Closed Thread
Results 1 to 6 of 6

Reload Thread: How important is fuse ratings on amps?

  1. #1
    CarAudioNewbie9's Avatar
    CarAudioNewbie9 is offline CarAudio.com Elite



    Join Date
    Nov 2009
    Location
    BFE
    Posts
    844
    Post Thanks / Like
    Mentioned
    0 Post(s)

    How important is fuse ratings on amps?

    I know it isn't the only factor, but how important is the fuse rating on amps? More specifically for class A/B amps. I know that class D amps are more efficient. But I see "2006 cea compliant" A/B amps that claim 600 RMS with only 40 amps of fusing and so on. I then see class D amps claiming 2000 RMS with only 140 amps and so on. I know "2006 cea compliant" doesn't mean much to the real car audio enthusiast, but it pisses me off when I see "2006 cea compliant" Kenwood amps claiming way more RMS watts then their fuse rating suggests. What are some good signs as to telling what the real RMS of amps are?







  2. #2
    kr15's Avatar
    kr15 is offline Polluting Residentials



    Join Date
    Feb 2010
    Location
    California
    Posts
    3,103
    Post Thanks / Like
    Mentioned
    1 Post(s)

    Re: How important is fuse ratings on amps?

    What are some good signs as to telling what the real RMS of amps are
    experience



    Team Flex Issues
    45s out the trunk..lowww

    REFS- Supergumby5000, Lastcall, 919motoring, hippishake, daboyfromdabx (great seller), beach22

  3. #3
    supermaxx123's Avatar
    supermaxx123 is offline CarAudio.com Elite



    Join Date
    Aug 2009
    Location
    I.E.
    Posts
    1,830
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: How important is fuse ratings on amps?

    Quote Originally Posted by CarAudioNewbie9 View Post
    I know it isn't the only factor, but how important is the fuse rating on amps? More specifically for class A/B amps. I know that class D amps are more efficient. But I see "2006 cea compliant" A/B amps that claim 600 RMS with only 40 amps of fusing and so on. I then see class D amps claiming 2000 RMS with only 140 amps and so on. I know "2006 cea compliant" doesn't mean much to the real car audio enthusiast, but it pisses me off when I see "2006 cea compliant" Kenwood amps claiming way more RMS watts then their fuse rating suggests. What are some good signs as to telling what the real RMS of amps are?
    most fuses will handle more than they are rated, maybe even double their rating. 600rms with 40 amp fuse? which amp?



    Bought from: tc3k101, vitveet, chico305, pieper88, Toxic Tuan, rusty_armadillo, tristanmay
    Traded with: modskwod, jmkanek
    Sold to: smd4life, AQHDC3, fastfocus00

  4. #4
    n2audio's Avatar
    n2audio is offline OPTIDRIVEN



    Join Date
    Dec 2001
    Location
    Lawrence, KS
    Posts
    4,288
    Post Thanks / Like
    Images
    4
    Mentioned
    0 Post(s)

    Re: How important is fuse ratings on amps?

    They'll give you a rough estimate of actual power. I only use them as an estimate when I KNOW I'm dealing with an over-rated amp. For anything decent quality the ratings should be much more accurate.

    I know for some amps to produce rated power on a bench the fuses have to replaced with shorting bars because continuous power tests require a lot more long term current than any music will and such tests will blow the fuses. In cases like that the fuses are a form of protection and will blow at the first moment the circuitry is at risk of being damaged.

    I'm sure there are other amps with the fuses sized in a way that will cause them only to blow to protect the amp from catastrophic failure.

    That is the biggest reason IMO, you can't just assume an amp is over-rated if its fuses are less than it seems they should be. Just as you don't know for sure an amp will DO rated power because the fuses seem large enough.

    But generally speaking I think fuse size x10 does get you in the ballpark.




  5. #5
    keep_hope_alive's Avatar
    keep_hope_alive is offline Acoustics Engineer keep_hope_alive is a Supporting Member of the forum!



    Join Date
    May 2007
    Location
    Quad Cities, IL
    Posts
    5,920
    Post Thanks / Like
    Images
    28
    Mentioned
    159 Post(s)

    Re: How important is fuse ratings on amps?

    i use the following:

    fuse size x 12.5V x efficiency

    for estimating usable RMS power. i assume 60% for Class A/B and 80% for Class D or the new hybrid designs.

    a fuse has a time/current curve that characterizes it's behavior. how much over current it can accept depends on the amount of time.



    have you been helped by me? i'd love to know. shoot me a PM.

    My 2014 Accord build log: http://mobileaudioforum.com/forum/showthread.php?6722-KHA-2014-Accord-Sport-SQ-Factory-Integration
    *My 2001 Accord build log: http://www.caraudio.com/forums/car-audio-build-logs-cars-trucks-suvs/536049-2001-accord-ex-sedan-its-long.html
    *2005 Scion tC Build Log: http://www.caraudio.com/forums/car-audio-build-logs-cars-trucks-suvs/516096-2005-scion-tc-sq-hertz-audison-pioneer-build-log.html
    *1998 Astro Van Build Log: http://www.caraudio.com/forums/car-audio-build-logs-cars-trucks-suvs/567468-kha-does-spl-build-1996-astro-van.html

  6. #6
    deez283's Avatar
    deez283 is offline Senior VIP Member



    Join Date
    Apr 2009
    Location
    Aberdeen, WA
    Posts
    295
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: How important is fuse ratings on amps?

    Quote Originally Posted by kr15 View Post
    experience
    Yup..




Closed Thread

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may post attachments
  • You may edit your posts

1e2 Forum