Low Pass Filter

[mkalsi]

Hi all,

I recently got a subwoofer fitted in my small car. It is a JBL CS1214 in a sealed box, with a JBL A3001 amplifier. The subwoofer is rated at 250W RMS while the amplifier is rated at 300W RMS. I have not upgraded the car speakers.

The problem is, I cannot get a good level of bass and sound quality from the subwoofer. I believe this is because the car speakers are in fact playing full range, while the subwoofer is just adding on top with anywhere from 30-320HZ depending on my LPF setting. I have experimented with different LPF settings, but I am having a hard time hitting the "sweet spot".

I want the extra bass without any holes in the frequency response. What can I do, if anything? Also, there is a bass boost function, which I know boosts 45HZ, but I try not to increase it.

Any help or comment is welcome.

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[LosIsATool 5,000+ posts]

Get bass blockers for the interior. Than lower the LPF on the sub till it blends with the midrange. 80hz range

 

[Jeffdachef 5,000+ posts]

You'll need a proper head unit that has high pass and low pass filters and some proper components+power to get that midbass 80hz+ kick

 

[mkalsi]

Very interesting replies, thank you. However, I do not wish to spend any more money on this car. It is an old car. I will be getting a new car in the future, where I will transfer the subwoofer setup to. There, I hope to do things properly, depending on the circumstances of the car's exsiting system.

I thought by throwing a sub into the boot will add extra bass, without thinking of the possible sound quality issues. I do have one question. Would the equaliser on a basic head unit change the signal coming out RCA?

 

[mkalsi]

I think I'm going to play a 100Hz sine wave and tune the sub so that the crossover doesn't go over. I'm to gradually decrease the filter till I hear the tone come off, then step it back a hair. I don't want any frequencies over 100 to be coming out.

Will post feedback.

 

[Massive spl]

Very interesting replies, thank you. However, I do not wish to spend any more money on this car. It is an old car. I will be getting a new car in the future, where I will transfer the subwoofer setup to. There, I hope to do things properly, depending on the circumstances of the car's exsiting system.
I thought by throwing a sub into the boot will add extra bass, without thinking of the possible sound quality issues. I do have one question. Would the equaliser on a basic head unit change the signal coming out RCA?

U can buy a nice HU and install it in your new car too. So your not wasting any money

 

[mkalsi]

I never knew you could get head unit's with crossovers. I thought people get amps +crossovers for these things and keep the head unit flat with RCA to the amps then to the speakers...

 

[pickup1 5,000+ posts]

Try reversing the polarity on the sub. May be 180° out.

 

[mkalsi]

*** UPDATE ***

I set the crossover on the sub to 100Hz. Gain is 1/2 on the amp. Sounds decent enough. Packs a punch. Although I have been turning the HU up to it's maximum non-distortion level and working the original speakers for some mid-bass. Ears hurt a little.

There are things I've learnt from all of the replies above. Thank you once again.

n00b basshead signing out