Originally Posted by Bond 007
Many speakers, as you know, suggested as center channels are not designed specifically to be used horizontally.
Agreed, and it mystifies me, because there are plenty of center channel speakers.
Of course not all center channels speakers are not the same. Some are W-T, some are MTM and some are hybrids.
Since the PC351 is, I was just wondering if you would still use it horizontally for LR. Thats why I asked my original question.
Yes, I use the PC351 horizontally for all three positions, LCR. That was the point!
Bill seems to think that ALL speakers are best used vertically regardless of design.
I'm not sure that is his position. I think that he and I agree that speakers usually have a built-in preferred orientation, and they are best used that way.
That seems strange to me but I don't know enough to argue to argue the point.
The story I see is at least partially historical.
Hi Fi started out repurposing speaker components built for use in theatres, which included horn tweeters. Horn tweeters were often used in home audio through the 60s but they are expensive to build right, which runs against the need of a mass market. Dome tweeters with very wide dispersion entered the market in the late 1950s were commonplace in the 1970s and dominant in the 1980s and later. Home audio doctrine favored speakers with broad dispersion.
Speakers tend to have dispersion that has the opposite orientation of the drivers in the speaker. You want a speaker with broad dispersion? Build a tall, narrow column!
Hence a preference for speakers being used vertically.
A relatively new trend is speakers with controlled directivity. This seems to me to be a natural line for improvement. First we learned how to build speakers that had a desired response on-axis and now we are learning how to build speakers that have the desired response off-axis. This begs the question as to what off-axis response should look like.
So far people seem to agree that off-axis response should be constant over the area where the listeners sit. I think that most agree that off-axis response should be smooth and probably dropping more rapidly off axis of the area where the listeners sit.
Horn speakers (waveguides) have been able to be designed since the 1980s to have a natural tendency towards constant directivity, but direct radiators tend to become more directional as the frequency rises. One way to somewhat even out the directivity of a direct radiator based speaker is to build a multi-way speaker that has drivers whose diaphragm diameter decreases with rising frequency. Another way to control the directivity of direct radiators is to put them in a waveguide.
Several studio monitor speakers put direct radiators into waveguides with good results. They include Klien and Hummel, Genelec, Mackie, and Behringer. Even the relatively inexpensive Berhingers have amazing directivity plots in the form of lines that radiate from a common point and have more rapidly decreasing response as you move further off axis.
FWIW, the Hsus seem to be direct radiator drivers in a wavegude:
and have been praised for their directivity control in reviews already mentioned in this thread.