Upgrading sound system and keeping stock HU

[G Thizzle]

Originally Posted by amthar

[b][i]
1. Line Output Converter (LOC). This device simply has speaker wires coming out one side and RCA jacks on the other. After splicing into the appropriate input wires coming from the stock HU, you will be able to connect the RCA jacks on the LOC to the RCA input jacks on your amp using a standard RCA interconnect cable. NOTE: If your amp does NOT accept differential-balanced input signals on its input jacks, you MUST get a LOC that is capable of converting the differential-balanced signals in the G35 to the standard single-ended signals the aftermarket amp is expecting on its input jacks. Soundgate makes an amp that does this.

which wires do you tap into and where??? do you tap into the back of the HU or where the speaker wires run into the external amp??? Does anyone have a DIY?? Has anyone used the Tsunami Line output converter... they have it at circut city for $19.99 here is a link to the Tsunami.... let me know if this would work!!!

http://www.circuitcity.com/rpsm/oid/...Detail.do#tabs

[amthar]

I would recommend tapping the wires where they go into the stock external amp. I would also recommend calling Tsunami or whatever manufacturer of whatever LOC you are interested in purchasing and ask if the LOC will adapt differential-balanced signals to single-ended signals... unless you go with an amp that acceps differential-balanced signals on its inputs.

[bconrey]

FWIW, it seems the eD amps also accept differential-balanced inputs. I purchased an LOC from eD along with my amp (they sell the Tsunami) but tried to connect the HU to the amp directly off the leads going to the Bose amp (long since removed), and it worked a treat.

[Valenti]

I know audio purists may frown on this upgrade, but for those who do not have the money to purchase a new head unit, double DIN (and required HVAC adapters), in addition to the amp and speaker upgrades, this is a very serviceable upgrade and the components will run a little over $1k.

Some of the components were chosen because they were what the audio shop carried, so you may wish to substitute your preferred brand of speakers, etc.

My primary concerns were 1) staying within a budget, 2) not losing ANY trunk room in my coupe (nor using the rear wall of the trunk, since I need to fold the rear seat down regularly), and 3) having a system that no longer sounded painful.

Components: Boston SL60 speakers (front)
Diamond D392i 6x9 in rear
Diamond D3-400.4 amp
Audiocontrol EQS

The Diamond amp accepted the Bose outputs without difficulty (or hum), and was chosen because it fit exactly where the old Bose amp used to sit. The Audiocontrol EQS sits on top of the Diamond, which still allows the original plastic piece to fit on top.

The EQS was needed to help compensate for the Bose HU equalization mess (discussed elsewhere). While the result is not as flat as if using a better HU, it sounds quite good. Best of all, the install is completely transparent.

[hahtbites]

I just tried this scenario of trying to save the HU. I was very skeptical of this approach as I couldn't understand why the HU would be any better than the rest of the system.

My setup included:

Amp: JL Audio 300/4
Front Components: Polk Momo MMC 6500
Wiring: Rockford 4 Gauge power, JL 16 Gauge speaker, Rockford Twisted pair RCA spliced into low voltage output from HU(As suggested in this thread).
I faded to the front channels so that I only heard the new speakers.

My findings:

First of all you won't be happy with it if you've ever used an aftermarket HU such as an Alpine, Kenwood, etc.... I'm not talking about features. I'm talking about sound quality. I tested this theory by connecting an old Alpine HU that I had from a previous car. There was no comparison. My suggestion is that you only do this upgrade if it's a stopgap until you can afford to replace the HU. I personally think it sounds awful. If anything the upgraded amp and speakers bring to the surface what could not be heard with the stock system. I plan to connect my iPod directly to the JL until I can afford the HU conversion. The iPod's signal is much cleaner than that of the HU. It should come as no surprise that the entire Infiniti/Bose system is junk for the masses as most stock systems are.

[badtziscool]

Going through this post again, we have good proof that the preouts for the bose headunit is pretty flat and of pretty good quality.

Does anyone know about the NON-BOSE head unit? From everything that I've read on this post and others, the head unit between the Bose and non-Bose are pretty much the same except for the fact that the bose has an external amp and the non-bose has a internal amp. Has anyone measured the frequency response of the non-bose outputs yet? I'm just curious since I'm having a heck of a time getting my system to sounding decent. It seems like 80-100 hz plays too loud. I can't determine whether there's equalization happening there or is it from my box design or if it's from frequency overlap, etc.

[Valenti]

A few additional comments:

First, the mods I performed had the caveat that they were a workable solution for those who could not or were not willing to change the HU. No argument that an after-market HU would be superior.

Next, unless we're disucssing microphone preamps, the preamp output on an HU--so long as it comes directly from the pre and not from speaker outs--is less of a factor than the amp being fed, and the speakers reproducing the sound. Again, a system will only be as good as the weakest link.

However, testing done in another form revealed what we've all seen, which is that the Bose HU has a variable EQ circuit designed to compensate for using cheap speakers and cheap amplification. The result is emphasis and de-emphasis at peculiar frequencies--hence the rationale for using the EQS.

I'm not an audio engineer, but I am a musician and I have a lot of recording studio experience. I trust my ears--but that doesn't mean they're "right" or "perfect."

The goal of this thread was how best to live with the existing HU.

[max first]

I have completed my install and have to agree...there is just something not right with the output of the factory head unit. I am even using Dave Navone's competition grade LOCs. I am not an engineer but worked at a high end stereo store for seven years while putting myself through school. What I need is a clean double din HU but not some 2000 investment such as the Z1. Anyone have any ideas? I would like to retain a 6 disc setup or at least IPOD/MP3 playback.

[Bimmer G]

Is there any way to hook up an amp for a subwoofer and keep the stock amp

[amthar]

yes but this isn't the thread to discuss it, open a new thread and people will jump right in

[oneslowxa]

There are a few pieces on the market which are relatively new.
JL has had thier clean sweep out for about a year or two now, and Rockford Fosgate introduced the new 360.1, and 360.2 Pieces...

They are basically Hi/low adapters but with more features and flexibility, and a whole lot better output...

Rockford had a demonstration using a very inexpensive (~$99) aftermarket kenwood radio, and the sound that came out of it was phenominal!

The only "drawback" about the Rockford piece is that it requires a Palm with bluetooth. It allows you to control the 360 like you would any other aftermarket unit. TA, Speaker level, Crossover points, EQ, all via bluetooth...
It's a pretty cool piece if you ask me. It also has a summed inputs (hi/mid/low on the 360.2) and three sets of outs, which is a superior advantage over using loc's.

I can not comment on the cleansweep since I have yet to hear it, but it seems like a pretty comparable piece.

[djphatinc]

Hello folks. I recently had upgraded my Bose system to the following:

1)Stock HU (cause the cost was more then what I bought for the rest of the system
2)4x 6.5" MB Quart Discuss
3)2x 10" Audiobahn subs 600w each
4)bandpass box front ported
5)440w Mag Dub amp
6)1000w Mag Dub amp (the price was right, and the subs are crazy strong)

Tsunami car kit for wiring. I will plan on getting the DUB cap, cause this is drawing WAY too much juice. I think its stuttering the car.

Now, this has been to Circuit City more times then I can count. I used the Hi Low on the AMPs, but they broke one lead to the sub amp. Then the door speakers started to go as well, using the same type of connection with the hi low. So they gave me the LOC's to the sub. Its been pretty mint on that end. WAY TOO MUCH BASS, from those 2 10" I can't turn it up any more without going deaf. The other amp was sent back were I bought it for RMA cause either CC broke it when the connected it up the first time, or it was just strait defective. Either way, I am using a loner sub from a friend, a Rockford Fostgate 600w 2channel. Just driving the front speakers.

I do get line noise. On the other amp before it was sent back. They finally got the pop when you turn the car off to go away, and the whine noise to go away as well. With this RF amp, the whine is back but no popping when I turn the car off. So, they need to fix that. I also don't like the EQ'n of the radio. I am guessing they hooked it up post bose amp, vs pre. I'll have to check that when I go back there. Something tells me they did that "pre" before but the signal was just too low to use. Turning up the radio to max was like listening at an ok level. Vs it being ear piercing loud like it is now.

I really want to change the HU. Not just cause of the features it doesn't have but, it can't sound like this with a aftermarket radio. I'm really not liking this Bose stuff in this car. The Altima sounded MUCH better with its stock Bose system. Not sure what happened here. Either way. I think it is livable. I am an audio engineer I went to school for it actually, DJ, and normally listen to pretty much anything from Rap, Rock, Jazz, Club, House, Reggae, Disco, whatever. I can live with the sound, once I get this new amp working, and hopefully the pop from turning it off, and really if they can get rid of that whine. All would be decent again.

[digital1986]

another great sticky!!

[kevinn]

So it isn't the speakers that suck, its the amplifier?

[Virge]

Anyone have any tips on putting a JL 500/1 where the stock bose amp is? Like mounting ideas etc...

tia

edit:
ok i found tihs thread: giving up spare tire, should i?

how'd you guys secure the amp in that corner? So it doesnt bounce around...