TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

Subwoofer range reduction?

Discussion in 'Model S: Battery & Charging' started by CZguy, Nov 26, 2015.

  1. CZguy

    CZguy Member

    Joined:
    Jul 16, 2015
    Messages:
    20
    Location:
    Prague, Czech Republic
    Folks,

    I have purchased the N.V.X. subwoofer system and it apparently draws 15-40A based on the amount of bass produced. I wonder if you have any real world experience of range reduction with the amplifier on on N.V.X. This would be similar on the stock HiFi system though it has a smaller sub.

    Thanks!
     
  2. pgiralt

    pgiralt Supporting Member

    Joined:
    Jun 16, 2013
    Messages:
    1,473
    Location:
    Cary, NC
    If you were to take the worst-case scenario of the subwoofer drawing 40A continuously (which is definitely not going to happen because you likely don't even have a 40A fuse on the amp that drives it nor will you likely have thick enough wires for that level of continuous draw, plus music is not just a continuous full volume continuous tone), that would be 12V * 40A = 480W. If you were to run it continuously for a whole hour, you would draw 480 Wh from the battery which is about 1.5 rated miles per hour (based on around 300 Wh/mi).

    In reality, I doubt you will notice any difference in range at all.
     
  3. CZguy

    CZguy Member

    Joined:
    Jul 16, 2015
    Messages:
    20
    Location:
    Prague, Czech Republic
    Thanks pgiralt. Very helpful and am embarassed that I did not figure this out myself. Pretty simple math :)
     
  4. supratachophobia

    supratachophobia Active Member

    Joined:
    Sep 24, 2014
    Messages:
    2,254
    Location:
    Columbus, Ohio
    This is roughly the same calculation we used when someone did the calcs for the JBL subwoofer install I did a year ago. With the 300 watt mono Class D NVX amp, it was something like .9 miles per hour reduction if the sub was blaring at full blast the entire time.
     
  5. grichard

    grichard Member De-Luxe

    Joined:
    Oct 2, 2015
    Messages:
    183
    Location:
    St. Louis, MO
    Yeah, the range reduction from the subwoofer is so small that... it's in the noise.

    (Thank you... I'm here all week...)
     
    • Funny x 1
  6. Khatsalano

    Khatsalano Member

    Joined:
    Mar 21, 2015
    Messages:
    659
    Location:
    San Mateo, CA
    Actually, I've found that subwoofers tend to increase range ... because you gots to drive slower. Will Smith best explained it:

    "Leanin' to the side but you can't speed through
    Two miles an hour so, everybody sees you."

    - K

     
  7. Frankman60

    Frankman60 Member

    Joined:
    Jun 21, 2016
    Messages:
    123
    Location:
    San Diego, CA
    This is interesting. If you purchase the Tesla premium audio system option, it must also have more powerful amplifiers to drive the extra speakers and sub. Does a Tesla with the premium audio system have less range when compared to a Tesla with the base audio system? Also, it seems that the Tesla premium audio system may use more power than a base audio system with an added NVX amp/sub because the premium system's main amplifier is likely more powerful to drive the additional cabin speakers. Does anyone have the specs on this to do an accurate comparison?

     
  8. bxr140

    bxr140 Member

    Joined:
    Nov 18, 2014
    Messages:
    702
    Location:
    Bay Area
    Its not simply a matter of adding up amplifier wattage. To drive a given sonic energy in the cabin (decibels) you'd more or less use the same amount of electrical power (watts)--any difference from the actual components will be small and...ahem...in the noise. :cool:

    Of course, a subwoofer is likely to mean higher sonic energy, so its most likely that you'll consume more energy than if it wasn't there...but unless you're a teenager you won't be able to listen at volumes high enough and for long enough to really make an appreciable dent in range. For instance, 1000 watts is LOUD--if you could possibly sustain that volume over the course of a ~2 hour supercharger leg, you're looking at losing ~6 miles range loss. A more practical SWAG is something on the order of 1-2 miles.
     
  9. DarkMatter

    DarkMatter Member

    Joined:
    Jul 13, 2016
    Messages:
    272
    Location:
    Olympia, WA
    It's not just adding watts, since most of the time you run at a tiny fraction of that power. If you're running the system hard enough to notice it in the range at all, your much bigger concern is deafness by age 40.

    Here's some quick shorthand for you: a really quite loud boombox can run loudly for hours off 8 D cell batteries, otherwise known as about 200 Wh. Even adding in a subwoofer you'll be hard pressed to notice in the range. If you hit 100 dB for two hours you've caused hearing damage. Many speaker systems are specified at 90 dB/W of efficiency, meaning 100W would get you 102 dB of volume.
     

Share This Page