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Contributor I
March 21, 2019

Sonos Amp LS50 Frequency Response Graphs (brightness, crossover, loudness eq)

  • March 21, 2019
  • 17 replies
  • 6986 views
I'd like to share my impressions of the new Sonos amp paired with kef LS50, id also like to share the frequency graphs i have recorded using REW to address some of the concerns on the amp being bright and the sub woofer crossover boosting the treble.

Positive:
The pair sounds good, I came from a much larger (older) stereo component setup looking to keep the HiFi sound but also have some of the always on convenience that I have found using the numerous PLAY:1s around the house. I now find myself listening to much more music as the amp is always on ready to go.

It also sounds good for TV/Movies using ARC (with my previous setup I always found the voices too quiet and i didn't want a large AVR) even with just having stereo speakers - I feed the amp Dolby 5.1 from the Apple TV4, the Amp down-mix very well to include a DSP centre channel (this sounds noticeably clearer than feeding stereo), I am looking forward to adding rear surround at a later date.

Hardware is built well, and i think the cost is reasonable - especially compared to over HiFi components.

Negative:
I am having a few issues with the remote, sometimes when changing volume, the sound changes normally but the volume OSD lags and sometimes doesn't move at all. I also checked within the Sonos app, and it does the same. I change volume and it will lag and the slider will jump to the new volume setting.

Requests:
Id prefer to have linear volume control rather than a curve, at the moment my volume is mostly set at 50% to achieve good sound. I have read that most of the power is reserved for after 50%. (Source: theverge) and this is noticeable, with lower efficiency speakers.

Id really like to either see TruePlay or even better a parametric eq/convolution ability on the amp. With everything in one box I cannot add third party room correction, so this would have to be a software add-on. This would really complete the package.

On to the Frequency Response Graphs

(Blue) LS50 + Sonos Amp (Ports Plugged) - fairly flat response, note no treble boost/brightness



(Yellow) Loudness Setting On - taken at 50% volume subtle tapered 2.6db boost to bass and treble frequencies



(Purple)Crossover (80hz)
I've seen some reports that turning on the subwoofer crossover makes the sound overtly bright - i thought id investigate.


The crossover works correctly sloping the output at 80hz however it does boost the overall sound 3db, the response above 80hz is the same just louder, the volume setting wasn't touched between taking the measurements.

(Red)Crossover (80hz Reduced 3db)
I reduced the volume 3db, this was 7 pressed on the volume slider


That's better, as shown the crossover setting doesn't make the sound bright, it just boosts volume. I'm not sure why, perhaps because of the lighter load Sonos is happier to increase the volume.

Thanks for reading, if you have any questions or want me to go into any more detail please let me know.
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    17 replies

    jgatie
    November 15, 2019

    .. feed the amp Dolby 5.1 from the Apple TV4..

     

    I'm considering a Sonos AMP for my KEF LS50's and found this post very useful. 
    But maybe a noob question, did you connected the AMP via your television HDMI ARC or directly to your Apple TV 4k and if so,  how would you get any images from the Apple TV to your television, since the Apple TV only has 1 HDMI ARC port. 

     

    Thnx in advanced.

    Greeting.

     

    Amp is designed to receive input from the HDMI-ARC connection on the TV.  The TV is then used to switch between sources.  

    hodgealAuthor
    Contributor I
    November 15, 2019

    .. feed the amp Dolby 5.1 from the Apple TV4..

     

    I'm considering a Sonos AMP for my KEF LS50's and found this post very useful. 
    But maybe a noob question, did you connected the AMP via your television HDMI ARC or directly to your Apple TV 4k and if so,  how would you get any images from the Apple TV to your television, since the Apple TV only has 1 HDMI ARC port. 

     

    Thnx in advanced.

    Greeting.

    Hi Oeds de Meer,

    I think my phrasing above might be confusing, as the other posters have said the chain would be 
    Apple TV > TV > TV HDMI ARC OUT > Sonos AMP.

    What i mean by “feed the amp Dolby 5.1 from the Apple TV4” is set your Apple TV settings to Dolby Digital, also set your TV digital out settings to Dolby Digital or Surround as well. This will pass this signal through the TV to the Sonos Amp.

    I have found - even only when using Stereo speakers that this sounds best as the Sonos Amp does a great job of down mixing. 

    Regardless of which speakers you choose, i would recommend the Sonos Amp and Apple TV combo, everything works well and dialogue is clear.

    Renowned Enthusiast I
    December 2, 2019

    Apple TV does not do ARC, as it is not a TV (despite the name). To use ARC you connect your source devices to your TV (or receiver), and use ARC on that device to the Beam.

    It’s not accurate to say ATV doesn’t support ARC just that it doesn't normally need to.

    https://www.soundandvision.com/content/how-do-i-connect-my-apple-tv-4k-surround-sound

    Airgetlam
    December 2, 2019

    I’m confused. The article says essentially that the Apple TV doesn’t have ARC, that a TV set is necessary to create the ARC channel. The Apple TV doesn’t have the capability to create the ARC signal. 

    Bruce
    Renowned Enthusiast I
    December 2, 2019

    I'

    Negative:
    I am having a few issues with the remote, sometimes when changing volume, the sound changes normally but the volume OSD lags and sometimes doesn't move at all. I also checked within the Sonos app, and it does the same. I change volume and it will lag and the slider will jump to the new volume setting.


    Id really like to either see TruePlay or even better a parametric eq/convolution ability on the amp. With everything in one box I cannot add third party room correction, so this would have to be a software add-on. This would really complete the package.

    I’m using the AMP with Revel Concerta 2 speakers and Sonos sub. 

    Are you talking about the Apple TV remote?  I have no issues with volume control.

    The only speakers that can Trueplay with the Amp are Sonance architectural which are designedI think there would be a market for indoor Trueplay tunable speakers but nobody seems to  have jumped on that yet.

    Renowned Enthusiast I
    December 2, 2019

    I’m confused. The article says essentially that the Apple TV doesn’t have ARC, that a TV set is necessary to create the ARC channel. The Apple TV doesn’t have the capability to create the ARC signal. 

    It doesn’t need to create it just work with it which it does.

    Airgetlam
    December 2, 2019

    Any HDMI source should send audio to the TV. It’s the electronics in the TV that “reflect” the audio back along the ARC. Apple TV is a normal HDMI source. 

    Bruce