The new post pics of yer HT thread....

[lavi]

yeah stereo imaging is suffering a bit, I'm going to move it from the wall about umm.... say 1 to 1.5 M, this should fix it (i hope).

I had a look at a forum member here where he made the bass traps himself and got me thinking! it's really strange as if i turn the sub around to face the same way the speakers are facing (next to the spekers of course not behind) the bass just drops really bad and it's like a hole, walk over to say the kitchen and the bass is all there so i basically moved the sub around as much as I could (around the tv set) until i got it there.

do bass traps kill any of the bass or just fixes holes around the room ?

[williamgoh]

omg what an annoying problem to have! im surprised this is happening to you as your floor is carpet. must be whats underneath that counts. ive got floorboards, and i hate it. the house is whole, all the bass just scares the ants away.

[Amfibius]

Originally Posted by lavi

do bass traps kill any of the bass or just fixes holes around the room ?

Bass traps flatten out the bass response.

Basically, any room will suffer from variable frequency response. Some frequencies are emphasized more than others, some are cancelled more than others (this is known as comb filtering, because the frequency response looks like a comb).

Bass frequencies are more prone to this because the wavelengths are longer. If you play an 80Hz tone and walk around the room, you will find some areas that some parts of the room, the tone is very loud. Elsewhere, it might be very soft. (You can download this freeware program that generates tones through your sound card. Click on "virtual minirator").

Bass traps work by absorbing bass and preventing it from being reflected into the room. This prevents the nasty constructive/destructive interference - i.e. lessens the effect of comb filtering.

Whether you get more bass or less bass depends on whether you are sitting in a compression or rarefaction "hole" in your room. You will get more even bass and less bass echo.

More about bass traps and acoustic treatment here. A very long read, but worth it.

[Dr feelgood]

+1 to the ethan winer site, very worthwhile.
One thing i might add is that to do bass traps properly you should get an spl meter (at the least) at findout as best as possibe what parts of your room require the traps, then you can use a combination of eq, traps and sub placement to get the best results.

Originally Posted by williamgoh

omg what an annoying problem to have! im surprised this is happening to you as your floor is carpet. must be whats underneath that counts. ive got floorboards, and i hate it. the house is whole, all the bass just scares the ants away.

yeah it is an anoying problem, but you would be surprised at how many rooms suffer the same problem but people never realise how much better they could have their sound. As far as carpet goes, the floor is only 1 of 6 surfaces that effect modes (in a standard room).

[tech.knockout]

Originally Posted by Amfibius

Bass traps flatten out the bass response.

Basically, any room will suffer from variable frequency response. Some frequencies are emphasized more than others, some are cancelled more than others (this is known as comb filtering, because the frequency response looks like a comb).

thats 'room nodes' i think. The frequency will be irregular with peaks or dips or both but technically its not necessarily a comb.

Comb filtering as mentioned in an audio context mainly occurs when two or more non directional drivers spaced more than one wavelength apart try to cover the same frequency.

[Amfibius]

Originally Posted by tech.knockout

Comb filtering as mentioned in an audio context mainly occurs when two or more non directional drivers spaced more than one wavelength apart try to cover the same frequency.

Pardon me if i'm wrong, but my understanding is that the room contributes towards comb filtering as well? When the wave hits the wall, it gets reflected out of phase and can interact with the incoming wave of the same frequency and contribute towards comb filtering. In any case you are probably better qualified than me ... all i'm going on is Yr 12 physics.

[tech.knockout]

Originally Posted by Amfibius

Pardon me if i'm wrong, but my understanding is that the room contributes towards comb filtering as well? When the wave hits the wall, it gets reflected out of phase and can interact with the incoming wave of the same frequency and contribute towards comb filtering. In any case you are probably better qualified than me ... all i'm going on is Yr 12 physics.

You're correct there can be cancellations and peaks, but this alone isnt called "comb filtering". The terms for what you describe are room nodes. If im not mistaken, room nodes generally dont produce many many spikes and dips to resemble a comb.

comb filtering mainly/certainly occurs in the situation i described.

Im not better qualified than you (yr12 physics as well), im only going by the DIY stuff and papers I read.

[Dr feelgood]

I am pretty sure you are both right, they are exactely the same thing and refered to as comb filtering with regard to speaker enclosure placement, driver placment within an enclosure and room mode/node, for the record I also have no particular education just P.A installation experience.

correct me if I am mistaken but a node is a point along a waveform or a point in a room (e.g point of compression or rarefaction) and a mode is the overall effect of a standing wave with regard to the freq' (e.g the tangental mode being the common standingwave resonance of my studio is 219Hz).

[lavi]

it's funny as my room apart from ceiling hadn't got a paralel wall, it's an appartment building 3rd floor in Milton, solid concrete walls and floors and sealings.

Funny thing is i still haven't found the right spot for the sub. There are places where i can walk and the bass is much better but so far that's the only place around the entertainment unit where is ok.

I got new furniture coming in, couches etc. This will probably abosorbe more then the currnet furniture. We'll see.

[TX3]

New home theatre, just set it up the other day.

-LG 42PC1DG (Plasma Screen)
-LG LH-W750TA (Surround + DVD Player/Receiver)


<--- Old set top box to lift new player/receiver.
<--- Wireless rear speakers.

[esemte]

Originally Posted by TX3

New home theatre, just set it up the other day.

-LG 42PC1DG (Plasma Screen)
-LG LH-W750TA (Surround + DVD Player/Receiver)

Very nice setup! Where'd ya get it from?

[HellsAngel]

Didnt they have that setup on special at Domayne?

[seaQuest_AMD]

Originally Posted by TX3

New home theatre, just set it up the other day.

-LG 42PC1DG (Plasma Screen)
-LG LH-W750TA (Surround + DVD Player/Receiver)

Sup LG LH-W750TA Buddy!

[HellsAngel]

Yeah how are those speakers? I found a good deal on those and was wondering if the wireless speakers and the whole system sounded good. Enough bass ect

[TX3]

Originally Posted by esemte

Very nice setup! Where'd ya get it from?

Rick Hart, discounted because my brothers, friends, dad owns a franchise

Originally Posted by HellsAngel

Yeah how are those speakers? I found a good deal on those and was wondering if the wireless speakers and the whole system sounded good. Enough bass ect

Each speaker is individually adjustable (through screen menu) for +-dB and distance. If your rear speakers are right near your head at the back (like mine) you can give them a +1 metre..... at least I think thats how it works. Very easy to use, menu structure is ok, didn't need the manual for anything.

Bass not tested yet with music. Has a pretty good inbuilt tuner, yu can just see the FM aerial under the wireless transmiter in the bottom left picture and its works perfectly with all the standard Perth stations.

Quality is fairly good for thin speakers, I like the big fat wooden ones myself though . Sound options (some useless like Hall and Studio) for movies, music etc...