Get Free, Friendly, Expert Advice
Call 1-866-244-8796 or email

Designed and Manufactured in Canada Since 1980


AxiomAudio Blog

Positioning Floorstanding Speakers

Our Newest Flagship Model: The M100

Why We Make Our Own Drivers

Wall'O'Fame
"Serenity Cinema", now with 40% extra Serenity!
Updated as requested.
Who's Online
5 registered (Wid, Socketman, onn, exlabdriver, St_PatGuy), 110 Guests and 14 Spiders online.
Key: Admin, Global Mod, Mod
Financing
Forum Stats
12652 Members
11 Forums
22679 Topics
400339 Posts

Max Online: 378 @ 02/24/13 04:33 PM
Top Posters
Ken.C 17695
pmbuko 16220
SirQuack 13309
CV 11053
MarkSJohnson 10666
Meanwhile On Facebook

8| Don't miss Andrew Welker's post on our message boards about the new subwoofer...

󾓲 The April Newsletter is out! Did you get your copy? http://www.axiomaudio.co...

Double-take! :O How well do you know our line? First one to spot the surprise...

Page 3 of 4 < 1 2 3 4 >
Topic Options
Rate This Topic
#147873 - 09/20/06 12:20 PM Re: Running two sets of mains [Re: pmbuko]
alan Offline
connoisseur

Registered: 01/29/02
Posts: 3178
Loc: Toronto/New York/Dwight
Peter,

That's true in general what you say about the imaging but I suspect that in a room that large, if it also has a high or vaulted ceiling, all talk of timing and "imaging" go out the window because of the huge reverberant space. In one such room with a cathedral ceiling that housed an excellent pair of large Canadian floorstanding speakers plus two big subwoofers at one end and the couch at the other, I did some listening comparisons with several of my listening panel members from the National Research Council.

What was amazing was that when we switched from stereo to mono, none of us could hear any difference! It was simply a huge reverberant wall of sound.

In a related experiment conducted in more formal testing conditions (double blind) in the NRC listening room, we discovered that simply running a second set of left/right main speakers set a few feet farther apart to either side of the main pair of L/R fronts produced an amazing improvement in overall realism and spaciousness, something akin to what we now experience when we listen to a stereo recording in DPLII that decodes really well into 5.1. At the time, were testing very early digital and analog "bucket-brigade" delay systems that routed the main channel signals, delayed by an adjustable amount, to several surround speakers on the side walls. This was long before the advent of Dolby Digital or Dolby Surround.

The addition of the extra stereo pair of main speakers up front provided as much realism as the delay devices, which were quite expensive back in the early 1980s.

In a room that large, I'd say go ahead and try an extra pair of M80s or M60s set up as described. Depending on the room, it might deliver a noticeable improvement in spaciousness and realism.

The NRC test was done in a standard IEC listening room that parallels a typical domestic rectangular living room of average dimensions.
_________________________
Alan Lofft,
Axiom Resident Expert

Top
#147874 - 09/20/06 12:23 PM Re: Running two sets of mains [Re: pmbuko]
alan Offline
connoisseur

Registered: 01/29/02
Posts: 3178
Loc: Toronto/New York/Dwight
pmbuko,

Thanks for the excellent diagram of series and parallel connections. I may have to borrow that for the next time I address this subject in the Axiom newsletter.
_________________________
Alan Lofft,
Axiom Resident Expert

Top
#147875 - 09/20/06 12:31 PM Re: Running two sets of mains [Re: cava]
alan Offline
connoisseur

Registered: 01/29/02
Posts: 3178
Loc: Toronto/New York/Dwight
Quote:

There really isn't much benefit to having double the speakers. There would be no gain in quality, unless m80's sound better at lower volumes for some reason (hence the combination of two at the same level would sound better). You could actually hinder some aspects of quality depending on placement. The amount of added spl would be minimal with only a 3 dB increase which is close to the threshold of a noticable difference in level. A doubling of sound pressure generates a 3 dB increase in level.




Cava, a modest correction: A 1-dB increase or decrease in SPL is the smallest (barely) detectable change in subjectively perceived loudness. A 3-dB increase is subjectively perceived by most listeners as "somewhat louder" (or "somewhat softer" if it's a 3-dB decrease in SPL).

Your other points I'd agree with.
_________________________
Alan Lofft,
Axiom Resident Expert

Top
#147876 - 09/20/06 05:06 PM Re: Running two sets of mains [Re: alan]
pmbuko Offline
shareholder in the making

Registered: 04/02/03
Posts: 16220
Loc: Leesburg, Virginia
You're welcome. I'll waive royalties in favor of QS4s.
_________________________
"I wish I had documented more…" said nobody on their death bed, ever.

Top
#147877 - 09/20/06 10:22 PM Re: Running two sets of mains [Re: pmbuko]
JohnK Offline
shareholder in the making

Registered: 05/11/02
Posts: 10304
Good thought, Peter, but you should ask for QS8s and then maybe settle for QS4s.
_________________________
-----------------------------------

Enjoy the music, not the equipment.



Top
#147878 - 09/20/06 10:53 PM Re: Running two sets of mains [Re: JohnK]
pmbuko Offline
shareholder in the making

Registered: 04/02/03
Posts: 16220
Loc: Leesburg, Virginia
I should hang around with lawyers more often.
_________________________
"I wish I had documented more…" said nobody on their death bed, ever.

Top
#147879 - 09/25/06 05:40 PM Re: Running two sets of mains [Re: alan]
cava Offline
enthusiast

Registered: 08/23/06
Posts: 33




Cava, a modest correction: A 1-dB increase or decrease in SPL is the smallest (barely) detectable change in subjectively perceived loudness. A 3-dB increase is subjectively perceived by most listeners as "somewhat louder" (or "somewhat softer" if it's a 3-dB decrease in SPL).

Your other points I'd agree with.





Yeah, I guess my definition of "close" was not close enough...haha. Although when I listen to one of those cd's that repeats a tone in 1 dB decreasing increments I can't really tell that each step is quieter, just that it definitely gets quieter after several steps.

Top
#147880 - 09/26/06 01:55 PM Re: Running two sets of mains [Re: cava]
alan Offline
connoisseur

Registered: 01/29/02
Posts: 3178
Loc: Toronto/New York/Dwight
Cava,

It's much harder to detect small increments or decreases in loudness using single-frequency test tones. A pink-noise signal simulates a typical music signal much better, and it's a more critical test signal for loudness levels.

Some types of music make it easier to detect slight increases. But by definition, a 1-dB step is "barely detectable".
I was just being my usual obsessive self. . .ha.
_________________________
Alan Lofft,
Axiom Resident Expert

Top
#147881 - 09/26/06 08:03 PM Re: Running two sets of mains [Re: alan]
cava Offline
enthusiast

Registered: 08/23/06
Posts: 33
I'm starting to realize that that is one of the reasons why I like this hobby so much. It allows me to obsess over little details, my OCD just eats it up, while my wallet coughs it up.

Top
#147882 - 09/26/06 09:39 PM Re: Running two sets of mains [Re: cava]
Rik Offline
hobbyist

Registered: 03/15/05
Posts: 29
Loc: Louisiana
I think this article has pertinence to this thread. It is about the Audyssey EQ, but on page two they talk about a 10.2 surround format and only one channel is in the rear the rest of the channels are across the front sound stage.
another Audioholic's article

Top
Page 3 of 4 < 1 2 3 4 >



Moderator:  alan, Amie, Andrew, axiomadmin, Brent, Debbie, Ian, Jc 

Home  |  Corporate Info  |  Products  |  Message Board  |  FAQs  |  Warranty  |  Site Map  |  Privacy Statement   |  Contact Us

©2014 Colquhoun Audio Laboratories Limited
All Rights Reserved.