Problem with Alpine SWR-12D4

[krokodill1]

I have alpine type r 12 inch subwoofer in sealed box. Before it was in ported box but the bass was too muddy and overpowered songs so i changed it to sealed and now it souns clearer.
The problem is that it doesnt play the bass that is in the background in songs. I dont know how to explain it but for example in this song

the bass plays in background and fills the room. When i listen to it in my car all i hear is when bass thumps. When i had a ported box it didnt play the background bass too.
At home i have logitech z623 sound system, it has 8 inch subwoofer and it fills the room with the background bass but alpine type r 12 all i hear is thump. Are 12 inch woofers not designed to hit this background bass and i should get 8 inch subwooferinstead to solve the problem or is it fault of the box that the woofer is in. I am using 1200w 1 channel amp i dont think the problem is in the amp.
Thanks in advance.

 

[lovinthehd]

Was either box modeled for that driver using appropriate software? What are the measurements of each box?

 

[William Lemmerhirt]

I haven't listened to the track yet but to me, "background bass" would be very deep/low bass. The answer to your question would be just the opposite. A larger driver would be more capable than a small one at reproducing that stuff. The fact that the Logitech sub plays this better(which is a little surprising)is only a testament to the overall design, by properly matching the driver to the enclosure. In your case, my question is similar to HD's in that, I'm wondering what specs were used to build either enclosure. It can't be overstated that the right size enclosure is key to any subwoofer, no matter what type.

 

[krokodill1]

Old ported box looked like that https://imgur.com/a/nFkX1. These are the specs invertor 100 mm x 150 mm, 40 L (1.41 cubic feet) , 18 mm MDF. This box was premade so probably the reason why it sounded bad. Now i have a small sealed box but im looking for a ported box but dont know which one to buy.

 

[Pogre]

Old ported box looked like that https://imgur.com/a/nFkX1. These are the specs invertor 100 mm x 150 mm, 40 L (1.41 cubic feet) , 18 mm MDF. This box was premade so probably the reason why it sounded bad. Now i have a small sealed box but im looking for a ported box but dont know which one to buy.

I'm pretty sure the box size has a lot to do with it. You need to get the t/s parameters of your driver. What is it (model number or name)? We might be able to help you out.

 

[krokodill1]

I'm pretty sure the box size has a lot to do with it. You need to get the t/s parameters of your driver. What is it (model number or name)? We might be able to help you out.

Umm not sure what you need to get the t/s parameters. All i know is that i have Alpine SWR-12D4 sub. Here is also subs guidebook maybe this has t/s parameters. http://vault.alpine-usa.com/products/documents/OM_SWR-1242D.PDF
Are there any premade boxes that would help me hit the lows with this subwoofer. Ive heard that all premade boxes are bad and that i should get a custom built one.
Thanks

 

[Pogre]

Umm not sure what you need to get the t/s parameters. All i know is that i have Alpine SWR-12D4 sub. Here is also subs guidebook maybe this has t/s parameters. http://vault.alpine-usa.com/products/documents/OM_SWR-1242D.PDF
Are there any premade boxes that would help me hit the lows with this subwoofer. Ive heard that all premade boxes are bad and that i should get a custom built one.
Thanks

You'll most likely be better off with a custom box, but you might get lucky

Lucky for you, all the info you need is right here.

Your driver is the fourth column from the left. It's a dvc 4ohm+4ohm woofer so you have a couple different wiring configurations you could use, but we're talking boxes right now! That chart tells you the recommended internal volume for a box, sealed or vented. Looks like you want 1.7^3' for a vented box with that speaker. They include port size too. The screenie I took has everything there. Hopefully someone with a little more diy skills will poke their head in here and take a look.

 

[TLS Guy]

You'll most likely be better off with a custom box, but you might get lucky

Lucky for you, all the info you need is right here.
View attachment 22257
Your driver is the fourth column from the left. It's a dvc 4ohm+4ohm woofer so you have a couple different wiring configurations you could use, but we're talking boxes right now! That chart tells you the recommended internal volume for a box, sealed or vented. Looks like you want 1.7^3' for a vented box with that speaker. They include port size too. The screenie I took has everything there. Hopefully someone with a little more diy skills will poke their head in here and take a look.

I am busy at the moment so I don't have time to model it, but at first glance that sub will work best sealed. Fs is 29 so it wont' play lower then around 35 Hz. Qts is 0.47 which in on the high side for a ported box. So it will incline to boom in a ported box. Alpine are car audio people, and so car drivers are generally designed for sealed application. Sealed, this unit has an F3 of 49 Hz so there will not be much bass in a sealed box without Eq.

So in the optimal sealed box it needs Eq of 12 db per octave starting at 50 Hz and a 12 db per octave roll off below 25 to 30 Hz at 12 db per octave to prevent driver over excursion.