Why is the Center speaker a different size that the Left and Right?

oddeomixer

Hi All,

It seems counter intuitive when the center speaker has different size drivers, more drivers, and different size enclosure than the main left & right speakers.

Often, I read that the center channel speaker has been designed to match the “timbre” of the left and right speakers. How is that possible? Seems to defy the laws of physics.

Someone please explain this center speaker philosophy.

The Left, Center, Right speakers in the movie theater are the same. The dub stages where movies are mixed have speakers the same size for the Left, Center, Right.

I’m getting ready to dive into the surround home theater.
Current set-up:
Sony stereo receiver
2 - Polk RTi28
Panasonic TC-P55VT30 Plasma

Updating to:
Denon AVR-X2000 referb (should arrive in a couple days)
Moving the RTi28 to the rears
Adding a Polk DSW PRO 550wi Sub
Adding 3 Polk RTiA3 for the L, C, R
BUT… it seems I can only purchase the RTiA3 in pairs.
SO… now the center speaker question

A little background about me…
My primary gig is working as the Supervising Audio Engineer for an organization that has 3 TV Studios, 2 Production Control Rooms, 3 Radio On-Air Studios, 2 Audio Post Suites, 9 Video Editing Suites, a Color Correction Suite, a Recording Studio, and a TV Remote Truck situated in a 100,000 sq. ft. broadcast building. Everything we produce for TV is done in surround.

I have also been the Re-Recording Mixer on a dozen or so independent features.

-Scott

BlueFox

Probably due to the fact that if the center were a tower it would block the screen, and be awkward to deal with horizontally. Also, I would suspect the center channel information, at least in a movie, not an SACD, is different from the information in the L/R channels. Thus different layout, driver size, etc. is justified. Of course, this is just a guess.

20hz

I guess timbre is a even vocal sound if it travels across the front 3 speakers , but the signal is rarely below 100 hz that is cent to the center so the best plan is look at the center as only doing 100-10k and what sounds best to you .
I use subs and polk bookshelves w/a kef 100 center , the kef has a great off axis response so w/that is not directional and angling the center is a inaudible waste of time .
I go subwoofer because I dont have crazy money for mains that are giant and I want my bass to start at 18hz so the only option was build my own subwoofers .

jbooker82

get a perforated projector screen and put a 3rd tower behind it for your center channel.

F1nut

Surprising questions coming from someone in your profession.

It seems counter intuitive when the center speaker has different size drivers, more drivers, and different size enclosure than the main left & right speakers.

The center usually has less drivers and often the same size drivers as the L&R. The enclosure is optimized for what it has in it.

Often, I read that the center channel speaker has been designed to match the “timbre” of the left and right speakers. How is that possible? Seems to defy the laws of physics.

The center is voiced the same as the other speakers in the same series. Really not sure why you would find that impossible or defy the laws of physics.

The Left, Center, Right speakers in the movie theater are the same. The dub stages where movies are mixed have speakers the same size for the Left, Center, Right.

Easy to do in a large movie theater, not so easy sticking a tower or even a bookie in front of a TV, hence the horizontal design of the typical center channel speaker.

Adding 3 Polk RTiA3 for the L, C, R
BUT… it seems I can only purchase the RTiA3 in pairs.

The center is arguably the most important speaker in an HT set up. The RTiA3 would be a poor choice compared to the CSiA4 and especially compared to the CSiA6.

WLDock

I've heard some awarding winning car audio systems that seem to defy the laws of physics. The car is seriously tough place to get coherent stereo sound.

In a home theater just like the car you do what you have to do to get it done. It's possible for a speaker designer to get a similar timbre and midrange to high end response from a home theater shaped center channel and towers. Look at the excellent frequency response of the LSiM center and mains:

The measurements of the LSiM 707 tower and the LSiM 706c center are fantastic. Although on-axis measurements are not shown in the accompanying chart, they’re as close to perfect between 500 Hz and 20 kHz as I can remember seeing: ±1.37 dB for the tower and ±1.49 dB for the center.

http://www.soundandvision.com/content/test-report-polk-audio-lsim-speaker-system-page-3

Even in the home if one went with the route of a dedicated room with a transparent screen and then identical LCR the ROOM for sure will alter the response of each speaker at the listening position. DSP with room correction is a nice thing to have.

Talk only goes so far....listen to a well setup home system and judge for yourself... Even one using a horizontal center.

GlennDog

Mixer, Welcome to CP !