LSIM 702 F/X Atmos Confuguration

sethgoosesethgoose Posts: 1
edited May 2018 in Speakers
I haven’t been able to find a discussion on this, so decided to finally create an account after years of lurking. I have a 7.1 setup with 707 fronts, 702 f/x sides and 703 rears. I am installing 4 C34E Atmos speakers next week and have a few questions.

1) Instructions say to mount the 702’s 6-8 feet high, but Dolby says to mount surrounds at ear level or slightly above for Atmos. Will this mount height work okay with these speakers?

2) Are these considered dipole, bipole, or what? I know Dolby frowns on dipole and bipole for Atmos.

3) For best Atmos performance, should I offload the 702’s for two more 703’s, or will it make a significant difference? Or should I consider moving the 703’s to side surrounds for better object location and move the 702’s to the rear?

Or am I just overthinking all of this and will be perfectly fine with what I’ve currently got set?

Thanks for any thoughts or insights!


  • shsshs Posts: 59
    I have been running LSiM 705s for left and right front, a 703 for center and 4 702 f/Xs for the surrounds. The surrounds were all about 8’ high with the side surrounds located slightly behind the Main Listening Position (MLP) at 120° and the rear surrounds about 6’ apart on the back wall above the sliding double pocket doors we use to enter the home theater.

    Then I got the upgrade bug and decided to go for Atmos. As you know, monopoles are recommended for Atmos, The 702F/Xs are monopole speakers designed for mounting on a wall with a bass driver in the center firing straight ahead, and the midrange and tweeter firing at about a 45° angle with left and right versions. It is therefore critical that you take off the grill and see which way the midrange and tweeters are pointing when placing them on the wall. You obviously want the drivers firing towards the MPL.

    When I went to convert the home theater to Atmos, I had to bring the 702F/Xs down to just above ear level and think carefully about their placement. The Atmos specs allow a range of placements for the side surrounds of 120-80° relative to the MLP, but many feel that to maximize the separation of the side surrounds from the rear surrounds, that placement at 80°, or just forward of the MLP is best. I tried 3 different placements from 120-80° at ended up at 80°, with the midrange and tweeter firing back at the MLP and second row of seats. The rear surrounds went just each side of the pocket doors, again just above ear level.

    I struggled with what to use for the Atmos (ceiling) speakers but settled on the Polk TL3s mounted near the ceiling with OmniMount speaker mounts that allow the TL3s to be aimed at the MLP. Since the TL3s have the same tweeter and a similar midrange to the LSIMs they blend very well or, as the say, are timbre matched. The TL3s are tiny and cute but will pack a punch if asked. If a larger version with the right tweeter becomes available for Atmos use, I may upgrade, but for now, the TL3s do the job and the whole system sounds incredibly good.
    SONY VPL-VW385ES, Da-Lite 92" 0.9 HD progressive 16x9 screen, Apple TV 4K, Oppo UDP 203, Anthem AVM 60, D-Sonic 4000 (800x3, 400x4) for bed layer, 2 Crown XLS 1002 (225x4) for Atmos; Speakers: Polk LSiM 705s, 703 front, 4 702F/X surround, 4 Polk TL3 (Atmos), Velodyne DD15 Subwoofer.
  • adabroadabro Posts: 215
    Thanks for the post shs - I'm moving my whole setup to a new room and may expand it a bit, maybe I'll test out Atmos with the TL3's. I'm using LSiM's, but don't want to spring for another pair
  • mrlorenmrloren Posts: 2,326
    Surround speakers sound best at or near ear level. Adding atmos is best to have in-ceiling speakers if you can. I've seen a few who use a small speaker pointing down to the listening area, not bad at all. A friend who rents his house and can't wall/ceiling mount anything just pointed some small speakers to bounce the sound off the ceiling. Actually works very well.

    Thing about atmos and DTSX is it adds space with a height dimension. Flying and a lot of water seen's are awesome.
    When I was a kid my parents told me to turn it down. Now I'm an adult and my kids tell me to turn it down.

    Family Room:
    Samsung UN75RU710DFXZA,
    Denon AVR-X4400H, Emotiva XPA3 GEN3
    Oppo BDP-93,Sony UBP-X800BM, WD Live HUB.
    Main: Polk LsiM 705
    Center: Polk LSiM 704C
    Front High/Rear High In-Ceiling Polk 80F/X RT
    Surrounds: Polk S15
    Sub: HSU VTF3-MK5

    Bed Room;
    Marantz SR5010, BDP-S270
    Main: Polk Signature S20
    Center: Polk Signature S35
    Rear: Polk R15
    Sub: HSU STF-2

    Working Warehouse;
    Sony 2100ES AVR, Sony DVP-NS3100ES for disc
    Cerwin Vega AT-12 (blasters) Advent Prodigy (listening)
    Old sony 12" Sub
    Mini tower PC with 400GB of music
  • shsshs Posts: 59
    In my case, I wasn't sure that my acoustic ceiling would be a good place to mount my Atmos speakers. By mounting them high on the soffit and pointing them at the MLP I was able to experiment with placement, just like I did with the side surround speakers.pd0h5tm9bhpa.jpg
    SONY VPL-VW385ES, Da-Lite 92" 0.9 HD progressive 16x9 screen, Apple TV 4K, Oppo UDP 203, Anthem AVM 60, D-Sonic 4000 (800x3, 400x4) for bed layer, 2 Crown XLS 1002 (225x4) for Atmos; Speakers: Polk LSiM 705s, 703 front, 4 702F/X surround, 4 Polk TL3 (Atmos), Velodyne DD15 Subwoofer.
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