MTX Subs + Amp to Stock Headunit

Moonesar · 12-09-2011, 11:02 AM

I just purchased MTX Subs and amp and 4guage wires to hook up to my stock E90 325xi.

I was informed i need some type of aux adapter that has rca cables to hook up the amp to the stock head unit but not sure where to find them.

I search crutchfield but couldn't find anything bmw specific, anyone know where i can get this item or if i even need it? Maybe i need more?

I searched but got miminal help.

Thanks

Moonesar · 12-10-2011, 10:01 AM

No one knows? Really?

Technic · 12-10-2011, 10:13 AM

Quote:

Originally Posted by Moonesar

I just purchased MTX Subs and amp and 4guage wires to hook up to my stock E90 325xi.

I was informed i need some type of aux adapter that has rca cables to hook up the amp to the stock head unit but not sure where to find them.

I search crutchfield but couldn't find anything bmw specific, anyone know where i can get this item or if i even need it? Maybe i need more?

I searched but got miminal help.

Thanks

What is the OEM system in your car?

Moonesar · 12-10-2011, 10:19 AM

Regular Professional .. no IDRIVE no LOGIC

Technic · 12-10-2011, 10:40 AM

Quote:

Originally Posted by Moonesar

Regular Professional .. no IDRIVE no LOGIC

Do you want to keep your OEM amp? I sell a harness to interface your sub/amp combo to the OEM amp without cutting or tapping the OEM wires. PM for details.

Moonesar · 12-18-2011, 07:43 PM

Hooked it up to stock headunit through the amp in the back .. it bumped so much harder in my friends truck that has a aftermarket headunit. Even with the gain all the way up it doesnt hit nearly as hard as in my friends truck. Is this because he's running an aftermarket headunit? Right now im running a high/low converter. What you guys think?

ctuna · 12-18-2011, 07:56 PM

http://www.e90post.com/forums/attach...2&d=1260829447

http://www.e90post.com/forums/attach...2&d=1266451970

http://www.e90post.com/forums/attach...1&d=1209780865

its because the BMW amp is so wimpy.
Also the BMW has lots of sound insulation

Moonesar · 12-18-2011, 08:32 PM

The bmw stock amp would effect how hard the aftemarket sub and amp are hitting? Overall besides the cabin bass the subwoofers were pumping more bass on his car, i just want verification that this is probably because of him having an aftermarket headunit to adjust the bass more in detail?

kaigoss69 · 12-19-2011, 05:27 AM

Quote:

Originally Posted by Moonesar

The bmw stock amp would effect how hard the aftemarket sub and amp are hitting? Overall besides the cabin bass the subwoofers were pumping more bass on his car, i just want verification that this is probably because of him having an aftermarket headunit to adjust the bass more in detail?

Negative. If connected and setup correctly, there should not be any difference between aftermarket and OEM HU signals. Which output of the OEM amp did you tap for the signal?

Moonesar · 12-19-2011, 08:40 AM

I took it to best buy and i had them set it up with a hi/low converter so im not sure which output on the stock amp they tapped into. Would this make a difference? I can check it out

kaigoss69 · 12-19-2011, 09:00 AM

Quote:

Originally Posted by Moonesar

I took it to best buy and i had them set it up with a hi/low converter so im not sure which output on the stock amp they tapped into. Would this make a difference? I can check it out

Oh boy. Search this forum for "wiring diagrams" and find the color code of the underseat woofer amp outputs for you audio system (sounds like you have HiFi). Make sure they used those outputs and that the polarity is correct. Also make sure they only tapped the outputs and did not completely disconnect them.

Moonesar · 12-19-2011, 09:12 AM

I do not think i have the HIFI system, just the base stereo system (i have a 325xi) would this system still have the underseat woofer amp outputs>?

kaigoss69 · 12-19-2011, 09:59 AM

Quote:

Originally Posted by Moonesar

I do not think i have the HIFI system, just the base stereo system (i have a 325xi) would this system still have the underseat woofer amp outputs>?

If you have tweeters in the sail panels (mirror triangles) and a center channel then you have Logic 7. If you're missing the center, you have Hifi. If you're also missing the tweeters in the sail panels, you have the base system.

In any case you have woofers under the seats. But the way you connect the aftermarket amp is different in the base system.

First tell us which system you have. You may also want t search for best buy since you would not be the first BMW install they f'ed up.

Moonesar · 12-19-2011, 10:47 AM

I have tweeters in the front and passenger window that i believe your talking about so i guess i do have the HiFi system. Had no idea, im in the process of contacting best buy as well.

kaigoss69 · 12-19-2011, 11:11 AM

In the left rear corner of the trunk there us a grey panel. Pop it off. The hifi amp is underneath. You can probably shine a flashlight in there and see which wires were tapped. DO NOT trust them to have hooked it up correctly and DO NOT let them touch it again. Look for the wiring diagrams and check yourself. If they wired it incorrectly I would correct it myself. Best post some pics of the wiring and we'll help you figure it out.

Moonesar · 12-22-2011, 07:39 AM

So i fixed the wires and now the subs hit the way they should

... however, after about 2 minutes they subs start fading in and out randomly. Figured a solution was to lower the gains which i lowered on the sub first and it didnt help much, eventually lowered the gains on the bass knob and lowered volume too with no luck. All wires are secure and it was working fine hitting really nice lows & highs.. but i dont know why the sub is going in and out randomly? Any ideas?

Moonesar · 12-23-2011, 09:57 AM

Rewired everything, i think the gains were too high as well as the settings on the headunit, everything was high. So the distortion usually comes when the gains are high, only way to remedy this of course is getting a stronger amp, but what do you guys think about a new headunit although i know its complicated with out cars. Think its best to get a new headunit to run RCA instead of these shitty stereo wires everything is hooked up with? Also, i do not have an official high lo convertor, should i consider buying a worthy high low? Any recommendations ?

kaigoss69 · 12-23-2011, 10:45 AM

You need a good hi-low converter. If you keep running without one, you will end up blowing your amp and or subs, if you haven't already done so.

Moonesar · 12-29-2011, 07:32 AM

Any recommendations on which 1 to buy and where from?

12-09-2011, 11:02 AM	#1
Moonesar Bimmer Stance 1 Rep 54 Posts Drives: Lexus IS300 & E90 325xi Join Date: Jul 2011 Location: NJ iTrader: (0)	MTX Subs + Amp to Stock Headunit I just purchased MTX Subs and amp and 4guage wires to hook up to my stock E90 325xi. I was informed i need some type of aux adapter that has rca cables to hook up the amp to the stock head unit but not sure where to find them. I search crutchfield but couldn't find anything bmw specific, anyone know where i can get this item or if i even need it? Maybe i need more? I searched but got miminal help. Thanks
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12-10-2011, 10:01 AM	#2
Moonesar Bimmer Stance 1 Rep 54 Posts Drives: Lexus IS300 & E90 325xi Join Date: Jul 2011 Location: NJ iTrader: (0)	No one knows? Really?
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12-10-2011, 10:19 AM	#4
Moonesar Bimmer Stance 1 Rep 54 Posts Drives: Lexus IS300 & E90 325xi Join Date: Jul 2011 Location: NJ iTrader: (0)	Regular Professional .. no IDRIVE no LOGIC
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12-18-2011, 07:43 PM	#6
Moonesar Bimmer Stance 1 Rep 54 Posts Drives: Lexus IS300 & E90 325xi Join Date: Jul 2011 Location: NJ iTrader: (0)	Hooked it up to stock headunit through the amp in the back .. it bumped so much harder in my friends truck that has a aftermarket headunit. Even with the gain all the way up it doesnt hit nearly as hard as in my friends truck. Is this because he's running an aftermarket headunit? Right now im running a high/low converter. What you guys think?
	Appreciate 0 Quote

12-18-2011, 07:56 PM	#7
ctuna Lieutenant General 1911 Rep 13,101 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	I might help to know what is in your car. http://www.e90post.com/forums/attach...2&d=1260829447 http://www.e90post.com/forums/attach...2&d=1266451970 http://www.e90post.com/forums/attach...1&d=1209780865 its because the BMW amp is so wimpy. Also the BMW has lots of sound insulation
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12-18-2011, 08:32 PM	#8
Moonesar Bimmer Stance 1 Rep 54 Posts Drives: Lexus IS300 & E90 325xi Join Date: Jul 2011 Location: NJ iTrader: (0)	The bmw stock amp would effect how hard the aftemarket sub and amp are hitting? Overall besides the cabin bass the subwoofers were pumping more bass on his car, i just want verification that this is probably because of him having an aftermarket headunit to adjust the bass more in detail?
	Appreciate 0 Quote

12-19-2011, 08:40 AM	#10
Moonesar Bimmer Stance 1 Rep 54 Posts Drives: Lexus IS300 & E90 325xi Join Date: Jul 2011 Location: NJ iTrader: (0)	I took it to best buy and i had them set it up with a hi/low converter so im not sure which output on the stock amp they tapped into. Would this make a difference? I can check it out
	Appreciate 0 Quote

12-19-2011, 09:12 AM	#12
Moonesar Bimmer Stance 1 Rep 54 Posts Drives: Lexus IS300 & E90 325xi Join Date: Jul 2011 Location: NJ iTrader: (0)	I do not think i have the HIFI system, just the base stereo system (i have a 325xi) would this system still have the underseat woofer amp outputs>?
	Appreciate 0 Quote

12-19-2011, 10:47 AM	#14
Moonesar Bimmer Stance 1 Rep 54 Posts Drives: Lexus IS300 & E90 325xi Join Date: Jul 2011 Location: NJ iTrader: (0)	I have tweeters in the front and passenger window that i believe your talking about so i guess i do have the HiFi system. Had no idea, im in the process of contacting best buy as well.
	Appreciate 0 Quote

12-19-2011, 11:11 AM	#15
kaigoss69 Brigadier General 300 Rep 3,969 Posts Drives: '08 335i Join Date: Jul 2008 Location: JAX iTrader: (6)	In the left rear corner of the trunk there us a grey panel. Pop it off. The hifi amp is underneath. You can probably shine a flashlight in there and see which wires were tapped. DO NOT trust them to have hooked it up correctly and DO NOT let them touch it again. Look for the wiring diagrams and check yourself. If they wired it incorrectly I would correct it myself. Best post some pics of the wiring and we'll help you figure it out. __________________ Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa OT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15
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12-22-2011, 07:39 AM	#16
Moonesar Bimmer Stance 1 Rep 54 Posts Drives: Lexus IS300 & E90 325xi Join Date: Jul 2011 Location: NJ iTrader: (0)	So i fixed the wires and now the subs hit the way they should ... however, after about 2 minutes they subs start fading in and out randomly. Figured a solution was to lower the gains which i lowered on the sub first and it didnt help much, eventually lowered the gains on the bass knob and lowered volume too with no luck. All wires are secure and it was working fine hitting really nice lows & highs.. but i dont know why the sub is going in and out randomly? Any ideas?
	Appreciate 0 Quote

12-23-2011, 09:57 AM	#17
Moonesar Bimmer Stance 1 Rep 54 Posts Drives: Lexus IS300 & E90 325xi Join Date: Jul 2011 Location: NJ iTrader: (0)	Rewired everything, i think the gains were too high as well as the settings on the headunit, everything was high. So the distortion usually comes when the gains are high, only way to remedy this of course is getting a stronger amp, but what do you guys think about a new headunit although i know its complicated with out cars. Think its best to get a new headunit to run RCA instead of these shitty stereo wires everything is hooked up with? Also, i do not have an official high lo convertor, should i consider buying a worthy high low? Any recommendations ?
	Appreciate 0 Quote

12-23-2011, 10:45 AM	#18
kaigoss69 Brigadier General 300 Rep 3,969 Posts Drives: '08 335i Join Date: Jul 2008 Location: JAX iTrader: (6)	You need a good hi-low converter. If you keep running without one, you will end up blowing your amp and or subs, if you haven't already done so. __________________ Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa OT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15
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12-29-2011, 07:32 AM	#19
Moonesar Bimmer Stance 1 Rep 54 Posts Drives: Lexus IS300 & E90 325xi Join Date: Jul 2011 Location: NJ iTrader: (0)	Any recommendations on which 1 to buy and where from?
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