

ciao
gr

[1] have to organize a mic and a laptop to get the sound profiles because existing PC does only onboard sound. And then the PC silencing issues.

 

[Soundstage]

Hi

ciao
gr

Sir,

Seeing the topography of the room, IMHO bass traps as proposed to be deployed by you may not really be effective. For starters, the corners to the extreme left of the pic, i.e. to the far side of the area not available for audio seem too far away to mar the bass frequencies. Moreover I presume that area will constitute the general seating area, so shall contain sofas and the like, which will automatically absorb unrequired reflections. The area on the far right is not really a corner so it is unlikely to create bass loading that a corner typically does. You do have one corner to the right and rear of the listening position, but I would try placing a large plant first.

All the Best!

 

[sound_cycle]

Moreover I presume that area will constitute the general seating area, <snip>The area on the far right is not really a corner so it is unlikely to create bass loading that a corner typically does. <snip>but I would try placing a large plant first.

I should have put in a pic or another from my sonodyne thread which show the beams and resulting corners which my diagram does not.

I was thinking of plants, bookshelves, and the like as diffusers initially but my net research suggests that they are as (not very ?) effective.

Thanks

ciao
gr

 

[soulforged]

I have a similar setup and faced a similar dilemma not too long ago. What I am currently experimenting with is positioning the speakers along the imaginary partition in your layout - one near the 'L' speaker and the other near the switchboard, about 2.5 feet away from the side walls and firing down the room towards your bedroom. I am not sure how your furniture is setup, but you might want to consider this setup.

I has worked for me in some measures. The soundstage has deepened and the bass has come to its own. While the lows could do with some help from the back wall, what I get now is very natural.

 

[sound_cycle]

one near the 'L' speaker and the other near the switchboard, about 2.5 feet away from the side walls and firing down the room towards your bedroom

Brilliant ! I guess you end up in a room mode killing position. V intrigued I have to see how this works in my room.

ciao
gr

 

[Soundstage]

I should have put in a pic or another from my sonodyne thread which show the beams and resulting corners which my diagram does not.

I was thinking of plants, bookshelves, and the like as diffusers initially but my net research suggests that they are as (not very ?) effective.

Thanks

ciao
gr

Thanks, the links give a clearer picture.

Since, in the current position the speakers are extremely close to the front wall and there is also no space between the listening position and the rear wall, sound is bound to be compromised.

Could you consider Diagonal placement? You could keep the rack (and the TV) in the corner and have the speakers flanking them. Your listening seat would then be on the opposite wall where the TV and the left speaker currently are. This does appear somewhat radical, but diagonal placements work very well in many cases. You could try this placement to see if there is any significant improvement.

Cheers!

 

[sound_cycle]

Hi,

In the completely unnecessary ION dept, suggestions about room rearrangement necessitated by the new speakers did not get any favorable response. I did however win a small concession towards experimenting with some absorbers.

Meanwhile read this article recently.

"Conclusion
To properly employ bass traps one must be aware of the room/speaker interaction, be sensitive to the type of music/audio, have a reasonable expectation of the rooms natural size, and understand energy transfer into modal resonance. Good bass trap design will correspond with the boundary dimensions. Care must be given to assure the traps are not over efficient or oversized.

Every room requires absorbers and diffusors with cut off points higher than low frequency bass traps, 125 500hz. This is the place to have the greatest quantity of absorption because this is the place where most energy transfer occurs.

Because there are many complex factors that determine the type of acoustic treatment necessary and appropriate for a given space and function, bass traps should not be wholeheartedly presumed to be the initial, necessary, or greatest amount of acoustic modification.

The idea now is to get a few panels in first and go on from there.

ciao
gr

 

[sound_cycle]

Hi

linkies

Take Me to Your LEDR! | Stereophile.com
Throwing Open the Window on System Performance: Achieving Proper Speaker Placement - The Audio Beat - www.TheAudioBeat.com

Tried out the audiobeat method and the LEDR tests last night.

Did not see much point in voicing the room (available speaker postions are severly constrained) but tried to get the speakers positioned for bass. I cannot get the imaging to work - the LEDR track up is supposed to start at the base of the speakers and travel up. Does not work.

I tried getting a blanket on my telly screen and some carpets on the floor but no cigar. It's worse than I thought :|

For the moment have ended up with the Zensor 5 almost exactly where I had the Sonodynes. With a similar level of toe in (which the Dalis apparently do not need)

I read that multi driver systems may not produce a correct "Up" image. Either that or the crossovers but first ofc the room.

For now the stereo illusion is just moh-maaya

ciao
gr

 

[mpw]

The speakers are new.. Let them play before judging the equipment. Stereo is more an effect of placement and positioning and tweaking.

Why don't you call FM sidvee or Nikhil over and work on this but after about 100 hours on the speakers.

 

[Thad E Ginathom]

LEDR... fascinating stuff. Here's some test on the net we can do without buying CDs...

Listening Environment Diagnostic Recording Test

~

 

[sound_cycle]

LEDR... fascinating stuff. Here's some test on the net we can do without buying CDs...

thanks. There are also little arrows which allow the .wav to be downloaded too.

Retried with these tracks and ended up with something better than where I was.

The large panel of glass behind (and between) the speakers definitely has something to do with. Padded that with an acrylic blanket and pulled the speakers out as far away from the back wall as I dare, in yesterday's effort.

I think I have located a source for a small quantity of Rockwool acoustic slabs, will know for sure after the long weekend ...

ciao
gr

 

[Thad E Ginathom]

The tests in that site blew my mid: I never knew it could be done like that! But I think that there is more to it than even the stress that the p.2 of the Stereophile article puts on room acoustics. It stretches even further: ear acoustics!

I haven't read further than the blind-testing site, but it seems that all this works because of the shape of the outer ear, so it is, to some extent, ear specific, and might not work for all.

Stereophile makes the point that systems that do well in this test turn out, generally, to be good systems in other ways too, but people should remember that thee LEDR recordings are made in a specific way, and that any particularly music recording is not necessarily going to suddenly develop extra dimensions on a well-performing-at-LEDR system.

My desktop system, by the way, which is low-cost speakers in an alcove, a trully dreadful listening space, does quite well. Well enough to astound me as I "watched" that sound move!