[andycsb]

Hello Everyone. Need feedback on how the front wall (wall behind speakers) made out of bricks would affect sound. Would it be warm or bright/dead or live etc etc? If possible, it's effects on highs, mids and bass.  It's either the brick wall or a smooth surface wall made of concrete. If the front wall is brick, side and back walls would be smooth surface concrete.

Thanks.  Really appreciate your time.

[JLM]

Relatively bright and draws attention to itself, but depends on the speakers (less of an effect on infinite baffles or monitors with narrow dispersion, more on dipole/open baffles).  Glass, marble, and the like are the worse.  The harder/less absorptive (smooth concrete would be worse than brick) the surface the more of this effect.  Absorption tends to make the walls/room seem bigger and have less of an effect.  This applies only to midrange/highs.  Bass travels in waves (not rays) and so is effected by room shape and size in our residentially sized rooms. 

[Mag]

Hello Everyone. Need feedback on how the front wall (wall behind speakers) made out of bricks would affect sound. Would it be warm or bright/dead or live etc etc? If possible, it's effects on highs, mids and bass.  It's either the brick wall or a smooth surface wall made of concrete. If the front wall is brick, side and back walls would be smooth surface concrete.

Thanks.  Really appreciate your time.

Fortunately for you I have a concrete wall in my audio room, which makes for lively acoustics. However I have acoustic dispersion panels all along the lower half of the room, which serves to dampen the room to some degree, but also retains the liveliness. I have no slap echo, so my room acoustics are good. I also use reflections off the back wall in an unconventional stereo set up. Which works with my Bryston Model T passives, other speaker may not be capable of using reflected sound in this manner. If your room is wide you can also go with a conventional stereo set up.

I would say my treble is on the bright side, bass is fast and articulate. I use a mixer however to adjust the sound to my liking.

With you having two hard surfaces I would try to deaden or dampon one of the walls. If you have no slap echo is the room you should be able to make it work.

[andycsb]

Thanks JLM and Mag. Appreciate your input.

I would like to achieve a "warmer"...ie...less bright (darker) sound signature than smooth surface concrete wall. Since it's the living room...aesthetics matter quite a lot.

Any pointers... besides overstuffed furniture etc etc on how to avoid a bright sounding room? I am toying with getting Vicoustics Wavewood (diffuser and absorber) or something very similar in looks. Probably a few of those on the front wall between the speakers. Is foam (viscoustics) a good idea?

[JLM]

Are there any measurements for the Vicoustics Wavewood (most don't)?  Based on appearances and descriptions they seem very heavy on aesthetics and very light on sound treatment (not uncommon).  Recommend visiting GIK here on Audio Circle.  They offer very effective products that can be customized in appearance and they have measurements.  I own and happily use ten 2ft x 4ft GIK 244 panels in my well shaped/designed room.  A couple of years back I helped out a local restaurant owner who had a terribly noisy dining room by lending him six of my panels and the improvement was obvious (he ended up installing 23 panels). 

My overall suggestion would be to first measure the room.  Humans are very adaptable, so we acclimate quickly to new surroundings, and make poor judges of such criteria.  Use Dirac Live with the recommended USB calibrated microphone, then call GIK for consultation.  Starting out with a given room, this is the best first step.  Next treat the room, and finally use Dirac to make final tweaks (as Earl Geddes says, use acoustical solutions for acoustical problems).  Note that REW (Room Eq Wizard) is free and more powerful than Dirac but harder to master.

Absorption will minimize the sonic effect of the walls and like anything can be over done (deaden the sound).  Practically diffusion only works on frequencies down to roughly 1,000 Hz due to those pesky laws of physics and the size of sound waves.  The best designs are two dimensional (not just vertical or horizontal) and based on quadratically derived variations in depths/widths of the diffusor elements.  Absorption is usually the first/preferred treatment method.  Highly recommend reading Floyd Toole's "Sound Reproduction" (3rd edition) to gain a basic understanding of how speakers and rooms behave. 

The GIK 244 panels use 4 inch thick Owens Corning 703 high density fiberglass pads which is perhaps the most effective sonic absorption material available.  Most diffusors are poor designs (artistic bad, industrial probably good) and don't use highly reflective materials (painted/sealed wood is good, hollow plastic is laughable).

[poseidonsvoice]

Thanks JLM and Mag. Appreciate your input.

I would like to achieve a "warmer"...ie...less bright (darker) sound signature than smooth surface concrete wall. Since it's the living room...aesthetics matter quite a lot.

Any pointers... besides overstuffed furniture etc etc on how to avoid a bright sounding room? I am toying with getting Vicoustics Wavewood (diffuser and absorber) or something very similar in looks. Probably a few of those on the front wall between the speakers. Is foam (viscoustics) a good idea?

Andy,

https://vicoustic.com/product/wavewood-diffuser-ultra

So in the link above, they do provide some measurements. Of course there is an element of marketing here. Whenever you use the word 'diffuser', the eyes of audiophiles light up immediately. But you don't get something for nothing. First and foremost, I can say that the Vicoustics Wavewood is really an absorber + scatterer mostly and not much diffusion. Diffusion MUST furnish 2 criterias. A good diffusor not only changes the reflections to propagate in different directions (1st criteria), but does so EVENLY in all directions (2nd criteria and harder to do). The next question is over WHAT frequency range does the diffuser you are looking at operate as a 'diffuser'? The best diffusers I have seen do so from about 500Hz all the way to about 5khz or higher. That is difficult to do, and you certainly cannot do that with a 0.25 inch thick piece of wood attached to a frame with some foam in it.

My advice would be to look closely at the Alpha series from GIK and the Impression series from GIK (4 inch thicknesses or more). They are both absorbers in the low range of frequencies. But in the high frequencies they are similar but with differences. One  (the Alpha) has some diffusion and mostly scattering in the higher range of frequencies and the other (the Impression series) is basically pretty to look at with and is just a  scatterer if anything. True diffusors are expensive and big. Like GIK QRD, Gotham Series, Polyfusor, etc...

https://www.gikacoustics.com/impression-series-vs-alpha-series/

Oh. A bookcase isn't a diffuser at all. It's at BEST an absorber over a narrow range of frequencies, and mostly scatters at other frequencies like a lot of NON ACOUSTICALLY  designed “everyday” objects. Bookcases being true diffusers is a major myth in high end audio.

Whether you need the Impression series or Alpha series strongly depends on where you are going to place them. Location is everything. If it is high up on a side wall, far away from your main loudspeaker, an Alpha series may work nicely, and it may work nicely on a back wall as well. But if it is something you are going to mount on your front wall (behind your loudspeaker) and your loudspeaker ISN'T a dipole then why would you use an Alpha series? Use an Impression series instead. You can use them to your advantage to help with the visual decor of the room.

That being said, there are no price differences between the Alpha or Impression series since the CNC machine has to be used for each one, it's just that the pattern for the Alpha series front wooden piece is a mathematical pattern to provide slight diffusion and mostly scattering benefits.

And whatever you do, try to use a device that is at least 3 inches thick (and preferably 4 inches thick) for best absorption benefits of the lower frequencies to minimize a skewed absorption curve that will affect the overall spectral response of the room. And I do have a preference for fiberglass or rockwool over foam based products.

See here: https://www.gikacoustics.com/comparing-foam-to-gik-244-bass-traps/

Best,
Anand.

[andycsb]

Sorry, I have been away for awhile. Thanks again everyone for taking the time to help. Really appreciate it. I am gonna go with brick front wall. When the time comes I will probably go with some treatment which are both functional and attractive like the GIK impression series.

[toocool4]

Depending on how far away you will be from the panels GIK Alpha series is worth a look, I use a combination of 4”, 6” GIK Alpha series and Art panels on the front and back walls. Here is what I have done so far, still work in progress. More work to do yet, what I have done so far has made a huge difference to the sound.