1x 12inch Sub LPF Optimal Setting

[ChrisGTL]

Is there a rule of thumb about setting the Low-Pass Filter for a subwoofer?

Sub is a single 12 inch in a 1.2 Cu/Ft non-ported box.

Power Handling, Peak 1400W
Power Handling, RMS 350W
Sensitivity 96dB (In car)
Frequency Response (± 1.5dB) 18Hz - 150 Hz
Frequency Response (±3dB) 18Hz - 150Hz
Impedance 4 Ohms
Mounting Depth 6-1/2"

Is it a case of putting a track on and playing with the LPF frequency or is there a optimal setting I should be looking at to get the best sound?

 

[UncleFester]

Need to know how you're powering it and what's providing the signal to it. What amp are you using and what headunit

 

[ChrisGTL]

Head unit (Sony CDX-F7500) http://www.sony.co.uk/view/ShowProd...ecs&imageType=Main&category=ICA+CD+Tuners#tab

to

RCA's & 4 AWG

to

Amp (Kenwood KAC-7201) http://www.carpartsforpimping.co.uk/acatalog/Kenwood_KAC-7201_Amp.html

to

Sub (Infinity K Perfect 12.1) http://www.infinitysystems.com/car/...ser=KPE&Language=ENG&Country=GB&Region=EUROPE

Auto Acoustic Sub Box http://www.autoacoustics.com/sbn-sl025.htm

 

[UncleFester]

First thing is to remember to choose whether you want the low pass filter set on the amp or on the headunit - you don't need to use both.

Try one first and then the other and see which sounds better, test it at whatever each frequency cutoff is.

I would try it somewhere around 90hz to start with. Play a good range of music so you can tell what works best for most of what you listen to.

If you use the adjustment on the headunit then at least you can alter it whilst you're listening to music, it's a lot harder to adjust it if you're.

Don't turn the gains on the amp right up and don't play it at stupid loud volume until you're SURE the setup is correct

 

[ChrisGTL]

First thing is to remember to choose whether you want the low pass filter set on the amp or on the headunit - you don't need to use both.

Try one first and then the other and see which sounds better, test it at whatever each frequency cutoff is.

I would try it somewhere around 90hz to start with. Play a good range of music so you can tell what works best for most of what you listen to.

If you use the adjustment on the headunit then at least you can alter it whilst you're listening to music, it's a lot harder to adjust it if you're.

Don't turn the gains on the amp right up and don't play it at stupid loud volume until you're SURE the setup is correct

I take it i'm looking for the pre-amp output on the Sony headunit page to determain the input sensativity on the amp.

So set it at 2.0V?

Cheers for your help UncleFester, I think the LPF settings on the headunit side are 78Hz, 125Hz or off.

 

[UncleFester]

I take it i'm looking for the pre-amp output on the Sony headunit page to determain the input sensativity on the amp.

So set it at 2.0V?

Cheers for your help UncleFester, I think the LPF settings on the headunit side are 78Hz, 125Hz or off.

If you turn the LPF on the headunit to off, you MUST have LPF enabled on the amplifier.

Gains on the amp should be adjusted carefully, turn the headunit to halfish volume and gradually increase the gain until you can hear / feel the sub - no gain should ever need turning up anywhere much past half. If you turn the gains up too far you can risk damage to the connected speaker(s).

 

[ChrisGTL]

Right,

Got it all installed at my local car audio specialist. Two of the chaps down there both have Ibizas and made nice comments about the Leon.

Installer was impressed with the MK1 Leon sub box too.


Sounds quite well, I've setup as follows:-


Set bass/treble/sub to 0 (can go from -10 to +10) on Head-Unit

Set the HPF on the head-unit to 78Khz (stop anything lower than 78
Hz going to the 4-door speakers, prevents clipping)

Set the input level on amp just below 2.0 (2.0 is recommended output power on my head-unit - thought setting this slightly lower would protect the Sub from too much power) 460w RMS amp / 350w RMS sub @ 4 ohms.

Turned the 'bass boost' off on the amp, I've done some research into 'bass boost' and many if not all the tests into it show even the upper range amps suffer from huge clipping with bass boost enabled - it creates 'artificial' bass and when plugging into a oscillascope the amount of clipping is .

Set the LPF on the amp to around 95Hz at the mo, I'm still finding it hard to search for a proper explanation for a optimal frequency on a 12" sub in a sealed box.

Using the 'all singing, all dancing' Sony EQ jobby on the headunit just gives over powering results, so I turn it off. Turn 'loud' option off, as I presume this just is like 'bass boost' and gives certain frequencies a big boost up the arse.

Like I said before, quite impressed with the results......amp seems to run the sub well. None of the door speakers distort at high levels due the HPF on the head-unit, treble sounds sweet cos they are nice and high/directional to the people sat in the car.

Gonna use the car for a week or so with a selection on CD's and change the LPF frequency between 90-110Hz to see what I like best.