leave subsonic filter off. low pass subwoofer where your midbass/woofers pickup. typically below 100hz somewhere.
you will not damage your sub by playing freq. below 25hz.
you definitely don't want your sub playing up to 500hz.
The answers you seek will come once it is installed, and playing nice with all other speakers.

 

Re: Questions about sub freq response

I'm not quite sure. My sub's rated freq response is 25-500 hz

1.Is this the range where the sub will work when getting sound waves?
2.If I play something under it's range, will it damage it?
3.Should I be setting my subsonic filter right under the frequency response of my sub?
4. Should I also set my low pass filter to it's max freq response?

1. That is the range where the speaker will play relatively flat.

2. In a ported box or sealed box, you should be able to send any frequency even below 25 Hz and not damage the driver. However, If you run the speaker in Infinite Baffle, then you should not send frequencies to the driver at or near its Resonant Frequency or damage can occur. That is where a subsonic filter would come into play.

3. Dont need to use one unless you are running IB. If so then set the subsonic to above the driver's resonant frequency to protect the driver

4. Low pass filter should be set to somewhere in the 80 Hz area or below. Above 80 Hz is about the area which one can tell the direction of where the sub is located. You want the sub to blend with your midbass and have it sound like its source is out in front of the winshield and not behind you.

 

Re: Questions about sub freq response

1. That is the range where the speaker will play relatively flat.

2. In a ported box or sealed box, you should be able to send any frequency even below 25 Hz and not damage the driver. However, If you run the speaker in Infinite Baffle, then you should not send frequencies to the driver at or near its Resonant Frequency or damage can occur. That is where a subsonic filter would come into play.

3. Dont need to use one unless you are running IB. If so then set the subsonic to above the driver's resonant frequency to protect the driver

4. Low pass filter should be set to somewhere in the 80 Hz area or below. Above 80 Hz is about the area which one can tell the direction of where the sub is located. You want the sub to blend with your midbass and have it sound like its source is out in front of the winshield and not behind you.

Okok. I have a sound ordnance prefab ported box. It's spec says tuned for 34hz. I don't think it's infinite baffle?

 

I can almost guarantee that box is not right for whatever sub you have. What sub do you have? Prefabs stink.

 

Right it's not. But it's all confusing and it sounds nice the way it is now.

 

Infinite baffle is basically no enclosure. There's a lot of variations of IB installs but basically free air. That's for another topic. Boxes have to be built to the speakers specs. So prefabs are sometimes horrible and sometimes tolerable, but never right.

 

What HRA said. Tuned to 34hz means nothing for your sub. Ports are very specific. A half inch difference will change the tuning frequency

 

So what should I set my subsonic to?

 

i always suggest using a subsonic filter on ported boxes...am i missing something?

 

Nope. I always use it if I got it. Especially if your high power. Easy to hammer a sub. I believe HRA would be in the minority with that one.

 

Yeah I know one thing you hit a typical sub with 600w at 15hz and you'll likely see the magical smoke.

 

Re: Questions about sub freq response

I'm not quite sure. My sub's rated freq response is 25-500 hz

1.Is this the range where the sub will work when getting sound waves?
yes it will work relatively flat

2.If I play something under it's range, will it damage it?
it can

3.Should I be setting my subsonic filter right under the frequency response of my sub?
COLOR="DarkRed"]yeah 25, or 30-Hz would be good[/COLOR]

4. Should I also set my low pass filter to it's max freq response?

low pass or high pass? 80, 100, 120... have a play with it and find the right point yourself

 

So play with the box design program called http://www.linearteam.org/download/winisd-07x.exe learn how to use it. There is a nice tutorial on here. Your sub will only take about 400 regardless of what the specs say. Tune it to 32 - 35hz in the program. It will give you a box size and port. And ask questions as you go.

Accept that you will build more than one "first" box. It's ok. I just screwed up a box and I've following box instructions for 20 years. Plus I build wood for a living. Yes build wood!

 

Listen to SkizeR and miniSQ on this one.

A ported box needs a subsonic filter close to the tuning frequency. Don't set it too much lower than the tuning frequency or you'll need to buy a new sub. MiniSQ's recommendation of 1/2 octave below the tuning frequency is pretty solid. You an easily play a sub beyond 120hz without any real localization. I've not had too much luck above that point, but then again, I've never needed a sub to play that high. One of the most important factors in preventing subwoofer localization is the rattles and harmonics. If you have panels buzzing, or a sub with high harmonic distortion, then you will hear the "sub" behind you.

 

As a matter of fact, I got something shaking and rattling in the back gotta figure it out. I think it might be the licence plate.

 

I've never used a subsonic filter with ported boxes and never had a problem. Not even with a mid 30's tune with more than rated power on the subs. I sure don't suggest using this practice but I like living on the edge

 

Below the tuning frequency the sub plays IB, the enclosure does nothing to keep the cone under control. A HPF is a really good idea, I wouldn't run a ported box without one.