Magna Center Channel

[freakeystyley]

Has anyone here built or heard of a center channel designed to work with Darren's Magna Coom Laudes?

I've been thinking about this, since I end up using mine for theater / video game duty more than half the time, and the transition from these monsters to most speakers is pretty dramatic, mostly because they can play so clearly at pretty much any volume.

I've been thinking of either coming up with something similar to Curt's UniCC, but using Tang Band drivers to keep it all in the family (W6-789Es flanking a W704D and the Dayton DC25TS-8 Titanium tweeter). Either that, or build another MCL. But more squat so it fits under the projector screen. Heck, maybe even the W6 and DC25 flanked by the two 12's for a CC on crack.

Any thoughts? Anyone willing to help or at least critique my design if I head down this path? I pretty much am looking for a center channel to keep up with the MCLs.

Thanks guys

[Mayhem13]

The orientation of the woofers isn't terribly important. Build the MT section as it is with the same driver to driver spacing and install the two woofers horizontally on either sides. Better hurry while the SD315 shielded is on sale......and still available. Looks like Dayton is obsoleting it's shielded drivers...first the RS and the SD to follow.

[Wolf]

Heh- *CCC!* Cracked Center Channel.

I think you should just do that. Who else would have a CC with 12" woofers?
Later,
Wolf

[freakeystyley]

Thanks for the advice guys.

The more I've meditated on it, the more I want to build this monster. Fortunately, I've pretty much got free rein over the man cave (how else would I have MCLs in a home theater) but the holidays are coming up, we just bought a new truck, etc. so spending another $225 on one speaker might not make it past the CFO (my wife).

In the meantime, I've got one of the surrounds I designed for the system pulling center channel duty. A little oddly shaped guy with a W704D and the Dayton DC25TS-8 that sounds pretty darn good, but doesn't quite keep up with the 120lb gorillas in the room.





Since I've already got another W704D and DC25TS-8 in stock at my house, I may buy two W6-789Es and the tweeter high pass and midrange low pass crossover components in the meantime and build something like the UniCC, but have the option to go out and buy the woofers, midrange high pass and woofer low pass sections after the holidays and finish the job.

How likely do you guys think it is that they will discontinue the 12" in the next year?

[Face]

I would just run a phantom center for the time being.

[freakeystyley]

I've tried that, and it works pretty well. Works great for me, since I sit in the primo spot - dead center, first row - but doesn't work as well for my wife who sits to one side. She gets blasted in the face by the left channel.

But when I'm down there alone, I certainly do occasionally set it to phantom.

[Mayhem13]

Thanks for the advice guys.

How likely do you guys think it is that they will discontinue the 12" in the next year?

It's already discontinued in the shielded variety......that's a selloff price.......and for the cost for a pair vs a pair of 789's the more economical move when considering performance gains. There's LOTS of LF content in the center channel so....

[freakeystyley]

It's already discontinued in the shielded variety......that's a selloff price.......and for the cost for a pair vs a pair of 789's the more economical move when considering performance gains. There's LOTS of LF content in the center channel so....

Well, I priced out the 789s against the SD315s, including crossover components, and the 789 setup will cost about $141, while the SD315 setup is $215. Even so, you are absolutely right; the performance of the 315 will be well worth the cash. I was just rationalizing the lesser speaker. Not to mention the fact that adding a second 789 and getting rid of the high-pass section of the crossover from the MCL design will most likely sound odd without some tweaking.

Thanks for talking sense into me, Mayhem. I guess I'll at least buy the 3D315s so I'm not left hanging when they're gone.

[johnnyrichards]

FWIW, I bought the new unshielded version of the 8" DVC and it was close enough to a drop in on my Datum subwoofer. The unshielded 12" might be close on that respect as well. The sensitivity is probably a little lower so a touch more padding on the MT section might be all that is needed.

[freakeystyley]

Thanks for the heads up, Johnny. The shielded ones are a good deal right now, so I should probably get them, but at least I have a backup plan.

[freakeystyley]

So I broke down and bought all the parts to build another Magna, including the now discontinued sheilded 12s. I think I bought some of the very last, since when I had 4 in my cart it told me there was insufficient stock, and then when there were only two in the cart I was able to complete the transaction.

Anyway, with these parts on order, it's time to get the enclosure going...

With the 12" woofers the speaker is going to be fairly tall, so options are limited without changing the depth of the speaker dramatically. Keeping the same depth, volume, and MT layout, here are a few rough baffle designs. Any comments?







Keep in mind my mains ended up being 49 x 16 with a 3 inch pocket underneath for crossovers, so they are taller than Darren's design, but the same internal volume.

[johnlinvell]

A great thread.....i have never heard this design but watching movies with this set-up i might be able to rid myself of all my subs....() .....Someday i will have my own man cave and i will look back on this thread and wished i would've said "what the ........" and did it...............

I don't know how wide the room is but the 36" wide might give better separation between center and mains...?

[bolland83]

I would go with the driver layout you have on the 2nd and 3rd drawings, make the box deeper and narrower, and down fire the ports. This will make it appear not so large, since it's already going to be a monster. Build a nice little stand for it as well. Just my 2 cents looks like you'll have a really sweet setup whatever you decide to do.

[freakeystyley]

I would go with the driver layout you have on the 2nd and 3rd drawings, make the box deeper and narrower, and down fire the ports. This will make it appear not so large, since it's already going to be a monster. Build a nice little stand for it as well. Just my 2 cents looks like you'll have a really sweet setup whatever you decide to do.

Thanks for the compliments, both of you. I tried out a deeper design. I rear fired the ports instead for now, but it wouldn't be hard to swap.

[freakeystyley]

And a quick mockup of the speaker in the room. Not too bad.



For a sense of scale, the mains are four feet tall and weigh 120lbs each, and the screen is 100" diagonal.

[johnlinvell]

Just how much LF would there be in the center channel for dialog ? I must misunderstand everything i have read about the center channel ? Please let me know what i'm missing.
TIA.

[ckmoore]

I was thinking the same thing. Since when do TV and film audio engineers send sub frequencies to the center channel? Since 99.9 % of all center channels do not have a driver larger than 7 inches.

[Wolf]

I was thinking the same thing. Since when do TV and film audio engineers send sub frequencies to the center channel? Since 99.9 % of all center channels do not have a driver larger than 7 inches.

Another opportunity would be to plate-amp the woofers in the center to provide an up-front subwoofer and run the LFE to it. Set the center itself to 'small'.

Later,
Wolf

[freakeystyley]

I was thinking the same thing. Since when do TV and film audio engineers send sub frequencies to the center channel? Since 99.9 % of all center channels do not have a driver larger than 7 inches.

Hey guys, my plan was more to keep the voicing between the mains and center channel as close as possible, so motion from side to side is more seamless. Also, the woofers (which are not setup as subs in this enclosure, playing up to 400hz) are there to take the burden of low end duty off the midrange, allowing these speakers to play as loud as your amp will allow.

I wanted my center to keep up with my mains at high levels.

Wolf, that's an interesting idea. I've got all the parts for the 400hz low pass for the woofers, but it might be interesting to try out the sub idea. I guess with the receiver set to small, it would have a high pass on it, and not beat up on the Tang band too much. And the LFE channel has a low pass on it, so I could use my QSC RMX 1450 to power them.

Anyway, do you folks think having the woofers so close to 3 edges instead of 2 will cause any issues?

[Wolf]

Wolf, that's an interesting idea. I've got all the parts for the 400hz low pass for the woofers, but it might be interesting to try out the sub idea. I guess with the receiver set to small, it would have a high pass on it, and not beat up on the Tang band too much. And the LFE channel has a low pass on it, so I could use my QSC RMX 1450 to power them.

Anyway, do you folks think having the woofers so close to 3 edges instead of 2 will cause any issues?

Yep, you understand perfectly!

Nah- should not be an issue.
Later,
Wolf