Now that I got the ported JL's in the rear well Subthump box I was thinking about something else. The ported box seems to pick up the low bass very well - unfortunately it misses a lot of the other frequencies. I was thinking about putting some other subs in the back similar to the millhouse box. Is there a box out there I can fit 2 12"s in - or do I have to make my own? If there isn't one - is it because of volume limitations or what...because I know there is enough space for one. I just want to put some cheap MTX's in there or some other cheap subs to pick up the higher bass frequencies in a sealed box. Thanks for your input.
Troy.

 

What is it that you're trying to do? Do you want to replace the well box with a Milhouse, or do you want to add a second box? You should not be lacking any bass with that setup. You should have a pretty flat and equal response down to your tuning frequency. If it is actually your subs that are lacking, make sure the low-pass crossover just isnt set to low. 80Hz is a good point. Also make sure you don't have any bass boost turned on anywhere because that could drown out the upper bass.

My best guess would be that your mid-bass drivers cannot keep up with the subs. With a dual ported setup you'll need some pretty strong components to keep your sound quality equal. Unless you have some decent components now, I would suggest you pick up a pair of Adire Audio Koda 6's and throw those in the doors. Those will be able to keep up with the subs and at $80 per driver it's a good deal.

 

You won't be happy with anything less than the setup you have. Unless maybe you try out some different subs and find some you like. But as for higher frequencies, Chameleon is right--the rest of you system probably cannot keep up. You'll need a good set of components with plenty of midbass. Are you running HU power to your speakers. That could be the reason. And like was mentioned, check you amp's settings. You don't really want subs kicking out a lot of mid frequencies anyhow.

 

Well, what I wanted to do was throw in a second box. When I had my Audiobahn setup the subs seemed much louder on a lot of songs, the JL's just don't seem to be hitting those notes. I have a pioneer 7400mp cd player going to it. I'll adjust the amp some to see what I can get - but I was thinking about trying to get it louder anyways so I would still want a second box in there.
I might be able to just go with some 10" subs maybe.

 

You must be a serious basshead then Have you considered installing some nice mids in the rear sails? If you're still wanting to go the 10s' route, I can build you a very simple box for them. What kind of power are you running? Is this the same amp you had on the audiobahns before? Maybe you have some friend that would let you demo different subs in there. Just a thought.

 

Never mix sub sizes or boxes. You'll end up with bass but very poor sound quality. Think about it. 35Hz on say a 12" JL in the ported box you're using is going to sound different than a 10" JL @ 35Hz in a sealed box. So you'll be hearng 2 different notes when you're suppose to be hearing one.

If you want more boom look at other ways or use the same subs in the same box volume wit hthe same tuning frequency.

What model are the subs in your poted box? What size? What impedance? What amp are you running? How is it wired? What is the box volume? What's the tuning frequency?

 

I am using 2 12" JL JL 12W3 4 ohm subs.
I am using a Lanzar Vibe 240
2 x 200 Watts RMS at 4 Ohms
2 x 400 Watts Max at 4 Ohms
1 x 800 Watts Max at 4 Ohms Bridged
2 x 375 Watts at 2 Ohms

Right now I have each sub wired in parallel drawing a 2 ohm load to each channel on the amp. ( 2 X 375 Watts)
I'm thinking about switching them over to each sub at 4 ohm load to each channel, or both subs connected via 1 channel at 4 ohm using the series & parallel combination. I'm not sure there would be any advantage using it bridged over using each channel at 4 ohms per sub.
Anyways, I have the frequency on the amp turned down to 40 Hz (lowest setting).

 

I assume you meant dual 4 ohm.

There shouldn't be any difference from 2 ohms per channel and 4 ohms bridged since the amp will see a 4 ohm load total either way.

But......you say: "Anyways, I have the frequency on the amp turned down to 40 Hz (lowest setting)."

do you mean the x-over is on LP@ 40Hz? If so that's the problem right there. You should have the x-over at about 80Hz or so and if the amp has it, set the subsonic filter to about 5Hz below the box's tuning frequency.

 

Agreed

Also, you don't have the most powerful amp. Did you just buy this amp? I don't recall. But if you could toss a few more watts at those subs it wouldn't hurt. Maybe you could look into getting a bigger amp.

 

So 4 ohms per speaker per channel would not be a good idea then? I was assuming that by: 2 x 400 Watts Max at 4 Ohms they meant - per channel at 4 ohms. Is this the case or not?

 

Seems to me that you're getting Max watts and RMS watts confused. Forget about Max power because it's vertually useless and makes an amp seem more powerful than it really is. Concentrate on RMS wattage, which is continuous power. If you're amp is stable at 2 ohms, I'd just run each sub parallel to each channel. But it still seems like your amp isn't all that powerful. Now if you had a JL 500.1 or JBL 1200.1 amp, then you'd have some juice for those subs. Don't forget to change the crossover frequency like x7x7 suggesed.

 

Alright. It actually is pushes the subs just as hard as I heard them in Aaron's car. I'm pretty sure I could get them to blow off this amp suprisingly enough.

 

Gotcha. So we know it's not a power issue. That's good. And what about the crossover setting? Have you changed that yet?? Just checking.

 

Well now that I know it's wired correctly i'll change that tomorrow. I still want some more bass - I had 4 subs in my car before (pic. on my page). It was sooo freakin loud. I just need some more thump - hmm...I guess I could pick up some more used JL's maybe to throw in a second ported box behind the seat.

 

My guess troy is with with everyone elses, just adjust your settings on your amp. With the amp I have I could hit the hard hit upper bass that your loooking for. I changed to that and lower bass all the time, but im a bigger fan of deep bass. Those 2 12s can pop yer head of if you want em too. Ive seen 2 12w3s hit 157 dbs