Hi i've had my fi btl in now for over two months and although im fine with it i've noticed its not hitting the highs quite as well as i want it too....but the lows are exremely awesome i have the box tuned to 33hz could that be the problem...any help is appreciated.

How big is your box? How much power do you have? What's it all in?

Perhaps you need to add some midbass drivers to your sound setup

Perhaps you shouldn't expect a sub to play anything but sub-bass.

^ You once told somebody they can use their sub to cover their mid-bass in their setup, it is defiantly doable. In your situation though you may need some additional drivers.

Subs shouldn't play anything but sub bass frequencies, hence the name subwoofer. I don't know the inductance specs on the BTL, but I imagine they would be on the higher side, and if they are, it owuld make it impossible to play past the natural inductance roll off no matter what the Low pass filter settings are.

^ You once told somebody they can use their sub to cover their mid-bass in their setup, it is defiantly doable. In your situation though you may need some additional drivers.

That someone actually spent time to make a thread that was useful to others reading. There is a time and a place for anything, but based on the information given my response is dead nuts on.

I have to agree that a BTL in a ported box tuned to 33Hz isn't designed for midbass. That LPF should be set to 50Hz, so that sub stays tight and hits hard and deep, like it's meant to do.

If you want midbass, try using 8" midbass drivers from someone like DynAudio, Seas, or Vifa. Then you can use them as rear fill too, and add a L-R differenced signal delayed about 20msec and band-pass filtered. That would be an outstanding addition to a sub and a 2-way component set up front.

I have to agree that a BTL in a ported box tuned to 33Hz isn't designed for midbass. That LPF should be set to 50Hz, so that sub stays tight and hits hard and deep, like it's meant to do.

If you want midbass, try using 8" midbass drivers from someone like DynAudio, Seas, or Vifa. Then you can use them as rear fill too, and add a L-R differenced signal delayed about 20msec and band-pass filtered. That would be an outstanding addition to a sub and a 2-way component set up front.

Its in a 4 cu. ft box with 2000 watts rms into it... it hits anything between 33 hz and 45 hz fine, but between 45 and 65 its not to its full potential it seems

Well also wats the goal your lookn for? do you want sq or spl? More info plz

Well also wats the goal your lookn for? do you want sq or spl? More info plz

well im looking for spl but im not looking to enter any comps...so basically the loudest it could possibly be while still being a daily driver

Well also wats the goal your lookn for? do you want sq or spl? More info plz

well im looking for spl but im not looking to enter any comps...so basically the loudest it could possibly be while still being a daily driver

Crossover setting basics link

read this plaese. set your sub's LPF to 50Hz, 18dB slope.

Set your HPF for components to 100Hz, 12dB slope.

See how that sounds to you. Worth a try.

It might not be so much that it isn't "hitting" in the 45-65hz range, but rather that the response between 30-45hz is so exaggerated that the upper-bass response pales in comparison which is giving you that perception. Basically, it might just be a frequency response problem.....too much on the bottom and not enough on the top. If you had easy access to an EQ (such as one possibly built into your headunit) I would recommend you try decreasing the level of bands in the 30-45hz range and either raise the level of the subwoofer some or use a little more range of your volume knob to get the overall output to the level that you desire. This might help bring the upper-bass to the level you desire while keeping the low end where you want it. Here an excerpt from my Dcon review when I tested it in a ported enclosure that might give you an idea of what I'm talking about;

After initially listening ported, the low end came alive but I lost upper end response. I tried various box positions just to be sure that it wasn't install related. I ended up bringing the overall sub level up 3-4db, effectively increasing power to the driver, and then EQ'd down the low end since it was a little peaky and overbearing down low for normal everyday listening with music (but it sure was fun when blasting the volume!). This brought the upper end response to the level it needed to be and smoothed out the low end.

But it would be useful to know what the rest of your system consists of and what settings you are using. It's hard to help without really knowing what you are working with.

Well also wats the goal your lookn for? do you want sq or spl? More info plz

well im looking for spl but im not looking to enter any comps...so basically the loudest it could possibly be while still being a daily driver

Crossover setting basics link

read this plaese. set your sub's LPF to 50Hz, 18dB slope.

Set your HPF for components to 100Hz, 12dB slope.

See how that sounds to you. Worth a try.

From a brief read, that crossover link overlooks some important information that is necessary to consider when properly setting crossover points and misstates some information.

In our environment, it's usually best to just set them by ear to what sounds best rather than using "rules" which don't really apply in most scenarios.

From a brief read, that crossover link overlooks some important information that is necessary to consider when properly setting crossover points and misstates some information.

In our environment, it's usually best to just set them by ear to what sounds best rather than using "rules" which don't really apply in most scenarios.

That was simply written to illustrate the reason not to set your crossover points to the same frequency for HPF and LPF, which most people initially try to do, which in turn causes warm spots.

If you want the more in depth version of how to set up a soundstage, this would be that article.

My link

Acoustics are a science. Everything that happens in a car, a room, or a field can be explained. Rules have their place. If nothing else, it's a good starting point, which is exactly what I stated that link to be. A place to start.

Impious, if you would care to add to, or correct that article, I'd be more than happy to add your thoughts to the page. I wrote that link to help folks, and answer commonly asked questions I've seen over the years to save having to re-write the same answers over and over again on forums. I'm always upen to input from people.

Let me know.