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Bronze Member Username: Foong_onePost Number: 41 Registered: Jan-07 | i bought a new Bassworx 12" Ported Box that says tuning is 42 Hz. Does this mean that i need to TURN my sub's crossover setting to 42 Hz on my headunit ? Somebody, please advise. |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12946 Registered: Dec-03 | oh god. 42Hz is high. It's going to sound very boomy. that said, here: http://www.diysubwoofers.org/prt/ In a ported box, the port makes the enclosure more efficient at the tuned frequency, so at (in your case) 42Hz, the box will be about +3dB louder in the car. You will need a subsonic filter set to 42Hz as well, to protect the sub from unloading and being damaged. |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12947 Registered: Dec-03 | http://www.bcae1.com/spboxad1.htm |
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Bronze Member Username: Foong_onePost Number: 42 Registered: Jan-07 | i still don't get it. So, what exactly am i supposed to do ? Sorry, i'm a real noob to car audio. So, somebody please tell me: should i turn my subwoofer x-over frequency on my headunit to 42 Hz ? Should i set my monoamp x-over frequency to 42 Hz ? Should i just leave it alone ? Etc., etc. |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12968 Registered: Dec-03 | adjusting the tuned frequency of a subwoofer enclosure is done by changing the length of the port slot or tube(s) used in the enclosure. It has nothing to do with the settings on the amplifier. |
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Bronze Member Username: Foong_onePost Number: 43 Registered: Jan-07 | Okay. Thank you. So now, where can i find my subsonic filter so i can set it to 42 Hz as well ? |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12971 Registered: Dec-03 | that setting will actually be on the amplifier, if it has such a filter. not all amplifiers come with one. it'll probably have a setting from maybe 16-50Hz. It's not the "LPF" or low pass filter that's used to set where the sub amp starts playing, though. Don't confuse them. It'll be called something like a subsonic or infrasonic filter. |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12972 Registered: Dec-03 | what amp do you use for the subs? make and model? |
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Bronze Member Username: Foong_onePost Number: 44 Registered: Jan-07 | i'm currently using a discontinued Kenwood monoamp: KAC 8152d. http://www.crutchfield.com/p_113KAC8152/Kenwood-KAC-8152D.html |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12974 Registered: Dec-03 | bingo! great link. thank you. here: "Infrasonic Filter: This amp features an -18dB/octave Infrasonic Filter. Ultra-low frequencies that cannot be reproduced by a subwoofer do not become sound but become unnecessary oscillations, which affect sound by causing distortion. These frequencies also waste amplifier power and can cause damage to speakers. Setting the Infrasonic filter switch to 15Hz or 25Hz cuts the frequencies below the respective frequency to improve the reproduction performance of the speakers by eliminating harmful distortion." Set your infrasonic filter to 25Hz, and you're all set. I'd recommend tuning the port(s) on your box to 28Hz, if you're having a box built. If you have a pre-fab box from a store that has a round port tube, that can be trimmed to tune it. You need to do some math to get the right length you'll need for that tube. If the box has a slot port that's the width of the box itself, there isn't anything you can really do for tuning. It came pre-tuned. |
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Bronze Member Username: Foong_onePost Number: 45 Registered: Jan-07 | Alright. That sounds good. Thank you. |