help!! adding subwoofer to factory head unit

[crosso]

I have a 2005 murano without the bose system. how do i add my own subwoofer to the factory hu?

[Simmsled]

You will need an external amplifier, a subwoofer, a sub box, wires, and Line Output Converter. I suggest a LOC from Soundgate. There are 2 I would suggest from them. The LOC4.2 (about $60 bucks) which has the best sound quality. OR the LOCA which is a budget minded LOC (about $30).

[PoorManQ45]

Simmseld, the line level converter isn't actually needed is it?

Hey Crosso, are you the person from http://www.the12volt.com

[elwesso]

If your amp has inputs for speaker level inputs, id recommend going that direction, instead of the lineout converter... For most people you dont need real clear sound for bass.. THen you can just tap your speakers and be done with it!

[Silvia2b]

If you have and amp that is flexible and allows a range of say 0.8V-18V of input then you don't need a LOC converter, if your amp has high level inputs or speaker level inputs then you'll also be fine without it.

The Stock Bose amp is located behind the trim panels on the left side of the cargo area. I'm not too sure about models without a bose if they have amps. How many speakers are in the factory system? Just one in each door? Or do you also have the tweeters in the dash?

First- You will need power supply, for the sub amp, so run a fused power wire from the battery throught the firewall and back to the amp mounting location of your choice.

Then find suitable ground. ( see link for ground info) zerothread?id=88476Connect your signal inputs remote turn-on lastMake sure that you make your speaker connections are correctly phased to maximize the subwoofer effect

[Simmsled]

Yes that is true. If your amplifier has speaker level inputs, then you can just go that route. Usually on entry level amplifiers you will find this feature. However, if the amplifier that you get or have does not have that feature... then you will need a Line Out Converter.

[PoorManQ45]

But isn't the signal from the Bose HU just like a standard preout from other HUs, it just has a different end connecter on it.

[crosso]

Thanks, for your input guys. I am going to connect a loc to the rear speakers of the HU wire harness add the amp and the subs that way. For the amp I am using the 12 AWG romex wire idea from an earlier post. the only obstacle I am facing now is getting through the fire wall to the battery.

[PoorManQ45]

Woot, I said the 12 gauge romex

[Silvia2b]

So the best place to go through the firewall is on the Drivers side on the auto transmission models (I don't think you can order a manual in the states) their are several large rubber grommets that can be used without making a new hole. I would suggest this method by carefully piercing a hole in it without severing any of the wires that are currently in that harness the easiest way to do this is with a hollow piece of pipe large enough to put the wire through the middle. like 3/8" or so grind down one end of it on your benchgrinder to taper it in to a point at one end. Or you can purchase one from a company that sells thexton hand tools. Here is a link to the part # you would need. http://www.thexton.com/vshop/s...id=35good luck

[crosso]

Thank for the in put (silvia2b) but i already drilled a hole on the driverside next to the wheel well. I ran the romex wires and connected the amp and the speakers, it plays good but when I turn off the ignition I get big blur of nothing but bass from my speakers for at lease 10 seconds then it cuts off. Can someone tell me what is the cause of that? I will post the pics when the project is completly done.

[Silvia2b]

This is usually caused by the amp staying powered up after the signal input source( cd player) has been turned off. When you turn off the kety and open the door your stereo turns off right? The stereo provides the signal to your LOC converter and when that shuts off the amp plays a single frequency or hum at loud volume. You can connect a relay and switch to the turn on wire and shut this off before the key to see if this eliminates the problem. I can help explain how to do this if you need help.

[audtatious]

But isn't the signal from the Bose HU just like a standard preout from other HUs, it just has a different end connecter on it.

The idea here is to tap into the sub wire (disconnect sub and use it for the converter or direct connect to amp). Since this is post-amp, it is a speaker-level input.

[Silvia2b]

Correct! Yeah, In Non-Bose system taking the speaker level signal to a factory sub usually works perfect, although it requires an RTA to determine the X-over point of the factory amp, if it has one.

I would prefer the pre amp signal when connecting to a Bose system since they add wierd EQ adjustments and other oddities not found in many aftermarket products signal chain.

Oh and in regards to PMQ comment- The signal from most BOSE head units to amps is usually slightly different than standard RCA outputs from a aftermarket style. Most pre-ampoutputs, unless they are balanced output, use a positve and a negative for each channel of a preamp. For example left and right front pre-outs have four conductors. With Bose they typically use a four channel output form the deck with only five conductors. (4 positive signals, and one common negative.) These types are found in Acura, Audi, Mercedes Benz, Infiniti, and probably others too. Does this make any sense or did I confuse everybody else too.

So anyways crosso how does it sound? Did you get the turn on delay resolved?

[audtatious]

Correct! Yeah, In Non-Bose system taking the speaker level signal to a factory sub usually works perfect, although it requires an RTA to determine the X-over point of the factory amp, if it has one.

I would prefer the pre amp signal when connecting to a Bose system since they add wierd EQ adjustments and other oddities not found in many aftermarket products signal chain.

I would not suggest simply swapping the sub. I'd use the subs speaker-level output and connect that to an amp (one that supports this or by using a converter). This will work with Bose or non-Bose systems.

I agree with the wierd EQ adjustments. Since I still have my factory 6CD Bose unit, I had to add a PPI pre-amp and crank the pre-amp volume way up to keep the bass strong. It seems that every increment over 5 starts dropping the bass levels on the Bose system. I assume this was done to keep people from blowing the factory system by cranking it to 30.

[PoorManQ45]

It seems that every increment over 5 starts dropping the bass levels on the Bose system. I assume this was done to keep people from blowing the factory system by cranking it to 30.

This is done to allow the system to play louder as awhole. Bass frequencies require the most power out of the entire frequency band. Attenuating the bass would "free up" power for other parts of the band, usually mid bass and mid range because they require the second most power.

[audtatious]

This is done to allow the system to play louder as awhole. Bass frequencies require the most power out of the entire frequency band. Attenuating the bass would "free up" power for other parts of the band, usually mid bass and mid range because they require the second most power.

Mid-bass is attenuated as well. They can't "free up" power since each amp channel is limited by their own RMS. You can't pull from one channel to another unless you have some form of automated switching which is unheard of and too cost prohibitive in factory systems.

Most factory systems start muting (db cutting) lower frequencies so the manufacturers don't have to keep replacing speakers when people turn it up too high. The best sound put out by a factory system is at low levels because of this reason. My older Kenwood and Eclipse systems would start doing this at 1/2 - 3/4 volume, so I simply designed around it.

[crosso]

How do you connect a relay and switch to the turn on wire and shut this off before the key to see if this eliminates the problem. please explain how to do this.