Axiom Home Page Forums General Discussion Home Theater Speaker height

So I just made the trip up to Axiom last week (well worth the drive, but more on that later) and now have all my gear! The basement home theater space will soon be drywalled, and I'm now agonizing over how high off the floor to be installing my in-wall speakers.

-Ear level at the listening position is ~40 inches
-Ceiling height is ~91 inches
-Dolby Atmos placement guidlines recommend 3.9 feet (not sure if this is the height of the bottom of the speaker, or middle, or middle of the tweeter)
-Dolby also recommends that overheads be 2x to 3x the height of listener-level speakers

All said and done, this will be a 7.1.4 setup with M5HP in-wall L/R, VP180 Centre, M3 in-wall side/rear surround, and M3 in-ceiling overhead. I need to get placement right the first time, so looking for all the advice I can get!

Consider placing the tweeter at or just above your ear height when seated.

Are we talking an inch or two? 6 inches? how narrow is the sweet spot for tweeters?

A big congrats on that system. I think you got a 600v4 as well, correct?

I have zero experience with Atmos, in-ceiling and in-wall. The best advice I can give you is to mock it all up and listen to it somehow before drilling holes. I think Blair's advice makes sense for all speakers except maybe the front left and right. I've found with my M5s, tweeters at a few inches below ear height helps them disappear better without any loss of treble detail or air. At that height, images in well-recorded music appear behind the M5 (as they should) rather than at the M5. I've found that to be dependent on MLP distance. At 10' away in my living room, tweeters at ear height works but at 13' away in my main room, tweeters below works better. This may also be dependent on the different adjacent reflecting surfaces in each room.

Since you have in-walls, the above may not apply. I am really curious if your in-wall M5s will give you the same holographic soundstage I enjoy so much.

Short answer- follow the dolby guidelines.

Long answer- Post dimensions of your room with furniture intended. In order for ATMOS to work correctly many factors must be considered.

The first question should be "how tall is my seating seatback?" The minimum height of the tweeter should be so that no listener is shadowed by either the seatback or an adjacent listener.

The second question is "What is the distance from the surrounds to the closest listener?" If some are seated very close, cheating the surrounds a little higher will reduce hotspotting and give more even coverage to the seating area.

The third question is "What is the ceiling height?" If the ceiling height is proportionally low to wall height, and you have cheated your surrounds higher for the above questions, you may find angled ceiling speakers are a good choice. This way you can avoid having to place ceiling speakers more narrow than the dolby layout and reduce hot spotting in lower ceiling designs.

There are a lot of factors to consider. To do it right you really should either research a lot or start a build thread and get help along the way or hire a professional to help.

Not the geek squad at BB either....

Thanks Mojo. Yes, got the 600v4 as well. I've tried all of the speakers in my office, just sitting upright on a table, and they sound great! The M5HP's sound particularly good, and I did get a very holographic sense with just those two connected.

The 600v4 is not doing it for me, sadly. I've tried it in multiple rooms, big and small, with a Yamaha RXV479, my Denon 4500H, and even my PC speakers (Simple Audio Listen, has a sub -out RCA connection). Even with the volume knob on the sub completely maxed, and +10 in the amps, I find the output to be underwhelming, especially at the lower end of the spectrum, where action/scifi movies really go nuts. I'm thinking that a ported sub will better suit my setup.

I haven't tried the 180v4 yet, but am pretty excited to hear what it can do!

Here is the room, almost perfectly to scale (1 grid square = 6 inches).

-Room is 12'x20' with ~7.5' (91 inch) ceiling height
-MLP is 9.5' from front wall
-Circles are in-ceiling
-Side surrounds are 3' behind MLP
-Rear surrounds are 10.5' behind MLP
-Surround Left speaker is as far forward as I can get it.
-Surround Right speaker could be moved forward a touch, but I figured it better to stay symmetrical.

[img:left]https://photos.app.goo.gl/gPGhR7jJSfFSFwKCA[/img]

Are you listening to a true .1 signal or are you using music to test the 600?

bman, Serenity is a pro. He does this for a living. He can apparently work magic with rooms and systems.

There is something wrong with your 600 or maybe the sub cable. If you have the time and desire, I would suggest you try to resolve this. A sealed sub is far more satisfying than ported and that 600 should be good for 7500 cu ft rooms. There's a big difference between boomy bass and smooth, transparent, articulate, linear bass. The Axiom sealed subs are designed to be ultra-linear with high dynamic power. There's a defect lurking somewhere. That defect by the way could be your ears or your expectations if what you were used to before was boom boom.

Tried both music and .1 source material. Crossover is maxed on the back of the sub, and set to 80hz on the amp

Have you tried a pure tone? Like 40Hz? Do you have a known good sub you can try with that cable to rule the cable out?

For reference, my 800v4 is at 1/3 gain on its knob, my Onk turns it down an additional 2 dB and it shakes the whole house when called for in movies and it's freakin' amazing with music. That's in a 4,200 cu. ft. room. You'd have no idea a sub is in the system because it blends so darned well.

Yep. My cheap 50W 10" ported Polk sounds like it has better output. I'm baffled

Sub defect. Send an e-mail to Deb at Axiom explaining the above. I'd hate to see you lose out on that absolutely amazing bass.

Good call by the way on setting everything up and trying it out before sticking it in the walls.

Yep I looped her in last week.

The testing seemed like a good idea, until I cranked the volume and an M5 knocked itself over with bass output. The M3s stay put though. I'm pretty blown away by how good just a pair of M3s can sound. Even the in-ceiling ones with the floating tweeter sound great.

Yeah...that's exactly what I discovered with the M3s. And as you know, I wasn't an M3 fan. However when you set M3s and M5s side-by-side, there is a big difference in everything. The limiting factor in your system now is the electronics - and I'm not talking about power but rather finesse that only great quality electronic design can dish up. I just found that out last night.

You're talking about clean amplification? I've gotta say that the ADA1000-3 sounds great to my ears (noticeably better than my Denon 4500H when driving the same speakers). I have the space to go with separates on all channels some day (big dedicated media closet with dual 20amp dedicated circuits) being built as we speak.

Clean amplification but also clean pre-amplification. Imagine how much better it would all sound with a clean pre-amp. I very much doubt that Denon's pre-amp is clean. I know my Onk's isn't.

I now know I need to pitch my once beloved Onk over my neighbor's roof and buy a pristine pre/pro. The question is, how do I judge "pristine" from spec sheets?

I want to pair a pristine pre/pro with Axiom active speakers.

Probably true, which would explain the slight hiss I can only detect with my ear right next to the speaker. What floors me is that dedicated pre-amps cost more than receivers despite needing external amplification. I'll wait until I feel an extreme upgrade itch or midlife crisis to go that route. The current upgrade is already lightyears ahead of my old Klipsch HTIB with budget Yamaha receiver.

I know how you feel. Read my second last post right here:

https://www.axiomaudio.com/boards/ubbthreads.php/topics/431074/Re:_Out_with_the_old_and_in_wi#Post431074

Yeah, crazy how you hear new things with a better unit. And then you want to dedicate a solid week to re-listening to every song/movie you've ever experienced.

I hold Ian accountable for all this. If he hadn't invested in v4, none of us would have this problem. Wait until you get your system installed and find it's like a drug. Then you'll be cursing.

Really looking forward to the full 7.1.4 setup. I'm watching Moana with my daughter in DTS-HD MA and the sound is impressive on just two M3v4s. Atmos will be insane.

WOW. SO much chatter about this in 1 day and I missed out.

Some advice about placement. For height, up front the general guideline, as mentioned, it tweeter at ear height during listening. If that is sitting up, then use that, if it is reclined, then use that. Again that is the guideline, but as also already mentioned, experiment a little bit with that guideline. A couple of inches should be easy to mock up before cutting holes. You aren't going to go nuts with putting them drastically out of that "few inches" range.

For speaker placement, you are correct to have your overheads in alignment with your front L and R.

From there things are a bit messy. Where are your seats going to be. For traditional 7.1, I would say pretty much in line with the side left and right surrounds. Looking at your overhead speakers, I would say that you were sitting in front of the big + marked on the page.

The side surrounds should be more in the middle (from front to back) of the overheads. Now I am not saying to slide them closer to the front of the room as your rear surrounds will seem like they are miles behind you.

You want the overheads to create sort of a "box" around you, but you also don't want to give up on good 7.1 base layer audio either.

Look at this actual diagram below from Dolby. The overheads creat a box (I marked it in red) around the seating/listening area, but the side surrounds are in line with the seats themselves (marked in blue).




The next MASSIVE challenge is ceiling height.

7.5 feet is really not good. Dolby says that the minimum is 8 feet for ceilings. I too struggle with 7'10" ceilings and have moved my overhead speakers twice now to make it better.

With overheads, there too are guidelines from Dolby (and DTS for DTS:X material) about how far in front and behind the listening area the speakers should be (using angles, not measurements since each room is different). The problem is that with low ceilings, this artificially puts them too close to the listening area.

So you will need to compensate for this with a bit of math, and then some tweaks. There is an article from a well respected home theater acoustical designer that talks about how to place overhead speakers for multiple seating rows in rooms with less than ideal ceiling heights. You will see that the general idea is to angle the speakers towards the listening area. Aimable tweeters don't compensate enough for this, so I would highly recommend getting on-wall speakers and mounting them to your ceiling at an angle. This is what I did, and I recall someone else here followed my advice on this too and Axiom actually worked with them to create a bracket or something for mounting on the back.

I originally followed this set of diagrams very closely since I have 2 rows of seats. It shows the rear overheads being between the two rows of seats. After initially placing them there, I changes and put them behind my 2nd row (ceiling/room limitation only allowed them to be about 1 foot behind the 2nd row), but this was a great improvement for all seats.

Here is that article.
DOLBY ATMOS: DISPERSION REQUIREMENTS FOR CEILING SPEAKERS

I've been investigating Atmos for many years and spend over an hour just talking to the Dolby reps directly while at CEDIA 2014 where they first announce Atmos for the home and I really dove into speaker type, setup, and room needs. In the end it ended up costing me thousands of dollars to implement Atmos in additional speakers, replacing by four quad-pole QS8s with four monopole on-wall M3s for surround duty, plus getting an Anthem MRX-1120 receiver to drive them all (about the only single-box solution at the time, and 3 years later still the current flagship for Anthem with a $3000+ USD price tag). I knew that if I was putting that much money into it, I wanted it to be right, thus the massive research that I did.

Hopefully something here is helpful to you as well.

Thanks for the advice! The + is the MLP (head position at the best seat on the sectional). Sadly I can't move the left side surround any closer to the fronts because of a 6' opening for barn doors. I could move the right side surround closer, but then they'd no longer be symmetrical.

The ceiling height issue is unfortunate, but I'm hoping being just 5" shy of the 8' mark won't hurt things too badly. I did some trigonometry to figure out placement that gets as close to the ideal 45 degree listening angle as possible. My wife would balk at any ceiling speaker that isn't flush, so aimable tweeters will have to do. The only real variable I can change at this point (with speaker wiring in place and drywall going in now) are speaker heights for the speakers on the listener plane.

For the fronts, I'm fairly sure I'll be putting the M5 in walls at 51" (tweeter at 47"). Surrounds would go around 50" to keep the same tweeter height.

As long as you know that you are well outside of specified placement and the sound imaging will be compromised, go for it. Just understand that there is a lot of science into why they need to be placed in specific locations and with specific guidelines. Many "experts" say to not even both with Atmos with under than 8foot ceilings, even with aimable tweeters.

We all have limitations to work around.

My ceiling is at 79". I'm still going to do it. If the effect isn't great, it's not great.

I'm sure the effect would still be great vs. zero in-ceiling speakers.