[j.f.leonard]

Originally Posted by david in germany

I think the stock hifi woofers are also 2ohm. The impedance isn't your issue.
The 400/4 looks to only have crossover variation to 200hz but I also doubt that would be an issue.
How are your gains set? Multimeter like JL recommends (voltage output), SMD DD1 or by ear?

Ive got it set by ear since I dont have any sort of equipment for that

[david in germany]

You need to pick up a multi meter and follow the JL manual instructions.

[j.f.leonard]

Originally Posted by david in germany

You need to pick up a multi meter and follow the JL manual instructions.

Okay so if Ido that and do everything as the manual tells me, you're saying the factory under seats are going to produce sound as crisp, clear and loud as my upgraded doors?

[david in germany]

Originally Posted by j.f.leonard

Okay so if Ido that and do everything as the manual tells me, you're saying the factory under seats are going to produce sound as crisp, clear and loud as my upgraded doors?

Can’t say that. Mid bass is never going to be crisp. Solid maybe. But tuned properly will rule out under driving them.
Did you ever mention what door speakers you installed?

Also can you post a pic of the control side of your 400/4?

[j.f.leonard]

Originally Posted by david in germany

Can't say that. Mid bass is never going to be crisp. Solid maybe. But tuned properly will rule out under driving them.
Did you ever mention what door speakers you installed?

Also can you post a pic of the control side of your 400/4?

I mentioned in my main post I believe that I installed the Helix Match component speakers in the doors. I dont have a pic right now but if you are looking to see what the gain is at it will be hard to tell because its just a little Phillips head screw and it isn't numbered or anything. They also label it as input sensitivity but from my understanding its the same thing as gain. I believe I have it turned right at about half way if that helps.

[david in germany]

Originally Posted by j.f.leonard

I mentioned in my main post I believe that I installed the Helix Match component speakers in the doors. I dont have a pic right now but if you are looking to see what the gain is at it will be hard to tell because its just a little Phillips head screw and it isn't numbered or anything. They also label it as input sensitivity but from my understanding its the same thing as gain. I believe I have it turned right at about half way if that helps.

I am curious of the overall crossover settings.

Yes, I am quite familiar with the JL labels on the amps(sensitivity vs gain) . Should be a flat head driver, not the Phillips.

Just trying to look at all the variables to get this figured out for you.

[j.f.leonard]

Originally Posted by david in germany

I am curious of the overall crossover settings.

Yes, I am quite familiar with the JL labels on the amps(sensitivity vs gain) . Should be a flat head driver, not the Phillips.

Just trying to look at all the variables to get this figured out for you.

Ah okay I thought is was a phillips but I wasnt sure. I will try to get a pic tomorrow of the 400/4. Out of curiosity, If it turns out I have everything properly set, what would the next step be?

[david in germany]

Originally Posted by j.f.leonard

Ah okay I thought is was a phillips but I wasnt sure. I will try to get a pic tomorrow of the 400/4. Out of curiosity, If it turns out I have everything properly set, what would the next step be?

You could reduce the sensitivity of the door speakers so they do not overpower the under seat woofers or add some type of signal processing to balance it out.

[mweisdorfer]

Originally Posted by j.f.leonard

Okay. First, i have upgraded door component speakers running off of a JL JX400/4. I use the signal from my 676 technic harness for that amp. I am using the lc2i to send signal to my sub amp as I had issues with the preout signal for whatever reason and was recommended the LC2i by many people. I have checked all of my filters on the amps and everything is right around where it should be. I am not saying the stock under seats sound bad, I am saying they arnt as clean as my upgraded doors and they definitely are not as loud at any given volume which I believe comes from the difference in impedance if there is one.

The stock BMW under the seat subs tend to be "muddy"; it's just the way they are.

[kaigoss69]

With your setup you will not be able to band-bass the midbass frequencies, since you can only use either high-pass or low-pass at the amp. I sure hope it is set to high-pass which means when only playing the underseats, you should be hearing high frequencies that are normally reserved for tweeters (but that should not be related to the problem of poor mid-bass).

[j.f.leonard]

So upgraded under seats would be beneficial? Im going to check my filters one more time in a few minutes and get a pic of the control side of my 400/4.

[j.f.leonard]

What should my under seats be low passed or high passed at? And then what should my doors be low or high passed at?

[david in germany]

Originally Posted by j.f.leonard

What should my under seats be low passed or high passed at? And then what should my doors be low or high passed at?

Since the 400/4 has the max of around 200hz high or low, the doors should get 200hz high and under seats 200hz low.

Originally Posted by j.f.leonard

So upgraded under seats would be beneficial? Im going to check my filters one more time in a few minutes and get a pic of the control side of my 400/4.

It will not make much difference in your case unless you can get the band pass frequencies you need from some type of processing.

[j.f.leonard]

Originally Posted by david in germany

Since the 400/4 has the max of around 200hz high or low, the doors should get 200hz high and under seats 200hz low.

It will not make much difference in your case unless you can get the band pass frequencies you need from some type of processing.

Okay gotcha. I will try that out and see what happens. I believe I had my under seats low passed at 180 but i put them at around 140 just now to see if i could hear a difference. Heres the pics i took. I appreciate everyones help!

[david in germany]

Crank both of your frequency knobs all the way to the right. Your sensitivity knobs do not seem to be set the same either.

[j.f.leonard]

Originally Posted by david in germany

Crank both of your frequency knobs all the way to the right. Your sensitivity knobs do not seem to be set the same either.

Gotcha, will do. Where should my input sensitivities be?

[david in germany]

Something else I noticed, you have 4 channels out from the technics harness, set your 400/4 to 2 channel input, use the front signal for the 400/4 and the rear signal to your sub amp. you can then remove the lc2i to have a flat signal without a boosted low signal. less wires to deal with as well.

Originally Posted by j.f.leonard

Gotcha, will do. Where should my input sensitivities be?

set via the multimeter as JL recommends in the manual.

https://www.amazon.com/AstroAI-Digit...s%2C344&sr=8-3

[j.f.leonard]

So I went and turned my filters how they should be and nothing improved, so I guess my next step will be to buy a multimeter tomorrow or as soon as I can and set the input sensitivities correctly and hope that does something. The under seats are still just so much quieter than the doors :

[mweisdorfer]

Originally Posted by j.f.leonard

So I went and turned my filters how they should be and nothing improved, so I guess my next step will be to buy a multimeter tomorrow or as soon as I can and set the input sensitivities correctly and hope that does something. The under seats are still just so much quieter than the doors :

The logic 7 under the seat subs are 2ohm and rated around 60watts. So, they probably won't keep up with your new Helix & Match door speakers.

You need some kind of DSP, a 6 channel amp & better under the seat subs that are mid bass oriented.

[j.f.leonard]

Originally Posted by mweisdorfer

The logic 7 under the seat subs are 2ohm and rated around 60watts. So, they probably won't keep up with your new Helix & Match door speakers.

You need some kind of DSP, a 6 channel amp & better under the seat subs that are mid bass oriented.

Okay. I think upgraded under-seats will be first, so what will be my best bet rated at around 100 watts or so? Im also on a budget, so nothing extremely expensive!

[david in germany]

Originally Posted by j.f.leonard

Okay. I think upgraded under-seats will be first, so what will be my best bet rated at around 100 watts or so? Im also on a budget, so nothing extremely expensive!

A used set of Logic 7 underwear woofers is where I would start looking. Avoid the Earthquake SWS woofers.

[mweisdorfer]

Originally Posted by j.f.leonard

Okay. I think upgraded under-seats will be first, so what will be my best bet rated at around 100 watts or so? Im also on a budget, so nothing extremely expensive!

I have read a lot of positive things about the pioneer shallow mount 8" subs. You can get them on eBay from reputable sellers for around $85-90 each. You will probably need some 8" mounting rings made of MDF.

Anything over a mounting depth of 2 1/8, you will need to offset it. You will need to be handy with s dremmel. You'll have to notch the mounting rings in order to get them to fit.

I had the logic 7 subs on a 60w amp abs didn't like them. They are too muddy for my taste.

https://www.crutchfield.com/p_130TSS....html?tp=68848