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Main amplifier for JVC equipped roadster?

Discussion in 'Roadster: Technical' started by jimmyz80, Jan 11, 2015.

  1. jimmyz80

    jimmyz80 Member

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    The previous owner of my 2010 2.0 roadster had told me that the original subwoofer amp died, and he replaced it with a similar Rockford Fosgate unit. So tonight I poked my head under the passenger side of the dash, and sure enough he did a nice install of a pretty slick little amp for the sub. I tweaked the gain and crossover settings to my liking, but now I'm confused about one other thing...

    Where the heck is the main amplifier for the full-range speakers? There's clearly a high-pass filter enabled downstream of the JVC head unit, since even with the crossover settings disabled on the head unit, there's still zero bass coming from the main speakers. The sub fills in nicely, but being able to adjust the high pass on the mains to allow for a little more bass through them would be REALLY nice. Can anyone point me in the direction of how to access the main amplifier? Thanks!
     
  2. jimmyz80

    jimmyz80 Member

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    Nobody knows how to get to the mysterious main amplifier? :)
     
  3. jbadger

    jbadger Roadster #506

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    I believe it is behind the drivers seat but requires a battery drop in order to replace as it's on the outside of the cabin.
     
  4. jimmyz80

    jimmyz80 Member

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    I thought that was the subwoofer itself. Isn't the main amp inside the dashboard somewhere? I know the sub amp is in the passenger footwell, and I can access that one no problem.
     
  5. supersnoop

    supersnoop Tesla Roadster #334

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    Is there a main amp? I thought the other speakers were powered by the head unit.
     
  6. shrink

    shrink Member

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    Yeah, I don't think there is an amp powering the front components or rears, just a small amp powering the tiny sub. The sub went out of my car, too, and was replaced under warranty.
     
  7. Jaff

    Jaff Active Member

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    #7 Jaff, Jan 13, 2015
    Last edited: Jan 13, 2015
    Jimmy, not sure if there is a "main amp" in the original setup...

    I replaced my Alpine with the Parrott Asteroid...had the tech "cut the wires to the 6" stock woofer (behind the driver's seat) as opposed to removing it as it was such a PITA to get at...the tech installed two new Rockford Fosgate amps in the driver's side front left, and installed a new 8" Kicker Sub in the passenger side foot well...I power the amps with a SMART 50ah Lithium battery mounted in the trunk...replaced the stock speakers with Morel Hybrid 402's and added a sierra wireless air card for the internet connection...very pleased with the sound quality & power.




     
  8. shrink

    shrink Member

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    Damn, Jaff - that sounds like an awesome setup! Well done.
     
  9. tvuolo

    tvuolo Member

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    Jaff, any chance you can update the wiki with info on what size speaker replacements will fit? Or tell me and I'd be happy to update the wiki.

    While we are at it... How much power can we safely draw from a 1.5? What was the wattage on factory installed subwoofer amp? What was the wattage on the Blaupunkt amplifier? Does anyone have make & model numbers for any of that? I'll put it in the wiki.

    #265 was originally purchased with the stock stereo, but the head unit was later upgraded to the JVC. I believe the JVC is still running off the factory Blaupunkt amplifier (it looks to still be hooked up). I'm wondering if I can put a thin 75W sub behind the driver seat to replicate the factory subwoofer. Something like the Kenwood KSC-SW11. Can I run that right to the unused subwoofer amp fuse in the fuse box? Then depending on the power in the Blaupunkt amp, replace it with a higher quality amp of similar wattage. And of course replace the speakers.
     
  10. djp

    djp Roadster 2.0 VIN939

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    Yes, there is a main amp driving the L/R F/R speakers. In the 2.0's it's an OEM Rockford Fosgate unit, and buried deep in the car - I'm told it's almost impossible to get to.
     
  11. jimmyz80

    jimmyz80 Member

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    There's most definitely a main amp somewhere in my car, since regardless of EQ and crossover settings on the head unit, there's zero bass coming from main speakers. Something downstream is filtering it out.
     
  12. jimmyz80

    jimmyz80 Member

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    Do we have any idea of where it might be buried deep? There's a lot of places one could start digging lol.
     
  13. Jaff

    Jaff Active Member

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    I'll let you update the Wiki if you don't mind...

    The Morels are the Hybrid series 402 ... HYBRID 2-way / Integra Morel ...they are 4", two way speakers ...same size as the Roadster's stock speakers, so an easy install...there appears to be a limited selection of quality 4' speakers out there.

    The Subwoofer is an 8" Kicker ...the tech suggested this sub as by installing it in the passenger side foot well, it would keep the loss of legroom to a minimum as this speaker model can adapt to a smaller (thinner) box...I drive alone most of the time, so losing a little passenger side legroom is of little consequence to me...even when my wife is with me, she doesn't need the legroom lol.

    My vehicle is a 2.5, so I can't speak to the "power you can safely draw from a 1.5 question...I'd ask your Service Center manager to contact the engineers in California to find out.

    When the install was complete, I was throwing 12v fault messages all over the place. I was advised (by Tesla) not to put larger than an 8ah 12v battery in the Roadster...I know some folks believe it is ok to put in a larger 12v battery, but I did not want to put my main pack at risk by going against Tesla's advice....so...

    I mounted the SMART lithium 50ah battery in the trunk and run the two Rockford Fosgate amps off of this battery...I had the tech leave the head unit on the Roadster's 12v system as it is trickle charged by the main pack and this way, I would not lose my NAV nor internet connectivity...(if the 50 ah 12v battery runs out of juice, I just lose sound)

    I have found that with regular daily use, I only need to charge the trunk battery once a week...if I am going on a trip (and therefore subjecting the 50 ah battery to much higher demand), I carry a 7 ah 12v lithium battery as an emergency spare...but, the 110v wall charger for the 50 ah battery is very light & compact and easy to transport.



     
  14. shrink

    shrink Member

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  15. jimmyz80

    jimmyz80 Member

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    How weird. This car definitely has a separate amp for the subwoofer channel.
     
  16. shrink

    shrink Member

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    Yeah, from that page:

    [TR="bgcolor: #EBEBEB"][/TR]
    Number of Channels:7

    Number of Speakers:7

    [TR="bgcolor: #EBEBEB"][/TR]
    Amplifier RMS Power:400 Watts

    Front Tweeter Size:1" Soft Dome

    [TR="bgcolor: #EBEBEB"][/TR]
    Front Speaker Size:4"

    Rear Speaker Size:4"

    [TR="bgcolor: #EBEBEB"][/TR]
    Subwoofer Size:6.5" SVC


    - - - Updated - - -

    I'm interested in this because when I had my subwoofer replaced under warranty last year, I could no longer control the subwoofer lever via the head unit. I was trying to play with the front sound stage only + the sub, but when I got the car back I could only hear the subwoofer when I had the rear speakers going. I even brought the car back up to Tesla service and the tech told me the subwoofer was wired through the rear speaker outputs.

    Well, if that diagram is right, then that tech was wrong.

    I'll get it fixed when I complete my 2.5 Double DIN conversion.
     

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  17. djp

    djp Roadster 2.0 VIN939

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    Even if you found the amp it wouldn't help. The OEM amps don't have user adjustable knobs or switches to change the filter/gain settings, just a set of wires in and out. You'd need to swap out the amp to change the high pass filter level.
     
  18. PokerBroker

    PokerBroker Member

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    Must go Focal for new speakers.
     
  19. tvuolo

    tvuolo Member

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    +1

    Although, I'd be interested to hear the Morels.
     
  20. jimmyz80

    jimmyz80 Member

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    Lame. :( Maybe I should invest in some dynamat first, and then reevaluate whether the mains need to be re-equalized.
     

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