high and low pass filters and Subsonic filter.

[neil4374]

Hey,

Well thanks for all you advice guys with my install. It sounds great. I still am confused in some areas especially high pass filters ,low pass filters and subsonic filters. I have enclosed two photos of my amp.

I understand what the above are for but the confusion starts when I look at the hz range of those filters. If the subsonic filter for the sub is 15 to 55hz and the low pass filter is 5ohz to 250 hz. why do the overlap each other?

its the same for the 3rd and fourth channels lpf and hpf

Sorry if this is dumb? Maybe I am over complicating things

View attachment 26556296View attachment 26556297

Click to read more...

 

[LosIsATool 5,000+ posts]

They don't overlap. You use them to create a bandpass. What you want the sub to play.

Subsonic covers the low end and will be set according to the subs enclosure. If it's sealed it can be opened up, low. If it's ported you set it 1/2 octave below the boxes tuning. LPF covers the top end. You set it just under where the mid bass speakers pick up. That one takes some listening to get dialed in.

HPF is for the mid bass.

 

[neil4374]

Thank you kindly again!

It is a ported sub.

These are the specs:

https://www.rockvilleaudio.com/rmw8p/

Would you be as kind as to look?

I don't understand the tuning/ octave part!

 

[LosIsATool 5,000+ posts]

SS at 35ish

LPF around 80

HPF around 100

Then use your ears to make adjustments. If you play it to far under box tuning it will break.

 

[neil4374]

Many thanks for looking at that for me.

Ok understand the ss and lpf.

The sub setting doesn't have a high pass.

Do you mean the high pass on my front component speakers?

 

[LosIsATool 5,000+ posts]

Many thanks for looking at that for me.Ok understand the ss and lpf.

The sub setting doesn't have a high pass.

Do you mean the high pass on my front component speakers?

Correct. It's their low point cut off. No filter is a brick wall it's just a slope. Meaning it will start to drop off past that point.

Like the sub. If the mids play to low they will break.

 

[neil4374]

Many thanks.

I am starting to get it.

Respect for your patience

 

[neil4374]

Sorry I just want to test my understanding.

So if the ss is 35hz and the lpf is 80hz as I correct in saying the sub

Will only play between sounds between 35 and 80hzbut taking into account they slope off at 35 and 80

 

[shredder1 10+ year member]

Yes, you are basically correct but every x-over has a slope... 6 db is gentle with a gradual rolloff... And then there is 24db which has a steep slope... These are guidelines and once set-up a fair amount of listening and adjusting has always been my favorite part... Mid bass has always been the tricky one for me... Of course once it's sounding good ... I rebuild... Always lookin' for more!

 

[neil4374]

And how do you know where 100 is on say a hpf.

It's easy on some of them as it's just 15hz to 55hz.

So it's easy to divide it up and estimate where the 35hz is.

But the hpf is 50hz to 300khz. That's more difficult to guess where 100hz is!?

 

[neil4374]

Yes, you are basically correct but every x-over has a slope... 6 db is gentle with a gradual rolloff... And then there is 24db which has a steep slope... These are guidelines and once set-up a fair amount of listening and adjusting has always been my favorite part... Mid bass has always been the tricky one for me... Of course once it's sounding good ... I rebuild... Always lookin' for more!

Many thanks

I am getting there!

 

[LosIsATool 5,000+ posts]

And how do you know where 100 is on say a hpf.It's easy on some of them as it's just 15hz to 55hz.

So it's easy to divide it up and estimate where the 35hz is.

But the hpf is 50hz to 300khz. That's more difficult to guess where 100hz is!?

Play tones. Move the filter until that tone starts to fall off.

 

[neil4374]

Ok I see!

I could make a cd with different sound ranges!

 

[shredder1 10+ year member]

And how do you know where 100 is on say a hpf.It's easy on some of them as it's just 15hz to 55hz.

So it's easy to divide it up and estimate where the 35hz is.

But the hpf is 50hz to 300khz. That's more difficult to guess where 100hz is!?

Now you see... You have to listen and adjust... pay particular attention to those low mid freqs... subs are easy just lowpass them at 80 to start... HPF is harder for mids... I've set them as high as 200 hz then brought them down... once you hear distortion, back offf and adjust your subs lowpass to blend those freqs... Ideally you should not be able to audibly locate the sub... Rockville?

 

[neil4374]

Now you see... You have to listen and adjust... pay particular attention to those low mid freqs... subs are easy just lowpass them at 80 to start... HPF is harder for mids... I've set them as high as 200 hz then brought them down... once you hear distortion, back offf and adjust your subs lowpass to blend those freqs... Ideally you should not be able to audibly locate the sub... Rockville?

Thank you, yes rockville