My car sub (JL Audio) is killing me.

Discussion in 'Archived Threads 2001-2004' started by Sheldon C, Apr 23, 2002.

  1. Sheldon C

    Sheldon C Second Unit

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    I think my car sub is not putting out very much low bass. No matter how I tweak the eq and sub levels all I get is very loud bass with not a lot of "feel". I have 1 12 inch JL audio sub with a JL Audio amp. I had been under the impression that these are pretty good subs, but I have been disappointed. My cerwin vega lw 15 in my house plays noticeably lower than my car sub, and it the cerwin is only rated to 28 although I doubt it even gets that low. I have tried the same parts of songs in both my house and the car and sure enough, in the car those low notes disappear.

    I have never tweaked with the dials on the amp itself, so I wonder if that could help although I would have no idea what I'm doing. This sub to me is the very definition of boomy. It's too loud on most bass notes, and doesn't play the very low notes at all.
     
  2. John Garcia

    John Garcia Executive Producer

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    What type of enclosure is the JL in? This can make a HUGE difference. What you describe sounds like a bandpass box or an improperly sized enclosure or vent for a ported sub. Getting good sound means more than just slapping a sub into any old box. I would recommend either building, or have built, a proper enclosure.
    I used to use my car (built myself) sub to test out material because it would hit both harder and lower than my home sub. (dual 10", parallel, isobaric, fed by a bridged 300w, in a hatchback [​IMG] eyeball vibrating to say the least)
     
  3. jeff lam

    jeff lam Screenwriter

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    What kind of car? What component's are you running. Be sure the High pass filter is not enabled on the amp if ther is one. With Cabin gain you should get very low with the JL. I had a JL 12W0 in my honda for a few years while I was in College and it got plenty low for music.
     
  4. Sheldon C

    Sheldon C Second Unit

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    Thanks for the responses,

    I have a 96 Maxima and I bought the sub already installed in a box from the retailer. My cd player is a pioneer (I think the model is a deh p4300).

    Looking at the amp manual, I see that I have a lot of switches and knobs (forgive my car audio ignorance). I have a amp LP filter that has three settings: off, 12 db, and 24 db (not sure which setting I should use). I also have a infrasonic filter that has two settings, off and 30 hz.

    Ah hell, it looks like I should just start playing with it and see what happens. Why is this so much more complicated than a home sub?
     
  5. Shawn Solar

    Shawn Solar Supporting Actor

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    Have you set the gain on the amp. Set it at half for now. Set the crossover slope at 12db. There should be a corresponding freqency with the lowpass filter. probably 80hz, 50hz and 120hz. set it at 80hz. There might be a bass boost on the amp set it at +3 to boost the low end. turn the infrasonic filter to off. check the deck settings and switch the eq on the deck. you should have superbass, natural, vocal, powerful,flat and a customizable. switch between them as vocal and natural and flat all have the bass volume turned down. I am not sure but there might be a crossover built into the deck. you may have to turn the lowpass filter on to activate the sub. That all I can think of for settings. The next step is to make sure the phase on the sub is set right. positive to positive and negative to negative
     
  6. Sheldon C

    Sheldon C Second Unit

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    Thanks Shawn, I'll try all of your suggestions when I get home tonight. Looking in my manual, it looks like I have all the settings that you are talking about on my amp. I guess I was wrong in assuming that the installer would properly set everything up. I don't know why I would think that, it's not like I would let someone else set up my home system![​IMG]
     
  7. Shawn Solar

    Shawn Solar Supporting Actor

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    Let me know how it turns out.
     
  8. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    "Looking at the amp manual, I see that I have a lot of switches and knobs"

    lol

    Anyways, when I had my sub installed for free the sub was horribly setup. I think the installers just put everything together and don't spend much time tuning the sub. I recall myself being very dissapointed upon first hearing it.
     
  9. Sheldon C

    Sheldon C Second Unit

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    God I love this forum! Thanks a lot Shawn and others for the help. Well, it was a bitch to get to my amp since it is bolted to the back side of my box which didn't have enough room to rotate without taking some wires out. The boost was set to zero so I turned that up to +3, the filter was turned on so I turned it off, and the slope was set on 24 and I changed it to 12.
    Wow, what a difference. Now my drivers seat shakes with the low bass that I was missing before!! One problem though, after coming back home after a short drive my ears were really ringing - guess I need to chill a little bit, huh.
    My opinion of JL Audio subs and amps has changed dramatically!!!! Thanks again.[​IMG]
     
  10. jeff lam

    jeff lam Screenwriter

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    I would have actually recommended the 24dB/octave slope but I like steep crossovers on subs (especially car subs). Looks like that infrasonic filter is a subsonic filter and if it was turned to ON, there would be no low bass at all. This filter is used for midrange drivers to keep them from producing low bass and distorting. Subs should not have a higher subsonic filter than around 20-25Hz.

    Play around with the 12/24dB slopes and use whichever sounds best to you.
     
  11. Shawn Solar

    Shawn Solar Supporting Actor

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    Yeah 24db slope may prove better. I suggested the 12db just so he could see if it gave more bass.
     
  12. Neil Weinstock

    Neil Weinstock Stunt Coordinator

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    By the way, JL Audio has in the past been very customer-friendly and eager to help, so you should definitely get in touch with them if you still have specific questions regarding your equipment when this is all said and done...
     

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