Axiom Home Page Forums General Discussion Home Theater VP150 as left, right, and center?

Hay Ya'll,

I've started researching speakers for my HT and I was wondering what you all thought of using 3 VP150s as left, right, and center speakers. My situation is this: my screen wall is 11 feet wide and I want to use at least 120" of that width as viewable screen area (Da-Lite High Power is the planned screen). Add 3" borders to each side and that only leaves me with 3" wall space to the left and right of the screen. So I was thinking about putting all three speakers above the screen. The next problem is that my ceilings are only 7 feet high, so speaker height comes in to play. I could probably drop the screen as far as 12" below the ceiling, which greatly opens up possibilites for other speakers, but thinner speakers up there would give greater flexibily in screen height placement. Any suggestions and comments would be appreciated. Thanks.


--James

Hi James,

In principal I think this works nicely. There are a lot of HT systems with 5 identical speakers and a subwoofer. But 2 things come to mind.

Don't know how big your room is or how far back you will be sitting but you may wnat to see the guidelines for viewing distance vs. size of screen in the Newsletter section of this site. If the screen is too big adn you are sitting too close you can see pixelation and you will have to move your head to see the whole screen. If you decided on a smaller screen, I would think about floorstanding sides.

Floorstanding speakers have a frequency response which goes lower than the VP150, some people claim this is nicer for music. The side channels play a lot of music even in movies. The VP150 is -3dB down at 85 Hz and the typical crossover for the subwoofer is at 80 Hz. I think it is debateable whether you will hear this when using a subwoofer, especially for HT.

Hello James,

Excellent advice from Speakerchooser and here are a few tips from me. Generally speaking, if you are viewing true HD material, you should sit no closer than twice the diagonal screen measurement. With DVDs, they look better if you are a bit farther back than that distance. Of course, most projectors have some zoom flexibility so you could reduce the image size somewhat to compensate if you can't sit farther back.

When I joined Axiom, I did elaborate listening tests and comparisons of all Axiom's models. During that time, I tested a VP150 and just for the heck of it, I tried it on its end in mono. I was surprised at how good it sounded and mentioned in a meeting at Axiom later on that we could sell it to use in a vertical orientation for special installations (it wasn't designed to be used that way but it just happens to sound very good).

Regards,

Pictures might help a lot with this situation. Are you sure you can't squeeze speakers on the side of the screen or have floorstanders in the front a litle bit?

How can I attach a picture to my post? Or put a picture in my post? Once you see the effect I'm after, you'll see that squeezing speakers on the sides would mean that they'd have to be really narrow speakers. And I've thought of setting them in front a little bit, but given that the screen will be nearly wall-to-wall, I wonder about someone sitting to the extreme left or right and having an ever so slightly obstructed view with the speaker just clipping the viewing area from that perspective. As far as the 120" wide screen requirement goes: it's just that, a REQUIREMENT! No compromise. Full stop. End of story. I realize I might be making things a little harder than what they need to be, but I'll work around it. I'll git r' done.

The Faqs will explain how to post a picture.

The VP150 is -3dB down at 85 Hz and the typical crossover for the subwoofer is at 80 Hz

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It's interesting. If you look at Axiom's own graph for VP150 it looks like it's -3 dB down at fc=100Hz rather than at stated 85Hz. I wonder if Alan can comment on that.

In addition , some recommend to cross at frequency about twice fc to get a smooth transition to sub. Overall, I would think that the sound quality will be sacrificed by not going to towers.

Get yourself some cardboard and make a box the size of an M60. Your projector's image is coming in at an angle and should miss the speaker. Sit in the side position and check it out. The floorstanders give a different sound you'll want for HT.

Okay, let's give this a try:



This picture was taken from my seating position 15 feet back. As you can see in the pic, the viewable image is nearly wall to wall (and for me, THAT'S home theater). I'll shrink it a little to accomodate borders, but as I said, 120" wide looks good to me from 15' back so I don't want to go smaller than that. In the image shown, there's ~13 inches between the top of the projected image and the ceiling. That's what I'm trying to work with, but...

...maybe I shouldn't have been so firm in my previous post (you know, "end of story" and all that jazz). I realize that shrinking my width requirement to 9 feet opens up a whole lot of options regarding tower/center combos. But after watching that 11' wide image for so long, 9 feet would seem downright small to me, especially with a cinemascope screen .

Oh well, my search has just begun. Thanks for the replies so far. They're very much appreciated.

That is a big picture!

How much room below?

Or maybe 60's in the space above sideways?

James, I'm curious as to what you are using for speakers right now. With a screen that big you need big sound

If you raised the screen as much as possible, how much height would you have under the screen?

When using the rated frequency responce of the VP 150 (Freq Resp +/-3db (Hz): 85 - 22 kHz) there is a 6 db "window" within the +/-3db. The graph of the VP 150 is taken in an anechoic chamber. When typical room gain is taken into consideration the VP 150 should have no problem meeting the stated specs.

May be, still kind of strange.

I mean, cover the part of the graph above 500 Hz and look at the low frequency part (that's what we are interested in). An immediate reaction would be: well, looks like the sensitivity is about 90-91 and there is an about 12db/octave roll-off with fc=100Hz.

The +/- 3dB describes some wobble in the mid- and high frequencies but I don't understand why it should change the corner frequency in the low part.

Anyway, even if it is 85 kHz, crossing at 80 would leave a dip in the overall speaker+sub responce. One should cross at at least 120 Hz.

Sorry if it comes up as some dopey arguing, it's not. I really want to understand all this stuff better.

Regards,
Gena

James,

That is cool !

It makes me want to do some shopping. I think I will move my 65" TV into the bed room.

It seems like this sight is full of audio biased people who don't care about the video. I got my TV first(fell in love with HD) and the audio was an afterthought.

But now I really think the audio, especially surround sound, is half the movie experience.

You won't go wrong with 3 VP150's but if it was me I would move the image higher( you can have the center under teh screen), make it a little smaller, or somehow accomodate M60s or M80s.

In reply to:

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I mean, cover the part of the graph above 500 Hz and look at the low frequency part (that's what we are interested in). An immediate reaction would be: well, looks like the sensitivity is about 90-91 and there is an about 12db/octave roll-off with fc=100Hz.

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I'm not quite sure I understand your concern with the roll off under the 85 Hz rating. Why would a steep roll off in the first two octaves be of concern when the 150 is typically crossed over @ 80Hz?

Hello James,

You seem to have my future problem except my pull-down screen is about 84 inches wide in a 143" wide room. My unfinished floor to ceiling height is 82 inches and once the flooring and ceiling go into place I will likely lose about 2 inches. While the room width gives me almost 30" on either side of the screen for "ideal" height placement of the speakers, the center channel will not be in-line at the same "ideal height" (my definition of ideal height is when the tweeters are about at ear level at the seated position).

I believe that in order to get a proper sound-stage, I have to keep all speakers in line. I am considering building a bulkhead over the screen that will house three in-wall speakers. The bulkhead will be built at a slight angle to aim the speakers directly at the listening area. This will also yield the benefit of better soundstage for a second row of seats.

Incidentally, are you using an anamorphic lens for you projector?

Rick,

Theoretically, it is recommend to set the cross-over at the frequency 1.5 to 2 times higher than the corner frequency. Example: for m60 fc=37-40Hz and it is recommended to cross it over at 60 or even 80 Hz. Indeed, when I set it at 40Hz I do hear the excess of 'boom'. My setting is 70z. Following this recommendation for VP150 it would result at at least 120Hz.

I have read that the crossover is recommended to go 10 Hz above the -3db point. So even going by this the VP 150 would be crossed over @ 95 Hz. Seeing that no receiver or subs crossover is a brick wall filter I would expect that even if it where to be set to an 80Hz crossover there would be no hole within the 80 Hz frequency. We also should take into account the other front speakers, even the M22s have an in room response down to 60 Hz. With that taken into consideration I don't see there being a problem.

jamesdmc,

How about 6 M3s. Two each L/C/R run in parallel for each channel. One above and one below the screen for each channel. I find that my M3s have a nice frequency range. Two M3s run in parallel have the same output as one VP150.

Add a EP600 horizontal and you're covered!

James, the answer to Dan's question would also interest me; what is the most room you could arrange to have below the screen? Tentatively I'd be thinking of three M22s at the bottom of the screen.

In its current configuration: 11.5" above; 22" below. The M22's will fit. But how would it sound having my L/C/R on the floor and surrounds above my head?

HomeDad asked: "James, I'm curious as to what you are using for speakers right now. With a screen that big you need big sound."

Darn it, I was hoping no one would ask me that question! Guys, be gentle.



In my defense:
1. I bought them when I was 19 years old and didn’t know any better.
2. I got them with a military discount.
3. I bought them when I was 19 years old and didn’t know any better.

As you can see, just by being here in this forum, I’m trying to better myself.

BruceH asked: Incidentally, are you using an anamorphic lens for you projector?

Yep, a Panamorph U50 (I think). Got it last year during an AVS powerbuy when they were introduced.

James, LOL I had them in white

This may sound silly but could you mount m22's on the wall below the screen with FMB's (Full Metal Brackets) and tilt them up toward the listening position?

James, the M22s should work very well in your situation, possibly with a slight tilt backwards so that the tweeters point at your ears. If what you mean is that the surrounds will be maybe 3' above ear level, that's no problem, it's supposed to be that way(I assume that you didn't mean that they'd be directly above your head).

Alright, I have been thinking about this some and I think I have thought up a winner. Possibly.

Raise the screen as much as possible, leaving maybe an inch from the ceiling.

The M50's will just fit below, they are 35 inches high, and you have 33 inches. Part with 2-3 inches of height on your screen, and they can fit. The 2-3 inches you can part with on your screen will GREATLY increase your sound quality. The margin of video size you are going to lose vs. the margin of audio quality you will gain will be great.

Anyways, I would suggest the following options:

1) 3 M50's across the front, including the center (You have the room, so why not)

2) 2 M50's and 2 VP150's. Here is my idea: You can have one center like normal, just under the screen. And since you have raised the screen far up, you could have the other VP150 ceiling mounted, pointing a little down about 2-4 feet forward from the screen so it doesn't block the projected image (assuming the projector is a little lower to the ground). Since you already have a VP150 below, it will create a great effect of the sound coming from the center of the screen. I think it would sound fantastic. If your projector is close to the ceiling, forget that idea.

3) Don't lower the screen and use M22's for L/R and use one VP150 above and one below the screen.

4) Don't lower the screen and use 2 M22's, 2 W22's (the in-wall version of the M22's), 1 VP150, and one W150(the in-wall version of the VP150). The W22's would go horizontally above the screen in parallel with the M22's. The reason I recommend the W22's above the screen is because if you put M22's above the screen, the porting would get blocked by the wall, which would hinder the bass output. The W22's have porting on the bottom (or in your case, the side) which will allow them to easily be mounted and have room for air to flow in/out of the ports. The center channels do not have porting, so you could put a VP150 above the screen if you could manage it and save a little cash.

If I were you, I would go with the 4th option. That would be...AWESOME to say the least, Everything would sound like it was coming from the screen! And, best of all, you could have your screen the full size like you want. The W (Architectural Series) of axiom speakers sound just like their other non-in-wall counterparts, if you were wondering.

Anyways, that would be a really, really...reaaally sweet setup if you went for that. It would sound just like a movie theater.

Wow Dan, you really have given this some thought! I've spent the last few days playing around with screen size, screen placement, and exploring other options in speakers. Its basically down to Rockets and Axiom. From the Axiom side, I'm leaning toward using either 3 M22's below the screen or 2 M22s L/R and a 150 center below the screen. However, I have concerns about the rear porting of the M22's. How far from the wall should they be? Snakeyes asked a question I'd like to know the answer to: "...could you mount m22's on the wall below the screen with FMB's (Full Metal Brackets) and tilt them up toward the listening position? " Will mounting them on Full Metal Brackets put them too close to the wall?

James, if you'll have room for an M22 in the center there's no good reason not to use it and have identical speakers across the front. As long as the rear port has at least 3-4" of "breathing room" there's no problem. I don't see any reason for adding the complication of a wall bracket instead of simply putting the M22s there and using something as a wedge under the front to tilt them back slightly.

I just had to post this. Never really got a chance to listen to the stereo VP100 system but I bet it would have sounded OK. Having said that, I would probably go with M22s for the sides anyways...

Yea, the VP100/150 are not ported in mind that they are going to be in tight spaces above TV's and such.

If you have the space behind it, you should go with the M22's all across the front.

In reply to:

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If you have the space behind it, you should go with the M22's all across the front.

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I agree. Sonically this would be the best option. With a great subwoofer and the QS8s, the system would be outstanding.

And, just a reminder, buy the speakers you want from axiom.

If you don't like them, you can send them right back no questions asked.

And, if you move your screen up and have your M22's right under the edge of the screen (horizontal if you want) I doubt you are going to feel something lacking if the voices aren't coming right from the center (vertically) of the screen, especially if you are sitting down low in your chair. Putting the screen and the M22's as high as possible will do just fine.

P.S. You could just splurge, leave about 10 inches or so on each side of your screen, and get some m80's. You would thank yourself for it. :-P


Good luck!