Recommended Center Channel for S30 Fronts 3.1 Setup

Since you already have a pair of Cambridge s30 speakers, why don't you lay them sideways for a couple days to see how you like the sound? If it still sounds good to you then you know another s30 on its side will be fine as a center.

www.audioadvisor.com has the s50 in stock if you want to try that center.
http://www.audioadvisor.com/prodinfo.asp?number=CAS50%20%20%20%20%20BLK

There's only half an inch difference in height between the HD Level3 center and the S30 standing up (HTD is 8.25" tall, S30 is just a hair over 8.75"). Sure you can't fit another S30 as a center?

You could try laying an S30 on it's side to test it out, but the two drivers are quite close so it's not promising.

I don't recall reading anything negative about the S50. (It's a uniquely small center being less the 5" tall.)

I've heard good things about the S50's sound quality, but what concerns me is its specs. While those should always be taken with a grain of salt--if not a whole cake of it--they say that the S50 only goes down to 80 Hz, which means that it will sound "thin" unless you cross it over to your subwoofer at a higher frequency, which would definitely be a compromise, as you may begin to hear sounds as coming from the direction of the sub (localization) and most subs aren't optimized to play that high anyway (even high-end ones), so they won't sound as good as a regular speaker.

The S30 is more than capable of filling the role of center speaker, provided that your room is not a large one, and a pair of S30s actually doesn't cost much more than a single S50, so you'll have a spare that you could keep around as a potential replacement or sell to somebody else who needs a single S30 for their center speaker.

I doubt that its performance as a horizontally-oriented center, in terms of dispersion for off-axis viewers, would be any worse than that of the S50, since the latter has two relatively widely-spaced midwoofers that will interfere with one another, in the most basic terms.

Using two centers is not always, absolutely a no-no. I almost always recommend against it for a variety of reasons, but I can imagine, for example, wanting to use one above and another below a large screen in order to vertically center the image of the center channel. It would have to be done carefully in a certain way, with certain types of speakers and orientation, but it may benefit a few systems enough to be worthwhile. However, what you're suggesting is almost definitely a no-no because it would perform worse for off-axis viewers.

Yeah, I noticed that, too. OP, if you could somehow possibly accommodate a vertically-oriented S30 as a center speaker, then that would be ideal. Otherwise, lay it down horizontally.

Why would the close proximity of the drivers be an issue? If anything, I think it'd help because it's closer to being a point source.

Now you have. I'm not saying that it's bad, but that the S30 is better.

Do you mean vertically?

Is it *that* close that you could squeeze in the comparatively enormous HTD Level THREE center, but not a vertically-oriented S30?

If the S30 is oriented vertically, then yes, and if it's oriented horizontally, then yes in all probability, but not quite as much. Let me further qualify this, though. You won't notice any improvement in the central "sweet spot" right in front of the center speaker. But as you move to the left or right, away from the center, you'll notice more and more that the sound changes. With most center speakers, which are 2-way horizontally-oriented MTMs such as these, it is the upper midrange that usually suffers the most, and this is where dialogue intelligibility can suffer, as well. This effect is usually much less pronounced when a typical 2-way bookshelf with only two drivers, such as the S30, is laid down sideways; there may be some asymmetry in the vast majority of cases, but off-axis performance is still typically better than that of horizontally-oriented MTMs. Now, a vertically-oriented S30 will still change its tonal character, among other things, as you move off-axis, but the effects are far less pronounced because the spacial relationship between the drivers remains constant from the perspective of your ears--you'd have to move much farther off-axis in order to detect a difference, and most of it will be in the upper treble (because of the limited dispersion of most tweeters) as opposed to the midrange.

This brings us to the question of how far you'd have to move off-axis in order to hear a difference. For example, if you're seated reasonably far from the front speakers and only have three viewing positions, all right next to one another, then you'd probably hardly even notice any ill effects in the left and right seats, even with the "dreaded" horizontally-oriented MTM--that's how most people can use these just fine. On the other hand, if you sit closer to the front speakers and have, say, five seats in your home theater, then it may become a noticeable issue, or even a real problem for those on the far ends (either way, sound quality will suffer for those who are off-axis, which would be most of the audience). In the latter case, a vertically-oriented center speaker would perform significantly better, as it does in my own home theater. Thus far I've only spoken in vague notions regarding distances to give you a general idea, but the real way to figure out the potential magnitude of the problem, if there even is one, is measuring angles (or calculating them from measured distances). With most MTM centers, you probably wouldn't want to be more than, say, 15 degrees off-axis or else they'll start to sound significantly worse--it's less for some specific speakers and more for others, but this is sort of the middle of the range, and those who are interested in making their system perform at its best should keep in mind that the degradation in sound quality is gradual, which means that it starts almost immediately as you go off-axis. For comparison, with a typical vertically-oriented bookshelf speaker, you could go 30 or maybe even 45 degrees off-axis, and it would still sound better, especially in the midrange.

By the way, since you brought up a different speaker (the HTD center), putting the above issues completely aside for the moment, in general it would be far more ideal to use a center speaker that closely matches the front left & right speakers, and you can't get any closer than identical. For that matter, it is preferable--albeit less critical for most uses--to use surround speakers that closely match the front speakers, but that is a whole other topic unto itself. To sum up, the best center speaker for your system would be a vertically-oriented S30, and failing that, a horizontally-oriented S30 would be the next in line.

No--not if you want the best performance you can get out of your system (for off-axis viewers).

You're not looking very hard:
http://www.ebay.com/itm/Cambridge-Audio-S50-Center-Channel-Speaker-in-Dark-Oak-/120810633734?pt=Other_MP3_Player_Accessories&hash=item1c20dffa06

I got my center channel from them. Arrived in 1 day. Perfect condition, all that stuff. You should just go get the matching center.

I assume you are using it with S30 mains. How do you like the S50? I am considering one for an S30 3.1 system

Its a natural companion to the S30s. I think its a no-brainer if you are going that route. That eBay seller has 100% positive feedback and a 30 day return if you are not satisfied. Just round out your setup and don't look back.

I would have preferred the NOIR color instead of the dark oak, but my AV stand has a cubby just for a center channel, so I don't see anything but the front of the speaker anyway.

Awesome!

You know, I neglected to mention tilting the vertical center , probably because what I said was quite enough for most people to absorb in a single post (and I got winded )--thanks for catching it. One of the advantages of horizontally-oriented centers is that they can be displaced vertically quite a bit without affecting sound quality much, which is useful for the way most people would place them. Vertically-oriented centers, on the other hand, often need to be tilted upward or downward (as mine is) to point close to the ear-axis (draw an imaginary line through the ears of the viewers ), if you will, to make up for their somewhat limited vertical dispersion--once this is done, then you can take full advantage of their superior horizontal dispersion. Good job.

That should do it.

Nothing matches better than another S30.

The S50 can be very useful if you need to fit a speaker into a tight vertical space, which is not at all uncommon, or if you simply prefer how it looks as a center speaker above or below the TV. There is nothing wrong with preferring it for these reasons, especially if no viewer is going to be all that far off-axis, but for those who are willing to accommodate a third vertically-oriented S30 for their center speaker, there can be no more natural a companion--or more ideally suited a center speaker for off-axis viewers in terms of sound quality--than that. On top of this, the S30 appears to be a higher performance speaker than the S50, matching and dispersion issues aside.
Edited by Robert Cook - 2/27/13 at 1:12pm

I thought that a rear ported speaker like the S50 would not perform well in a cubby.

Its open across the back, more like a shelf than a true closed in cubby.

Plus the Dolby / DTS channel seperation tends to put voice and like sound in the center; not much base or anything getting pushed out of it were a buffeting effect in the cubby / shelf might come into play.

I think they sound quite good all paired up.

It depends on the speaker, the cubby, and the frequency at which you cross over to your subwoofer. If you cross over well above the tuning frequency of the port(s) and the cubby is open at the rear, then the speaker will probably perform just fine (relative to speakers of different enclosure designs). On the other hand, if either of these conditions is not met, then there will most likely be sound quality issues, the nature of which depends on the speakers, the cubby, and which conditions you did not meet.

That's a good thing. What subwoofer crossover frequency are you using for your center, by the way?

That depends on the individual soundtrack and the subwoofer crossover frequency. Some soundtracks are VERY center-heavy, including explosions, crashes, and music, while I've seen at least one soundtrack that has ONLY dialogue in the center channel (although some dialogue can get somewhat deep, on occasion).

I'm sure that they do--we're just talking about optimizing a system for the best possible performance at the widest angles. I'm not trying to say that those who use the S50 as a center speaker with S30s are doing the wrong thing, because that depends on a lot of different factors.
Edited by Robert Cook - 2/27/13 at 2:45pm

Thanks for the offer, but I'd rather spend the extra $110 and get an extra speaker - for backup, for use as surrounds if I decide I don't want a center, for use with a mono radio in study, etc.