Center Matching Mains..??

[Andrew747]

I have been reading a lot on the forums and realize that the centers should match the mains. However my question is how close do they really need to match.

My mains are based on Dr. K's MTMs towers. They are two Dayton RS180S-8 7" with the Dayton RS28AS-4 on this link DrKMTM.

The centers I want to build are from CJDs project http://www.eldamar.net/audio/rs150mtm/
I was thinking about using the seas tweeter for this design instead of the dayton.

This is where the centers would differ from the mains: a different tweeter, different crossover point and a 6" woofer (instead of 7" in the mains).

Are these subtle differences going to make a big difference in sound?
Should i Just build another Dr.K MTM for my center?

Thanks a ton
Andrew

[Kal Rubinson]

How they are constructed is only indirectly related to the issue of whether they are timbre-matched. Best bet is another of the two you have and, of course, used vertically.

Kal

[Andrew747]

Thanks Kal.

Please help me with my thinking on this.

I was thinking I dont want to replicate my mains because they are 7" woofers. I would like to think that smaller woofers of mids would be better for the center channel. Preferably I would like MMTMM to with 4" to 5" inch mids to best reproduce the vocals for the center. However I dont need or have the skill to design my own center with the Dayton RS series to match my mains.

So instead I found CJDs project with the 6" RS series that I believe would work better. Also the smallER box for a center channel would work better for my setup.

Does the smaller woofer throw off the sound that much?
Also I am not sure what you mean by "timbre-matched"??

[dawaro]

I have been reading a lot on the forums and realize that the centers should match the mains. However my question is how close do they really need to match.

My mains are based on Dr. K's MTMs towers. They are two Dayton RS180S-8 7" with the Dayton RS28AS-4 on this link DrKMTM.

First question is are you happy with the mains? I only ask because there have been a lot of varied opinions on that design. If you are happy, great stick with them. If not there are several designs using that driver/box combo/placement. The difference is in the xover implementation. Roman has a comparision of the different designs on his site RJB Audio

The centers I want to build are from CJDs project http://www.eldamar.net/audio/rs150mtm/
I was thinking about using the seas tweeter for this design instead of the dayton.

This is where the centers would differ from the mains: a different tweeter, different crossover point and a 6" woofer (instead of 7" in the mains).

Look closer at CJD's project page, at the bottom you will find versions for both the RS28A and the RS28S. That could fix your concerns with different tweeters. The xovers and drivers are going to be very close in timbre.

Are these subtle differences going to make a big difference in sound?
Should i Just build another Dr.K MTM for my center?

Thanks a ton
Andrew

Using the same drivers with comparable xover points the differences are going to be subtle between the RS180 & RS150 designs. CJD's MTM is going to be your best bet for a center because it was designed with that in mind. Turning the others horizontal is going to cause response issues because they were never intended to be used this way.

[technimac]

Zaph's ZDT3 CC may do the trick......

Here's something to consider if you really want a high quality, RS180-based CC.

You could build Zaph's ZDT3 WMTW CC, which has the phenomenal performance of the RS 52, combined with the highly rated Dayton ND20. It would probably be a bit larger than what you want, but after you experience the quality of sound from this CC, you'll more than likely be glad you chose it. Probably because the CC "anchors" the dialogue on the screen and is often the primary speaker used by performers in a concert setting.

For instance, on Diana Krall's "Live in Paris" DVD, all her vocals and piano are mic'd to the CC. And a three-way WMTW does justice to performances like this.

The ZDT3 WMTW CC enclosure is 9" high and can be made deeper for rear-venting. The baffle layout would look like WillyD's sealed version, shown here:



John Krutke is presently redesigning the tweeter filter to accommodate the Dayton ND20 because the Aura NT1 isn't available.

I'm very happy with the Audax WMTW CC that is currently anchoring the LCR of my home theater. It replaced a MTM and the difference in SQ & off-axis response was remarkable.

That's not to say the Chris's RS150-based MTM CC isn't a good performer, (from what I've heard, it is) but there are other advantages to using a WMTW design for your CC.

Other, more knowledgeable folks here will probably be able to give you a technical explanation on why this is.

HTH, Bruce

[---k---]

I'm not convinced how much a center needs to perfectly match the mains. It seems like this is a great topic for internet forum racing. But, in the real word, if the designs are similar, the placement and room has more affect on the way the center sounds than anything else.

If you were talking about building very expensive speakers, in a perfect room I would suggest that you build perfectly matching centers. But, with the Dr. K mtm and CJD's MTM, I think the differences will be close enough that you'll be very happy - especially if your receiver has a decent room correction eq.

Don't get hung up on perfectly matching the center to the mains. I'm very confident that you'll enjoy these. Maybe next time around, you can build perfectly matching speakers, but it isn't anything to sweat.

[Andrew747]

Thanks for the great responses, I hope to get my CC underway real soon.

Andrew

[wettou]

If you can the three front channels should be the same.

[Blktre]

Im currently building Zaphs RS180 WMTW CC as well. Once he gets the redesigned tweeter and crossover and the ZDT3 build gets back online, you will notice that Johns CC design is a front port design. WillyD's CC I do believe is a sealed design so It would fit into a closed cabinet. The front ported design John has I'm pretty sure isn't as tall, but is wider. I picked this design because Ive heard Stangbats ZDT3 towers in 2channel music and knew for sure that the RS180 WMTW CC 3way design would match perfectly. Not that this helped you in any way other than the fact if you chose to build this center, the size could matter to you.

[technimac]

Johns CC design is a front port design. WillyD's CC I do believe is a sealed design so It would fit into a closed cabinet. The front ported design John has I'm pretty sure isn't as tall, but is wider.

I saved the PDF drawing of the ZDT3 CC and it's 12.25" deep, 31.88" wide and 9" tall. By making it ~16" deep with rear-venting, it would be possible to reduce the baffle width from ~32" to ~24". The 9" height on WillyD's is the same as it is in the drawing.

HTH, Bruce

[WillyD]

I agree with Ryan.

And I need to try out that Live In Paris DVD, Bruce. I have it but haven't listened to it with my ZDT3 center.

[---k---]

The other thread on this subject got closed - for good reason. I think, maybe we all should just move on now.