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Audio Settings 101....noob question


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Hi goke,

 

LPF Woofer, this is the frequence that the woofer plays. 80hertz is a normal standard for a woofer at top40 music

If you play Reggae music you can change this to 50 or 63 hertz, that means that the bass would be lower and more feeling.

HPF: this is an option to let your speakers play less bass so the play better on high volumes.

It's better to try it and hear what you like you can always reset the funtions if you made a mess of it :)

 

Good luck

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The above information is needs some clarification. A low pass filter (LPF) allows frequencies under the crossover point through to your subwoofer. If you set it at 80Hz, then all frequencies below 80Hz will pass through to the subwoofer. Lowering that crossover point to 63Hz or 50Hz won't make the woofer play any deeper (it just wont play as high). In conjunction, the HPF does the opposite and allows frequencies above the crossover setpoint to get to your main speakers. The crossover point isn't a hard cutoff, so it's not like 81Hz won't play through your subwoofer. The slope determines how drastic the frequencies roll off. 

 

Example: A LPF set at 80Hz with a slope of -18dB/octave means that the output will be 18dB quieter for every octave lower. So if you have a 80Hz tone coming out of your speaker at 90dB, it'll theoretically be 72dB at 40Hz (one octave down is half the frequency, one octave up is double the frequency). One octave is the same as hitting a middle "C" on a piano, then playing another C either lower or higher. That difference is one octave. Or if you sing a simple major scale, "do-re-mi-fa-so-la-ti-do", the difference between the two "do" notes is the same note, one octave apart.

 

Your subwoofer's crossover is set @ 200Hz in your picture. That's probably too high. Yes, you'll get more sound coming from your subwoofer, but it might get a little muddy. It may also be localizable. A good rule of thumb is that frequencies below 80Hz are omnidirectional. If you let your subwoofer play higher than that, then you'll easily be able to pinpoint where your subwoofer is located. You don't really want that. It might be fun for a while to hear all that sound coming from your sub, but that's not a proper way to tune a system.

 

Lots of good reading here. Her writing is more interesting and easy to follow than most:

http://www.carstereochick.com/category/tuning-wiring-how-to-guides/

 

Here's a great link that shows you what the real-world relationships are between frequencies and music. 

http://www.independentrecording.net/irn/resources/freqchart/main_display.htm

 

Once you understand the relationship between the mathematics involved and actual music, it'll open up your ears and brain to be able to better tune a system. 

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Hi goke,

 

LPF Woofer, this is the frequence that the woofer plays. 80hertz is a normal standard for a woofer at top40 music

If you play Reggae music you can change this to 50 or 63 hertz, that means that the bass would be lower and more feeling.

HPF: this is an option to let your speakers play less bass so the play better on high volumes.

It's better to try it and hear what you like you can always reset the funtions if you made a mess of it :)

 

Good luck

 

 

The above information is needs some clarification. A low pass filter (LPF) allows frequencies under the crossover point through to your subwoofer. If you set it at 80Hz, then all frequencies below 80Hz will pass through to the subwoofer. Lowering that crossover point to 63Hz or 50Hz won't make the woofer play any deeper (it just wont play as high). In conjunction, the HPF does the opposite and allows frequencies above the crossover setpoint to get to your main speakers. The crossover point isn't a hard cutoff, so it's not like 81Hz won't play through your subwoofer. The slope determines how drastic the frequencies roll off. 

 

Example: A LPF set at 80Hz with a slope of -18dB/octave means that the output will be 18dB quieter for every octave lower. So if you have a 80Hz tone coming out of your speaker at 90dB, it'll theoretically be 72dB at 40Hz (one octave down is half the frequency, one octave up is double the frequency). One octave is the same as hitting a middle "C" on a piano, then playing another C either lower or higher. That difference is one octave. Or if you sing a simple major scale, "do-re-mi-fa-so-la-ti-do", the difference between the two "do" notes is the same note, one octave apart.

 

Your subwoofer's crossover is set @ 200Hz in your picture. That's probably too high. Yes, you'll get more sound coming from your subwoofer, but it might get a little muddy. It may also be localizable. A good rule of thumb is that frequencies below 80Hz are omnidirectional. If you let your subwoofer play higher than that, then you'll easily be able to pinpoint where your subwoofer is located. You don't really want that. It might be fun for a while to hear all that sound coming from your sub, but that's not a proper way to tune a system.

 

Lots of good reading here. Her writing is more interesting and easy to follow than most:

http://www.carstereochick.com/category/tuning-wiring-how-to-guides/

 

Here's a great link that shows you what the real-world relationships are between frequencies and music. 

http://www.independentrecording.net/irn/resources/freqchart/main_display.htm

 

Once you understand the relationship between the mathematics involved and actual music, it'll open up your ears and brain to be able to better tune a system. 

 

 

Thank you for responding guys....I have since lowered my sub woofer's crossover to 100Hz

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...Example: A LPF set at 80Hz with a slope of -18dB/octave means that the output will be 18dB quieter for every octave lower. So if you have a 80Hz tone coming out of your speaker at 90dB, it'll theoretically be 72dB at 40Hz...

Ummm... that's describing the effect of a HPF (high pass filter).  An LPF of 80Hz@-18dB is -3dB at 80Hz and continues to fall off as frequency increases.  At 160Hz, the filter output is -21dB of full spectrum input signal.

 

The reason the crossover frequency is -3dB is for matching HPF to LPF.  When both are -3dB at the same frequency, the high output plus low output combined is equal to 0dB.

 

The speaker level adjustments are to compensate for variations in driver sensitivity, amplifier gain differences, and SPL falloff due to relative position of drivers.

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Ummm... that's describing the effect of a HPF (high pass filter).  An LPF of 80Hz@-18dB is -3dB at 80Hz and continues to fall off as frequency increases.  At 160Hz, the filter output is -21dB of full spectrum input signal.

 

The reason the crossover frequency is -3dB is for matching HPF to LPF.  When both are -3dB at the same frequency, the high output plus low output combined is equal to 0dB.

 

The speaker level adjustments are to compensate for variations in driver sensitivity, amplifier gain differences, and SPL falloff due to relative position of drivers.

 

You're right, thanks for reading that carefully. 

 

That sentence should have read, "...Example: A LPF set at 80Hz with a slope of -18dB/octave means that the output will be 18dB quieter for every octave HIGHER..."

 

Additionally, I was unaware that there was some sort of inherent -3dB at the crossover frequency. Makes perfect sense to avoid a 3dB bump at that frequency when the speakers are coupled. I should read up on this more to find out why exactly.

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You're right, thanks for reading that carefully. 

 

That sentence should have read, "...Example: A LPF set at 80Hz with a slope of -18dB/octave means that the output will be 18dB quieter for every octave HIGHER..."

 

Additionally, I was unaware that there was some sort of inherent -3dB at the crossover frequency. Makes perfect sense to avoid a 3dB bump at that frequency when the speakers are coupled. I should read up on this more to find out why exactly.

Honestly, all this is geek speak to me, and as such is potentially impressive but it's not helpful for me.

 

I too have difficulties to find the perfect sound balance, but the interface of my 8100NEX is really not user friendly for a non-audio expert. What's missing is a simple interface that allows for intuitive sound exploration without having first to understand sentences like this one: "A LPF set at 80Hz with a slope of -18dB/octave means that the output will be 18dB quieter for every octave HIGHER..."

 

This should be MUCH easier.

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...

 

This should be MUCH easier.

 "MUCH easier" does exist.  This is where the autoEQ supposed to do it for you... but I've found it to be less than effective to my taste in sound reproduction and would rather do it by ear, or use a third party means.

 

It could also be programmed such that LPF and HPF frequencies are automatically set the same... but then the setup person fails to have total customization.  In some instances, there are advantages to have different LPF and HPF crossover frequencies because of the natural rolloff of the involved drivers is compounded with the filter rolloffs.

 

Say you have a higher frequency driver with a 80-xx,xxxHz frequency response.  The 80Hz bottom is the -3dB point in the response curve... and let's say natural rolloff below that is -6dB.  If you set the HPF for 80Hz with a -6dB rolloff, in effect, you will hear a -12dB rolloff.

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