Axiom Home Page Forums General Discussion Home Theater QS8s at ear level for surround only in ATMOS setup

Hi everyone,

So if I'm understanding this thread correctly, you're all saying that QS8s are a bad idea if you plan to go with an Atmos or DTS:X setup, and that direct firing surround speakers are actually better?

I'm seriously considering getting LFR1100s for the fronts and QS8s for the surrounds, which would be on stands at approximately ear level, but now I'm concerned that it wouldn't play nicely with Atmos and DTS:X...

It certainly seems Dolby had monopoles in mind when creating Atmos, with the potential for more precise placement of the audio objects, but I'm still looking forward to reading impressions of experimentation with alternate setups.

However, if you're starting from scratch and are gearing your system toward object-based home theater applications, I'd probably go M22s all-around, wait a little bit to see if they update the in-ceiling speakers at all, and put the money saved from the LFR1100s toward an EP800 or two, assuming you don't have your subwoofer situation settled. How would the rest of you do it?

But don't forget to budget for your 4K TV that does the REC2020 Wide Gamit. Then you will need to make sure that your receiver properly handles the HDMI2.0 and HDCP2.2. What about Dolby Vision support??

I agree with CV, nobody knows if the QS series surrounds won't sound pretty good with Atmos or DTS:X. Yes, Dolby and DTS specs state that all speakers should be monopole for best results. This makes a lot of sense from a physics perspective...

Think of every monopole speaker as a laser (I know, sound waves expand as they get further away from the speaker, but just go with me on this). Now, lets say that you need to have a sound object appear to the right of center, but to the left of the right speaker (basically between the center and right speaker), but about 2 feet overhead and half way between the front speakers and your ears... So take that "laser" from each speaker and make a line to that exact spot that the sound object is to come from. They all come together in a point. Now again, sound isn't pin-point like that, so look at the closest speakers to that point, since they can't be laser focused, the closest speakers will play the sound louder and the further away you get from that point, the sound coming from those speakers will be quieter or even non-existent.

So now take an amazing quadpole (or di/bi-pole) surround speakers. They broadcast a very, very wide sound field up/down/right/left and this makes it have "4 lasers" in our scenario, but none of them are pointing *into* the room. Thus the speaker needs to increase volume of a particular sound object to get it into the 3D sound field of your room, the problem is that when it does that, it also shoots that sound out on 3 other directions that you don't want it to.

Again, not saying that it is *that* bad, and I am using the idea of a pinpoint laser to represent sound waves that aren't pinpoint, but hopefully this goofy scenario example helps to show why monopole perform better for creating objects, but unlike my example, we don't know how quadpoles will work in real world Atmos setups.

So if you are wanting Atmos at some point and are starting from scratch, I would go with monopole speakers all around. I really like my M3 on-walls for surround duty and their frequency range. They are a good match to my M60 fronts.

Nick the problem I see with your scenario is that a speaker is more like a flashlight. And given the speed of sound vs the size of the room along with both early and late reflections your theory may have some holes in it. Our ear/brain is quite good and gathering what it needs and rejecting what is not needed. On a strictly theoretical level what you posit would make sense but if you are sitting on the right side of the room when the right speaker produces a sound you are unlikely to hear the direct sound and more like to receive a reflected sound especially with higher frequencies.

This is just how I see it and maybe I am out in left field I doubt I will ever be able to test this theory but maybe one day when your up and running you can give us some real world feedback. I do get what your saying though, probably will not work as well as direct as per dolby recommendations.

This post is speculative, so keep that in mind.

Is there a polar response plot floating around for the QS series speakers? I would guess it would be clover shaped in the nearfield. The center lobe of the clover would be from the top and bottom drivers's off axis response -again guessing.

The on axis 1w/m measurements as tested in sound and vision were very low iirc. When I asked here it was explained the db sensitivity spec was combined over a wide listening window. Directly in front of the speaker is an acoustic shadow. -guessing again.

The qs series speakers rely on reflections and boundry effect to create their soundfield. I'm not sure how this would translate into a dialed in x,y,z coordinate system like atmos etc. It's like asking a grenade to only hit one target within an area. They kind of do 'grenade' immersion all the time without specific instructions. Its good in a way if you think about it. It allows you to sit really close without a hot spot and good surround effect. But at a distance or with x,y,z instruction, they are relying on a lot of room influence to get their job done. If you arent sitting close to them, or dont have them on the wall, their response may be difficult to predict.

Thanks Socketman, yes a flashlight would be more accurate. I used the term "laser" just because we are trying to make pinpoint sound locations, or at least pretty close ones. I did, as you will read, note that sound is obviously NOT laser precise and that I was just trying to make a visual picture.

Again, I also continue to tell people that what I am talking about it purely "ideal" conditions as directed from Dolby, and the somewhat limited DTS information. We rarely live in that ideal space in our listening rooms, but that doesn't mean that we shouldn't strive for the more "ideal" instead of starting with a "compromise" as the starting point.

Exactly....

Sorry for any snippy tone in my posts. It is Monday, I am at work dealing with morons, and I have been running on hardly any sleep for the past 2 week, plus sick for the past 8 days.

A quote i really liked was "Morons, they come a dime a dozen. I want to know who is supplying all the dimes?"