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  #1  
Old 06-26-2019, 01:03 PM
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antonis antonis is offline
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Default Dolby Atmos Ceiling Speakers - Rear vs Front Ported Speakers

I am just about to complete the installation of a Dolby Atmos rig in a small room (tracklay and possibly premixing).

I am typing this a bit on the hoof here (I can give more details, dimensions and so on) but my query has to do with the ceiling speakers. I am about to install four Genelec 8020a's which are rear ported and due to the room dimensions (very high ceiling) I am not sure they are ideal.

I am thinking of buying customised ceiling acoustic panels that allow the Genelec ceiling mounts to go through them. But I do have a few older 1029a's sitting in a cupboard which are are front ported.

Any advice?
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  #2  
Old 06-26-2019, 01:44 PM
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Default Re: Dolby Atmos Ceiling Speakers - Rear vs Front Ported Speakers

Quote:
Originally Posted by antonis View Post
I am just about to complete the installation of a Dolby Atmos rig in a small room (tracklay and possibly premixing).

I am typing this a bit on the hoof here (I can give more details, dimensions and so on) but my query has to do with the ceiling speakers. I am about to install four Genelec 8020a's which are rear ported and due to the room dimensions (very high ceiling) I am not sure they are ideal.

I am thinking of buying customised ceiling acoustic panels that allow the Genelec ceiling mounts to go through them. But I do have a few older 1029a's sitting in a cupboard which are are front ported.

Any advice?

This guy has done several rooms for me and it the best IMHO. Does a lot of composer friends in LA also. Big time and small time people. He is expensive, but is worth it if you need a good person. G

http://bobhodas.com

Also my friend Chris Huston, a legendary engineer and producer, is also a fantastic studio designer. Check out HIS portfolio. You can use my name Greg Ives to access him for a consultation. VERY easy to talk to. Maybe try him first.

http://www.hustondesigngroup.com
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Old 06-26-2019, 02:49 PM
quadraphonics quadraphonics is offline
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Default Re: Dolby Atmos Ceiling Speakers - Rear vs Front Ported Speakers

This might not be a big issue. The HT RMU software has the option of setting bass management up. The frequency of that would really nullify the effect of the rear port.

If you are not going to use bass management for those speakers, the rear port will only become an issue depending on how close they are to the ceiling. There is some conflicting information on this, but recently I have seen more than a few acousticians mention that you can place the speakers nearly flush with the wall (or ceiling in this case) and be mostly fine.

Randall


Quote:
Originally Posted by antonis View Post
I am just about to complete the installation of a Dolby Atmos rig in a small room (tracklay and possibly premixing).

I am typing this a bit on the hoof here (I can give more details, dimensions and so on) but my query has to do with the ceiling speakers. I am about to install four Genelec 8020a's which are rear ported and due to the room dimensions (very high ceiling) I am not sure they are ideal.

I am thinking of buying customised ceiling acoustic panels that allow the Genelec ceiling mounts to go through them. But I do have a few older 1029a's sitting in a cupboard which are are front ported.

Any advice?
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Old 06-26-2019, 02:56 PM
BScout BScout is offline
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Default Re: Dolby Atmos Ceiling Speakers - Rear vs Front Ported Speakers

Rear ported or front ported won't matter as long as give about 4" behind the speaker (and the genelecs can be mounted on threaded rod to put them on the ceiling.) Just remember that ports aren't directional "speakers" -- they operate at omni frequencies. You just need to make sure they are clear of obstructions so the air is not blocked off or create port noise (chuffing) from air turbulence hitting the rear surfaces. 4 inches is more than enough for any port to work fully.

However, the 8020 most likely is not close enough to any Atmos spec for output level or FR. If you have a high ceiling, that output level is going to be even more of an issue.
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Old 06-27-2019, 07:06 AM
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Default Re: Dolby Atmos Ceiling Speakers - Rear vs Front Ported Speakers

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Originally Posted by BScout View Post
Rear ported or front ported won't matter as long as give about 4" behind the speaker (and the genelecs can be mounted on threaded rod to put them on the ceiling.) Just remember that ports aren't directional "speakers" -- they operate at omni frequencies. You just need to make sure they are clear of obstructions so the air is not blocked off or create port noise (chuffing) from air turbulence hitting the rear surfaces. 4 inches is more than enough for any port to work fully.

However, the 8020 most likely is not close enough to any Atmos spec for output level or FR. If you have a high ceiling, that output level is going to be even more of an issue.
Agree, the 8020´s are not ideal to meet Dolby specs. We just recently completed a new room and installed 8330´s with a 7360 sub for bass management of those ceiling speakers. We opted for the Genelec short ceiling mounts and the rear ports do not pose a problem as the mounts are about 15 cm from the ceiling. We use acoustic tiles on the ceiling. On the mounts area, we however had to install wood tiles, but are not having any problem with it. Our ceiling is about 3.20 meters high. Its a false ceiling, as the room has in fact around 5 meters. If going Genelec, I would recommend to install SAM speakers so that you can run GLM for small corrections, speaker delays etc.
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Old 06-27-2019, 08:02 AM
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Default Re: Dolby Atmos Ceiling Speakers - Rear vs Front Ported Speakers

I am not bothered to hit the Dolby HT specs, not with this particular installation. I'd be moving this to a bigger room to do exactly that in about 9 months time. This particular room is a tad small.

I would be using the Genelec ceiling mounts, unless anyone can recommend a better alternative.

All speakers will be calibrated by the SPQ card in the MTRX. There will be a preset ProMon preset with bass management.

Good tip about the chuffing I'll think about that.
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  #7  
Old 06-27-2019, 09:01 AM
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Default Re: Dolby Atmos Ceiling Speakers - Rear vs Front Ported Speakers

This might be a good article to read for the person posing the question here:

Bob Hodas tunes studios around the world, from Sony in Tokyo to Abbey Road in London and all parts in between.

https://www.tvtechnology.com/opinion...-in-the-studio
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