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  1. Join Date
    Mar 2008
    Posts
    31
    #1
    my current setup : amp JBL gt5 a604, seps JBL GT6c, coaxial JBL GT6 6. please recommend the optimal size of subwoofer for my setup. im not planning on getting an extra amp for the sub and would just use the amp mentioned above and have the stock hu ( stock 2013 honda city) power the coaxials. please be specific with your recomendations guys. please recommend the type of installation aswell ( under seat, trunk...) and lastly what type of enclosure. i am not looking for a boom boom setup. just want that extra oomph to complete the sound experience while driving. budget will be 8 to 10k ( includes speakers and installation cost)

    thanks guys!

  2. Join Date
    Jan 2004
    Posts
    3,361
    #2
    Quote Originally Posted by extrarice311 View Post
    my current setup : amp JBL gt5 a604, seps JBL GT6c, coaxial JBL GT6 6. please recommend the optimal size of subwoofer for my setup. im not planning on getting an extra amp for the sub and would just use the amp mentioned above and have the stock hu ( stock 2013 honda city) power the coaxials. please be specific with your recomendations guys. please recommend the type of installation aswell ( under seat, trunk...) and lastly what type of enclosure. i am not looking for a boom boom setup. just want that extra oomph to complete the sound experience while driving. budget will be 8 to 10k ( includes speakers and installation cost)

    thanks guys!

    Your optimal size for just extra oomph is a single 8 or 10" driver in a sealed box in the dimensions recommended by the manufacturer. You may have to play with rear facing or forward facing, but since it's a box it has to be in the trunk.

    Not familiar with the a604 but you either need to get a new amp to power your sub or wire your amp so that it powers the fronts and the sub.

  3. Join Date
    Aug 2010
    Posts
    3,526
    #3
    *scratches head*

    Okay, first off, I hate buying unnecessary products. So I'll teach you nalang in the most simple terms I can phrase them.

    Your current system diagram looks like this: Head unit -> speaker level -> line out converter -> JBL A604 -> GT6-6c (front), GT6-6 coaxials (back).

    Now there are plenty of stock head units that have built-in filters. This is done by manufacturers as to not damage your stock speakers by letting them play frequencies that they aren't suited to. But assuming you don't have the filters and it plays a full-signal, we'll simply optimize your midbass instead.

    Now before you do this, set all tone controls to flat muna. No +3 on the bass and treble.

    Amplifiers nowadays usually have built-in crossovers on them. Take a look at your amplifier (Picture 2 of 4 for JBL GT5-A604) and you'll see crossover/x-over frequency. Now what a crossover simply does is that it filters the sound. Most installers do a standard 80hz high pass filter on them.. what this means is that your midbass plays from 80hz to.. whatever frequency your passive crossover between the tweeter is (usually it's at 2.5khz, 5khz, 6.3khz, etc.).

    Now what you want to do is to decrease the HPF to something like 70hz (start here) or 63hz. As the knob doesn't say where it is, simply approximate nalang. This makes your midbass dig down lower ;)

    This is safe as long as you don't crank it up to idiotic levels. Of course, don't pass it at 32hz.. maghihirap speakers mo niyan, so play it safe sa knob. And because you say that you aren't the type to try to impress other people with volume, I first suggest this route for you so you can save your 8,000pesos for womanizing duties instead :naughty2:. The sole reason why installers go for a standard 80hz cutoff is because some people go boom-boom with their windows down. The higher the cutoff, the louder they can safely play. And not one installer would want angry customers blaming them for their own foolishness

    After this, you can now play with your tone controls, try a +3 on the bass and see if you're satisfied with the sound. It might not "complete" the sound setup but you'd be surprised how big a 1/3 octave of frequency difference is.

    ===

    Still, the most optimal scenario is still to buy a subwoofer. This is because displacement is the budget king when it comes to output/SPL. And when it comes to completing the sound spectrum, you'll need a sub.

    First and foremost, I suggest you can mount the subwoofer wherever it's convenient. Ignoring the exotic price tags of specially mounted drivers, the best and most inexpensive option is to throw them in a box.

    8" would suffice since you don't play at relatively loud levels, but if would suggest 10s or bigger if you plan on throwing them sa trunk. Oh yeah, and don't believe in the whole "bigger drivers are slower than smaller ones", that's utterly BS.


    From your last thread, your aim was to throw a subwoofer sa baba ng seat mo. Now this is quite possible but limited ka lang sa 8". This photo is Jerome's 09 City doing a 0.6-0.7 sealed box on an 8" Polk MM840 subwoofer alongside his underseat amp. (I don't think he'll mind naman.. he copied my front stage layout after all )

    Now a Polk MM840 will set you aside around Php6.5k, however I would suggest you go for an Infinity Reference 860W (Infinity Reference 860w 8inch SVC Subwoofer) that costs a hair below 3k. The thing I love about JBL/Infinity is that it's very easy to get accurate measurements regarding their drivers.. and this makes modeling a whole lot easier. To cut things short, open and print this PDF (http://infinitysystems.com/tl_files/...860W_PI_EN.pdf) and tell your installer you want the ported box system.

    Why a ported box? Efficiency. Your feeding 180W into your subwoofer, and that amount isn't large at all. So we'll compensate by doing a port so that at 40hz, you get a +7dB boost on the 40hz. Don't underestimate +7dB.. that's like going from a 180W amplifier to a 600W amplifier. Don't worry about the peak because at low frequencies, we're insensitive to volume. 90dB in midrange would be "loud" for us but 90dB in bass is simply "normal". There's a reason why nobody plays house music at polite volumes :naughty2:
    Last edited by jhnkvn; May 22nd, 2013 at 03:38 AM.

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recommend a subwoofer for my entry level setup