[PhiDeltBeers]

Not an audiophile here. Where do I need to set the crossover on the amp for optimal sound? 12" is really bigger than I wanted but got a good deal on it. I'm probably going to adjust the gain low. I mainly wanted to capture the lower frequency sounds that the stock 8" subs cant get. Anyone know where to set the crossover on the amp in order to pick up where the stock 8's fall off on the low end? Should it be a sharp (low frequency curve) or should it be more broad and "mix" in with the 8" curve. Wish I knew what the 8" curve looked like.

[PhiDeltBeers]

Oh, I have purchased...

12 " JL Audio W0v2-4 in a sealed JL Audio Prowedge box with an attached JL Audio J2 500.1 Amplifier.

Box and Sub: http://mobile.jlaudio.com/products_e...=9&prod_id=532

Amp: http://mobile.jlaudio.com/products_amps.php?amp_id=557

[kaigoss69]

Originally Posted by PhiDeltBeers

Not an audiophile here. Where do I need to set the crossover on the amp for optimal sound? 12" is really bigger than I wanted but got a good deal on it. I'm probably going to adjust the gain low. I mainly wanted to capture the lower frequency sounds that the stock 8" subs cant get. Anyone know where to set the crossover on the amp in order to pick up where the stock 8's fall off on the low end? Should it be a sharp (low frequency curve) or should it be more broad and "mix" in with the 8" curve. Wish I knew what the 8" curve looked like.

Not sure what you mean with "curve". The L7 amp subwoofer channel is low-passed at around 150Hz. This means the 8" subs play all frequencies below 150 Hz. Above 150Hz, the door speakers take over. Due to the speaker design and enclosure, the subs naturally roll off somewhere around 35 Hz IIRC. Normally, a trunk SW should be low-passed at around 80 Hz and not much higher. Try that setting, as well as 70 and 60. You will obviously have some overlap between the trunk sub and the underseat subs, which should normally be avoided, but you have no choice unless you also put an amp to the underseat subs and bandpass them into dedicated mid-bass drivers.

There really is no recommended setting, you just have to play around with it. You also have to find the right gain setting, to blend with the rest of the system. There are a few posts here with similar set-ups, go ask there what their x-over settings are.

[PhiDeltBeers]

That's kind of what I initially thought (there was going to be overlapping). I wish that JBL MS-8 would come out, but it's been in the making for 4 years, it seems. The last thing I want from the 12" JL is that 17 year old kid boomy sound. I want a nice tight bass drum kick. Not looking for overkill by anymeans. Quality beats quantity (volume) in my book. Anyone can throw in a couple a 12" speakers and be heard a mile away. I'm 32 with a wife and child and just want a nice clear sound, but I found the stock 8's a little weak. I had an infinty basslink in my Lexus IS, but wanted something a little better this go around. So....just play around in the 60-80 range with a modest gain setting?

[kaigoss69]

Originally Posted by PhiDeltBeers

That's kind of what I initially thought (there was going to be overlapping). I wish that JBL MS-8 would come out, but it's been in the making for 4 years, it seems. The last thing I want from the 12" JL is that 17 year old kid boomy sound. I want a nice tight bass drum kick. Not looking for overkill by anymeans. Quality beats quantity (volume) in my book. Anyone can throw in a couple a 12" speakers and be heard a mile away. I'm 32 with a wife and child and just want a nice clear sound, but I found the stock 8's a little weak. I had an infinty basslink in my Lexus IS, but wanted something a little better this go around. So....just play around in the 60-80 range with a modest gain setting?

X 10000000000000000000000000000000000000000000000000 000000

I've got a complete aftermarket system (minus head unit) sitting in my garage and I am not sure if I should start cutting and slicing just yet, in case the MS-8 comes out anytime soon. What intrigues me the most about that piece is the fact that they installed their prototype into an e90 325i with L7, left ALL the stock speakers in place, added three L7 tweeters and a trunk sub, and consequently won an IASCA SQ competition !!! Furthermore, de-eq'ing the HU processing and tuning is done automatically by the unit, which is a big plus for me since I have no clue whatsoever what to do to make the damn car sound good - I just know when it does!

So much for me, LOL. Your problem is going to be a "hole" in between the trunk sub and the door speakers. IMO that hole can only be filled by amplifying the underseat subs and turning them into midbass drivers. They actually sound very good with some added power, as long as you cut them off below 50 Hz.

[VP Electricity]

Originally Posted by kaigoss69

Your problem is going to be a "hole" in between the trunk sub and the door speakers. IMO that hole can only be filled by amplifying the underseat subs and turning them into midbass drivers. They actually sound very good with some added power, as long as you cut them off below 50 Hz.

LOL. X infinity.

Oh, the xover point? Turn it until it sounds good

[PhiDeltBeers]

Originally Posted by kaigoss69

So much for me, LOL. Your problem is going to be a "hole" in between the trunk sub and the door speakers. IMO that hole can only be filled by amplifying the underseat subs and turning them into midbass drivers. They actually sound very good with some added power, as long as you cut them off below 50 Hz.

Ok, ok. Easy enough. How much power will those stock 8's handle? What amp to buy?

The problem comes in here: adding another amp. Is this the point I have to jump up to something other than a PAC LOC. I've already bought my equipment. I've read enough to understand how to install a sub and an amp. 2 amps make me a little nervous as far as the install goes.

[kaigoss69]

Originally Posted by PhiDeltBeers

Ok, ok. Easy enough. How much power will those stock 8's handle? What amp to buy?

The problem comes in here: adding another amp. Is this the point I have to jump up to something other than a PAC LOC. I've already bought my equipment. I've read enough to understand how to install a sub and an amp. 2 amps make me a little nervous as far as the install goes.

You would need another 2 channel amp with a high-pass filter. You can get the signal from the JL amp's RCA (pass-through) output or you can split the signal coming from the LOC if the signal is strong enough. Or you can just get a 4-channel amp that can do it all. The underseat subs will play nicely with 100 - 150W per side.

[PhiDeltBeers]

Do I just disconect the stock speaker wire from the stock subs and run new speaker wire from the new amp?

[VP Electricity]

Easier. Cut the speaker wire coming out of the OE amp. Extend both sides, one side to the input or LOC you are using, and the other to the output.

[PhiDeltBeers]

That's easy enough! Couple more questions... Do I need to run another power wire to the battery for this (2nd) amp, or can I just tap into the existing power wire I ran to amp number 1. Also, if I want the stock 8's to run from 150 hz and cut off at 50 hz, how do I accomplish that??? On the 2nd amp, if I set it on 150hz, doesn't it just fall off like it does with the stock amp?? How do I cut it at 50hz and then set the 12" at 50 hz and below? Do I need more equipment for that? Geeze, this started so simple! I'm learning though and I appriciate you guy's help.

[kaigoss69]

Originally Posted by PhiDeltBeers

That's easy enough! Couple more questions... Do I need to run another power wire to the battery for this (2nd) amp, or can I just tap into the existing power wire I ran to amp number 1. Also, if I want the stock 8's to run from 150 hz and cut off at 50 hz, how do I accomplish that??? On the 2nd amp, if I set it on 150hz, doesn't it just fall off like it does with the stock amp?? How do I cut it at 50hz and then set the 12" at 50 hz and below? Do I need more equipment for that? Geeze, this started so simple! I'm learning though and I appriciate you guy's help.

- Better off running a new fused power wire and ground wire.

- For the underseat subs, you engage the amp's high-pass filter and set it for 50 Hz. This means all frequencies ABOVE 50Hz will get passed through to your speakers. The signal is already low-passed at 150 Hz by the factory amp, so you are essentially running a bandpassed signal (50 Hz - 150 Hz) to those subs.

- For the trunk sub, you engage the amp's low-pass filter and set it for 50 Hz. This means all frequencies BELOW 50Hz will get passed through to your sub.

BTW, I would seriously look at a 4-channel amp instead of 2 separate amps, for the sake of simplicity and a much cleaner and nicer looking installation.

[PhiDeltBeers]

Ah ha! So this is pretty simple. I didn't understand the high pass...low pass thing. I would just buy one amp, but I already bought this:

http://www.shopatron.com/products/pr...23922.0.0.0.0?

Do all amps have a high pass...low pass filter? Also, do you guys have any recs on what amp to get? Preferably inexpensive and small (in size).

[PhiDeltBeers]

Originally Posted by kaigoss69

- Better off running a new fused power wire and ground wire.

- For the underseat subs, you engage the amp's high-pass filter and set it for 50 Hz. This means all frequencies ABOVE 50Hz will get passed through to your speakers. The signal is already low-passed at 150 Hz by the factory amp, so you are essentially running a bandpassed signal (50 Hz - 150 Hz) to those subs.

- For the trunk sub, you engage the amp's low-pass filter and set it for 50 Hz. This means all frequencies BELOW 50Hz will get passed through to your sub.

BTW, I would seriously look at a 4-channel amp instead of 2 separate amps, for the sake of simplicity and a much cleaner and nicer looking installation.

Here is the amp I bought that's attached to the box and sub. I don't see a high/low pass on it? I assume it plays from 50hz down when set at 50hz????

http://mobile.jlaudio.com/products_amps.php?amp_id=557

If this is the case, the 2nd amp WILL HAVE to have the high/low filter....correct? Unless I'm, in fact, missing the swith on the JL amp.

[PhiDeltBeers]

I think this will work in conjunction with everything. Has the hp/lp filter. Found it for $139 shipped. JL Audio J2 360.2

http://mobile.jlaudio.com/products_amps.php?amp_id=557

[kaigoss69]

I will not recommend a 2 channel amp. Instead I will recommend this one because it is such a phenomenal deal:

http://www.sonicelectronix.com/item_...n+KAC-X4R.html

This amp has everything you will ever want. It has the crossovers you need. Power is just right for what you are doing (100W x 2 for the fronts and 300W x 1 for the sub, rated at 14.4 V). It is digital meaning it will draw much less power from your system than two class A/B amps. It even has digital processing (you can set time delays to compensate for the distance to the speakers and it has a built-in parametric EQ). It is a steal at this price! There are many good reviews on this unit on the net.

I would put your JL amp on ebay and the difference you'll have to pay will be about the same as another (mediocre) JL amp.

This is just what I would do, however, so choose wisely!

[PhiDeltBeers]

Here is the completed install. Still playing with the tuning, but it's getting close. Some music sounds really good while others (old 311) can be a little overwhelming. Outside the car, the truck was rattling pretty bad to some John Mayor. Is rattling just going to happen or is there an easy fix??? Anyway here is a pic.






Here's a pic of the car dropped on eibach prokit as well.