My gear

[Fincave]

I recently decided to upgrade my gear and also do some room treatments as I had a lot of reflections in my room, basically every surface was hard with not much in the way of soft furnishings. I ended up changing my speakers from JBL to a local manufacturer Amphion. I also went from 6.1 to 5.1 as the extra speaker just was not doing much, also probably overkill as my room is not very large, about 20 sq.m The Amphions are bookshelf speakers/monitors and the improvement in soound was immense. They are just so much more accurate and where my previous speakers were slightly subdued the Amphions are the opposite, everything just sounds clearer and more pronounced, unfortunately bad recordings become really horrible to listen to, an example being Johnny Cash- The man comes around, his cover of Hurt gets pretty painful towards the end of the track as there is just so much noise going on.

To combat the reflections I decided on putting up acoustic panels. A lot of planning and work later I am very pleased with the end result. The panels look good and the improvement in sound is huge, no more echo when I clap my hands and sound is just more natural now. I also decided to bulid two QRD diffusors, can honestly say that I have not noticed any difference in SQ, the diffusors are not in their final position yet so maybe there will be a difference?

My room is not a dedicated theatre, it doubles as my lounge so I tried to keep it looking half decent. Still need to hide some cables and upgrade my receiver but for now am very pleased with the results.

The gear: Amphion Argon2, Amphion Origo, Amphion Helium2(rears), BK Electronics Monolith sub, Yamaha RX-V 640, Onkyo cd, Pioneer 575, Sanyo Z3, DIY screen, Xbox, BFD, Topfield 5100 Masterpiece, assorted cables, Ecophon acoustic panels. Any comments are most welcome.

[Tommy]

Everything looks nice. Can you explain more about the reflections, what was it echoing or something? Are the walls regular sheetrock or was anything else done to sound proof?

[Fincave]

A bit difficult to explain the reflections as am not really into the technical terminology. Basically clapping my hands together resulted in a almost 'ringing' sound that lingered. It seemed as though sound basically bounced around in my room and detail was not good. Now when I do the clapping test the sound stops, is deadened or absorbed by the panels. SQ seems a lot clearer and more detailed and maybe tighter. The room is an apartment built in the 70's and so is basically just concrete/cement slabs that are thrown together, also the floor is laminate and so every surface was hard and reflective, not really much to absorb sound. After doing research on the net I gathered that for good SQ a room needs diffusion, reflection and absorption, hence the diffusors, panels covering some of the walls leaving the rest as hard surfaces allowing for some reflection. As I understand it is not good to deaden a room completely and so I used thinner panels (20mm), also they are only effective from about 100hz upwards, if my memory is correct. It probably still is not perfect but is much better and so I am very satisfied!

[Tommy]

Thanks bro. I saw pics of someone elses HT that had the walls carpeted and I really like how it looks but as you mention I'm worried about the opposite effect of it deadening the room. Would you think the opposite would work, hanging posters to cause some reflection?

[Fincave]

Really am no expert! Am pretty sure that framed posters with a glass front would give you reflection as it would be a hard surface. Hopefully somebody with some more knowledge on the subject can provide some pointers.

[Sonnie]

Wow! Very nice!

[JCD]

TommyW wrote:

Thanks bro. I saw pics of someone elses HT that had the walls carpeted and I really like how it looks but as you mention I'm worried about the opposite effect of it deadening the room. Would you think the opposite would work, hanging posters to cause some reflection?

You're correct, too much absorption will make the room sound horrible -- I was in a HT room recently that was way over treated and it sounded AWFUL. The trick is to absorb the "early" reflections, in particular at the higher frequencies. The way I understand it is if you have two signals of the same frequency hit you less than x milliseconds (not sure what the number is) apart, your brain combines the two signals as one. This is gonna degrade the imaging and sound quality of the music. If the signals hit you over x milliseconds, your brain perceives the second signal as an echo and doesn't mash the two together. This is not a bad thing, in fact, you do want some echo otherwise the room is going to sound dead/bad. I'll admit that I may have the reasoning a little mucked up, but I know (regardless of the reason) early reflections=bad.

Carpet isn't really a great absorber because it will absorb only certain frequencies -- it acts sort of like a notch filter for different frequencies. For example, it may absorb 800Hz-825HZ OR 1kHz-5kHz. The result would be that in those zones, you'd have the proper absorption, but everything else would be doubled up. The best material I know of for absorptions is compressed fiberglass (e.g., Owens Corning 703 or it's equivalent).

Generally speaking, I'd want absorbers at 4 different spots:
1) First reflection on the left
2) First reflection on the right
3) First reflection on the ceiling
4) First reflection on the floor -- this one is a little problematic, compressed fiberglass panels just don't look so good on the floor. A nice Persian rug is probably the best compromise, notwithstanding my advice above about carpets.

(Optional?) I've also heard that having absorbers on the walls behind the speakers is a good thing too.

At the back of the room is where I'd put up diffusers (if I had them).

Regarding the posters, I wouldn't use them to "liven" up a room. This isn't a problem as long as you don't over treat a room. Now, I wouldn't NOT put them up either, except at the first reflection points.

The website you might take a look at is Ethan Winer's website. This guy has forgotten more than I'll ever know about acoustics.

JCD

[JCD]

Oh, and those speakers are gorgeous! And the room looks awesome! Very impressive!

JCD

[Sonnie]

I agree with JC here... I'd worry about the first reflections. I've done something similar to what he's referencing... here's an old pic:



I got the first two reflections off the side walls and the first off the rear. Then of course I've got the carpet and 6 cloth La-z-boy's too. Personally I couldn't really tell any difference in mine and it may be because of the carpet and cloth recliners, I just don't know. Or maybe it's that I just can't hear well... but it's done none the less.

[Wayne A. Pflughaupt]

Man, I have screen envy! Certainly a beautiful room.

I saw pics of someone elses HT that had the walls carpeted and I really like how it looks but as you mention I'm worried about the opposite effect of it deadening the room. Would you think the opposite would work, hanging posters to cause some reflection?

My experience with carpet hasn’t shown the same results that JCD mentioned, notching at certain frequencies. But then, I can’t say that I’ve taken any measurements, so I’ll just say my experience has been that carpet is the most desirable floor covering for acoustics. It usually won’t fully deaden a live room, but typically by the time you add the other furnishings, things are sounding acceptably dampened. If carpet (on the floor) and furnishings aren’t sufficient, then you can look into additional treatments. As Fincave noted, the goal is “no more echo (or “tail”) when you clap your hands” – a low-tech but fairly reliable way to tell if your room is too live.

Regards,
Wayne

[JCD]

I have to plead hearsay for my answer regarding carpet. For the most part, that information was based on information such as this.

But I'd defer to someone's real world experience over my internet wanderings.

JCD

[Tommy]

Just wanted to apoligize to Fincave, sorry bro I didnt mean for it to get so off topic and hijack your thread about carpets.

Anyway can ya tell me more about your room dimensions and the screen itself. Now that these guys got me talked into a projector system and screen rather then the plasma I was planning on, I'm starting to think about what type of screen and size I need and all that happy crap.

I like how yours looks, fixed with a border around it. I dont need anything to be able to retract into the ceiling (although it would be neat (boys with toys right))

So what size screen is that, and the size of the wall. Trying to figure what size screen I'll need and how much space I'll have around it on the wall.

[Fincave]

No need to apologise, if someone learns something or gleans some useful info was the purpose of my original post (ok, maybe I also wanted to show off my system a little!).

About the screen. Cannot remember the exact dimensions but roughly equates to a 110", viewing distance is about 4m (12ft). I made the screen using MDF (6mm), there is also a frame on the back of the MDF with two additional beams sort of evenly placed running from top to bottom, the idea being to keep the screen rigid and stop it from warping or bending. The wood used for the frame on the back was roughly 45mmX40mm, so fairly sturdy! The border was made using regular skirting board cut at 45 degree angles and painted black, it is about 42mm wide and in hindsight could have been a bit wider still. I spray painted the border as it should be matt black and spray was the best way to go. The screen itself is painted using latex paint with pigment added. I am using a Sanyo Z3 and so to help outwith contrast the screen is grey in colour. Hanging the screen on the wall was a bit tricky as it is fairly heavy, about 35kg. In the end I used L- shaped brackets that are screwed into the wall, think I used six in total, I put a dab of glue on the edge brackets just to make sure the screen does not come down. The screen is just lifted onto the brackets and was up for two weeks before I added the glue, it did not move at all in that time!

Hope this helps you. Give me a shout if you need more info, will do my best to help.

[Tommy]

How wide is the wall itself? Also what is the height of the wall and the screen?

[Fincave]

Not at home at the moment so this is off the top of my head. Floor to ceiling is about 2,6m. The screen is about 2.35m X 1.1m and there is about 80 cm on each side of the screen, ie the front wall is about 3.95m (12ft)

[Wayne A. Pflughaupt]

JCD wrote:

I have to plead hearsay for my answer regarding carpet. For the most part, that information was based on information such as this.

But I'd defer to someone's real world experience over my internet wanderings.

JCD

Oh yeah, that guy...

I like Ethan, he’s a super-nice guy and highly intelligent, but I have a hard time buying some of the things he says – like this one about the carpet notching certain frequencies. For a carpeted floor, any notching you might get would be more than offset by the direct signal and other “un-notched” reflections (yes I know, there’s no such word...). I can’t see where this would be a problem at all, unless you had every surface in the entire room covered with carpet. But then if you did that, notching would be the least of your problems...

Regards,
Wayne

[Ayreonaut]

One layer of just carpet on the walls may not be ideal. (as someone said) But on the floor when combined with a thick pad it can provide decent absorbtion down to about 250hz. Or so I've read.