Left center and right center speakers

I am running a 7.3.4 Dolby atmos system.  I have been doing research on dispersion of dedicated center speakers for home theater vs a book shelf or tower speaker to replace the center speaker.  This supposedly helps with dispersion for all seats in the theater.

I am currently doing some upgrades of the front and Surround speakers of the room.  I will have 2 left over bookshelf speakers.  I was going to use one bookshelf as the center and it will match the new incoming full range tower speakers.  Should I just use the one bookshelf in the middle or run a left center and right center speaker set up?  Part of the upgrade is a Trinnov Altitude 16 Processor.  I think it should be said if I am running a Trinnov seperate Amps are given.  So basically a 8.4.4


That is a GREAT question. I run two center channel speakers, one below the screen and one above the screen (top center), you can see the pic in my profile.

I would NOT do that with your two left over book shelf speakers though.

As for the BEST use of those two left over book shelf channels I would recommend using them as wide channels (again, see the pic in my system of the wide channels). You need to set them at a 60 degree angle to your MLP and you will love it. Make sure the tweeters are the same height as your front channels.


The extra channels are called Left and Right Wide, Height, and Back Surround, and each requires its own speaker. The Wide speakers should be located at ±60 degrees from the center—that is, well outside the main L/R speakers but still in front of the listener. The Height speakers should also be located outside the main L/Rs at an angle of ±45 degrees, and they should be raised above the plane of the other main speakers at a vertical angle of 45 degrees. The placement of the two Back Surround speakers is not well defined, but they should be directly behind the listeners.

Why add these channels? Audyssey's extensive research clearly indicates that human perception of directionality is much more precise in front of the listener than behind. Thus, expanding 5.1 to 7.1 by adding back-surround speakers is not nearly as effective as adding speakers in the front. According to Audyssey's findings, adding the Wide speakers is the most effective at increasing the sense of envelopment, followed by the Height speakers. Adding Back Surround speakers is the least effective because our sense of directionality is relatively poor to the rear—in fact, a single Back Surround speaker works perfectly well.

A demonstration this week at Audyssey's facilities in Los Angeles definitely showed the effectiveness of the system.


A great center channel speaker can really help with the imaging regardless of seating location, but not all center channels are the same. 3-way centers tend to be a lot better than 2-ways because the dedicated midrange in the middle of the speaker throws a wide soundstage.

Alternatively, using a vertically placed 2-way (non-center) can work really well.

Here's a center channel I designed and  built.  Super smooth sounding, but narrow dispersion due to the 2-way design:


Kota1, I didn't think of wides, but that is a great idea.  My room has a small alcove to the right with the door, so everytime I go into the room I would need to move that speaker out of the way and put it back once everyone is in the room.  It is usually just me for hours, so not a big problem, and I have room to store it.  Thank you for the idea.

Erik, thanks for the link.  I would love to build a speaker, but it would take me forever to do that, and it would come out looking cheap.


Im not suggesting you DIY, just wanted to show an example of a narrow dispersion center.

Erik, the more I look at centers they just seem to be narrow.  I am trying to widen the dispersion.  In my room the left to right movement of the screen just disappears in a couple of my seats.  I currently have a 3 way Center, but it is just missing that mmovement.  It is a b&w cm s2 center.

@dmaddox77 , if you want to widen the dispersion you can place 2D diffusor or combo panels on the front wall between the center and L and R channels (again you can see the example in my pic).

Remember, when you get the trinnov the room correction can be used to assist. When you take measurements make sure to take a couple where you seem to need more coverage.

If you post pics of your room it would help if we can see.

I am hesitant to say this because I have seen these forums go south saying I am pitching product of another person.  There is a video of my room on the Accoustic Fields YouTube channel.  I purchased everything except 2 of the foam pieces on my doors.



Wow! Looks fantastic, have you tried moving your CC forward away from the wall a bit?

@Kota1 Thank you.  The room needs coat of paint.  That doodoo brown color has got to go.  I haven't moved it out, but as you can see space is limited.  I have maximized every square foot.

OP:  The dispersion of my center isn't terrible... for my small living room and couch it's fine... but if you want to do a larger seating area then it will be easily bested by 3-way centers.  One of my faves is Monitor Audio

Erik, thanks for your knowledge.  I watched a video on YouTube Channel Erin's Audio Corner that made me start thinking about this topic.  He didn't bring up doing what I was thinking, but it made me think about dispersion.  He likes 3 ways with some exceptions.


I'll have more to say about this topic next year. :)  I'm planning on doing a fully active, high-end 3 way when budget allows

By bringing the center forward it will widen the dispersion area. I know you are tight on space but maybe just test it to see if that helps.

I think you’re moving in the right direction using a monitor for a center.  The best center speaker I heard for dispersion was a B&W Matrix center that consisted of a tweeter mounted above a single midwoof driver, so it was not unlike a standard monitor speaker in that regard.  I wouldn’t use two monitors as centers as you’re likely to create more problems than it’s worth, and one monitor should be fine as long as it gets down to 50Hz or so I’d think.  Love your mistress BTW.  Nicely done!

@soix, my wife still tells me to go spend time with the Mistress.  I married a unicorn.  I have been debating whether to move away from the Denon AVR and go straight to the Trinnov and separates.  Then upgrade the LCR.  Every sales person I have spoken to loves the B&W CM8 s2 speakers.  They think I would have to go up to the B&W 802 or higher.  They all say it isn't worth the upgrade.  I just need to get those small speakers up about 6"-1' off the ground.

Before you go for the trinnov get the pro upgrade for the Denon ($200 in msft store) and the calibrated mic they recommend (about $50) my system was night and day different when I upgraded my marantz processor to the pro version of audyssey.

You can use isoacosutic stands to get those speakers off the ground.


For the BEST use of those two left over book shelf channels I would recommend using them as wide channels.

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