It is currently 28 Mar 2024, 12:17




 Page 1 of 1 [ 2 posts ] 
Author Message
 Post subject: Improving on centre channel with anti-phase centre
PostPosted: 08 Aug 2015, 15:54 
Confirmed Padawan
Confirmed Padawan
User avatar

Joined: 10 Oct 2006, 17:10
Posts: 3742
Location: United Kingdom
Has thanked: 5 times
Been thanked: 4 times
"Improving on centre channel with anti-phase centre" (Is a little idea of discovery I came across myself a few years ago January 2010 and was only wired up for few weeks I think but it did wonders that was so cheap). The below text is what I typed a few years ago so doesn't make much sense to me now :mrgreen: kidding.

I was trying to remember how I had this wired up at the present time so its main AVR LR out to Yamaha DSR70pro or any pro-logic that has a (invert phase) otherwise this will not work. There are two centre phase outputs in-phase and out-phase. I need one other processor to wire this up to so that I can control the levels of two summed centre signals.

One of the centre is out of phase form main AVR and the other is centre phantom form the LR signal I know it sounds complicated but the idea came to me within a few seconds.


Quote:
January 2010
Okay what I’ve done is sent centre from the main AVR decoder to the Yamaha DRP-100 seen in the diagram. The centre invent is helped from the left and right from the main AVR decoder.

The role of the task is to get a signal sent to the Yamaha DSR-70Pro Dolby pro-logic to place an anti-phase signal to cannel or reduce the amount of signal on the (centre main signal) which shouldn’t be on the (main centre channel of ‘2010’).

There is downside since the signal will reduce some portions of the signal and (will inject a signal from centre phantom left and right). If there is signal of similar sound / frequency or mirror image it will be cancelled out thus freeing the centre front by a small degree.

The test signal I used was the dts calibration music and demonstration set-up disc (track 14, all-channels) which is a wideband pink noise signal.

I activate the Yamaha DRS-70Pro which sends out the same pink noise that is being sent to left and right front. I then adjust the centre level on the Yamaha DRS-70Pro so that the pink noise will cancel out the centre. Its only reduced (all or part of the lows) mid and highs are reduced down to very faint sound. Reason is the Yamaha DRS-70Pro has limited bandwidth down to 100Hz so tiny bit low end is heard but its reduced most of the directional.

Now before most of you start jumping around up and down, this doesn’t wreak the sound no worse than it already is. This helps by reducing the centre main will still perform most of its original level.

There it is, simple. I guess this can be improved upon with fancier audio electronics.

This can also remove normal half panned sounds from the centre for clearer left and right stereo sound field. Often the phase tends to have you shifting around in the sofa to catch a clearer left and right sound.

I tired this out a few years ago, with ‘Beverly Hills Cop’ (1984) when Foley gets tossed out a window and then cops show-up. There’s subtle effects left and right that had half panned sound filed mixed onto the centre and I found it distracting at the time.

Today I place a little delay on the DCX2496 centre LF/HF to gain a clearer left and right sound filed, or I can extend it further with the approach that I have just shown you.

Image
Offline
 Profile  
 
 Post subject: Re: Improving on centre channel with anti-phase centre
PostPosted: 08 Aug 2015, 15:59 
Confirmed Padawan
Confirmed Padawan
User avatar

Joined: 10 Oct 2006, 17:10
Posts: 3742
Location: United Kingdom
Has thanked: 5 times
Been thanked: 4 times
There is a Yamaha DSR70pro cheap going on ebay USA. There are Yamaha DSR100 but checked they don't have centre invert on them so need a DSR70Pro.

http://www.ebay.com/itm/Yamaha-DSR-70-P ... 1ea2015824
Offline
 Profile  
 
Display posts from previous:  Sort by  
 Page 1 of 1 [ 2 posts ] 


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to: