Room basics

[john61ct]

18' wide, 25' open space living / dining area, kitchen along the back wall.

Glass doors toward the back of right, hallway opening opposite from the left.

The walls I can mod are flat reflective by default, but currently I have lots of floor to ceiling baker's racks on casters filling up one corner, stacked with boxes of Stuff with no other place to go :-(

Rather than those on one side only, flat wall opposite, better to line both side with the racks, for balance, cut down reflections? Big couch will likely go from the side wall to out in the center, MLP tbd.

Can hang tapestries or rugs from / over the baker racks' faces.

What about the front wall? The A/V gear will be racked, big TV can hang from a rack or go on top of Kallax shelving but eventually will get a rolling stand.

And yes currently prepping a PC to get REW going...

 

[Keith_W]

Get a copy of Toole and read what he says about room treatment. In a nutshell, most rooms can meet the required standard with normal furnishings alone.

Then take a look at the book in my sig for some tips on how to take and interpret the measurement. Don't spend any money on room treatment unless you know what your goal is.

 

[john61ct]

Yes to that last.

But be aware neither "normal furnishings" nor room treatments are part of my plans.

I'll try to make time to read Toole, but will need to shift my racks of boxes before that

 

[DVDdoug]

You don't usually want to eliminate all reflections. Some people prefer a "dead room" for "studio sound", but most listeners don't and early reflections can improve voice intelligibility (according to Floyd Toole.) As long as the reflections/reverb don't sound bad, you're probably OK (except for bass which is almost always a problem).

And yes currently prepping a PC to get REW going...

Right... "Diagnosis before treatment"

Standing waves in the bass range are more troublesome but not as easy to deal with. Bass traps can help but they are bulky. Bass traps absorb the bass that would otherwise be reflected and that smooths both the dips and bumps. Another solution is multiple subwoofers at different locations.

EQ/Room correction can also help but the dips caused be wave cancelation are difficult... because the direct and reflected waves are canceling. Bumps can be knocked-down with EQ and the good news is that the bumps are more "annoying" than the dips.

hallway opening opposite from the left.

An opening is like a bass trap, or it is a bass trap... Nothing gets reflected. But it's "small" compared to total wall area.

One thing you have going for you is a larger than average room. But I always say ALL rooms in homes are "small" (compared to music halls and theaters) which causes the bass problems.

 

[Bear Cub Studio]

If this were a dedicated studio build, I might suggest making your own absorption panels with 10cm, 80kg/m³ density rockwool, mounted slightly off the wall at a slight angle — but that's not really what we're dealing with here, right? Haha.

For early reflections on the side walls, I'd say just try placing some absorbers or furniture there, and if you like how it sounds, keep it — if not, remove it. No need to overthink it.

Your idea of splitting the racks that are currently clustered in one corner and distributing them across both side walls is a great approach. It introduces acoustic symmetry and promotes better diffusion throughout the room.

Hanging tapestries or rugs over the front of the racks would increase absorption but could eliminate the high-frequency diffusion effect the racks provide. This is another thing worth experimenting with — go with whichever sounds better to you.

As for the big couch, in typical studio monitor setups it's often placed against the rear wall behind the listening position. This isn't just for clients to sit on — it sometimes doubles as a large bass trap. Due to its size, a couch can have a meaningful effect on the low-mid range. How much it affects the highs depends somewhat on the surface material, but since you presumably already own the couch, I wouldn't worry too much about that.

If you ever consider treating the front wall, absorbing the area behind the speakers can improve stereo imaging and reduce coloration. With thick enough absorptive material and an appropriate air gap, it can also help reduce SBIR.

Great to hear you're getting REW set up too.

Wishing you a wonderful listening experience!

 

[Bear Cub Studio]

I do mixing work, so I've spent time studying audio and room tuning — but I'm embarrassed to say I hadn't come across Floyd Toole's book until now. I've only skimmed it so far, but it's full of insights that resonate from an engineering perspective as well.

Yes to that last.

But be aware neither "normal furnishings" nor room treatments are part of my plans.

I'll try to make time to read Toole, but will need to shift my racks of boxes before that

Thank you for the REW measurement PDF. I haven't fully mastered REW yet, so it was incredibly helpful.

If this were a dedicated studio build, I might suggest making your own absorption panels with 10cm, 80kg/m³ density rockwool, mounted slightly off the wall at a slight angle — but that's not really what we're dealing with here, right? Haha.

For early reflections on the side walls, I'd say just try placing some absorbers or furniture there, and if you like how it sounds, keep it — if not, remove it. No need to overthink it.

Your idea of splitting the racks that are currently clustered in one corner and distributing them across both side walls is a great approach. It introduces acoustic symmetry and promotes better diffusion throughout the room.

Hanging tapestries or rugs over the front of the racks would increase absorption but could eliminate the high-frequency diffusion effect the racks provide. This is another thing worth experimenting with — go with whichever sounds better to you.

As for the big couch, in typical studio monitor setups it's often placed against the rear wall behind the listening position. This isn't just for clients to sit on — it sometimes doubles as a large bass trap. Due to its size, a couch can have a meaningful effect on the low-mid range. How much it affects the highs depends somewhat on the surface material, but since you presumably already own the couch, I wouldn't worry too much about that.

Treating the front wall with absorption is a good idea. Absorbing the wall behind the speakers can improve stereo imaging and reduce coloration. If you use thick enough absorptive material, depending on the depth of the air gap and the thickness of the material, you can also reduce SBIR.

Great to hear you're getting REW set up too.

Wishing you a wonderful listening experience!

Really insightful response.

Building on that — in typical studio monitoring setups, early reflections are primarily controlled with absorption, while later-arriving reflections are treated with diffusion, or a combination of both.

My take on Toole's point about early reflections is that treatments should be chosen with clear purpose rather than applied as a ritual. I even know an engineer who deliberately uses tatami mats instead of conventional absorbers at the side wall first reflection points.

it really does come down to each room and finding what works best to achieve a well-defined stereo image.

 

[Audionaut]

CARA was a good room acoustics program at the beginning of the millennium. I have no idea if it has been further developed.

AMTITLE :: Wissen - CARA, Computer Aided Room Acoustics

www.audiomap.de

HiFi-TUNiNG.com, Entwicklung, Herstellung und Vertrieb von HiFi & High-End Komponenten

HiFi-Tuning.com, Bernd Ahne, Berlin, Entwicklung, Herstellung und Vertrieb von HiFi & High-End Komponenten

www.hifi-tuning.com