Indirect VS direct sound radiation for surrounds? - AVS Forum
Forum Jump: 
 
Thread Tools
Old 04-15-2008, 08:03 PM - Thread Starter
Member
 
SiXeVeN's Avatar
 
Join Date: Dec 2007
Posts: 40
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Anyone have an opinion about direct radiating surrounds vs indirect (angled drivers, dipole, bipole).

I would think that best system for believable surround would be ALL the speakers being the same. (All bookshelves for instance). When we were running old dolby pro logic the diffuse rear sound was needed but now with specific sound tracks recorded to each channel it would seem that indirect radiation would muddy the channel? Is this logic wrong? I would love to hear some opinions.
SiXeVeN is offline  
Sponsored Links
Advertisement
 
Old 04-15-2008, 08:50 PM
AVS Special Member
 
rynberg's Avatar
 
Join Date: Sep 2001
Location: California
Posts: 2,846
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11


EVERYONE has an opinion on this topic, it has been discussed ad nauseum for years and in many threads on this forum. If you already have your own belief for best sound, why do you care what anyone else thinks?
rynberg is offline  
Old 04-16-2008, 06:59 AM
AVS Special Member
 
Terry Montlick's Avatar
 
Join Date: Jul 2003
Location: State of Rhode Island and Providence Plantations
Posts: 3,261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by SiXeVeN View Post

Anyone have an opinion about direct radiating surrounds vs indirect (angled drivers, dipole, bipole).

I would think that best system for believable surround would be ALL the speakers being the same. ...

Perhaps for music, but not for movies. All major releases are mixed on rather large dubbing stages, which are configured like commercial movie theaters. There are many surround speakers, and the best acoustic match to this for the home theater is using indirect radiation for surrounds.

Regards,
Terry

Terry Montlick Laboratories
Home Theater Acoustics
Critical Listening Rooms
Design, Evaluation, Alpha Certification®
www.tmlaboratories.com
Terry Montlick is offline  
Old 04-16-2008, 04:05 PM - Thread Starter
Member
 
SiXeVeN's Avatar
 
Join Date: Dec 2007
Posts: 40
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Interesting! So the back channels are supposed to blend? It would seem to make sense that a diffuse back area would present a more realistic sound envelope but at the same time I can imagine that a perfectly matched set of 4 speakers all with great imaging would create the same impression.

Is it more an issue of rooms being to corrupted to present good imaging with direct speakers? Or, are the channels in a movie sound track designed to be diffusely projected and trying to do it with direct projection leads to a loss of sound envelopment?

Sorry about the questions, but i'm trying to design a system where the listener feels enveloped in a sound stage and not just detecting sounds from front or back.

For instance, I have always been sensitive to the subtle differences in timbre that exist between a set of mains and their supposed matched center channel. When a movie scene pans accross the sound stage the small difference in SQ ruins the aural effect for me. It sounds less like something moving from left to right and more like the speakers turning on and off left to right (if that makes sense).

It seems there are two options. Indirect radiation of the Fronts AND Rears with a center channel to "anchor" the vocals. OR Direct sound in perfectly matched speakers so the sound fields blend into one another creating a 3D imaging effect.

Given what i'm trying to create... Which of those options seems to be the better option? Or is there another option??? Thanks all!
SiXeVeN is offline  
Old 04-16-2008, 05:15 PM
AVS Special Member
 
krabapple's Avatar
 
Join Date: Apr 2003
Location: in a state bordered by Kentucky and Maine
Posts: 5,360
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 177 Post(s)
Liked: 229
Quote:
Originally Posted by SiXeVeN View Post

Anyone have an opinion about direct radiating surrounds vs indirect (angled drivers, dipole, bipole).

I would think that best system for believable surround would be ALL the speakers being the same. (All bookshelves for instance). When we were running old dolby pro logic the diffuse rear sound was needed but now with specific sound tracks recorded to each channel it would seem that indirect radiation would muddy the channel? Is this logic wrong? I would love to hear some opinions.


For mixers where you are meant to be able to localize where the 'surround' sound is coming from, direct firing is recommended. E.g., many multichannel rock/pop music mixes.

For mixes where the surround sound is supposed to provide 'ambience' or envelopment rather that well-localized sounds, indirect firing is recommended.
E.g. many movies, multichannel classical and jazz mixes.

So it's really mix-dependent. The ideal all-purpose surround speakers would allow two configurations, switchable as needed.
krabapple is offline  
Old 04-16-2008, 06:08 PM
AVS Special Member
 
lwien's Avatar
 
Join Date: Jan 2004
Location: Arcadia, Calif
Posts: 2,105
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by krabapple View Post

The ideal all-purpose surround speakers would allow two configurations, switchable as needed.

Do any other speaker manufacturer's other than M&K (defunct, but trying to arise) with their SS-150thx's make surrounds that you can switch from:

Dipole
Tripole
Tripole with Attenuated Dipole Elements
Tripole with Adjustable Attenuated Direct Radiator
Tripole with Adjustable Attenuated DiPole Elements
Tripole with Maximum Output from All Drivers
Direct

These surrounds are super configurable, and I would think that other manufacturers would attempt to put out something similar, no?
lwien is offline  
 
Thread Tools


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off