Axiom Home Page
Posted By: autoboy Why can the M22 handle more than the VP100? - 06/10/09 05:15 PM
My brother is building his home theater and he's pretty confident that Axiom is the way to go, but now he's been all over these forums and is worried about lobing effects from horizontal centers, Off axis response from the VP100 and VP150, and he's worried that the VP100 can't handle a seating position beyond 12 -15 feet.

I have a VP100 and it is wonderful. I only sit 10 feet away though.

But, the m22 uses the same drivers, likely a similar crossover, and it is ported. Sealed boxes like the VP 100 tend to handle more power than a ported enclosure. Why all this fuss that he needs an M22 for the center, or a VP150, when nobody is ever concerned with the M22 in a medium sized room of 14x19x10?

Shouldn't the VP100 be able to play as loud,, if not louder as the m22 without distortion?
Personally, if he has the room for an M22 as a center I would do it. I find the M22 to handle male voices slightly better than either the VP100 or VP150. A vertical center also has better dispersion charcteristics than a horizontal center which does, IMO, yield better sound quality for all seating points.

So far as what you can read at other sites about lobing etc, I know Ian/Alan have both mentioned it is a quality that can be measured but very rarely affects Sound Quality and I have to agree. I have had no issues with either the VP100 nor the VP150.

Both of Axioms centers play very loud, just the 150 is capable of more SPL due to extra drivers.
He is going to try and hide the speakers behind acoustic fabric. The speakers will be mounted on shelves to either side of the screen. The center will be mounted above or below the screen, also hidden. Should he be worried about rear ported speakers when mounting them like this?

How should he design the cabinets that hold the speakers? Should they be mostly enclosed wood except for the front, or should they be made of wood skeletons with open sides and front, covered all the way around with fabric?

If he doesn't have the space for a vertical m22, how about 3 m3s across the front? Or m22s and two m2s top and bottom?
2 M2's from all reports works extremely well for those that have run this above and below configuration. 2 VP series speakers above and below works very well too, which I have tried with my VP100 and VP150.

Mounting M22s close to a wall actually helps re-enforce the lower frequencies but I would try to keep the box as open as possible to allow the rear port to do its job.
Has he considered an acoustically transparent screen? Then he can put all three speakers behind it, and it will allow the center to be in the middle and all three fronts can be the same speaker.

If this is not an option, I think the single center above/below only really becomes an issue if you have more than one row of seating, in which case he may want a pair. With one row you can just aim the center right at it. Axiom will recommend the 150 over the 100 when you get more than about 12' from it.
He has two rows in his 19 foot room. He considered a transparent screen but I was under the impression that it limited your audio quality and your video quality so if we can do it without a transparent screen we should. Since we are building the theater from scratch, it shouldn't be hard.
From what I have researched a decent A/T screen will only decrease sound by about 2 db, not a big deal after the system is calibrated. They do tend to allow light from the projector through though, so they work best in a room with complete light control.
there are no windows in the room.
An AT screen should not alter the sound that much, maybe 1dB or less. Also, if he is using a shelf, make sure there is enough room behind the speakers for the rear ports to filter low freq's into the room.
Definately something to look into

You can build a sub wall about 2 feet out, and place all the speakers (sub included) back there. Use an a/t fabric on the rest of the wall where there is no screen, and you're golden.

I was going to go this route, but you really need to put sound absorbing material in the cavity between the walls and it was just a bigger project than I wanted to take on. It is a great way to do it though.
Potato,

I'm not sure I understand what you are saying. Building a fabric wall would bring the screen forward too much and the front seats would then sit too close.

I was suggesting a skeleton structure to hold the speakers that was very open.

The screen would sit on the drywall but I would build two towers out of 2x2s that would hold the speakers at the right height but would otherwise be totally open. These would be covered with black acoustic fabric around the whole thing. They would sit on either side of the screen. The center channel and sub would be in another open skeleton below the screen but this one would have wood on top to support the weight of someone sitting on it. The top center speaker would probably also live in a similar fabric box.
Ahh, I see, so you want to build the speaker frames out and around the screen, gotcha. Most people just build a wall the whole way across and put the speakers behind the screen. I don't know that you would want to only run the center behind the screen and leave the other two only behind the acoustic fabric.
I was thinking something like this theater. Instead of the step in front, it would have a bench across the front, giving more room for a low center channel and some serious bass. His speaker cabinets seem to be closed on the side. I would want to leave the sides open so the speakers don't get boomy. It would look identical because it would be covered with fabric.

http://www.avsforum.com/avs-vb/showthread.php?t=996159
I have seen that one before, very nice setup... Even has QS8's in there.
That's one sweet looking HT!!!! One question, I thought I read in here somewhere that the QS8's should be 2 feet from the ceiling, is that correct?
They are QS4s
Is he putting in shelves and the acoustic cloth just for the speakers?

Why not go with the W22 & w100/150. You can paint the front face and grill cloth to match the wall colour. Someone here has already done that and it looks great.

I have dual M2s as centers and they work very well.
 Originally Posted By: fredk
Is he putting in shelves and the acoustic cloth just for the speakers?

Why not go with the W22 & w100/150. You can paint the front face and grill cloth to match the wall colour. Someone here has already done that and it looks great.


Because he still needs a place to hide the sub. Because he likes the look of an inset screen, and because he wants the flexibility to upgrade audio if he ever wanted to.

We thought about it and I even have some posts on this forum about it but once we saw that theater build with the shelves we thought it looked nicely finished. Better than just a blank wall with 3 speakers hanging on it. Plus, they hide the sometimes awkward looking vertical center if that is what we decide to go with.

The wall will be black so there would be no need to paint.

What speakers are you using for your mains paired with the m2s?
M80s. I couldn't resist.

If the walls and shelves are black and he gets black speakers, I don't think that he will need the screen. He could always start without and put it up if needed.
 Originally Posted By: Micah
One question, I thought I read in here somewhere that the QS8's should be 2 feet from the ceiling, is that correct?
Judging from Axiom's own ceiling mount brackets for the QS8s, it looks like you only need 5-6 inches....mine are about 1 ft. but it's possible that some people preferred the way they sounded with a little more space above them.
© Axiom Message Boards