Good Price/Performance Center Channel

[Gir]

My soon-to-be-roommate and I are going to be building a sound system for our apartment next semester and we couldn't quite decide on a center channel. Right now I'm in the process of getting enough money to finish my two mains, which are Mark K's RS225/RS28A. We were thinking of building the same design for the rears but with a slightly shorter depth (suggestions welcomed for any cheaper designs). As for the sub I decided on a big 'ol sonosub

My question for you guys is what is a good price performance center channel that would fit well with the system? We're willing to go upwards of $300 or $400, and the size doesn't matter. It's a somewhat large room since we'll be on the first floor which has a 13 foot ceiling. The dimensions I think are roughly 20x10x13, but I'm bad at guessing distances :roll:

Any help would be greatly appreciated!


-Tyler

[WillyD]

I think your budget is big enough to go with the Dayton WMTW 3-way.

https://www.htguide.com/forum/showthread.php?t=15323&page=1&pp=35

[Gir]

I think your budget is big enough to go with the Dayton WMTW 3-way.

https://www.htguide.com/forum/showth...3&page=1&pp=35

AHHHH! 48 pages! I better start reading! 8O

[cjd]

You could also go with another of the 225/28A TM if you have room to place it vertically

Modula MT would be a viable surround alternative as well I think.

Of course, you may discover you're really going to use the TM's you have as surround and build a whole new front TMWW/WTMW setup.

[Gir]

You could also go with another of the 225/28A TM if you have room to place it vertically

Modula MT would be a viable surround alternative as well I think.

Of course, you may discover you're really going to use the TM's you have as surround and build a whole new front TMWW/WTMW setup.

Heh, I actually have been thinking of that :B

It's a bit of a weird situation, but my roomie and I are actually each building half the system... I have the mains and sub, he has the center and rears, and oh yeah, a 37" HDTV with 1080p. Dave, if you're reading this I love you

But anyways, once we each get some more money we'll each separately finish out our own systems. I'm starting to like the idea of line arrays, but that probably won't happen for at least another year or two. It's all good, though, since we plan to stay in that apartment together for 3 or 4 years.

On another note, will the Modula MT have a good off axis response? I haven't really looked into those at all, but I'm looking for something with a good off axis response since during movie nights there will be some people on the floor and some on the couch. I'd say possibly up to about 20 or 30 degrees depending how I position it.

BTW, size isn't a factor. The tv will be wall mounted about 4 - 5 feet up, sonosub in the left corner with the mains about 3 feet from the tv and about 3-5 feet from the wall. One rear will have to be in the corner (one of those corner couches), and the other will be along an outward facing corner (opens to hallway), so I can position the rear to point into open space.

Are there any speakers that would function well as rears close to walls? Will it be much of an issue to have the rears against the wall? Wouldn't doubling up the rear baffle and some stuffing help with it?

[Dennis H]

The tv will be wall mounted about 4 - 5 feet up, sonosub in the left corner with the mains about 3 feet from the tv and about 3-5 feet from the wall.

Then it's a no brainer. Build another speaker like the mains and put it between the mains, about the same distance from the wall. That will give you a seamless soundstage.

Are there any speakers that would function well as rears close to walls?

Jon has a revised version of the Modula MT crossover for mounting on the wall. I'd say that would be your best bet. Build the boxes according to the main thread in the Missions accomplished section and use this crossover. You'll probably want the version with the RS28 tweeter to match your mains.

https://www.htguide.com/forum/showthread.php?t=22625

[cjd]

I agree with Dennis - build a third of Mark K's TM as a center, place it vertically.

But it sounds like you may have room for the WWMTM's as mains.

C

[Gir]

But it sounds like you may have room for the WWMTM's as mains.

Oh, I've got plenty of room, just not plenty of money...that's why I'll have a 5'5" tall sonosub! :B

[Gir]

Then it's a no brainer. Build another speaker like the mains and put it between the mains, about the same distance from the wall. That will give you a seamless soundstage.

Hmmm, perhaps I'll do just that then. It almost seems weird to have a vertical center...

Jon has a revised version of the Modula MT crossover for mounting on the wall. I'd say that would be your best bet. Build the boxes according to the main thread in the Missions accomplished section and use this crossover. You'll probably want the version with the RS28 tweeter to match your mains.

https://www.htguide.com/forum/showthread.php?t=22625

Sounds promising!

[cjd]

It almost seems weird to have a vertical center...

And yet the "classic" horizontal MTM is *horrible* for a center, layout-wise. Unless you don't count physics as meaning anything...

C

[Gir]

On a (slightly) different note, I'm buying the components for Mark K's crossover design. It would be great if you guys could verify the components I'm buying.



DAYTON DNR-16 16 OHM 10W NON-INDUCTIVE
2xDAYTON DNR-20 20 OHM 10W NON-INDUCTIVE
2xDAYTON DNR-5.1 5.1 OHM 10W NON-INDUCTIVE

2xDAYTON DMPC-1.5 1.5uF-250V POLYPROPYLEN
DAYTON DMPC-2.0 2.0uF-250V POLYPROPYLEN
DAYTON DMPC-10 10uF-250V POLYPROPYLENE
2xDAYTON DMPC-15 15uF-250V POLYPROPYLENE
3xDAYTON DMPC-20 20uF-250V POLYPROPYLENE
DAYTON DMPC-60 60uF-250V POLYPROPYLENE

JANTZEN .90mH 18 GA AIR CORE INDUCTOR
JANTZEN 1.00mH 18 GA AIR CORE INDUCTOR
JANTZEN 1.80mH 18 GA AIR CORE INDUCTOR
JANTZEN 2.50mH 18 GA AIR CORE INDUCTOR
JANTZEN .33mH 15 GA AIR CORE INDUCTOR
JANTZEN 1.20mH 15 GA AIR CORE INDUCTOR

Some of them I picked out to put in series or parallel:

1.5uF + 2.0uF in parallel = 3.5uF
20uF + 15uF in paralell = 35uF
20 Ohm + 5.1 Ohm = 25.1 Ohm (need 25.0, close enough, right?)
unwind .33mH to .30mH
unwind 1.80mH to 1.75mH

is 1.20mH instead of 1.25mH okay? Would it make much of a difference at all? And are the types of components I'm using good? Thanks in advance

[---k---]

Not to offend, just a strole down memory lane, but ever time I read one of these posts, I just think to myself:

For four years of undergrad (94-98), my roommate and I only had a 1981 19" Zenith console TV, no remote, and wasn't cable ready. And if that wasn't bad enough, for the three years that we lived in the dorms, the dorm doesn't give out cable boxes, so we used a left over one found in my grandpa attic that was from the late 70s. It had a dial channels 1-36 and no still remote. And for a stereo, we just had a cheep bookshelf system, on a shelf up about 6' high.

Not much tv watching or music listening going on.

[cjd]

My wife and I only had the old hand-me-down TV she got from her dad (built ~1983) for a while. :P But we DID have slightly better audio.

On the parts list, it looks good BUT - take a look at Madisound for some of the inductor values you're looking to "unwind" to. And maybe call 'em and see if they'll wind to spec for you. Great folks over there and I'm pretty sure they wind their own for the house-brand stuff.

C

[---k---]

Oh, I forgot the the initial VCR we had was a circa ~1980 Quazar top loader with corded remote. It was very retro cool (and free!).

[Gir]

Not to offend, just a strole down memory lane, but ever time I read one of these posts, I just think to myself:

For four years of undergrad (94-9, my roommate and I only had a 1981 19" Zenith console TV, no remote, and wasn't cable ready. And if that wasn't bad enough, for the three years that we lived in the dorms, the dorm doesn't give out cable boxes, so we used a left over one found in my grandpa attic that was from the late 70s. It had a dial channels 1-36 and no still remote. And for a stereo, we just had a cheep bookshelf system, on a shelf up about 6' high.

Not much tv watching or music listening going on.
__________________
-Ryan

I can beat you. Right now we have a 10" TV circa 1980 (maybe older; it only goes up to channel 24, but we have a VCR hooked up to it to get all the channels), with no external audio source. Oh, and it's on top of the microwave, so sometimes the picture goes crazy lol

On the parts list, it looks good BUT - take a look at Madisound for some of the inductor values you're looking to "unwind" to. And maybe call 'em and see if they'll wind to spec for you. Great folks over there and I'm pretty sure they wind their own for the house-brand stuff.

I'll definitely take a look at that, thanks! I'll be ordering all the parts sometime next week, so I'll let you know how that goes.

I was also wondering if there are any other crossover designs for a RS225/28A that would have a better off axis response. Mark K's website is down right now, but if I remember correctly there was a pretty good dip around 10kHz when you get to 15 degrees horizontally, and a lot worse as you go out. Are there any crossovers for the Modula MT that have better off axis response?

[---k---]

I can beat you. Right now we have a 10" TV circa 1980 (maybe older; it only goes up to channel 24, but we have a VCR hooked up to it to get all the channels), with no external audio source. Oh, and it's on top of the microwave, so sometimes the picture goes crazy lol

Wow, that is pretty pathetic.

Good luck on your project here.

[Gir]

Wow, that is pretty pathetic.

Good luck on your project here.

Heh, yeah, not much TV watching goes on in my room...
BUT NEXT YEAR...

[cjd]

but if I remember correctly there was a pretty good dip around 10kHz when you get to 15 degrees horizontally, and a lot worse as you go out. Are there any crossovers for the Modula MT that have better off axis response?

That's allllll tweeter. Nothin to do with crossover at that frequency.

Off-axis response above 10k is a number of different issues, including dome size. The best off-axis response comes from the smallest domes. And they don't go low enough to cross to a RS225.

C

[Gir]

Ah, it turns out the old link I was using for Mark K's site doesn't work, but the site is still up. Theres a dip at 1.5kHz and at 15kHz off axis of the vertical. The horizontal is great though. I guess at 15 degrees the vertical isn't too bad, so long as I have the sweet spot during the movies I'm sure noone else will even notice =D

[EDIT] Here's Mark's graphs
Horizontal (to the left) 0-15 degrees

Image not available

Vertical off-axis

Image not available

Image not available

I think the most anyone is going to be off the vertical is about 15 degrees, and since the horizontal seems pretty good I'm a happy camper :T

[cjd]

Well, theoretically they should be off-axis ABOVE the tweeter on a center channel (which measures almost identically at 15 degrees off-axis), no? Or are we talking floor-loungers? Seriously, that stuff is actually quite good, could be far worse.

FWIW the ~3dB dip above 10k is a phase plug thing, and it's far more benign (and not really audible) compared to NOT having the phase plug as it is. They did a good job on that tweeter.

C

[Gir]

Yeah, I'm more worried about people lounging on the floors, but after hearing your thoughts on it that makes me feel much better about it

Allow me to be a noob for a minute here...define phase plug ^_^

[cjd]

You're not going to find speakers that don't exhibit that type of performance in the vertical (well, horizontal MTM's will be good vertically but have worse off-axis in the horizontal than this does in the vertical!) outside of single-driver and probably full line arrays and stuff...

Phase plug is common on metal dome speakers - not really phase plug but phase shield. In this case, it's a dot of felt (?) on the inside of the grille. Some metal domes have much more obvious "things in front of the dome" - often a circle of plastic centered on the middle. It does phase shifts to try to keep sound from entering a bizarre time warp ... er... or something. I had some wine with supper and my wife wasn't able to finish hers so I have a little more and the world isn't quite as simple as it seemed...

C

[Dennis H]

Wall-mounted surrounds don't need to point straight ahead. Tilt them down so they aim at the ears in the 'money chairs' and the vertical polar response concerns go away. Same goes for the front three if they aren't mounted at ear height. Tilt them so they aim at your ears.

[cjd]

Dennis, college kids don't have ears that fix themselves in space nicely... could be anywhere between 2" above the ground to about 6' above the ground.

C

[Dennis H]

Yeah, I remember it well, Chris. Still, if you aim the speakers at the seated ear height, they won't be all that far off if you stand up or lie down.

[Gir]

The nice thing is that I can pretty much mount them at any height and angle. I'll be building the stands for all the speakers myself. As long as I have the sweet spot I'm good

[Gir]

Just curious, is there any kind of special wire to use when putting the crossover together or can I just use regular 14 guage or something?

[ThomasW]

Several of us like to use the 14 and 16 gauge mil spec from

http://apexjr.com/wire.html#Teflon

[digital desire]

If you have a local West Marine or Boat U.S., I find the marine wire (very fine condutors, each tinned) nice stuff. Plus, it is awg vs. sae (or vis versa) -anyway- it does run thick, and seems like quality stuff sold by the foot and color.

[wkhanna]

Oh yes, marine grade is something I came across some while ago. Good stuff, IMHO.

[Gir]

If you have a local West Marine or Boat U.S., I find the marine wire (very fine condutors, each tinned) nice stuff. Plus, it is awg vs. sae (or vis versa) -anyway- it does run thick, and seems like quality stuff sold by the foot and color.

Meh, none near me. I live near Harrisburg, PA (Hershey to be exact; yes, the Chocolate town). Would the wire I could pick up at Lowe's or Home Depot work just fine? Or is there really a difference across different types of wires?

[digital desire]

Gauge and "workability" are the most important factors here.
The apexjr.com stuff is well regarded.
The stuff at the HD or Lowe's is probably fine. Get the right gauge 14 or 16 should be more than enough for crossover stuff.

[Gir]

Gauge and "workability" are the most important factors here.
The apexjr.com stuff is well regarded.
The stuff at the HD or Lowe's is probably fine. Get the right gauge 14 or 16 should be more than enough for crossover stuff.

That's what I needed to hear, thanks! :T

[Ecir38]

Me i just bought a 14 gauge extension cord and stripped it.

[Gir]

Me i just bought a 14 gauge extension cord and stripped it.

Ahhh, ingenuity :B

[Gir]

I ordered the crossover components for one of the mains today. I won't have enough money for anything else until the summer, given the current estimate of $150 for my girlfriend

Ahhhhh, the wonders of being a broke college student...