Problem setting gain with dmm

Discussion in 'Car Stereo Amplifiers' started by mspec, Jul 18, 2010.

  1. mspec

    mspec Member

    Hey all,

    Thought I would Have a go setting up my amps using a dmm today, I have successfully done my monoblock for my sub but I'm having a wee problem with my 2 channel component amp I have a slightly older Sony explode 2 channel with 60x2 cea rated @ 4ohm powering my jbl splits 50rms my calculated voltage is 14.1v but when adjusting the amp gain upwards using a 1khz test tone I can only get 12v with max gain I'm measuring the positive and negative of each channel separately with the same result any ideas?
     
    Last edited: Jul 18, 2010
  2. mspec

    mspec Member

    I was just thinking perhaps the 1Khz test tone was not the right one to use? perhaps if I use something like 125Hz or 150Hz I may produced the desired result?

    anyone?
     
  3. fstrfvo

    fstrfvo Full Member

    Are you using a line driver, I'm not aware of any Sony amp that will handle more than 10 volts input or are we not talking about the same thing?
     
  4. fstrfvo

    fstrfvo Full Member

    nevermind I had a brain fart.
     
  5. mspec

    mspec Member


    lol nevermind I have these all the time haha.
     
  6. pedro quiroga

    pedro quiroga Well-Known Member

    ive always done this by ear. last time i did one with a DMM was to gain match my 4ch cause i was running it as a two ch.

    i used a 50HZ tone and was getting only 8v out and it was damn loud. so i matched then to 6v out. was plenty loud and clean sounding.

    A lot of people dis the sony amps for being crap, but for a mids and highs amp they are good. but for subs they blow fuses when cranked up.

    just an FYI to those wanting to bash the sony explode.
     
  7. mspec

    mspec Member


    Hey thanks for you comments, I have the next generation down sony amp, I have herd the the newest generation are not as good as they used to be, mine seems to work great for my comps, I use a Fusion Monoblock for my Polk 15". Anyway I found the solution to my problem whilst tampering with things today:rolleyes:

    So I thought I would provide some feedback for once, to help others that are as silly as I:(

    Appart from the sub level controller on my new pioneer head unit, I found something called 'Source level adjustment" this seems to allow you to adjust the level of each source seperately eg. IPOD/CD etc.. they were set at default 0, adjustable from -4 to +4, I then set them to +4 and re measured my readings at the speaker outputs of my amplifier, to my suprise it easily achieved my desired 14.1v

    Not sure if this was the best way to go about things but "it works" and very well indeed. So for thoose of you who may encounter similar issues, the newer generation pioneer units have allot of flexibility and adjustments so always start there before setting your amp gains or you might find yourselves a little stumped as i did resulting in unneeded time spent calibrating gains over and over again

    cheers,;)
     
  8. pedro quiroga

    pedro quiroga Well-Known Member

    my 4.5 yr old pioneer has SLA as well. mine has individual line level adjustments too for front rear and the sub. not fader mind you but a separate level adjustment.

    its a life saver in competitions as i can turn my front and rear outputs down to -20 so i don't damage them during a run.

    any pics of your set up?
     
  9. mspec

    mspec Member


    Hey Pedro,

    Nope unfortunately don't have any photo's of my setup, It's pretty standard nothing too flashy or customised. But sounds pretty awesome for a a daily driver. Now I just need to defeat the dredded rattling licence plate issue as i have noticed the polk starting to loosen up now. I must admit It puts out some pretty good base in it's custom ported enclosure and the cone is hardly moving. However as with most ported set ups tuned reasonbly low (mines at 32Hz) it doesn't like the upper base lines like my 12's used to, but geez when you get low frequency bass it really does blow my mind.
     
    Last edited: Jul 21, 2010