[platinumcars]

Hey guys, I'm currently runnning an KICKER 500watt amp and 2 12" alpine type-s subs in a ported box through my LOGIC 7 in my 2007 e90 335i.

The stock subs under my front seats are turned off, the guy said it would distort.

I find I'm not feeling crap up front, my passengers feel it but I dont. I'm always messing with the whooptiknob and I'm still not happy. What can I do to get a cleaner bass out of this? Should I turn on those subs under my seat? I want better sound!!

[kaigoss69]

Originally Posted by platinumcars

The stock subs under my front seats are turned off, the guy said it would distort.

First off, the guy is an idiot! The speakers under your seats are largely midbass speakers, not subs. By turning them off you are loosing some lower midrange frequencies, from about 180 Hz down to where your trunk sub is crossed over at. Re-connect the underseat woofers to the Logic7 amp, then adjust the gain and crossover on the Kicker amp to the point where everything starts to blend together. If you still cannot hear any significant amount of bass coming from the trunk, then you need to look at the install and make sure that everything is connected correctly. The signal for the Kicker amp should be spliced into both of the L7 amp woofer outputs, run through some sort of line output converter, and then connect to the RCA inputs of the amp.

[platinumcars]

wow thank you so much, I knew something sounded off to me. But overall what do you think of my setup?

[kaigoss69]

Originally Posted by platinumcars

wow thank you so much, I knew something sounded off to me. But overall what do you think of my setup?

Well, it's not much of a set-up! See if you can get it to sound good and make sure it is connected correctly. I'm not a big fan of Kicker, honestly, but you may be able to make it work to your liking. A step up from your set-up would be to integrate another amp so you can actively bandbass the signal going to the L7 woofers (i.e. you get rid of the overlap with your trunk sub) which will help blend the mid- and sub-bass frequencies together and allow you to extract a lot more performance from the L7 woofers, especially in the "kick" bass area.

[platinumcars]

I'm calling my installer right now to tell them that is what I want done. Not sure if I'm going to add the second amp right away as I might save that for my m3 next year, hopefully what you said helps.

Thank you!

[kaigoss69]

Glad I could help. I'm not sure if you can still return these items but if you can, I would advise to go a slightly different route, because once you put some adequate power behind the L7 woofers, AND you high-pass the signal at the amp, then you will find that you need less bass output from the trunk, since the trunk sub now only needs to play from the bottom (around 30Hz in L7) up to the point were you high-pass the L7 woofers (50-60Hz). So the sub duty it basically split up, if that makes sense. In that case a 4-channel amp and a single 10 or 12 in woofer would be all you need to have a MUCH better sounding system. As far as amps, you should look at digital because of heat and efficiency, at about 150W per channel, with high AND low pass crossovers on each output channel pair.

The sub box you can try to tune for 40Hz, which maximizes its output in a very narrow frequency range (what you are looking for) and makes it more efficient.

[platinumcars]

hey i dont have L7 subs, I have alpine TYPE s and a kicker amp. cheers

[fdriller9]

Originally Posted by platinumcars

hey i dont have L7 subs, I have alpine TYPE s and a kicker amp. cheers

He means the stock Logic 7 (L7) woofers under the seats.....not the kicker, square L7s.

You should have the underseat woofers bandpassed. And your trunk subs low passed. But you need an external amp to bandpass the underseats. You can even just high pass them because the L7 amp actively low passes the underseat channels.

I have my L7 woofers externally amped, bandpassed from 60Hz to around 200hz. I think the underseat channels are actively low passed around 150hz though.

And my trunk sub is low passed around 65Hz.

[kaigoss69]

Originally Posted by *********

He means the stock Logic 7 (L7) woofers under the seats.....not the kicker, square L7s.

You should have the underseat woofers bandpassed. And your trunk subs low passed. But you need an external amp to bandpass the underseats. You can even just high pass them because the L7 amp actively low passes the underseat channels.

I have my L7 woofers externally amped, bandpassed from 60Hz to around 200hz. I think the underseat channels are actively low passed around 150hz though.

And my trunk sub is low passed around 65Hz.

Exactly, and I was trying to remember who did that exact set-up and now I know!

[platinumcars]

without buying another amp is there a way to do this ? i believe my amp is the dx500

[fdriller9]

You would need a bandpass filter but doing a quick google search doesn't bring up many options. You can make one your self with some resistors, capacitors, and some other components.

The filters I did find are pretty expensive and it's better to just get a 2-channel amp and high pass the signal.

Any 2-channel amp that can supply anywhere from 70-150W of power @ 4ohms x 2 should be ok. The stock L7 woofers are amped at 70W, 4ohms. So just be careful when you set the gain if you're using more power.

[platinumcars]

fuck all these numbers are getting to me, I paid these arses out the ass and I specifically asked for them to give me the best setup so i dont have to come back.

So far ground wire has fallen out, and I am currently experiencing the bass cutting out if I turn up the music at all, amp cant handle the subs I'm guessing? I told them to give me the expensive alpine amp and they kept saying kicker this kicker that underrated this underrated that.

GRR

[fdriller9]

Originally Posted by platinumcars

fuck all these numbers are getting to me, I paid these arses out the ass and I specifically asked for them to give me the best setup so i dont have to come back.

So far ground wire has fallen out, and I am currently experiencing the bass cutting out if I turn up the music at all, amp cant handle the subs I'm guessing? I told them to give me the expensive alpine amp and they kept saying kicker this kicker that underrated this underrated that.

GRR

The reason why the sound is cutting out at higher volumes is probably because of the LOC they used. The L7 system outputs a pretty high signal for the underseats so you need a LOC that can handle at least 60W. 70W would be ideal but I'm using one that can handle 60W without issues.

I would buy an amp online (Alpine's can be had for much cheaper online, F300 would be perfect for the underseats) and tell them to install it the way I described. Also have them replace the LOC with one that can handle more power.

You might want to look into Technic's harness. He makes a harness that has a LOC already spliced in. So you don't need to mess with cutting and splicing/soldering wires.

Also the ideal way to integrate your amps would be to use high level inputs. I know the Alpine F300 accepts high level inputs...not sure about the kicker amp you have though. Using the high level inputs doesn't require the use of a LOC. So it cuts down on the chance of noise entering the system.

[platinumcars]

ok you guys are honestly amazing, my appointment is tomorrow @ 1 and i printed off everything you guys said. Thank you! I will post back with results.

[Atorsesh]

Originally Posted by *********

The reason why the sound is cutting out at higher volumes is probably because of the LOC they used. The L7 system outputs a pretty high signal for the underseats so you need a LOC that can handle at least 60W. 70W would be ideal but I'm using one that can handle 60W without issues.

I would buy an amp online (Alpine's can be had for much cheaper online, F300 would be perfect for the underseats) and tell them to install it the way I described. Also have them replace the LOC with one that can handle more power.

You might want to look into Technic's harness. He makes a harness that has a LOC already spliced in. So you don't need to mess with cutting and splicing/soldering wires.

Also the ideal way to integrate your amps would be to use high level inputs. I know the Alpine F300 accepts high level inputs...not sure about the kicker amp you have though. Using the high level inputs doesn't require the use of a LOC. So it cuts down on the chance of noise entering the system.

I've used quite a few Kicker amps (have 2 installed in my gfs 2008 328i) and they accept high level inputs. One is a 2006 model the other is a 2008 and both accept them perfectly fine. I was told by Kicker that the RCA's can handle 9 volts.

[platinumcars]

I am so happy I bought a 4 year warranty, these guys are gonna hate seeing my face once this is all said and done lol.

[kaigoss69]

Originally Posted by liliceman13300

I've used quite a few Kicker amps (have 2 installed in my gfs 2008 328i) and they accept high level inputs. One is a 2006 model the other is a 2008 and both accept them perfectly fine. I was told by Kicker that the RCA's can handle 9 volts.

See this post where I measure the sub output of the L7 amp. It seems 9V will not cut it! (and the voltage will increase even more with bass "boosting" in the OEM HU).

http://www.e90post.com/forums/showthread.php?t=315767

[kaigoss69]

Most audio shops, especially the big guys like Best Buy, don't know a BMW from their ass. Working on these cars and selecting the right equipment requires some very specialized knowledge and experience. I can probably very easily make the argument that the vast majority of experience with BMW e9x audio systems in this country lies with the members of this (sub)forum!

[platinumcars]

^^ +1 on that, you guys are quick and seem to know everything lol anybody in Toronto?

[platinumcars]

ok so quick update, dropped the car off saturday @1 , got it back around 7pm, sound is SO MUCH CLEANER! Those mid bass subs were definately what I was lacking, they also had informed me that one of my 12"s were blown so they replaced that, (any idea why a brand new 12" alpine type s would go so soon ?) . Anyways, it all sounds amazing now, thye have tuned it down and told me not too touch it for a few months, I can feel that if I were to turn it up just a bit it would be a really crisp bass and kick, but I'm scared. anyone wanna chime in?

[kaigoss69]

Glad it sounds better now. Turning up the gain on the amp is fine, as long as you keep feeding it a clean signal. Did they install a different LOC or are the inputs going straight into the Kicker amp? You need to make sure that you are not overloading a) the LOC or b) the high-level inputs of the Kicker amp. Keep all head unit bass adjustments flat and make adjustments ONLY on the amp. Nothing worse than amplifying distortion, which is probably how you blew the first subwoofer.

[platinumcars]

they have it so I have the bass adjustment knob set to 11 and cant turn it up anymore, on the logic 7 eq I have bass turned up though, so I should turn it to middle? should I keep treble and bass flat or just bass thanks. Not sure how they did it exactly all I did was open up this thread and drop off the car. Sounds right to me though.