Poor HD Radio Reception After Powered Sub install

  1. sesty

    sesty Senior Member

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    #1 sesty, Mar 8, 2018
    Last edited: Mar 14, 2018
    Felt the low end was lacking in the Si and got a slim 8'' powered subwoofer installed by Best Buy. After the install I noticed my FM radio reception is terrible. Depending on the area its totally unlistenable...

    The tech talked me out of shoving it under the driver seat and convinced me to install the sub on the back of the rear seat. Jumped the OEM sub wire to a LC2i down to the sub (JBL BassPro SL)

    Is the amp interfering with the signal? Or is more likely the tech buggered the install somehow or knocked the antenna wire loose? I am bringing it back in this weekend to hopefully get it sorted out or have them disconnect it all.

    FYI - The JBL doesn't make too much of a difference in sound - bought it off a friend - now know why he was selling lol

    EDIT: little sub sounded pretty good even in the trunk... doesn't bump but fills in the low end after messing with some settings
     
  2. Doublestack00

    Doublestack00 Senior Member

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    I'd be willing to bet its the amp. I had the same issue in my 2013 Si, I had to switch to a different kind of amp that would not interfere.
     
  3. JDM_DOHC_SiR

    JDM_DOHC_SiR Uncle Dave

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    sesty

    sesty Senior Member

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    Yea I’m sure it’s this amp... the JBL sounds a bit after playing worth the settings and leaving the half seat down, but I can’t deal this interference.

    I actually was looking to get that Cerwin Vega but I got a deal on the JBL. Will look to swap it with the Vega or just sacrifice some trunk space more money in a amp and box
     
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    sesty

    sesty Senior Member

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    Disconnected the sub and issue went away... Shop isn't going to charge me to take out the old stuff. Since I have to upgrade the gauge of the power wire to put in anything else - I decided to go the route of a sealed 10" RF Ps14-10 and Alpine MVR-500M amp under the seat. I can always turn it down right?

    Considering upgrading the front door woofers to 6-3/4 Kicker DS while I am at it. Will there be any sound issues upgrading only the fronts? I think the amp puts out 22W for the 9 speakers. These speakers are rated for 60RMS and are fairly sensitive (90db).

    Basically worried about the DS's being quieter than the other speakers since they will be under powered compared to the rest of the set up. - not sure if thats how speakers work lol - appreciate any help.
     
  6. streetwise

    streetwise Senior Member

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    im running 10" powered sub, 8g power wired, taped to rear speakers. no change in fm station
     
  7. jakabony

    jakabony Senior Member

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    It might be because you tapped into the factory sub signal. I tried both the sub signal and left rear speaker signal and found that the sub signal yielded some really weird results. It sounds much better when you tap into the left speaker signal.

    Also, if you mount a powered sub in the trunk, you are going to lose a ton of volume. Powered subs aren’t really all they high powered, so they are going to be very muffled in the trunk. They are designed to be in the cabin. I have a Cerwin Vega powered sub that I put under the drivers seat and it hits way harder than I expected.
     
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    sesty

    sesty Senior Member

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    I actually didn’t mind the sound in the trunk, obviously lacks the punch but not terrible for a small 8”. Pretty amazing what a little low end can do to the sound in this car.

    Can’t wait to hear it with some upgraded speakers and a small box in the trunk.
     
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    sesty

    sesty Senior Member

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    does anyone know if a 6-3/4'' speaker will fit in the front doors?
     
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    sesty

    sesty Senior Member

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    swapping the JBL with an amp / sealed sub combo & the radio interference went away. Have the amp under the drivers seat and 10" RF in the trunk. New speakers up front sound a bit better than OEM - kinda wanna swap the tweets now too.

    Some songs sound amazing others are meh - Much better over all with the low end filled out.
     
  11. optikalillusi0n

    optikalillusi0n Senior Member

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    Any pics ?
     
  12. OP
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    sesty

    sesty Senior Member

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    only of the sub, amp is under seat.

    sub.jpg
     
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