AVS Forum banner
Status
Not open for further replies.
1 - 7 of 7 Posts

·
Registered
Joined
·
897 Posts
Discussion Starter · #1 ·
Couple of questions here...first off i have a HK7000 AVR (5.1 DD,DTS)and as L and R mains i have a pair of Infinity IL50's an Ifinity centre,IL100 sub and a pair of IL40's for the SL and SR.The il 40's do not have built in subs but the 50's do.The first thing i was thinking was to upgrade to a 7.1AVR,possibly the new pioneer VSX 49TX and buying another pair of IL50's to replace the 40's as SR and SL and putting the 40's in the RL RR positons.So my question is do most DD5.1 and EX/ES 7.1 movie soundtracs incorporate bass to the R,L,SL,SR,RR,RL channels?Is it a plus to have speakers with built in subs for these channels or is it unessasary and should i simply get another pair of IL40's(without subs in them) for the RR and RL channels?DVD audio is also of concern here and the question of bass in the 5.1 format in music is of question as well.Thanks
 

·
Registered
Joined
·
15,087 Posts
dreamstate,


In general, movies with multichannel DD and DTS soundtracks do send full range audio to all of the speaker channels except the LFE channel. It's typically limited to sounds below 120Hz.


Unfortunately, the wavelengths of low frequency sounds are comparable to the dimensions of most rooms. This results in standing waves and audio interference patterns when several speakers generate the same low frequencies at the same time. These effects cause different locations in the room always to be louder than normal or quieter than normal as the reflections add to or cancel one another.


Brian Florian recently posted a very clear explanation showing why you should set all of your speakers to small and use a single high quality subwoofer for the bass frequencies. Take a look at the thread http://www.avsforum.com/avs-vb/showt...threadid=12580 His message is about halfway down the page.


I hope this helps a little.
 

·
Registered
Joined
·
897 Posts
Discussion Starter · #3 ·
If this is the case then if a movie(such as The haunting in DTS wich is supposed to have full bass in all six chanels)has full rotating bass in a scene to all the chanels and i don't have speakers with full base capabilities then i'll miss out on that effect won't i?
 

·
Premium Member
Joined
·
2,468 Posts
I recently auditioned the PSB Image 2B for rears because of their low bass capabilites for a stand-mount. I was previously using NHT SuperOne's.


I just love the audio mix on Phantom Menace.

In the scene where Liam Neeson first rescues JarJarBinks from getting running over by the "tanks", there is a wave of deep bass as the tank runs overtop of them. This starts at the front and finnishes at the back. Having rear spakers that could deliver this front to back wave of bass really added to the scene - it was as if a rumbling tank passed through my living room.


A smaller bookshelf speaker cannot produce this sensation. Despite having a great sub, I feel there is still a good amount of bass that needs to be localized at the rears.


- Andy
 

·
Registered
Joined
·
897 Posts
Discussion Starter · #5 ·
My thoughts exactly!I just happened to be using that exact scene to test this bass theory out and i've set all my speakers to small and turned off the subs in the mains.It was a dismal failure.Turning back on the subs brought life back into those two mains and the movie effects in those channels.I really didn't hear an improvement or a decrease in fidelity when setting all my speakers to small so i'll assume that i shoud leave them that way (small) but i will be getting another pair of IL50's with integrated subs for the left and right surrounds!
 

·
Registered
Joined
·
388 Posts
Theoretically:


If you set all you speakers to small and use an 80 Hz crossover to the sub, the low frequencies should be omnidirectional. That is you cannot determine the source of the sound in space. However, many low frequency sounds have over tones and harmonics at frequencies greater than 80 Hz. So you will hear the low frequncy component of an explosion form the sub and be able to localize it with the higher frequency components comming from the other speakers. If the all the sound comes from the sub at frequencies below 80 Hz you should not be able to pinpoint the direction from which the sound came, theoretically.


The problem occurs when the crossover frequency is set higher than 80 Hz as is the case for small satellite - subwoofer systems. For example if the cross over is at 120 Hz and all of the sound is below 120 Hz with some of it above 80 HZ, it will all come from the sub and you will be able to point to the sub and say it is comming from there.
 

·
Registered
Joined
·
420 Posts
here! here!

very good denisT


I agree fully with your explaination!!

ben
 
1 - 7 of 7 Posts
Status
Not open for further replies.
Top