[drunkpenguin]

Heres my dilema. My current yamaha speakers sound ok but when the center speakers fires off you can tell its different from the left and right. For instance, when a car drives by accrost all 3 speakers the center sounds different. So in my mind Im thinking 3 identical towers would create a more even soundstage. The problem is Im limited in speaker choice to 35" or less to stay under the screen.


So my questions:


1) would 3 identical speakers be the way to go? Or would upgrading to better speakers with a better "center channel" eliminate what I am hearing?


2) do towers that were meant to be lefts and rights make for good centers? will they produce voice duty pretty good?

 

[Kal Rubinson]

Three tower is just dandy. The big point is that the front three should be identical in sound and configuring a center, even with the same drivers, in a different arrangement makes that a problem.

 

[sivadselim]

can't resist

Center-channel speakers, although designed to serve that function, are, in reality, an accommodation for people that need a horizontally-oriented speaker to "fit" in their center location. Most people can't place a vertically-oriented tower or even a bookshelf in the center; hence the need for "center-channel speakers".


But a vertically-oriented speaker actually disperses sound horizontally, into the room, much better than a horizontally-oriented speaker, which disperses sound vertically, toward the floor and ceiling, providing a very narrow "sweet spot" and producing unwanted reflections off the floor and ceiling. That's why most "normal" stereo speaker pairs are, and have always been, vertically-oriented; they disperse sound best, horizontally, the way you'd prefer them to. You also want your center speaker to disperse sound best, horizontally, with a wide "sweet spot", so that everyone in the room can hear it equally well.


Additionally, horizontal MTM speakers (midwoofer-tweeter-midwoofer; the design that the majority of horizontal center channel speakers exhibit) suffer from something called "lobing", which is, basically, an interference phenomenon caused by adjacent placement of two identical drivers that are producing acoustically identical output. The result of lobing, with respect to the horizontal mid-woofer to mid-woofer arrangement and distance encountered in most MTM center channel speakers, is a dip in horizontal, off-axis midrange frequency response. Since most dialogue relies heavily upon the midrange frequencies for the reproduction of human voices, a midrange dip is exactly what you do NOT want from your center-channel speaker.


There ARE many designs that attempt to alleviate the problems associated with horizontal center channel speakers; both the dispersion issue and the lobing issue.


Horizontal MTMs are usually designed with a lower crossover point between the midwoofers and the tweeter, so that the single tweeter produces some of the midrange content that would normally have been cancelled due to lobing.


Sometimes, an offset tweeter design is used which allows for closer spacing of the 2 midwoofers, which helps reduce the lobing effect.


Another common method utilized in horizontal center speakers to reduce lobing is to simply add a midrange driver, arranged vertically with a tweeter, both located between the two midwoofers (the so-called WTMW design), which, for the most part, at least sidesteps the lobing issue altogether.


There are also some asymmetric 2.5-way crossover designs where both midwoofers operate at the lowest frequencies, but only one midwoofer operates through the critical midrange frequencies where lobing can occur.


One design which lends itself very well to center channel speakers, is the 'coincidental array' design (such as that used by KEF and Tannoy, among others) where the tweeter is located in the acoustic center of a single midwoofer. This design, with only a single midwoofer, completely eliminates the lobing issue.


But none of these designs can completely eliminate the vertical dispersion issue that is simply inherent to almost all horizontally-oriented speakers.


So, the horizontal center-channel speaker, no matter the design, is not ideal. It is a compromise. Many people incorrectly assume that the best choice for their center channel speaker must be the speaker that the manufacturer of their speakers markets specifically as a "center channel speaker". But the BEST center channel speaker would actually be a single, vertically-oriented tower, bookshelf, or LCR (vertical MTM) that identically matches your front left and right speakers.



As Kal says, 3 towers would be "dandy".

 

[Mr. Audio]

The only problem I see with getting three towers is; how in the world do you get one tower? Speakers are normally sold in pairs only. 3 of the same speaker would be more ideal if you have the room though.

 

[sivadselim]



Quote:
Originally Posted by Mr. Audio /forum/post/12942533


The only problem I see with getting three towers is; how in the world do you get one tower? Speakers are normally sold in pairs only. 3 of the same speaker would be more ideal if you have the room though.

Towers are very often available singly. In fact, they are often sold as $/ea.. Bookshelves are much tougher to buy singly as they are usually sold $/pr..

 

[Mr. Audio]



Quote:
Originally Posted by sivadselim /forum/post/12942585


Towers are very often available singly. In fact, they are often sold as $/ea.. Bookshelves are much tougher to buy singly as they are usually sold $/pr..

Really, I did not know that.

 

[Tulpa]

My Athena AS-F2.2s were sold individually. As are Polk R50s (and most Polk towers, for that matter) from Frys that I considered buying. Both are popular entry level towers, judging by posts here.

 

[Apollo5]

Where would you place the third tower in the center without having to mount the TV high above it? I'm guessing that behind would not be so good, but how else can you do it?

 

[Tulpa]

That's why most people opt for a standard horizontal center channel mounted above or below. Or three bookshelf speakers if a third can fit vertically. For most, they can accept the compromise.


Three towers could work if you had an acoustically transparent screen and projector setup. Or mounted the TV higher, as you said.

 

[sivadselim]



Quote:
Originally Posted by Apollo5 /forum/post/12944437


Where would you place the third tower in the center without having to mount the TV high above it?

Nowhere else. You'd mount the TV, as you said, above it. HERE , lets look at the tower just mentioned by Tulpa, a Polk R50. It's 36.75" tall. Now, get your tape measure out. 40" is not really THAT high.

 

[Apollo5]

No, but sitting on my couch 8 ft away, it would mean that I would be looking up at the screen at an uncomfortable angle. I was hoping there was some magic solution.

 

[JBLsound4645]



Quote:
Originally Posted by drunkpenguin /forum/post/12941966



So my questions:


1) would 3 identical speakers be the way to go? Or would upgrading to better speakers with a better "center channel" eliminate what I am hearing?

That’s what I’ve been saying for a few years till I was blue in the face. I’ve been using matching JBL control 5 for 17 years, now then. Matching fronts LCR is the way to do it.

Quote:
Originally Posted by Mr. Audio /forum/post/12944281


Really, I did not know that.

Place all three at the front and yes they need to be (positioned at the same height level).


Place the fourth at centre back rear for spot location, that’s doable, and then buy another pair and place them next to the sidewalls.


The back one would present a small problem, it would only serve one or two people, so another pair placed beside it, on the left and right, spaced out evenly and toed in slightly, that should cover the rear with three playing the same signal.

 

[drunkpenguin]

Thanks for all the replies. I had a feeling my thoughts of 3 identical speakers were on the right road. And yes, I do have a PJ and screen mounted to the wall. This is a dedicated HT room. The screen is mounted to the wall and the entire wall is sound treated around the screen. This is why my speaker choice cannot exheed 35". Moving the screen would not be an easy task for me. But I have found several towers that I am interested that fit my height requirements. As soon as I can narrow down to 1 Ill make the jump.


Thanks again!

 

[jwatte]

Bookshelf-sized speakers don't need to have bookshelf sound. They can easily go as deep as most towers.


Try some Mackie HR824s, or some Genelec 8040s or 8050s. I went with the 8040s, and have matching sound all around (6.1 setup). With that set-up, I don't have to worry about imaging problems at all.