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PostPosted: Sun Jan 29, 2017 9:54 pm 
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Location: Pocatello, Idaho
Year and Trim: 2001 SSEi, 2001 SSEi, 2003 SSei
Before I say much, please let me explain, that I have many years in the electronic audio repair and listening business. Most of my experience goes back some years, but have fooled with product enough to get a sense of decent audio sounds. When in the profession installing quality systems in Colorado, we learned that you could have the greatest system in the world if you were willing to spend enough money. It has not changed today. And, too often there seems brand loyalty or non-loyalty based on the loudest marketer! My roots carry me back to the early days of Altec Lansing and JBL. Anyone in the audio profession realizes the quality of such product in its time (And still today!) :beerchug:

Typically I have never been a Bose fan. My experience suggested these systems were too synthetic and “cosmetic” and lacked presence and dynamic range. They too, were often over priced in my opinion. One cannot compare a quality home system to a car audio system simply on the basis of a whole different sets of environments. [-X

I have read for hours with interest on posts of those who love their Bose and or Monsoon systems in the Bonneville and a good hunk of those who tear the system down using adjectives to describe Bose as “junk”, “terrible”, etc. When you look at the system, with cost, mass production, and “reasonable” sound as criteria to create audio for the automobile I believe they did quite well. So, I thought how could I improve on the system because I wanted to keep the dash look, the steering wheel controls, and not spend a fortune to convert. Now I know you can purchase all of the devices to continue use of your steering wheel controls, a converter to install that new head unit, a new head unit, a new sub-woofer with a sub amp, a new set of at least four or six speakers, an expensive aftermarket equalizer to rework the EQ of the Bose head unit, and the many hours of labor. So I set out to try to improve upon what I had in my 2001 (Bose) and 2003 (Monsoon) “Poncho Bonnies”. :dontknow:

The criterion at the outset was to create a sound that delivered a dynamic range presentation with presence and clarity. I further wanted to create the strongest presence in front with the ambient sound coming from the rear, which I believe is the best stage setting for listening pleasure. Our Bonnies are cruisers; loud earth shaking bass that rattles the trunk becomes tiring in time. I do not need to impress my neighbors by my purchase but rather enjoy the sound in the cabin of my Bonnie that is pleasurable over a longer period of time while I am cruising! (My current adjustment to the Bose with minor additions still vibrates the rear window if I turn it up without distortion!) So I set out to improve. I am pleased with the results and saved many hundreds of dollars! =D>


First of all I replaced the front speakers both 6 ½” and tweeters with JBL GTO speakers. I could position the tweeters to point directly at myself in the cabin, thus direct radiant high presence. The combination of these speakers gave me 2 ohm impedance. Left the rear door and rear 6 by 9 Bose speakers in place secondly installed a 12” JBL quality subwoofer and JBL power amp, and connected the units to the line out rear speakers off from the Bose head unit with a converter. The wiring for the amp was very simple as the trunk is so close to the rear where the battery is located. I further tapped into the power (pink) wire that runs to the trunk. All of the wiretapping from the Bose head unit was completed in the trunk where the wires run into the Bose power amp. I stripped back the wires and wrapped them with those needed to hook up to the converter and soldered all of joints for long term reliability.

Now the trick was balancing the HU with my present inventory. (Some of this information I secured from a GM post)

I found I could set the volume at 4 or max 5 bars for a very loud listening experience. I did not need to go any louder. Above 5 was UN pleasant to my ears. I was getting good sound without a lot of EQ boosting on the HU. Seems the best dynamic transparent sound quality is at 4 or nor more than 5, depending on the source (CD, radio, IPHONE) levels. You may want to play with this a bit but typically many set the EQ on the radio at +6 Treble 0 mid and +6 on bass. You will get a poorer quality sound with these settings because of the “cut-Off” curve built into the Bose HU. Please NOTE: the HU does not increase bass from “O” with volume increase, built in limiters in the EQ, but it does increase the highs as the volume increases! The peak frequencies for the HU bass are 50 HZ the peak on the mids is 635 HZ and highs is 12K. (I did not measure this but secured the info from a GM post). These are the frequencies when the bass, mid, and highs are increased or decreased within the HU). Thus it seemed logical for me to try and blend what I had to create a dynamic transparent sound. Realizing the bass does not increase with the volume from a low setting, I realized the adjustment for bass would have to come from the sub, so I tuned the sub to maximum output without distortion. (Realize many of the Bose or JBL GTO speakers would not go low enough for a clean bass boost at higher levels. Thus I let the sub take the lower frequencies. Now knowing that the treble and mids would increase I needed to adjust them just the same on the head unit. Each system will be different and has to be played with. I finally set my system with following on the HU. Set the bass at a -4 (with this setting your bass will increase proportionally with the volume and sub presence-sub set at maximum NON DISTORTED OUTPUT), the mids at -2 and I chose the treble at +6. (I like the crystal clear sound of the JBL tweeters at +6 for some they could be set down). I now can turn the radio up to levels that are unpleasant to my ears without distortion. The highs are crystal clear the mids mixed well, and bass very clean clear and transparent with the body of the music. I am very pleased with the results for the low level labor and cost.
Thus in a nut shell.
Add quality speakers in front-Match the ohm in the Bose system for maximum DB output (Third party experts on the net rate JBL higher than the JL, Rockford Fosgate, Alpines and other "popular" brands) (Third party may be more reliable than Johnny's view down the street)
Add a quality sub-woofer and amp
Adjust the EQ’s of the HU and the sub amp
Sub set a max output WITHOUT DISTORTION!
Bass set at -4
Mid set at -2
Highs set at +6 or a little less depending on your wishes
And enjoy! :beerchug:

Post script. I am sure there are many who will say this does not work. Here was my thinking. I will start with this 1st level and add to each stage as I need to get better quality sound. If I started with quality product, I could always add new rear speakers, a Head Unit, an interface unit for the steering wheel controls, an interface unit for the new head unit, and on and on. I could spend many, many extra hours in creating this system. Well, in my judgement I did not need to do so. I am very, very happy with the hidden quality that really is already there with Bose and Monsoon. I believe I just needed to readjust that quality. My neighbors down the street may not hear me but I sure enjoy the pleasant sound in my cabin when I play Boston, Cusco, Mannheim, Pink Floyd, The Doors, and yes even BOB DYLAN!,and the many, many great musicians! The last I checked my hearing was still ok and I am in my 70’s!!!! Happy Cruising in one of the greatest cars in my opinion on earth-The Bonnevilles! What a great site!!! :)


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PostPosted: Tue Jan 31, 2017 2:20 pm 
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I'm a fan of the OEM look and do all the work behind the scenes...

I think a couple of the main things most look to right away, as being the weakness of the OEM system(s);

1) Speaker quality. Most OEM are higher resistance, cheaply made speakers and are quickly blown even with the OEM headunit
2) The variable potentiometer (or whatever it's called), that as you turn up the volume, it reduces bass automatically in an effort to keep #1 intact.

The OEM headunit is usually fine powerwise for most people's needs to be honest. But I'm not an audiophile, so... As long as it's loud enough to overthrow the road noise and be clear/legible and sound good, is all I care about.

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PostPosted: Tue Jan 31, 2017 9:23 pm 
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You are so right I posted this finding realizing folk who wanted better sound could get it from the stock system and keep the neatness of the dash. The JBL speakers are very close to Bose and Monsoon at about 2.6 ohm. I was able to wire a JBL TWEETER AND 6 1/2 SPEAKER AND MANAGED A 1.98 ohm load. The highs are excellent and mods the same with JBL. A JBL sub in the trunk and arranging the EQ ON THE STOCK HEAD UNIT GIVES SUBURB SOUND WITH CLARITY AND PRESENCE! This was done with minimul cost and time as I suggested. Do not mean to offend anyone but I am not sure what an audiophile really is. BTW not sure why JBL does not get the recognition deserved guess it is because they are engineered in America!! All Ferrri's have custom installed JBL systems installed. When I was in Italy we went through the plant and they touted JBL as their choice of speakers! :beerchug:

PS have a set of JBL GTI's and they really are
AWSOME! Rumor has it that Harmon was purchased for the reason of acquiring the JBL trade mark and going after the car market. If you purchase high end car JBL much of their designs are from the professional division. We all have heard this sound in theaters, stadiums and the world
For over 60 years =D>
Happy driving and listening


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PostPosted: Wed Feb 01, 2017 6:37 pm 
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hi, I'm glad you got the sound you like - for me, the stock setup is perfect!!!! I love it!!!!!

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PostPosted: Thu Feb 02, 2017 8:37 am 
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Thanks for this info, Johnrich. Have you done this on both the Bose and Monsoon? Are the recommended settings similar? Can you recommend a particular JBL amp and sub, and a converter? Also, are you using the JBL series of speekers, or speakers out of a late model GTO? Just realized there is a GTO series of speakers sold by JBL!


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PostPosted: Thu Feb 02, 2017 1:24 pm 
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johnrich wrote:
I found I could set the volume at 4 or max 5 bars for a very loud listening experience.
I'm having trouble understanding what you mean with the various numbers you mention, and bars. I have a 2001 Bose-equipped Grand Prix GT, which I think is the identical system as the 2001 Bonneville with Bose, and I don't understand how the numbers you mention like setting mids at -2 and treble at +6. . . Are you referring to the graphic EQ on the head unit?

I've been trying to do the same thing with mine: retaining the head unit and improving the speakers, adding a sub, etc. and have not had great results yet. I'm still working on it, though.

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PostPosted: Mon Feb 06, 2017 6:21 pm 
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You ask some great questions! Let me take a shot at JBL equipment. There really are two divisions, the pro and the consumer with Harmon as we speak. If you purchase the higher end of the consumer often you are getting quality Professional product, like the the stuff you normally hear in theaters, stadiums, etc. The consumer JBL's have three levels at the time. The GTi's are premier (from the professional line) and in my judgement perhaps some of the best out there. (They are steep in price, running $2,ooo retail but can get them for $900 for now) The down side is they are expensive!!!! I have a pair 6 1/2" Gti's in my Trans Am (Fourth generation) and they give you chills when they play. Crystal clear, as loud as you want them, the subs are just awesome, and I run the systems with the JBL/Crown amplifiers. These are "old school" quality. Some may argue but the "Old School" are built like sherman tanks and they last a long long long time. Problem older design bigger, but not a problem for me in the TA or Bonneville both big cars. The newer amps have a tendency to be manufactured with the current philosophy, they are created with less quality and run for less years. (This is MY OWN OPINION and do not mean to offend anyone or start a debate! :dontknow: From the GTi's (Competition professional series) down JBL made the Power series, and now the GTO series, with latest production line the Club. Both (Power Series and GTO)have ceased production but there still are many out there on ebay, etc. The power will handle many more RMS watts with stronger cones, than the GTO. The GTO, however, are very solid speakers that will easily handle the power you are throwing at them with the BOSE or MONSOON system. They are engineered in America and made in China, similar to the Rockford Fosgate and not sure but i think the JL lines. The JBL lines are closest to the the ohm ratings of the BOSE and MONSOON systems thus in my judgement a great match for upgrades we are attempting. I find them to run between 2.3 and 2.7 ohms. When you run the front parallels you can get pretty close to the match. I believe the JBL,s are much clearer and distinct on highs than the stock MONSOON or BOSE. Hope this helps. In my judgement the best cost price for performance expectations are the GTO's in our stock Bonneville systems. In fact JBL designed these to replace stock factory units closer to the 2 ohm typical match. I would purchase the GTO's over the Clubs. I have the Power Series in my Vette and they really honk, but YOU DON'T NEED THAT POWER CAPACITY in the stock systems. Hope this helps.
Here is what I put in
JBL 6 1/2" coaxial in the front with the JBL tweeters, Make sure you include the cross over capacitor when do this with your tweeters. JBL makes the GTO with component, the 6 1/2" and tweeter seperate that in my judgement are excellent for what we are doing with the head unit connections. They cost more and I happen to have the coaxials and tweeters from another project. Put 5 1/2" in the back doors, but if your stock speakers are ok I think you can cut some cost and leave them in. ( I believe the presence should be up front so I drive the front stronger than the rear doors-to create an ambience sound from the rear. Left the 6 x 9's in tack, no change, they really add little but just leave them save some time!
Then I taped in BEHIND the head unit and BEFORE the amplifier with a converter. Switched the sub in conjunction with the radio at the connector in the trunk.
Used a 12" cast JBL sub in a 1 cubic foot enclosure,and drive it with 300 watt RMS JBL GTO amp. ( JBL sub was listed as either 1st or 2nd of a third party review of the best "10 Subs" for 2016! The woofer is turned way down. The amp gives you three settings to tune your system. It takes patience but I believe comes out great! :beerchug:
Too I realize this is NOT A COMPETETIVE system like often audiophiles enjoy, but it improves the quality of the stock system to a very, very pleasing level. BTW a couple of notes, I believe the Monsoon delivers a bit more power than the BOSE (I can not verify but most posts claim, 200 watts RMS). Converted both a 2001 and 2003. When we cruise down the highway my wife and I have to turn it down substantially if we wish to talk. :bwoohoo:

Most of the car audio shops in our area, really have not "heard" of JBL for some reason, usually the Rockfords (Good Stuff) JL's (Same) and of course Alpines. The later brands are substantially more expensive and may offer a greater profit margin, I am not sure. I have test listened and frankly, CAN NOT declare they sound any better or if they sound as good. When you compare to the same level JBL's well.... JBL has been around for over some 60 years and their specialty is speakers!

Happy driving! :)


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PostPosted: Mon Feb 06, 2017 6:43 pm 
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Sometimes hard on here to explain in words. I had the same questions at first. Let me try this.
You have basically four independent circuits in the radio
First the volume
next the treble
than the mids
than the highs
when I spoke of the bars I was speaking of the volume, thus around 5 on my unit is VERY LOUD, proportional to the source (CD RADIO STATION ETC)
When I play with the equalizer on the Head Unit I am setting the BASS MIDS AND HIGHS.
So I set the BASS at -3 or -4(THE JBL AMP AND SUB provides most of the bass) (Remember by in large the BASS on the BOSE from zero on up on the head unit actually cuts it!)
The Mids at 0 or a -1 or -2
and the highs at a +4 or +6
Bass is loud and pleasant the mids mix well and the cymbals and guitar strings, etc., demonstrate a great deal of pleasing presence!
From this point I had to adjust the subwoofer. With volume around 5 on the radio, I would adjust the sub until I could basically no longer hear the vocals. Then further set the sub so it distorts and then back it off for a pleasing subtle soft but solid bass. You have to tweak with these settings to get it right. Hope this helps. Again I am very happy with the stock unit. BTW one of our larger dealers in the area said that the market is getting interesting, he explained many of the stock units have improved so much customers are not willing to spend the high buck to get that "audiophile" system! Interesting huh. :dontknow:
And the value added feature. I was in the Navy and operated aircraft and guess what? Redlights, with a few amber mixed in covered the entire cockpit! Shifting from RED to dark is least straneous on your eye correction. It worked for me in the Navy and it works for me in the Bonne! White and bright Green is the worst at night! #-o


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PostPosted: Mon Feb 06, 2017 6:53 pm 
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OOPS ERROR up above! :banghead: You have four independent cirucits in the Headunit
The Volume
The Highs
The Mids
and the BASS!
Sorry for the error :sad:


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PostPosted: Mon Feb 06, 2017 11:21 pm 
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Can you elaborate what you've done on your 4th gen? Does it have monsoon?
I have been contemplating removing my aftermarket HU and putting the original Monsoon back in.

Lack of equalizer slide controls is the main issue I have with the factory 00+ bonnevilles.
I can adjust the preset so it sounds good with radio but then adjustment is needed when switching between CD/Cassette/mp3.
There are not enough presets to cover all the variations.
For this reason I prefer the 5 & 7 bands of the previous generations - despite the lack of overall sound quality.

The aftermaket HU I have in my 4th gen is even worse in this respect. It does not have an eq button to change between presets like the bonneville. You have to scroll through several menus to switch presets.
My original F-body Monsoon does have an equalizer with slide controls - so I'm imagining the best of both worlds.

Bugsi - does your Grand Prix have sliders or presets?


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PostPosted: Tue Feb 07, 2017 2:45 pm 
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Not sure of your question when I talk of the fourth-generation I'm talking about a Firebird Trans Am. I had monsoon in this car but took it out. Have an aftermarket system with JBL and the GTI series I believe the system is awsome.


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PostPosted: Wed Feb 08, 2017 5:03 am 
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In addition to Bonneville, I have an 01 Trans AM that I was referring to.
I was thinking you were using 6 1/2" Gti's with your Trans Am Monsoon and got the F-body Monsoon to sound awesome.

Previous owner of my TA installed Kenwwod HU, 6 1/2" Alpines, Kicker sub & amp.
I keep thinking of putting the Monsoon HU back in mainly because I'm a fan of old school equalizer slide controls.


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PostPosted: Wed Feb 08, 2017 2:23 pm 
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John- Do you know what size tweeters go in the 2000+ Bonneville?


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PostPosted: Thu Feb 09, 2017 4:15 am 
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Not sure the dimension, but I used the JBL Power series tweeters. The diameters are very close to the grills on the stock top door housings for the stock tweeters. There is plenty of mounting "hardware" that comes with the tweeters. I had to grind out the opening a bit and install the JBL's. They fit perfectly! Another great feature on the JBL tweeter is that you can position the speakers in the door panels as they adjust in many directions so that you can create that close to "perfect" direction from each corner. They have really increased the treble and highs, in my opinion. There are many of these tweeters on ebay. Hope this helps. :)


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PostPosted: Tue Feb 14, 2017 8:47 am 
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Another question, John. Did you wire the tweeters using the original tweeter wiring, or are they connected to the door speakers using a crossover? Thanx for all the info!


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PostPosted: Tue Feb 14, 2017 10:16 am 
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maxi426 wrote:
John- Do you know what size tweeters go in the 2000+ Bonneville?


hi, the stock tweeters on my 2000 SSEi are mounted on the front door pillar and are 1 inch diameter.

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PostPosted: Wed Feb 15, 2017 3:08 am 
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Hi Maxi Sorry have not been on for
Awhile. I used the same wiring from the stock connections
And transfered the capacitor over to the JBL tweeter .seems
To
Work
Jus t fine. Happy listening. I have been
Running the change quit a bit and again very pleased with the sound for
Minimal cost
Upgrades! Happy listening.


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PostPosted: Wed Feb 15, 2017 3:13 am 
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Just a note. The GX JBL's if you wish to use are a bolt in and they are 2.3 ohms the same as the Bose speakers! :eek2:


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PostPosted: Sun Apr 30, 2017 1:28 pm 
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Interesting thread. I've been contemplating an audio upgrade for some time, and have run into the usual problems with the Bose system for upgrades - hard to manage a good sound upgrade without gutting the factory system, and I have no desire to replace the factory head unit at all.

Something that would be very useful - although I can follow the process you've described fairly well, it would be helpful to include the actual model numbers of the components you used. For instance, are the GX JBL's you mention the GX600C series? Did you use the JBL crossovers, or leave the stock crossovers in place? Would it matter? Which amp did you use? And so on...

There are so many choices out there, it would be nice to have a working baseline from which to start. Thanks!


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PostPosted: Wed Oct 25, 2017 4:40 pm 
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I recently completed extremely similar work on our 2001 Grand Prix GT with Bose, which I believe shares the same head unit and trunk amplifier as similar year Bonnevilles with Bose.

Here's what I did:
-I designed a built a power-line filter for the head unit from a big choke coil that I hand-wound, and a 4500µF Capacitor. I spliced this in series to the power line going to the head unit, and of course it has a ground, which I wired to a common ground under the dash.
Image Image
Nothing fancy here, just 25 feet of 14 gauge wire hand-wound on a 2.4" diameter ferrite core sourced from eBay. I measured the inductance as 30mH, which I paired with a 4500µF capacitor for a high-cut corner frequency of 13Hz. I wired them up on a small perfboard and housed them in a plastic soap-bar container that I tied shut with nylon wire ties. It does a really good job of suppressing alternator whine from the head unit.
-I performed the AUX input mod on the factory head unit, adding a switched 1/8" stereo jack spliced into the CD audio out lines inside the stereo. This procedure is described in detail in one of the Grand Prix forums. Link: http://www.grandprixforums.net/threads/ ... 7-03-Radio
-Then I cut the wiring harness lines behind the head unit that connect to the radio's front and rear line outputs. I spliced on RCA female and male ends to the cut wires. Rockford Fosgate sells ready-to-splice RCA wires for this purpose. These: http://a.co/7MfLm0l and these: http://a.co/6zsu52l
This allows me to undo the process and put my system back to factory if I choose to.
-I ran a pair of twisted pair RCA line cables from the head unit to the trunk, down the driver's side cable channel under the doors. Again, I used Rockford Fosgate twisted pair RCA's. These: http://a.co/eDCgw1m
-I ran a new power wire from under the hood to the trunk down the passenger side cable channel under the doors. This was a properly fused amp wiring kit. I don't recall the gauge offhand, but either 4 or 8 or something like that. In the trunk I ran a same-gauge ground to a common grounding point on the body.
-I installed a 5-channel Alpine amplifier in the trunk. This is an older model MRP-F356 that I used to have in my Bonneville. I've been into it to replace the original PSU filtering capacitors.
-I tapped the turn-on wire from the harness that goes to the Bose amp in the trunk, and spliced it to a turn-on wire for the Alpine amplifier. I connected the power and ground wires to the Alpine amp.
-I replaced the front door speakers with Infinity-Reference R 5022 cfx speakers. (This is a Grand Prix, and I'm not sure if similar year Bonnevilles use a different size speaker.) I installed Boston Acoustics tweeters from the old component system that used to be in my Bonneville in the upper door tweeter pods, with a capacitor for a crossover, wired to the door speakers below.
-I replaced the rear 6"x9" speakers with Polk Audio DB691 3-way speakers. I left the factory 4" speakers in back, but disconnected them. (I don't know if Bonnevilles had these, but Grand Prix's did with Bose.)
-Finally, I have a 10" JL sub in a sub-box leftover from my Bonneville, and I hooked that up to the Alpine 5-channel amp.

The system sounds phenomenal. An iPod as a source, plugged into the new AUX input just sounds great. I can dial the bass up or down with the head unit's bass slider, and I made fine adjustments to the front/rear balance on the Alpine amplifier's trim pots. I never knew the factory head unit could sound so good.

Note: I originally tried to skip the twisted-pair line-signal cables from the head unit to the trunk, and tried to use the existing wiring harness that carries these same signals to the Bose amp in the trunk, figuring "If they're already in the trunk, no need to run new wires." Unfortunately, when I did that, the resulting sound was pretty abysmal, and had some nasty alternator whine noise in it. There's no comparison to the quality obtained by running a pair of dedicated twisted pair cables and putting a solid noise filter on the head unit's power wire. Retail power line filters may work fine. I opted to make one because I'm cheap and I have the electronics background to whip such a thing up. I'll post some info on what parts I used and how the choke coil measured for inductance.

I'm really happy with the result, and totally agree that the audio quality the head unit is capable of is *really good* but really needs aftermarket speakers and amplification to come alive.

_________________
PontiacDad at WCBF `08: "By any chance, was his name. . .Radomir?"

R.I.P. 10/31/15: 1997 SE: "Silver Shadow"
`05 Mercedes S500


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