high and low pass filters

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calisonic

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Could somebody please explain what these functions do on my cd player. I have the following frequency options for low pass filter: 80 100 120 140 160 I then have a lpf normal and reverse option.
For high pass filter I have the same frequencies.
Thanks
 
A low pass filter will pass the low frequencies (low notes), if it's an 80 Hz low pass filter, it will block the frequencies above 80 Hz and let 80 Hz and lower, "pass".

Same with a high pass, it will let the higher frequencies pass and block the lower frequencies.
 
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I see. So if my sbs are rated to 18 - 300 hrtz I should set it to 160 or nothing?

And then what is the normal and reverse for?
 
If you meant subs, you want your low pass to be set on 50 and then you can add more bass by giving it plus numbers. Mine is set at +2 but it's system specific.

Careful though, I have my sub stand alone so I only up the the sub level on my head unit. I'm running a pioneer, you?
 
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It's a sony. But yes I have a seperate adjustment for the subs which safe on their own rca out puts of plus or minus 10.
 
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On a similar note, i recently upgraded to 2 12s. They came in their own box and sounded great but the box wont fit under that basket of electronics that hangs under the rear deck.
So i put them in my old sub box which i built my self which is smaller but fits. Apparently it is too small because in this box they are about half as loud as the box they came in.

So i need to build a new box and here's the question.

Does the shape of the box matter as long as it has the same cu ft?
Because the box they can in has the same height and width but is shorter than the one i built. It is like a cube but stretched to a rectangular prizim.

Now the one i will be building will be just wide enough to fit between the wheel wells,and just short enough to fit under that basket of electronics, plus clearance for the speakers themselves which will be facing up. It will then be longer from front of car to rear of car wise to make for the same volume as the box these new ones came in.

So overall, the distance from the sub magnet to the back of the box will be less than the box the came in which is basically two perfect
cubes glued together.
Will this produce the same sound?

Thanks!
 
Lmao! Talk about hard to imagine, but you wrote it well so I understood. You're gpnna get the best sound facing the speakers towards the rear of the car in a sealed box. This uses the actual trunk space as a type of enclosure giving air for the subs to "rebound" off of, thus giving more dynamic bass. If the subs are free flowing (potted box) then facing them up is ok. But in a sealed box, facing them up will require way more power to sound good because you're now "moving the air" in the passenger compartment instead of just the trunk.

I had two 15's facing the rear of the car at an angle, it sounded clean and not all sloppy because of the placement.
 
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But there isn't enough room between the carpet and that stupid basket to fit a box where the subs are facing the rear. Or at least that's how it seems.
 
The plastic/cardboard/carpet thing under there actually pushes up quite a bit. Let me find a picture of mine....

DSC00292.jpg

DSC00431.jpg

DSC00430.jpg

DSC00432.jpg

DSC00433.jpg
 
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Yeah, i tried removing that cover.
I thought you said they should face the rear?



That's exactly how mine is (in your pictures) but its too small for the two 12's to sound very good.



To be honest it looks like your box in those pics is small. Are those 15's ?
 
Last edited:
I did say they should face the rear, I also said mine were only angled because they are 15's. The second to last picture shows the angle, obviously they are more angled up but thats the most I could angle them because of the magnets.

My box was a little small...I ended up ditching one of the 15's when I installed my air horns.
 
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Sorry to ressurect this, but I still don't know what to set my lpf and hpf to. J had 50 hertz but my lowest option is 80 and if I block everything below that I know ill be loosing some important frequencys that are often used.
Additionally, if I set the hpf to 160 I am loosing some other common bass frequencys right?
 
It all depends on what you wanna hear and the size of your sub. I had my sub at 50 (or maybe 80) hertz and modified that amount up or down based on how much bass I needed. That way it only adjusted my sub's bass and not the stock speakers. I'm running a 10" in the Honda.
 
calisonic said:
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Sorry to ressurect this, but I still don't know what to set my lpf and hpf to. J had 50 hertz but my lowest option is 80 and if I block everything below that I know ill be loosing some important frequencys that are often used.
Additionally, if I set the hpf to 160 I am loosing some other common bass frequencys right?
Click to expand...

Remember, the low pass filter Passes the frequencies Below your 80 Hz setting, and filters out the frequencies Above 80 Hz.

It sounds backwards, but that's the way it works.

It's kind of like your oil filter, it passes the oil, but filters out the dirt.:)
 
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J said:
It all depends on what you wanna hear and the size of your sub. I had my sub at 50 (or maybe 80) hertz and modified that amount up or down based on how much bass I needed. That way it only adjusted my sub's bass and not the stock speakers. I'm running a 10" in the Honda.
Click to expand...

Wouldn't I be able to control tha)e amount of bads with the sub volume option?
 
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Edit: and what is the actual purpose of lpf? I can understand if its at say 20 or 50 hertz be because many suns wont produce sounds that low, but this is just 80 hertz. Isn't some of the loudest bass at around 60 hertz?

Also, what happened to the edit button?
 
the purpose is to only pass frequencies to the subwoofer that it is capable of reproducing. the "low pass" cuts all frequencies *above* what you set it to, so that they don't interfere with the quality of the sound.

Get two or three CDs that you like. (Right.. CDs, *not* mp3s. mp3 files cut the high and low ends as part of the compression algorithm.) Hit play, and tune by ear. My guess is that 80 will work quite well for you, which would give you everything 80 Hz and below. It does vary dramatically though from one "space" to another. (And by what increments your unit allows you to adjust by) If you like 100 hz better. (Which again, would be 100 and below,) go for it.
 
calisonic said:
Wouldn't I be able to control tha)e amount of bads with the sub volume option?
Click to expand...

No, this just sends more power to the sub via the head unit. If you're using the wrong low pass frequency, this will make it sound worse.

How I use my equalizer.

Bass on stereo to -3, mids +3, highs +4
50htz +2-3 depending on rap/rock
Sub volume +1

I use my sub for 80% of my bass so there is no need to send bass to the stock door speakers (same setup on my Lincoln back in the day). Use the stock door speakers for treble only and save the bass for the sub.

Start from scratch. I always have a level all zero starting point where bass/mid/treble is at zero.

Get the sub to sound how you want by setting the htz/sub volumne levels. Then adjust your mids/treble on the door speakers.
 
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Thanks j ill try that.
On what Tixer said,don't most subs have a frequency response if at least 300 hertz? Even the cheap ones? Aren't the subs better suited for producing the 80 to say 250 range better than the interior speakers?
Thanks again.
 
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Well here's an interesting bit. Yesterday I had my audio test cd and had it play a steady 50 hrtz tone. I went.through all settings of hpf and lpf but the sound was exactly the same. So I guess the damns thing is just for show.
luckily there is one on the amp so ill try that.
 
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