Center Channel vs Back Wall Placement

[luft262]

My center channel speaker is rear ported. My home theater speakers are crossed over with the subs at 120Hz. I know that's high, but it gives me the best curve as measured with a UMIK-1. Should I worry about how close my center channel is to the rear wall due to the rear porting?

Thanks for your input.

 

[DonH56]

Chances are the port is tuned below your crossover so shouldn't matter. The usual rule of thumb for minimum spacing is to place the port opening at least one to two times the port diameter from a boundary.

 

[luft262]

Chances are the port is tuned below your crossover so shouldn't matter. The usual rule of thumb for minimum spacing is to place the port opening at least one to two times the port diameter from a boundary.

If you had to guess at what Hz would a typical center channel port be tuned?

 

[luft262]

Chances are the port is tuned below your crossover so shouldn't matter. The usual rule of thumb for minimum spacing is to place the port opening at least one to two times the port diameter from a boundary.

My center channel has two small ports on the back would I have to measure the diameter of both or just one to determine the minimum recommended distance from the rear wall?

 

[DonH56]

If you had to guess at what Hz would a typical center channel port be tuned?

My center channel has two small ports on the back would I have to measure the diameter of both or just one to determine the minimum recommended distance from the rear wall?

Good questions for which I am incompetent to answer (not my day job).

Center speakers have a very wide range of frequencies, but generally the port is tuned to boost the bass as the main driver(s) fall off, so tuning is around the low-frequency limit of the speakers, say a little above the -3 dB point. Reviews often state the port tune, and impedance plots will show it as a dip in impedance (at tune the port provides "all" the output and the bass driver is "stopped" from moving so minimum impedance).

The required distance allows air from the port to eject sufficiently before hitting a boundary, which can influence (raise) the port's tuning frequency. If the two ports are close together I would place the speaker at twice the total diameter; if they are far apart (more than 2x their diameter), I would space it about the diameter of one port away.

All of the above a quasi-educated guess on my part.

HTH - Don

 

[Kimbrough Xu]

Good questions for which I am incompetent to answer (not my day job).

Center speakers have a very wide range of frequencies, but generally the port is tuned to boost the bass as the main driver(s) fall off, so tuning is around the low-frequency limit of the speakers, say a little above the -3 dB point. Reviews often state the port tune, and impedance plots will show it as a dip in impedance (at tune the port provides "all" the output and the bass driver is "stopped" from moving so minimum impedance).

The required distance allows air from the port to eject sufficiently before hitting a boundary, which can influence (raise) the port's tuning frequency. If the two ports are close together I would place the speaker at twice the total diameter; if they are far apart (more than 2x their diameter), I would space it about the diameter of one port away.

All of the above a quasi-educated guess on my part.

HTH - Don

Thank you for your explanation, but I am a newbie to audiophile, could you please tell me what benefit can I get from a center speaker? My current system is a pair of Klipsch R-51M.

 

[DonH56]

Thank you for your explanation, but I am a newbie to audiophile, could you please tell me what benefit can I get from a center speaker? My current system is a pair of Klipsch R-51M.

For movies and multichannel music the center speaker "anchors" the sound so you have a centered focal point for the listeners. A single person sitting in the center between left/right speakers may get by without a center speaker since the L/R speakers will create a "phantom center". However, if you move out of the center listening spot (or have other listeners with you), then the sound shifts to the left or right and you lose that center sound "anchor". Most of the sound usually comes from the center, whether movies or music, so adding a center speaker makes it easier to maintain a good sense of where the performers lie in the soundstage. For me that image stays in place better for listeners on either side of the center "sweet spot" with a center speaker.

IMO - Don

 

[luft262]

Thank you for your explanation, but I am a newbie to audiophile, could you please tell me what benefit can I get from a center speaker? My current system is a pair of Klipsch R-51M.

I believe in Floyd Toole's book they tested phantom center vs a center channel and listener preference was much higher with an actual center channel than with phantom center even when seated in the ideal listening position, but don't quote me lol.

 

[Flaesh]

If you had to guess at what Hz

~41 Hz if your center is Focal Aria CC 900 https://www.audiosciencereview.com/...l-aria-900-series-amp-load-measurement.19058/

 

[Kimbrough Xu]

For movies and multichannel music the center speaker "anchors" the sound so you have a centered focal point for the listeners. A single person sitting in the center between left/right speakers may get by without a center speaker since the L/R speakers will create a "phantom center". However, if you move out of the center listening spot (or have other listeners with you), then the sound shifts to the left or right and you lose that center sound "anchor". Most of the sound usually comes from the center, whether movies or music, so adding a center speaker makes it easier to maintain a good sense of where the performers lie in the soundstage. For me that image stays in place better for listeners on either side of the center "sweet spot" with a center speaker.

IMO - Don

Thank you, that really helps.