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Why do I need to tell my amplifier the distance of my spea..

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April 8, 2005 5:14:29 AM

Archived from groups: rec.audio.tech,alt.home-theater.misc (More info?)

On the setup for both my DVD player and my amplifier I'm asked what
the distance is for my front speakers, my center speaker and my rear
speakers. (the distance from my ear to the speakers). I'm also asked
in the setup if the speakers are small or large, if the rear speakers
are behind me or at the side, and if the rear speakers are ear level
or above ear level.
Is this information needed for surround sound movies, or surround
sound from a stereo source?
The only reason I can think of for these measurements is to determine
the reverb delay between the front and rear speakers.

If my front speakers are different distances should I choose the
closest or longest distance when entering info in the setup menu?

Regards Brian
Anonymous
April 8, 2005 5:14:30 AM

Archived from groups: rec.audio.tech,alt.home-theater.misc (More info?)

On Fri, 08 Apr 2005 01:14:29 +1200, Brian <bclark@es.co.nz> wrote:

>On the setup for both my DVD player and my amplifier I'm asked what
>the distance is for my front speakers, my center speaker and my rear
>speakers. (the distance from my ear to the speakers). I'm also asked
>in the setup if the speakers are small or large, if the rear speakers
>are behind me or at the side, and if the rear speakers are ear level
>or above ear level.
>Is this information needed for surround sound movies, or surround
>sound from a stereo source?
>The only reason I can think of for these measurements is to determine
>the reverb delay between the front and rear speakers.
>
>If my front speakers are different distances should I choose the
>closest or longest distance when entering info in the setup menu?
>
>Regards Brian

The distance allows the system to dial in appropriate delays, so
everything reaches you at the same moment. Take the average distance
if you can't specify them individually.

As for large and small speakers, if you opt for large, the full
frequency range will be sent to all the speakers. If you choose small,
only the subwoofer will get the low bass, and the ret get high pass
filtered sound. You may find this setting best even if you have large
speakers.

d

Pearce Consulting
http://www.pearce.uk.com
Anonymous
April 8, 2005 5:14:30 AM

Archived from groups: rec.audio.tech,alt.home-theater.misc (More info?)

In <a3ca519gu41u6rrjco6aife5fmajmug5ir@4ax.com>, on 04/08/05
at 01:14 AM, Brian <bclark@es.co.nz> said:

>On the setup for both my DVD player and my amplifier I'm asked what
>the distance is for my front speakers, my center speaker and my rear
>speakers. (the distance from my ear to the speakers). I'm also asked
>in the setup if the speakers are small or large, if the rear speakers
>are behind me or at the side, and if the rear speakers are ear level
>or above ear level.

There are considerations for all of these positions. Essentially, the
receiver is asking about your conditions so that it can optimize for
your situation.

>Is this information needed for surround sound movies, or surround
>sound from a stereo source?

It's mostly for surround, but some receivers may use the information
anytime you have processing enabled (all modes except STEREO).
Certainly, the bass management will be used at all times.

The ".1" part of the 5.1 refers to the LFE (low frequency effects)
channel (subwoofer) dedicated to adding "thump" to surround movies. If
you have very small speakers (in front, rear or both) you can ask that
the bass that would normally be sent to them to be sent to the
subwoofer instead. If you don't have a subwoofer you can ask that the
LFE channel be sent to the front speakers.

>The only reason I can think of for these measurements is to determine
>the reverb delay between the front and rear speakers.

Yes, but we will "wince" a bit at that analysis. Many recording are
made in a relatively dead (no echos) studio. This is useful for
controlling things at the time of recording, but results a not so
interesting listening experience. "Reverb" can be though of as a type
of echo added to the music that attempts to simulate the natural echos
that would be present in a typical music hall.

In a surround sound setting, think of what happens if there is a
gunshot in the film and the original microphones were placed where the
viewer would be seated. Essentially, you are a fly on the wall in that
scene. The sound from that gunshot will splash around the studio, be
captured by the microphones, and eventually be released in your viewing
room. There is a time relationship (sound takes time to travel from
point to point) between the sounds captured by each of the microphones.
If these time relationships are preserved on the way to your ears,
you'll be able (at least in theory) to locate the original sound and
experience the ambience of the original scene. The chances of your room
being exactly the same dimensions as the studio are very small, but
through careful control of your listening environment, you could
arrange that the components of that gunshot sound arrive at your ears
simultaneously. If your receiver knows the distance from your listening
position to each speaker, it can adjust the timings appropriately to
assure simultaneous arrival of the gunshot components.

>If my front speakers are different distances should I choose the
>closest or longest distance when entering info in the setup menu?

Do the best that you can, use an average distance. Some receivers allow
individual speaker timing, others will adjust only the center speaker.
If you have limited adjustment capability, keep your listening position
as symmetric (with respect to the speakers) as possible -- especially
left to right.

-----------------------------------------------------------
spam: uce@ftc.gov
wordgame:123(abc):<14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13> (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------
Anonymous
April 8, 2005 5:14:30 AM

Archived from groups: rec.audio.tech,alt.home-theater.misc (More info?)

Believe it or not, sound actually travels pretty slow. Don't get me wrong,
its damn fast, but at the same time its slow enough for humans to notice in
many situations.

One great example comes from a reggae festival I usually attend every year.
The entire 3 day concert is broadcast over a local radio station. I usually
camp out in the camping area which surrounds the concert bowl. To keep in
touch with what performers are playing currently I keep a small radio back
at the camp-which isn't all that far from the concert bowl. Listening to
the radio is really wierd because I can hear the concert on the radio BEFORE
I can hear the concert right next to me. There is a significant delay in
the actual audio from the concert compared to the radio. The reason being,
radio waves travel at roughly the speed of light (roughly) where as sound is
in the neighborhood of 600ish MPH. Anyway, thats my example of how slow
sound really is.

--Dan

"Brian" <bclark@es.co.nz> wrote in message
news:a3ca519gu41u6rrjco6aife5fmajmug5ir@4ax.com...
> On the setup for both my DVD player and my amplifier I'm asked what
> the distance is for my front speakers, my center speaker and my rear
> speakers. (the distance from my ear to the speakers). I'm also asked
> in the setup if the speakers are small or large, if the rear speakers
> are behind me or at the side, and if the rear speakers are ear level
> or above ear level.
> Is this information needed for surround sound movies, or surround
> sound from a stereo source?
> The only reason I can think of for these measurements is to determine
> the reverb delay between the front and rear speakers.
>
> If my front speakers are different distances should I choose the
> closest or longest distance when entering info in the setup menu?
>
> Regards Brian
Anonymous
April 8, 2005 5:14:30 AM

Archived from groups: rec.audio.tech,alt.home-theater.misc (More info?)

In <eId5e.568$RQ7.434@newssvr14.news.prodigy.com>, on 04/07/05
at 05:02 PM, "dg" <dan_gus@hotmail.com> said:

[ ... ]
>One great example comes from a reggae festival I usually attend every
>year.

[ ... ]

> Listening to the radio is really wierd
>because I can hear the concert on the radio BEFORE I can hear the
>concert right next to me.

[ ... ]

When amplifying sound in large halls or outdoor settings, one must
delay the sound in remotely located speakers so that their output
matches the arrival of direct sound from the stage. An under the front
edge of a balcony seat can be particularly deadly because one must
almost always amplify the sound for seats well under the balcony, but
some of that sometimes "early" amplified sound leaks forward to collide
with the direct sound from the stage.

-----------------------------------------------------------
spam: uce@ftc.gov
wordgame:123(abc):<14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13> (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------
April 8, 2005 5:14:31 AM

Archived from groups: rec.audio.tech,alt.home-theater.misc (More info?)

"dg" <dan_gus@hotmail.com> wrote in message
news:eId5e.568$RQ7.434@newssvr14.news.prodigy.com...
> > >
Listening to
> the radio is really wierd because I can hear the concert on the
radio BEFORE
> I can hear the concert right next to me.



I experienced this phenomena at a sporting event, and it's a weird
feeling.
Clay
!