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Old 16th June 2015, 15:39   #2386
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Default re: The Home Theater thread

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It can get excited with even a bookshelf speaker
fair enough but with multiple bookshelf speakers in a HT room again the same logic of averaging out applies. However the bass is the trouble area.

For instance, a 14 foot long room would have a mode at 40 Hz but (hypothetically) if the listening position were placed at this half-way point, you'd hear very little at 40 Hz (due to destructive interference).

This link explains it better than I can
http://www.audioholics.com/room-acou...om-acoustics-1
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Old 16th June 2015, 15:40   #2387
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if the listening position were placed at this half-way point, you'd hear very little at 40 Hz (due to destructive interference).
But what about the multiples?

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However the bass is the trouble area.
My point was that the room modes can be excited even with the bass from normal speakers, with a sub it will always be there in one way or the other.

Last edited by ::CMS:: : 16th June 2015 at 15:44.
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Old 16th June 2015, 15:42   #2388
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A room with 12 by 10 feet and 8 feet high, it can get excited by 47 Hz, 57 Hz, and 71 Hz respectively. Additional level boosts occur at harmonically related multiples: 94, 141, 188 Hz, and so forth for the 12 foot length, and likewise for the two other dimensions.
Sir this is all good for stereo, but when it comes to multi channel AV the practical applications are limited. At higher frequencies room furnishings (curtains, carpet, sofas, filled bookshelf of CD rack or LP rack etc..) will supress some of the modes. Most AVs comes with DSPs and mics to offer some degree of correction for bass. I am not saying there is no use of bass traps, I just question their practicality in the case of multi channel AV.

http://www.audioholics.com/room-acou...trapping-ideas

Last edited by navin : 16th June 2015 at 15:46.
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Old 16th June 2015, 15:57   #2389
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Default re: The Home Theater thread

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Originally Posted by ::CMS:: View Post
It can get excited with even a bookshelf speaker, depending on the room dimensions. Please check the room mode calculators, the freqs can be in the range of low-mids too.

A room with 12 by 10 feet and 8 feet high, it can get excited by 47 Hz, 57 Hz, and 71 Hz respectively. Additional level boosts occur at harmonically related multiples: 94, 141, 188 Hz, and so forth for the 12 foot length, and likewise for the two other dimensions.
While all of this may be true, you do not want your room to be an anechoic chamber, because then everything sounds flat,dull and lifeless. The boosting of certain frequencies may be benficial to your actual sound quality because we are not only listening to individual frequency sine wave tones, or sweeps.

Some frequencies when boosted may enhance your enjoyment or otherwise of the content. So room treatment, be it of an absorptive or diffusive nature is not always necessary. There are times when leaving it alone works better than trying to do something about a nonexistent problem "if it aint broke then no need to fix it"

You have to apply common sense and listening experience to when you need to do something about a problem that you have identified. If it cannot be identified as a problem then leaving it alone just simply produces better results.

Last edited by naughty001 : 16th June 2015 at 15:59.
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Old 16th June 2015, 15:58   #2390
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Default re: The Home Theater thread

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Originally Posted by navin View Post
Sir this is all good for stereo, but when it comes to multi channel AV the practical applications are limited. At higher frequencies room furnishings (curtains, carpet, sofas, filled bookshelf of CD rack or LP rack etc..) will supress some of the modes. Most AVs comes with DSPs and mics to offer some degree of correction for bass. I am not saying there is no use of bass traps, I just question their practicality in the case of multi channel AV.

http://www.audioholics.com/room-acou...trapping-ideas
I dint get you, it will be more complicated in a multi channel than a 2 channel setup.

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While all of this may be true, you do not want your room to be an anechoic chamber, because then everything sounds flat,dull and lifeless. The boosting of certain frequencies may be benficial to your actual sound quality because we are not only listening to individual frequency sine wave tones, or sweeps.

Some frequencies when boosted may enhance your enjoyment or otherwise of the content. So room treatment, be it of an absorptive or diffusive nature is not always necessary. There are times when leaving it alone works better than trying to do something about a nonexistent problem "if it aint broke then no need to fix it"

You have to apply common sense and listening experience to when you need to do something about a problem that you have identified. If it cannot be identified as a problem then leaving it alone just simply produces better results.
Again, the tuning based on ones listening interest like in car audio comes in, not what the creator wanted (eventhough not possible exactly with the limited resources).

Last edited by ::CMS:: : 16th June 2015 at 16:05.
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Old 16th June 2015, 16:02   #2391
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Default re: The Home Theater thread

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I didn't get you, it will be more complicated in a multi channel than a 2 channel setup.
Not really, in multi channel the locations of the speakers themselves serves to average out some of the modes. Try it.
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Old 16th June 2015, 16:07   #2392
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Not really, in multi channel the locations of the speakers themselves serves to average out some of the modes. Try it.
Tried and tested long time back. Either the speakers has to be in a big room almost at the centre with kinda near field listening or with lot of compromise with what we are trying to eliminate. Moreover I am not a fan of AutoEQ, I never liked them.

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average out some of the modes.
Modes created due to sub freqs can no way be eliminated with positioning, some not even with multi-subs

Last edited by ::CMS:: : 16th June 2015 at 16:18.
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Old 16th June 2015, 16:18   #2393
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Modes created due to sub freqs can no way be eliminated with positioning, some not even with multi-subs
you are totally ignoring the findings of Earl Geddes

https://mehlau.net/audio/multisub_geddes/
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Old 16th June 2015, 16:24   #2394
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you are totally ignoring the findings of Earl Geddes

https://mehlau.net/audio/multisub_geddes/
Noone is ignoring anything, I had mentioned some of the modes, check its limitations related to the room size and number of subs. Main limitation is that with the freqs at which it can work, ~50-100s, not with the freqs where the movies demand most, <50s, esp ~20s.

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Old 16th June 2015, 17:03   #2395
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Noone is ignoring anything, I had mentioned some of the modes, check its limitations related to the room size and number of subs. Main limitation is that with the freqs at which it can work, ~50-100s, not with the freqs where the movies demand most, <50s, esp ~20s.
What you are definitely ignoring, is that my system is fairly entry level so if i experience some nulls between 20hz to 30hz, then im expecting those, because i do not have an expensive monster subwoofer, with 1200 watts of amplification.

I have a simple dual 8" subwoofer so i would be happy if i was getting down to 40hz with a fair amount of authority. I really cant be worried so much about spending more than the subwoofer is worth to place bass traps all around the room. When i upgrade to 4 velodyne DD15 subwoofers and those 4 subwoofers cost as much as an average car then i would be glad to get those subwoofers to work flat all the way down to 20hz but right now for a dual 8" Sony subwoofer thats around 20 years old i would be insane to spend money on bass traps.

You definitely need to inject some perspective into priorities. No-one said my system was supposed to be perfection, but it does have many giant killing attributes nevertheless. Adding bass taps for my simple little Sony Subwoofer would be similar to saying that i want to add two turbo's and a free flow exhaust to a Tata Indica while ignoring the brakes and suspension. to put it mildly there are many other problems to address before that and way more problems for me to address in my system before i see a need for bass traps.

Last edited by naughty001 : 16th June 2015 at 17:05.
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Old 16th June 2015, 22:44   #2396
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Default re: The Home Theater thread

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What you are definitely ignoring, is that my system is fairly entry level so if i experience some nulls between 20hz to 30hz, then im expecting those, because i do not have an expensive monster subwoofer, with 1200 watts of amplification.

I have a simple dual 8" subwoofer so i would be happy if i was getting down to 40hz with a fair amount of authority. I really cant be worried so much about spending more than the subwoofer is worth to place bass traps all around the room. When i upgrade to 4 velodyne DD15 subwoofers and those 4 subwoofers cost as much as an average car then i would be glad to get those subwoofers to work flat all the way down to 20hz but right now for a dual 8" Sony subwoofer thats around 20 years old i would be insane to spend money on bass traps.

You definitely need to inject some perspective into priorities. No-one said my system was supposed to be perfection, but it does have many giant killing attributes nevertheless. Adding bass taps for my simple little Sony Subwoofer would be similar to saying that i want to add two turbo's and a free flow exhaust to a Tata Indica while ignoring the brakes and suspension. to put it mildly there are many other problems to address before that and way more problems for me to address in my system before i see a need for bass traps.
As I had mentioned before, nobody cares if somebody is ignorant of the basics of sound reproduction in a closed environment and it has nothing to do with my posts. But dont mislead others by saying thats the way to go. Its science and irrespective of the setup, even a basic setup, will improve the performance if the room is treated properly (not on assumptions). If you know what you are doing, room treatment is not an expensive job too.

FYI, you can check many HT rooms or listening rooms done by people in HFV including mine several years back, you will get a fair amount of information how it can be done scientifically.

Last edited by ::CMS:: : 16th June 2015 at 22:56.
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Old 16th June 2015, 23:23   #2397
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As I had mentioned before, nobody cares if somebody is ignorant of the basics of sound reproduction in a closed environment and it has nothing to do with my posts. But dont mislead others by saying thats the way to go. Its science and irrespective of the setup, even a basic setup, will improve the performance if the room is treated properly (not on assumptions). If you know what you are doing, room treatment is not an expensive job too.

FYI, you can check many HT rooms or listening rooms done by people in HFV including mine several years back, you will get a fair amount of information how it can be done scientifically.
[sarcasm] Ah okay, i did not know that you were the only one in this place who knows everything . Other people do not about things like REW or microphones and cannot measure stuff, and cannot do things scientifically like build bass traps and diffusers or dont know about room nodes etc. It seems like you are the only one who knows, so everyone else can rather shut up, because everyone else is ignorant. [/sarcasm]

Yet i can confidently tell you that as cheap and, and unscienific as my system is it probably sounds way better than your scientifically built one.

Anyways have fun discussing your scientific methods with yourself since the rest of us are so ignorant we do not deserve to be here.

Last edited by Gannu_1 : 17th June 2015 at 10:16. Reason: Only 2 smileys are permitted per post.
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Old 17th June 2015, 06:19   #2398
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[sarcasm] Ah okay, i did not know that you were the only one in this place who knows everything . Other people do not about things like REW or microphones and cannot measure stuff, and cannot do things scientifically like build bass traps and diffusers or dont know about room nodes etc. It seems like you are the only one who knows, so everyone else can rather shut up, because everyone else is ignorant. [/sarcasm]

Yet i can confidently tell you that as cheap and, and unscienific as my system is it probably sounds way better than your scientifically built one.

Anyways have fun discussing your scientific methods with yourself since the rest of us are so ignorant we do not deserve to be here.
Sorry sir, nobody said that, again all are your assumptions

Last edited by Gannu_1 : 17th June 2015 at 10:16. Reason: Quoted post edited.
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Old 18th June 2015, 07:38   #2399
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HD audio formats like Dolby TrueHD and also DTS-HD(ma) are only going to be transmitted by HDMI cable (because of HDCP which is high definition content protection) so they probably wont work from the TV unless maybe your AVR is utilising ARC (audio return channel) over HDMI to give you the audio via the AVR

And playing it from a flash drive on the PC to the AVR, you need the PC connected via HDMI and your sound drivers configured to play the HD audio codecs as well (proper HD audio will not work over optical and coax but only over HDMI).
Many thanks for the crisp and elaborate explanation. Mine is a 5yr old LCD and it doesnt support ARC. But have a PS3, but not sure it does. Can some one confirm?
If it supports, just to get the Dolby feel, will source in some Bluerays and test.
BTW, does the optical cable transmit these?
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Old 18th June 2015, 12:00   #2400
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Mine is a 5yr old LCD and it doesnt support ARC. But have a PS3,
BTW, does the optical cable transmit these?
Since you have :

1. PS3
2. Yamaha AVR with 5.1

Your setup can play Dolby or DTS files via HDMI or Optical cable.

You can also play HD formats like DTS HD if:

1. PS3 is connected to AVR by HDMI
2. Enable DTS HD decoding in PS3, so AVR gets lossless Audio on HDMI
3. If AVR supports HD, then just connect and play.
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