b&w center channel advice requested

[danpritts]

Hi,

I've been a luddite regarding surround sound.

I've got a pair of B&W P4's that I love to death, with adcom 2-channel amp & preamp.

I came across a pair of B&W DM600i's at a garage sale (!), and decided that it must be a sign, so I bought them with the intent of using them as rears.

For now, I probably won't buy a subwoofer.

I now need to figure out what an appropriate (used) center channel might be. I haven't paid attention to the audio marketplace since I bought the P4's in 1996. I poked around on ebay, audiogon, and b&w's site, but there are lots of center channels that have come out in the intervening years, and it's hard to figure out what would be a good match.



I have a sony 34" tube hdtv. (mmm, black blacks)

I have a reasonably small room, with an unfortunate long and narrow shape. Due to the fireplace, the TV & couch are on the long walls. It's maybe 12' from the screen to my eyes & ears.

My budget is up in the air; I was thinking $200-300 for the center channel and $500 for a receiver, but hey, the kids don't really need to go to college, right?


If you're inclined to think about receivers, I haven't figured out what kind of A/V receiver to buy yet, thinking maybe the Pioneer VSX-21TXH. I worry whether it can drive the DM600i's (4 ohm load), although at the low volumes i'll be playing them I'd think it would be OK. Thinking Pioneer because of good experience with my first receiver (1985 SX-40 which was great for what i paid for it), various car audio products of theirs, etc.

 

[m_vanmeter]

I can't help you with B&W P4's and a center - you might ask the tech's at B&W what they would recommend. If you can't stay in the B&W line due to price, then at least try a center channel with a similar tweeter ....construction, cone type, material...etc. You may a reasonably close match.

As for receivers, you might also look at Denon and Onkyo, both brands have units on a similar level to the Pioneer Elite series.

 

[lsiberian]

Hi,

I've been a luddite regarding surround sound.

I've got a pair of B&W P4's that I love to death, with adcom 2-channel amp & preamp.

I came across a pair of B&W DM600i's at a garage sale (!), and decided that it must be a sign, so I bought them with the intent of using them as rears.

For now, I probably won't buy a subwoofer.

I now need to figure out what an appropriate (used) center channel might be. I haven't paid attention to the audio marketplace since I bought the P4's in 1996. I poked around on ebay, audiogon, and b&w's site, but there are lots of center channels that have come out in the intervening years, and it's hard to figure out what would be a good match.



I have a sony 34" tube hdtv. (mmm, black blacks)

I have a reasonably small room, with an unfortunate long and narrow shape. Due to the fireplace, the TV & couch are on the long walls. It's maybe 12' from the screen to my eyes & ears.

My budget is up in the air; I was thinking $200-300 for the center channel and $500 for a receiver, but hey, the kids don't really need to go to college, right?


If you're inclined to think about receivers, I haven't figured out what kind of A/V receiver to buy yet, thinking maybe the Pioneer VSX-21TXH. I worry whether it can drive the DM600i's (4 ohm load), although at the low volumes i'll be playing them I'd think it would be OK. Thinking Pioneer because of good experience with my first receiver (1985 SX-40 which was great for what i paid for it), various car audio products of theirs, etc.

If you want a center channel make sure you have the setup for one. You will want at least 8 feet between your L-R channels.

 

[danpritts]

Thanks for the suggestions.

Looking through the used listings on audiogon and ebay, there are several B&W center channels in my price range, just trying to figure out which one(s) would be good matches to what I have already.

Thanks for the tip about having enough distance between L & R, there's plenty of room.

I'm certainly not tied to Pioneer on the receiver, but it's been so long since I paid attention to the market all I know is that I probably can't afford replacement Adcom gear. I saw Denon & Onkyo, as well as Sony, Yamaha, and Marantz gear all in my price range. Looked like Yamaha's lower end models had crappy amps, or else crutchfield put the wrong numbers in the THD field on their website.

Once nice thing about the Pioneer is that it has pre-outs so I can continue to use my existing amp for the main pair, and maybe upgrade to a 5-channel amp sometime (or, it occurs to me, just buy a couple more 2-channel GFA-535's used - redundant array of inexpensive amplifiers?)

 

[skers_54]

You don't need to use a center channel. You can run a "phantom" center in which the dialog is rerouted to the L and R channels. IMO, this is preferable to using a mismatched center. The downside is that this only works optimally if you sit in the sweet spot. I'd try to find another P4 first, and then whatever B&W suggests as a good match.

 

[TLS Guy]

Hi,

I've been a luddite regarding surround sound.

I've got a pair of B&W P4's that I love to death, with adcom 2-channel amp & preamp.

I came across a pair of B&W DM600i's at a garage sale (!), and decided that it must be a sign, so I bought them with the intent of using them as rears.

For now, I probably won't buy a subwoofer.

I now need to figure out what an appropriate (used) center channel might be. I haven't paid attention to the audio marketplace since I bought the P4's in 1996. I poked around on ebay, audiogon, and b&w's site, but there are lots of center channels that have come out in the intervening years, and it's hard to figure out what would be a good match.



I have a sony 34" tube hdtv. (mmm, black blacks)

I have a reasonably small room, with an unfortunate long and narrow shape. Due to the fireplace, the TV & couch are on the long walls. It's maybe 12' from the screen to my eyes & ears.

My budget is up in the air; I was thinking $200-300 for the center channel and $500 for a receiver, but hey, the kids don't really need to go to college, right?


If you're inclined to think about receivers, I haven't figured out what kind of A/V receiver to buy yet, thinking maybe the Pioneer VSX-21TXH. I worry whether it can drive the DM600i's (4 ohm load), although at the low volumes i'll be playing them I'd think it would be OK. Thinking Pioneer because of good experience with my first receiver (1985 SX-40 which was great for what i paid for it), various car audio products of theirs, etc.

This will be your closest match if you buy new.

 

[jostenmeat]

This will be your closest match if you buy new.

danpritts, I'm sure it's more than what you want to spend, but as mentioned, I'd rather leave alone than mismatch at this point.

And even if it's more than what you want to spend, please realize that this center is a WTMW which invariably are more expensive. They produce much better dialogue intelligibility, and audio in general, across the horiz plane. Horizontally redundant woofers cause issue with "lobing", and since these woofers are crossed significantly lower than your typical horiz mtm, probably about two or three octaves lower, the audible lobing effects should hopefully be greatly diminished. IOW, you are paying for something, to at least some extent.

 

[danpritts]

danpritts, I'm sure it's more than what you want to spend, but as mentioned, I'd rather leave alone than mismatch at this point.

And even if it's more than what you want to spend, please realize that this center is a WTMW which invariably are more expensive.

Thanks for the feedback. I am willing to go higher than the $200-300 i mentioned but the cm2 is definitely out of my price range.

I hadn't considered the possibility of skipping the center completely. perhaps i'll buy a receiver and see how things sound before investing further.

WTMW? woofer treble mid woofer? the distinction being that when you have two woofers, you want a 3-way instead of 2-way design so the woofers' crossover can be lower?

Some further googling finds a review for the Matrix HTM center that mentions it was a good match for the reviewer's P4s.

I can't post the URL since i don't have enough posts on audioholics yet but if you google for B&W matrix htm it's the first hit.

Any thoughts on that speaker? I see one listed on ebay for $300 right now, which is certainly in the budget. But I dont' want to make things worse, as you mention.

 

[jostenmeat]

Thanks for the feedback. I am willing to go higher than the $200-300 i mentioned but the cm2 is definitely out of my price range.

I hadn't considered the possibility of skipping the center completely. perhaps i'll buy a receiver and see how things sound before investing further.

Good idea. FWIW, a lot of folks say that the center becomes more imperative when the viewers are spread out. However, I personally think it's important to point out that this is EXACTLY when the weakness of a horiz MTM rears its ugly head. The centering might* not be quite as good, but the dialogue intelligibility is just about always better in my experiences, when being off axis and comparing phantom vs horiz mtm. Again, just fwiw.

WTMW? woofer treble mid woofer? the distinction being that when you have two woofers, you want a 3-way instead of 2-way design so the woofers' crossover can be lower?

Yes. It's not a 3 way vs 2 way issue. The specific problem is the redundant drivers playing the same exact audio, while on the same horiz plane. Once you are at different distances from these two woofers, playing the same exact thing, you suffer random sets of boosts and cancellations depending on the angle you sit, due to the interference known as "lobing". What makes the typical horiz mtm so bad is what I alluded to before, and that is because the xover point is so high, that the set of lobing frequencies is very great, covers an enormous part of the freq spectrum, and inevitably compromises dialogue intelligibility.

That's the crux of the paradox. People tend to recommend the center speaker when being offaxis, yet it is precisely when you are off axis that it sounds worst, as far as the individual center speaker being mtm. If you are rather on axis to the speaker, I think mtm is fine. Depending on the design, normally you want to be within 20 deg cone, but I think straight on is the only way.

Now, ok, you're right in the sense of the 3 way, because having that single dedicated midrange driver allows the woofers to xover much lower from the rest of the speaker, so that lobing issues are much less offensive. In fact, some WTMWs (you guessed it, B&W), are designed so well with horiz WTMW, that lobing is simply inaudible (a big reason being that lobing starts very low, where we are insensitive to the effects).

Other tidbits/factoids: a horiz MTM could be better designed if the woofers are closer together (the "differing distances" are reduced when off axis, make sense?), and the xover point is lowered. However, I don't think I've ever once seen such a design, though I'm sure they exist. I'm sure the issues with driver limitations must come into play.

I copy/pasted some results, with highlighting here:
http://forums.audioholics.com/forums/showpost.php?p=632842&postcount=11

which came directly from this AH article:
http://www.audioholics.com/education/loudspeaker-basics/vertical-vs-horizontal-speaker-designs/conclusion-rankings-and-evaluation.html

Some further googling finds a review for the Matrix HTM center that mentions it was a good match for the reviewer's P4s.

I can't post the URL since i don't have enough posts on audioholics yet but if you google for B&W matrix htm it's the first hit.

Any thoughts on that speaker? I see one listed on ebay for $300 right now, which is certainly in the budget. But I dont' want to make things worse, as you mention.

I didn't google it sorry. What I will say is that the actual best possible match for your center speaker is yet another P4. Best is to put it vertical. If above TV, it's fine to flip it upside down. If horiz, you suffer lobing at and around the xover point, but it's better in the sense it's not everything below the xover point.

 

[danpritts]

Thanks for the links on horizontal speaker design, very informative.

Interesting food for thought regarding finding another P4 as the center, but it'd have to end up atop the entertainment center, 2' above the screen. Not sure how the wife would feel about that

 

[jostenmeat]

Thanks for the links on horizontal speaker design, very informative.

You're very welcome.

Interesting food for thought regarding finding another P4 as the center, but it'd have to end up atop the entertainment center, 2' above the screen. Not sure how the wife would feel about that

I googled the speaker for images, and I now understand. My immediate thoughts:

1. Just forgo center for now, as you are thinking. When you get the receiver, simply tell it that there is no center connected. This channel will then be downmixed into your mains. Voila.

2. In the case that you ever seriously consider finding another p4 as a horizontal speaker, I'd first ask if it's going to work out fine enough. I don't know enough to tell you. From the one fuzzy pic I found, I can't tell if there is any directional waveguide or phase diffuser on the tweeter, but if so, it becomes a poorer idea. Also, just as with horiz mtms, etc, the spacing between the tweeter and woofer is important (and closer will be better). It is a risky proposition, but it's worth asking about.

3. I trust TLS recommendations in general, regarding speakers, but it's also worth contacting BW directly for their thoughts. Break it down to multiple questions, asking for different price point recommendations, with the compromises involved. Sure, they're going to want you to buy BW, but that's what you're going to want anyways. Specifically ask for superceded/discontinued items that may work, so that you can keep your eyes peeled. Make sure that they include bookshelf possibilities as well.

Good luck. I think you'll be happy with phantom 4.0 however. If you have just one couch situated directly towards the system, even more so. You can shop for a sub instead, during the meanwhile.

 

[danpritts]

2. In the case that you ever seriously consider finding another p4 as a horizontal speaker, I'd first ask if it's going to work out fine enough. I don't know enough to tell you. From the one fuzzy pic I found, I can't tell if there is any directional waveguide or phase diffuser on the tweeter, but if so, it becomes a poorer idea. Also, just as with horiz mtms, etc, the spacing between the tweeter and woofer is important (and closer will be better). It is a risky proposition, but it's worth asking about.

The tweeter is a simple dome; I think that would be fine. But it would look awfully silly sitting on its side. The alternative of having it sitting on its head on top of the entertainment center isn't much better.

it's also worth contacting BW directly for their thoughts.

I was going to ask my local dealer. The guys i bought these from no longer carry the line/have a different name now, but the current dealer replaced a driver for me and was really good to work with. Depending what they say I'll ask B&W too.

Good luck. I think you'll be happy with phantom 4.0 however. If you have just one couch situated directly towards the system, even more so. You can shop for a sub instead, during the meanwhile.

Occasionally we have people sitting off to the side, but with two young kids, mostly we put them to bed on Saturday night and the two of us collapse in front of the tube.

Thanks again for all the advice. I'll post back here when I finally buy something, which will be around christmastime.

 

[Mika75]

Before buying anything, try a small bookshelf speaker in the center channel position....

 

[danpritts]

Based on everyone's advice here, I went out and bought a HT receiver (denon avr590). I was a little nervous that it wouldn't have the oomph to handle the 4 ohm dm600i's in the rear position, but it's fine so far.

As predicted, a simple 4-channel setup sounds just great. With our small room and limited seating, we're never out of the sweet spot and the lack of a center channel is not noticeable.

The P4's have never been bass-heavy, and a I'm quite confident a subwoofer would make more improvement to the sound than a center channel would. That said, it sounds pretty good as is so i'm not sure i won't get some other toy for christmas.

Thanks again for all your advice.