Yet another ZDT3.5 question...

[djsixbillion]

In keeping with the current trend, I've got all the drivers to build three of these. What I'd like to do is build three of the center channel speakers, to all be placed horizontally, LCR fashion, under an ~ 8-foot wide projection screen (on short stands). From reading Mr Krutke's description, it's clear that he does not recommend using the center channel vertically, but does anyone see a problem with doing what I propose?

[Blktre]

This speaker is built for horizontal placement. The crossovers are a little different between the tower design and the CC design. Musically, id think there would be a difference in sound. So are you just planning to use this strictly for HT? Are you planning a 5.1 system? How big is the room?

[stangbat]

I don't think you read or interpreted his comments correctly. He isn't stating that using them upright is the problem, the problem is that: "There's too much in the design that is specific to center channel usage but not suitable for mains." Look at the differences between the two crossovers and you'll see evidence of this. Turning them upright or laying them flat isn't the whole reason to not build all three and use them as mains and the center.

Of course you can do whatever you want. But the best use of your money and the best results will be obtained by building them as designed.

[Dennis H]

"There's too much in the design that is specific to center channel usage but not suitable for mains."

John usually designs his mains to be placed well out into the room. If they're going to be placed near the wall, the center might be a better choice.

[djsixbillion]

If they're going to be placed near the wall, the center might be a better choice.

This was sort of my thinking, as these would be placed maybe 18-24 inches from the wall (measured to the front of the baffle). Then there's the aesthetic considerations - basically these speakers would be for HT only, with a separate pair of stereo towers for music only placed to the left and right of the screen and driven by totally separate electronics, etc. I'll try to get a picture of the room up if its hard to visualize.

I initially got this idea from another thread on this forum where someone had done much the same thing with three of the RS WMTW's as LCR, kgveteran I believe was the builder?

[jkrutke]

I have a tight schedule today, but I'll be back to this thread in a while to comment on that placement situation.

[djsixbillion]

Thanks!

[Blktre]

I don't think you read or interpreted his comments correctly. He isn't stating that using them upright is the problem, the problem is that: "There's too much in the design that is specific to center channel usage but not suitable for mains." Look at the differences between the two crossovers and you'll see evidence of this. Turning them upright or laying them flat isn't the whole reason to not build all three and use them as mains and the center.

Of course you can do whatever you want. But the best use of your money and the best results will be obtained by building them as designed.

I was just re-enforcing the horizontal placement. But i agree that using a CC as LR isn't ideal. But, im interested on what John has to say about that more than placement.

[jkrutke]

There's two primary design considerations that are specific to the center channel: the tonal balance is a little brighter to compensate for being placed near a boundary, and the mid to tweet lobing is directed forward and up.

If the center is placed out in a room, even if horizontal, it's going to be a little lean and forward sounding.

If the center is placed vertically, anyone to the mid side of the speaker will have a null in the response, with the depth of the null determined by how far they are off the design axis. This is the one I really want people to avoid, as the center design is just not meant for it.

Your configuration with three horizontal channels would be fine horizontal dispersion-wise, however, using a flat projection screen against the wall removes one of the near-speaker boundaries that helps out the low end. It would work well, but it would be a little lean. You could compensate to taste with the mid and tweeter level. It's a flexible design.

[djsixbillion]

Thanks for the reply John, it basically reinforces what I was thinking. Whenever these speakers get completed (hopefully within the next few months!), they will probably be paired with one of the newfangled AVR's that employs some form of room EQ (Audyssey, etc.). Do you think that this EQ would be enough to compensate for the slight brightness of the speakers, or would some extra padding on the mid/tweeter still be in order?

[treytexag]

This is not a question for John - but if one of you other knowledgeable gents could answer this aggie question, I'd appreciate it. I've read about changing resistors on the tweeters L-pad to adjust it by ear in a room.

John says "It would work well, but it would be a little lean. You could compensate to taste with the mid and tweeter level. It's a flexible design." - what is he saying one might do exactly?

A little lean means lean on bass? And how could you / would you "compensate" to taste with the mid and tweeter level? Is John talking about adjusting resistance on the tweet's L-pad here? Does adjusting the resistance on the L-pad also "compensate" the mid too?

Please advise how this works guys - thanks for the assist.

Trey

[peter_m]

Trey, he provides mid-range options as well. Looky here: http://zaphaudio.com/ZDT3.5-options-R6.gif The link is part of the section called "Tower Options"

Peter

[treytexag]

Trey, he provides mid-range options as well. Looky here: http://zaphaudio.com/ZDT3.5-options-R6.gif The link is part of the section called "Tower Options"

Peter

Cool, got it. Still noobing out on this stuff here. Thanks Peter.

[treytexag]

3 of these ZDT3's across the front would work?

So it seems like, just checking here, that three of these centers across the front, FR and FL sitting on the shelf and the center a little lower in the cabinet on a shelf, would work well? For about $1K with PE cabinets, I could do three of these, and was hoping the sound stage up front for 50% two channel and 50% HT would be outstanding.

Gents, would this work well, or shall I really pursue some other vertically shelf mounted solution for the FL and FR?

See the photo of my den attached.

Thanks guys.

Trey

[WillyD]

I'd still want to have the L and R vertical, but you could still reduce their BSC some. I don't see how it would make much of a difference as far as aesthetics to have them vertical.

[---k---]

So it seems like, just checking here, that three of these centers across the front, FR and FL sitting on the shelf and the center a little lower in the cabinet on a shelf, would work well? For about $1K with PE cabinets, I could do three of these, and was hoping the sound stage up front for 50% two channel and 50% HT would be outstanding.

Gents, would this work well, or shall I really pursue some other vertically shelf mounted solution for the FL and FR?

See the photo of my den attached.

Thanks guys.

Trey

I think with the way you have them in that photo (all close to the back wall), it would work about as well as anything.

You may want to consider seeing if you can get the height all at the same level, rather than the stagger. Mine aren't this way, but I think it would be helpful in the soundstaging presentation. Also, when you order your parts, order a few extra resistors so that you can play with the levels to suite your taste.

[treytexag]

I'd still want to have the L and R vertical, but you could still reduce their BSC some. I don't see how it would make much of a difference as far as aesthetics to have them vertical.

Yes, I'd prefer to have the L and R vertical too, and you're right, I'll need to adjust the BSC down some. Aesthetically, not too concerned I think.

John says this on his site: "It's worth noting here that some builders may be wondering if it's a good idea to just build 3 of this design and use them turned upright for lefts and rights also. In a word, no. There's too much in the design that is specific to center channel usage but not suitable for mains. Controlled vertical off axis with wide horizontal off axis, along with low BSC are perfect for a center, but turn into serious shortcomings when used for an upright left and right."

So, because of the apparent lack of horizontal dispersion from this center channel design oriented in the vertical position, I thought I could just use three of these laying horizontally. Also, the horizontal orientation keeps the tweet near ear level, as opposed to higher than ear level that an MTM design oriented vertically would yield.

Despite all this, I would prefer a "higher end" proven design here for my fronts, at a minimum - my preference too would be vertically oriented L and R. Already running a 15" sub on a bash amp for the LFE, so everything is crossed at 80 Hz anyway.

Appreciate everyones input here.

Thanks,
Trey

[peter_m]

Trey,
People stick to conventions just because they look like what they expect. Is it rational? 3 horizontal centre-channels will be just fine. If I were you, I would definitely try to have all 3 at the same hight and as close as possible at the bottom of the screen.

Cool project, nice living room.

Peter

[WillyD]

So, because of the apparent lack of horizontal dispersion from this center channel design oriented in the vertical position, I thought I could just use three of these laying horizontally. Also, the horizontal orientation keeps the tweet near ear level, as opposed to higher than ear level that an MTM design oriented vertically would yield.

That should work fine.