Axiom Home Page Forums General Discussion Home Theater HT Mains Setup Quest-Help!

Well,

After much research and study, I'm ready for the warmer M3's for the fronts and QS4's for the surrounds, but have become indecisive (see display) as to where to mount the mains. I'm trying to get ahead on the install (wiring\shelving) in my "Theater Room" (actually a great\family\entertainment room) of the 5.1 SS system (EP500 already in the house), in particular the fronts L-C-R, and am curious what you might suggest!

After 9 months of searching, I finally found an Entertainment Center that fits my big 67" DLP. Actually, I had to shim the left\right piers 1\8" on either side to get it to squeeze in, but it really does fit the display...Like a Glove!

Here's a pic with the new home entertainment center in place along the 20' wall. With the double doorways, there's 2' on either side for corner placement of the mains. As the center speaker will be mounted on top the EC, shelving in the corners (to be installed at the same 7' height) to support the mains could help project the sound-stage above the room decor (couch, chairs, etc.).

However, I wonder how the L-C-R fronts would sound-stage with all 3 set on top the entertainment center, with a total spread between the mains of about 9'. This would be simple and easy, but do you think the idea of corner room shelf placements for the mains would work\sound better for this room, in particular with a rear-ported enclosure (M3's)? My listening\viewing position is about 18' away. Neither setup scenario will be a great solution for music, but should work well for movies (95% of viewing\listening).

Rest of the room (4840cf) can be viewed by clicking on the posted image!



Any comments or suggestion would be greatly appreciated!

Thanks,
Ted

p.s. Please, no "cube" flaming...they just came with the house...ready to upgrade my 5.0 audio-In a Big Way!

Hi Ted,

First of all, that's a very nice, clean-looking room. I love the hardwood and the high ceilings.

Placing the M3s on either side of the doorways puts you at the sweet spot of an almost equilateral triangle 18 feet away. You can't get any better than that. Just make sure you toe them in a bit.

Your ceilings appear to be about 12 feet tall. You'll have a direct acoustic path length of 20 feet from each front and a reflected path length of about 28 feet from the ceiling. This will give you a reflection delay of about 7 msec and a reflection level of -3dB at your sweet spot. This is wonderful because that ceiling reflection will result in some image broadening when you are listening to stereo. Don't you dare treat that ceiling . And ditto with the floor.

You also don't need to worry about any reflections from your side-walls. Given your room dimensions, the reflection level will be low enough and the reflected path lengths large enough so that direct and reflected wavefronts will almost be perceived as a single sound to your ears. You will experience some perception of spaciousness but not large enough to create an echo.

Another advantage with the reflected sound is a reduction in the amount of power that you will need. You will probably be fine with a couple of watts nominal.

Given the width of your room, you'll have a first mode at 28Hz. The height of your room will result in standing waves at 47hz and its multiples. And it looks like your room is 30 feet deep giving rise to modes at 19Hz multiples. At your sweet spot you'll likely be immune at the low end but will start experiencing cancellations above 100Hz.

You may want to think about corner treatments in the future and maybe some treatments at the front and back. I would discourage you from treating the sides though as that will add expense and possibly require a power increase for no good reason.

Ted, the simplest answer is try both locations.
With all three speakers in the centre you may find the imaging is too collapsed in the middle but with both L&R out far to the sides, you may have to play with your seating distance to ensure they blend well with the centre channel to produce a seamless soundstage up front.

Reflections, reductions, distance calculations, room treatments can drive you crazy and may not produce the effect or sound quality one desires though they can provide you with a good starting point for ideas and concepts.

Your room is huge, no doubt. With speakers that small, and less efficient than full size towers, i suggest you buy as much power as you can afford in a receiver or amp. There's nothing more aggravating than having little sound come out of little speakers because the amp cannot provide enough power reserve at higher volumes.
If you had the option, i would personally consider buying the M50s or M60s and putting them in the corners on platforms.
Having tried the M22s in the past, i know i would not prefer such a small sound if i were sitting at 18' away. Heck, at 12' sitting distance i wanted something more full and robust, but that's just me.

The image will definitely be too collapsed with the speakers on the EC.

Ted, although you studied this carefully, it isn't clear how the answer came out M3s, since your room is bigger than average and you're going to be sitting an unusually long distance back. As chess commented, the M50s might have seemed a likely candidate if you were looking for the slightly more recessed M3/M50 sound rather than the M2/M22/M60/M80 presentation.

Nevertheless, if you do proceed with the M3s, the location just a foot from the corners should be significantly better, as Mo explained, since you'd have close to the generally suggested equilateral triangle arrangement with the mains being separated about as much as your listening distance from them. Mounted that high it ordinarily might be suggested that they be angled slightly downward so as to have the tweeters pointing at your ears, but that may be unnecessary because of the sitting distance, especially if they're positioned upside-down. If they're on shelves, have them forward enough so that they're at least even with the front of the shelf, to minimize reflections and refractions.

Ted, you're already getting great help from three of the big dogs, so I'll just say wow, nice room.

I've been called a top dog but never a big dog .

Thanks Mojo, Chess, John and CV,

I really appreciate the great help from you guys!

Sorry I didn't clarify details better, but my room is 20'w x 22'd x 11'h. I have the Emotiva UT Series separates (LPA-1\LMC-1) and the EP500 along the left wall, under the side table.

My reasons for choosing M3's:
1. Smaller Size (WAF-She happens to like the cute little cubes...Go Figure)!
2. On a shelf 7' up, the sound stage should be well above room decor and even with the center. None of the towers are tall enough and stands wouldn't meet the WAF certification!
3. Actually, the Bose already project a very large and loud (100db+...with the Emo's) sound stage for movies, but they really *%&#@ with music.
4. I expect the M3's to be Light-Years ahead of the cubes in accuracy and output, thus satisfying SHMBO and ultimately, me!

I will probably experiment with the L-C-R arrangement on top the EC, but also feel the sound stage may be too collapsed, especially considering our sitting distance. Guess it's time to install the corner shelfs and run C3 speaker wires through the walls.

I'm also considering several m-t-m designs from Emotiva, Ascend, AV123 and eD, but the M3 is my #1 bookshelf choice!

Heck, I just may have to have my own private "Shootout"!

Anymore suggestion\ideas are very welcome!

Ted

Ted,

Any idea how much you have to crank the Emotiva to get the 100+ dBs with the Boses? Any idea what the power level is? And are you referring to stereo or 5.1?

I'm really not surprised about this. It would just be interesting to know the above.

The Axioms will make a huge difference especially in the midrange. Right now, you've got no midrange to speak of. Those cubes are probably ok between 1000 and 7000 Hz. And your bass is probably ok between 60Hz and 250Hz. About 70% of the musical spectrum is being lost with that system.

Theo,

If you are stuck on bookshelves, I would highly suggest the M22s. I believe the M3s would blow if you push them too hard in your room size.

The M22s will provide more output than the M3s, and thus higher volume. I did not read the entire thread of everyones suggestions, so I apologize if this has been repeated. I would suggest M22s mounted on the very sides of the room (in the corners) which will (like Mojo & JohnK said) give you almost an equilateral triangle.

It will also provide more of a wider soundstage than just sticking the speakers on top of the unit. If you are able to mount your speakers, this would be the best choice IMHO.

Ted,

Nice looking room. I can understand why your wife doesn’t want to clutter it up with speakers. If it were my room, set up as shown with the entertainment center you have and furniture arrangement, I’d have a hard time figuring out what to do to get optimal sound but yet maintain the flow of the room. Bad news is your entertainment center is too dam big. It leaves you with few options to work with. I can understand why you have cubes where they are. I was looking at the EC thinking how you could modify if and place some book shelves in it, but I’m drawing a blank, and I’m pretty good at coming up with innovative cabinetry designs.

I think your only option is to go with speakers in the corners of the room. I would ditch the book shelf idea and go with M60 towers. I would take some close up pictures of the entertainment center and floor, and send them to Amie and ask her to send you some wood samples that would match the entertainment center, or possibly the floor (depending on what you wife thinks would be the better match). When you get them, you could then involve your wife and figure out which species of wood, which stain color and what finish would be the better match.

I suspect that if you take this course, you and your wife will enjoy the end result much more than trying to compromise and screwing up the flow and overall, very nicely decorated room. A set of real wood speakers with a nice piano finish looks more akin to a fine piece of furniture than an ugly misplaced obstacle.

Plus, when you get the bosses buy in, you can typically buy more stuff……(it’s that whole inclusion thing)

Ted,

I second what mdrew is saying here. Believe me, my wife and I have butted heads whenever I tryed to add anything at all to the home theater/living room. But, trying to get wood samples so that the towers match the entertainment center is the best compromise. Be persistent, you will thank us later. If you just give in then you won't be as happy in the end, due to the size of your room.

- Nick

Mojo,

Power levels, hmmmm? With most of my 5.1 HD-DVD movie soundtracks, dynamic music\sound effects will hit clean 100-105db peaks, with nominal averages of 80-85db reference levels. This equates to a pre-pro (LMC-1) setting of about 45-50 on it's scale of 0-80. I use to hear my Sony ES 100-watt receiver strain, become compressed and harsh trying to achieve these levels. But the UT Emotiva setup Remains clear, uncompressed and Always musical and dynamic! Even though the LPA-1 is just 25% more rms power (<1db), I clearly discern 5db-6db more of dynamic and open headroom (big power supply)!

As far as midrange, the cubes are eq'ed by the acoustimas module. I've been around stereo a long time (ADS studio monitor systems, Paradigm, Boston Acoustics, Pro Hafler, HK) and I've not found any drop outs with the full range cubes, just lack of detail, clarity and extension. The EP500 SURE livened up the bottom end, though!

Robb,

Thanks for the suggestion, but I've heard the M80's in a big, well setup room with Great power, but didn't care for their top end signature (sibilant, bright and fatiguing). Since M22's & M60's have similiar signatures, thought the warmer M3's (similar to M50's, but will fit in my room best) should work just fine. If the Bose can fill the room, for sure 5-M3's should blow them away!!

Mike,

Appreciate the very kind comments, we both love the great room. Yes, the EC is big, but that is what we wanted to fit the large display, hold all the gear and hide 500+ DVD's (still need to modify the L\R bottom cabinets). Your "custom speaker" suggestion is a great idea, certainly could help the HT blend in with the room decor! Seems you too understand the "SHMBO" survival slogan real well.

Nick,
DITTO!

Thanks for the great inputs,
Ted

I think you're making a great choice with the M3s particularly given your desire for a more "laid back" sound.

The previous comments on color-matching are excellent given your room decor.

I'll have to think a little about the comments you made on power. I don't know what those settings mean in terms of total power out.

Ted,

One note on your ‘bright’ comments. I have no intension to get into that debate (it’s long since bored me to tears and I care not for discussing again), but I will say that I also found the M80’s to be a little bit too forward. I installed some resistors that Axiom will send you if you ask. Problem went away. (they lower high freq a tad) After a year or so, I moved them to another room and found that the high’s were now missing some, so I pulled the resisters out. It sounded better to me, but still just tad too forward for my tastes. I threw a big assed wool rug down on the hardwood floor in front of them and now love the sound. The key word being “wool”.

So before closing the door on the M22/M60/M80 siblings, I suggest you play with room treatments first and if that doesn’t work, ask for and install the resistors. I would even bet that if you ask, Axiom will send you the speakers with the resistors installed. (this company is unbelievably accommodating to their customers wishes).

I suggest that you not go with M80’s in your particular room because you will have to tuck the speakers into the corner to not interrupt the walkway in/out the doorways. M60’s are a lot more forgiving with corner placement than M80’s. Or, I should rephrase that to….M80’s are finicky to where you place them.

Good luck with the boss.

Did you install one resistor per tweeter on your M80s?

Since the 15dB peaks require 1A @120V, that's 120W. And if the amps are 70% efficient, that's 84W going into your two fronts and 36W heating your room.

So if at 85dB the power is P, at 100dB the power will be P + 84. 100dB requires 32 times the power compared to 85dB. So, P + 84 = 32P and solving for P gives 2.7W. So your nominal power is a few watts like I estimated before.

So when you get your Axioms, are you planning on an A/B test with the Bose?

I wasn't sure if Axiom gave you one resistor per tweeter or one resistor to connect at the tweeter output of the cross-over.