Dual Centers as L/R?

[mk05]

I read, perhaps dogma and incorrect, that the Center Channel is extremely "important," because most of the verbal information - voice ranges - is reproduced on center channel. Therefore the speakers should be designed to give provide more clarity/resolution than other channel designs, good sound power and low distortion in that important range - look below at acoustic power for R2c from 500-3000Hz. Take for example, KEF R2c vs R5. It seems to me that the design is a R5 without the tower column.

- Could someone enlighten me where the bass has disappeared to in the FR of the R2c? Is it because of the assumption I made above, that Center Channel design is to provide more clarity, therefore removes lower FR and excess demand from the driver?

- I have then read that Center Channel has poor horizontal directivity, which is why you use dedicated L/R design. So why can't someone just flip the speaker 90d?
The white paper also states that the directivity for the R2c should be excellent. Perhaps then, one could use two of these speakers as L/R? Why is this not done? I would really love to see measurements for R2c!

I like the R3, but read many who opined that it could be augmented with another driver to relieve demand on the driver. R5 was my choice because of this. However, the more I researched, the more people seemed to agree that 5.25" isn't enough to necessitate a tower, and that the correct decision for a tower should be R7's 6.5" drivers.

Bookshelf owners want a 2.0 option, but reading @amirm reviews of with/without subwoofer listening scores, I wonder if buying 2x C as Left and Right is an interesting solution for those who consider (already have) 2.1 solution, with interest in the voice range? Again, I am going off an assumption and most likely am interpreting things incorrectly, so please educate me! Thanks for entertaining my curiosity

 

[pjug]

I think the R2c is sealed. If you want 2.0 with bookshelves that go deep you should be able to find other solutions but the R2c do not seem suitable for L and R.

 

[mk05]

I think the R2c is sealed. If you want 2.0 with bookshelves that go deep you should be able to find other solutions but the R2c do not seem suitable for L and R.

You are correct, R2c is sealed. Personally, I don't need speakers to go deep, because I own a subwoofer.

The more important part of the query was whether a center will be clearer in resolution and detail, with weight - whatever that is supposed to mean. I understand these are qualitative notions. Outside of measuring neutral, these are real qualities of a speaker that people look for, along with "holographic image" and "expansive soundstage." That said, I think excellence in the above characteristics are attributed to good speaker designs, since I assume people prefer "holographic image" to not, or speakers that "disappear," for example.

I keep asking these questions to understand if there are measurement values to represent these. So far I haven't gotten a clear answer...of course, it's possible that someone did, and I missed it - or discussed in the past but in correct scientific terminology. Please link me to any threads or material that explain which graphs depict how to properly measure expansiveness of soundstage and holographic imaging projected by a loudspeaker.

 

[pjug]

I guess I misunderstood. I thought you were not wanting to use a sub. I can't imagine any advantage of using a center speaker as L/R, though, only disadvantages since that is not what they are designed for.

 

[Chrispy]

Why take a compromised speaker design outside of the use it was compromised for?

 

[detlev24]

There is absolutely nothing wrong in using a C loudspeaker for all (other) channels. The main difference, as you noted, lies in the bass roll-off, which allows for easier crossover with subwoofer(s); as intended by a multi-channel setup. And yes, distortion levels at higher SPL are generally lower on those loudspeakers, since the low frequencies are taken over by the subwoofer(s). No different focus lies on measurement evaluations for C channel loudspeakers! Furthermore, in 'professional audio' [most of the time] the same loudspeaker model is used for all channels - to have them perfectly matched to each other. For another application example, see the "Revel C52 Speaker Review and Measurements" -> Conclusions.

Even the desired characteristics for horizontal and vertical dispersion, wider or narrower, depend mainly on the seat arrangement(s) vs. loudspeaker placement and the acoustic interference with the surroundings/with the room. Whether you can simply flip the loudspeaker by 90° depends on the intended use [provided, that the loudspeaker's dispersion in both planes is usable]. It is quite common to flip, e.g., Genelec 'The Ones' in both 0° and 90° orientations, but one has to consider the different dispersion patterns - even for such a coaxial design.

One reason why, generally, bigger woofers might be more beneficial (if crossed over at or above 250 Hz/300 Hz) lies in the "speaking range" of bass instruments; explanation linked there.

Regarding soundstage and imaging, if we take any loudspeaker that measures reasonably well and again, there is no difference on the metrics for a C loudspeaker; those depend mainly on your room acoustics. DSP can fix a few things but has certain limitations. Proper treatment of early reflections and further application of bass trapping are crucial components, regarding room acoustics. The beneficial effects of acoustic room treatment are, by their nature, not covered on typical loudspeaker measurements; like with the Klippel NFS.

Altogether, you might get a much better "net" overall performance with the R2c + properly integrated Subwoofer(s) for L/R channels, than with the R5.