Advice on dual Sub use in Atmos

User16905742007233904949 (Qualified Sound Studios) asked a question.

August 22, 2023 at 9:00 AM

Hi, I wonder if people can assist. I have an Atmos system going in and I need to think about bass management. Currently I have a Genelec 5.1 sub, which has 5 channels I can use for bass management. But obviously I would be short for my 7.1.4 setup. So would I be able to use a second sub to take care of the tops and one of the rear speakers. 2 subs would give me 10 channels, but I would have to place the subs in the room separately. I can’t afford the other alternatives at the moment, like a JBL Intonato, but would this 2 sub idea cause acoustic issues? Being that bass is omnidirectional, would this really matter, would there be issues?

I will have sonar works doing the lifting when it comes to room tuning etc. anyway, any help would be appreciated! Thanks! See my drawing re how I planned to use my speakers with the subs

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AdamP (Dolby Labs)
3 years ago
Hi, Using two sub for bass management of different sets of speakers is viable but in your explanation I'm not seeing where the bass management for the overheads and surround speakers would come from. While low frequency is more omnidirectional, low pass filtering introducing phase shift which make placement of subs tricky to avoid exciting room nodes and cancellation at the mix position. I'm not sure Sonarworks would be able to address this with two subs. That is probably a question best directed to them.

Best,
Adam
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- User16905742007233904949 (Qualified Sound Studios)
  3 years ago
  Thanks so much for your reply!
  
  Sorry if I wasn’t too clear, so the L, R, LS, RS, LRS, would be in sub 1. Sub 2 would have LTF, RTR, LTR, RTR, and RRS. I would drop the centre channel from using any bass management as I won’t be using that channel for much in reality. The subs would strictly handle bass management via the internal crossovers in the subs. The LFE channel could be used on one of the separate LFE channels in the subs, but generally I won’t be using that much anyway. As far as I can tell Sonar works can handle several subs, but being this is bass management I might set it up as a .1 system, that being the LFE channel.
  
  So doing it this way, would the phase shift of the overheads (being managed on a seperate sub) be problematic with the lateral surrounds on a second (different) sub? These are small subs, Genlec 7050c’s, so that can be placed quite close together or in different locations in the room. I have the ability to move them and generally get a good position.
  
  Thanks!
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