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JustGreg
Joined: 07 Mar 2006 Posts: 3098 Location: Kenosha, WI
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| Posted: Thu Oct 25, 2007 8:20 pm Post subject: Test Your Audio Knowledge |
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http://www.electronichouse.com/article/sound_advice/
It's official. I suck. I'm an audio idjit.
I know more than I did before taking the test but I shouldn't be allowed to even TOUCH the power buttons in my HT. Oh the shame.
It did lead to a desire to better understand more about reflection, absorption and diffusion tho. No wonder I can't hear for sh*t in my HT, no matter HOW loud I crank it. I'm like the dude in the hearing aid commercial set in a movie theater with his wife and he keeps saying, "Whadhesay? Whadhesay?".
Greg
_________________ Greg
"Is it ignorance or apathy? Hey, I don't know and I don't care!" --Jimmy Buffett
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zaphod
Joined: 16 Jun 2006 Posts: 2002 Location: Cloverdale
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| Posted: Thu Oct 25, 2007 8:30 pm Post subject: |
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10 for 10. that would explain the traps, the bryston and the logans. sigh
and i'm still tweeking the darn room ...
_________________ walk gently. leave a good impression.
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JustGreg
Joined: 07 Mar 2006 Posts: 3098 Location: Kenosha, WI
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| Posted: Thu Oct 25, 2007 9:35 pm Post subject: |
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Yeah I actually got 8 out of 10 (who couldn't with all the silly assed options) but what trashed the audio portion of my HT was additional research into how to make my HT accoustically efficient. I have some work ahead of me.
I don't have the greatest speakers in the world but it shouldn't be as bad as it is. I have ALOT of hard surfaces I need to address...on a shoestring budget.
Greg
_________________ Greg
"Is it ignorance or apathy? Hey, I don't know and I don't care!" --Jimmy Buffett
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ecrabb Forum Moderator
Joined: 13 Mar 2006 Posts: 15909 Location: Utah
TV/Projector: JVC RS40, Epson 5010
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| Posted: Thu Oct 25, 2007 9:39 pm Post subject: |
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10 for 10 here too, but no esoteric equipment or traps in my room! Just a mid-range receiver and mid-range THX-select speakers, and simple absorption panels that I haven't had time to hang on the wall... that have been sealed in plastic leaning against the wall since June. After I got the panels hung, I do need to work on sub placement a little - I have a nasty node in the second row. Doesn't sound too bad on movies, but is pretty nasty for concerts and such.
Acoustics and acoustic treatment is like everything else in this hobby: The more you learn about it, the more frustrated you become with the problems and the more expensive the solutions are. Sometimes, I with I could go back to being ignorant of all the "issues".
SC
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perisoft
Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY
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| Posted: Fri Oct 26, 2007 3:41 am Post subject: |
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I guess I test well. I've never done anything with audio to speak of but I got 10/10 without reading the article. I love it when tests answer themselves...
This, of course, makes me question the usefulness of the test, if I knew the answers without knowing anything. I would guess that this is a case of empty platitudes disguised as useful information - a common theme in 'enthusiast' publications of all stripes...
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perisoft
Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY
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| Posted: Fri Oct 26, 2007 3:42 am Post subject: |
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Oh, and what the hell is up with "eliminate excessive low-frequency sounds"? That's like eliminating Ferraris in your garage, or eliminating time wasted with good sex. Does NOT compute!
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paw
Joined: 08 Mar 2006 Posts: 1176 Location: Arvada, CO
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| Posted: Fri Oct 26, 2007 3:42 am Post subject: |
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9 out of 10 but some of the choice were obviously not it. DUH!
Some one help me understand #3.
_________________ Aubrey
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oliverg
Joined: 15 May 2007 Posts: 800 Location: Melbourne, Australia
TV/Projector: Sony G90 X2 - Vidikron Vision 1
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| Posted: Fri Oct 26, 2007 8:09 am Post subject: |
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10/10 woohoo ;0
No 3 - front and sides reflective panels will disperse the sound throughout the whole room. You wont get so many dead spots.
Think of the sound waves as light (no getting into whether light is a wave or particle OK??) and the panels as mirrors that also diffuse the light as well as reflecting them to the places where the "dead" spots are. In a lot of cases though, there is sufficient volume and dispersion, especially in a small room that this isn't needed. In larger rooms f+s reflective panels are a "definately should have" feature.
_________________ ( R ) G ( G ) 9 ( B ) 0 ( R ) G ( G ) 9 ( B ) 0
( R ) G ( G ) 9 ( B ) 0 ( R ) G ( G ) 9 ( B ) 0
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J Kildare
Joined: 28 Sep 2006 Posts: 164
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| Posted: Tue Oct 30, 2007 3:50 am Post subject: |
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9/10
I just found out I pissed away good money putting absorption for the first 4' down the side wall.
Also found out I pissed away good time setting up the mirrors to avoid 1st reflections at the prime seating position.
Jim
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ecrabb Forum Moderator
Joined: 13 Mar 2006 Posts: 15909 Location: Utah
TV/Projector: JVC RS40, Epson 5010
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| Posted: Tue Oct 30, 2007 4:18 am Post subject: |
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WTF? I just realized I got #3 wrong, apparently. That's completely the opposite of everything I've ever read on the subject. I think they may have that one wrong, in fact.
Direct-radiating mains should have dispersion characteristics such that nothing but a little absorption would be necessary. If you have a huge (wide) room, then presumably the mains are too far away from the side walls for a reflective panel to accomplish much in the way of "reflecting to dead spots". If the room is smaller, then you *don't want* reflection (you want absorption, in fact). If you use a reflective material (untreated drywall, for instance), early reflections will muddy imaging and definition... NOT something you want from your front soundstage. Same with the front wall. There is NO reason whatsoever you'd want anything reflective (diffuse or not) BEHIND the speakers. That REALLY makes no sense.
Surrounds, on the other hand are a different issue. There, you typically want something more diffuse - hence bipole and triple radiators. In the back of the room, you typically use a diffuse material so that the room isn't completely dead... a black hole of sound that sounds lifeless and requires lots of amplifier to sound good. A diffuse surface at the back of the room will diffuse the reflected sound from the front of the room.
Reflective panels on the front and side walls... that's a new one to me.
SC
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perisoft
Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY
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| Posted: Tue Oct 30, 2007 4:28 am Post subject: |
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My theory is that the likelihood of an assertion in the audio domain being correct is inversely proportional to the cube of the complexity of the assertion in question. This applies to all such assertions simultaneously.
Therefore, anyone discussing any audio topic over a certain level of complexity is provably full of sh*t.
This nicely dovetails with ecrabb's experience; naturally his frustration level has increased as the complexity of his undertakings has increased, because there is less and less chance of there being any validity to the attempted procedures.
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ecrabb Forum Moderator
Joined: 13 Mar 2006 Posts: 15909 Location: Utah
TV/Projector: JVC RS40, Epson 5010
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| Posted: Tue Oct 30, 2007 4:45 am Post subject: |
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I know what you mean, but I think acoustic treatment methodology and best design practices for home cinema (and cinema in general) is pretty fleshed out. I don't think there's a lot of "theory" or "opinion" about it. I've read hundreds of posts from some pretty well known guys over at AVS... Ethan Winer, Dennis Erskine, Terry Montlick and Ted White. I can't imagine how many hours I've spent reading posts by those guys trying to get a decent handle on HT acoustics. With all that reading, I think I have a decent basic understanding of the goals of HT audio and the basic methods with which to achieve them. Of course, like I said - the more you learn, the more you realize you have way more to learn.
I'm definitely not saying that all those guys agree 100% on how to do everything to achieve the best results in all situations, but there are some basic rules to follow that they would all agree on.
The thing is, I don't recall anybody ever suggesting reflective surfaces on the side walls or the screen wall. It simply doesn't make any sense. I think it's a mistake.
SC
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ecrabb Forum Moderator
Joined: 13 Mar 2006 Posts: 15909 Location: Utah
TV/Projector: JVC RS40, Epson 5010
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| Posted: Tue Oct 30, 2007 4:55 am Post subject: |
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A post from Dennis Erskine in the Acoustical Treatments Master Thread @ AVS:
| Quote: | Requirements for multi-channel (more than 2) are different than that required for 2 channel.
In multi-channel, the entire wall behind the front speakers is treated. You want none of the back reflections to overlay the surround field or the bring the reverberent field forward (your reverberent field and surround field is created by the multi-channel processor or mix, not so much the room as is mandatory for 2-channel). Depending on speaker placement, this treatment is brought forward along the side walls. Wall treatments are floor to slightly above ear level (where exactly is also a function of front speaker heights). While one could argue the sound at their feet is of no concern, often that square footage of treatment is required to bring the room's RT60 down to the lower levels required for multi-channel playback.
If you have soffits, the bottom of the soffits is also treated...several reasons, right tricorners among them. |
Notice the reasoning for treating the screen wall (behind the speakers). There's more good info on the first few pages (or you can read all 50 if you're REALLY into it.
SC
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