2020 LT Trailboss Bose System audio upgrade

[Cesar Ramirez]

I recently installed two audio control amplifiers (D.4-800 and LC-800) coupled with infinity kappa CSX 90 and CSX 60 component system for the highs and (2) P3 15” subs for the lows. 
 

I’m having trouble getting a frequency ranges from 15 kHz to 35 kHz from the factory radio to the amp.
 

We double checked the wiring coming in from all the inputs from the Bose system and everything checks out.

 

I am very disappointed with the way my new system sounds. Do any of you guys know what’s the fix on this?

 

Long story short my tweeters sound like ******.

[topgear1224]

If the factory signals are as chewed up as they sound to my ear you might need a sound processor.

Sent from my SM-N975U using Tapatalk

[jweezy]

On 7/25/2020 at 9:19 PM, Cesar Ramirez said:

I recently installed two audio control amplifiers (D.4-800 and LC-800) coupled with infinity kappa CSX 90 and CSX 60 component system for the highs and (2) P3 15” subs for the lows. 
 

I’m having trouble getting a frequency ranges from 15 kHz to 35 kHz from the factory radio to the amp.
 

We double checked the wiring coming in from all the inputs from the Bose system and everything checks out.

 

I am very disappointed with the way my new system sounds. Do any of you guys know what’s the fix on this?

 

Long story short my tweeters sound like ******.

Your D 4.800 should have the capability to clean that up. Where did you gram your signal from and what is the dsp set up to? I'm about to do the same speaker set up on my doors, I've always liked the way Kappa's have sounded. I ordered the 20mx 3 way add on and I'm gonna try to go full active with the DM 810 off of two T1000x5ad. Got any pictures of the sub set up you have?

[Rodek]

The normal human hearing threshold  is 20hz -20khz or 20-20,000hz.  As you can see 15khz is starting to get into that upper frequency range and 35khz or 35,000hz is outside of human hearing. By amplifying frequencies outside of the human hearing range, you're wasting amplifier power.  

 

Of course this doesn't matter if your source unit (Stereo) is not capable of reproducing those frequencies. For example, if your stereo only produces frequencies between 25-18000hz, then that's what you and your amplifiers have to work with. 

 

I suggest taking your truck somewhere to have the audio system tuned. You can then have frequencies cut or boosted in order to get optimum sound reproduction within the limits of your audio equipment. High and low pass crossovers will be set as well as a subsonic filter (to filter out power wasting inaudible low frequencies from your subs.) Time delay can also be utilized to allow sound from each speaker to arrive at the driver's seat or front passengers at the correct time to give you a realistic sounding sound stage. 

 

 

[austinwamboldt]

The only proper way to upgrade that truck is to start with Nav Tv's ZEN AVB module that replaces the OEM amp, and converts the AVB Bus system to 6 low level channels.

[Rodek]

14 minutes ago, austinwamboldt said:

The only proper way to upgrade that truck is to start with Nav Tv's ZEN AVB module that replaces the OEM amp, and converts the AVB Bus system to 6 low level channels.

Excellent info. Although even with 6 low level (RCA) outputs, the system will still be limited to the frequency output range that the head unit is capable of.  

[austinwamboldt]

That’s why you’d need a DSP processor

Edited August 19, 2020 by austinwamboldt

[austinwamboldt]

The Nav TV module is also full range giving you a 18Hz to 24kHz frequency response output. 

[Rodek]

8 hours ago, austinwamboldt said:

The Nav TV module is also full range giving you a 18Hz to 24kHz frequency response output. 

Alright, I'm trying to get my bearing here...

 

The head unit is the first component in the signal path. Let's say the head unit is only capable of producing 30hz to 15khz (common FM radio response). Now, if you send the 30-15khz to the DSP  can it inject lower frequencies (18hz into the FM broadcast's low frequency side(that is only transmitted at no lower than 30hz) and sound up to 24khz on the high frequency sound side of the broadcast (that is cut off at 15khz)?  Does the DSP inject harmonics into the music like say an Epicenter does but with multiple frequencies? 

 

or....does the NAV TV bypass the headunit and therefore become the source unit? If so, that makes perfect sense and would indicate I was on the wrong rabbit trail. 

 

Sorry to debate. I don't want to mis-inform. I've simply been an audiophile for over 30 years. Both in the car audio segment and home audio. I've been fortunate enough to take the experience over the globe for 22 of those years. Sadly, an explosion left me with a TBI and hearing damage. I can still enjoy music but in a slightly different way. 

 

That DSP must be an awesome device! 

 

With that said, I'm more than open to learning about devices such as the NAV TV. You appear to have knowledge and a passion for sound. It makes me happy to see that the passion still exists. 

 

[Greyhound6.2]

the Nav tv unit is specifically for The bose system and that system uses an audio data buss system instead of traditional high/low level signals. the Nav tv unit converts that audio data buss to traditional RCA level to feed in to an amp or dsp. 

[PaulpHebert]

Correct on the NAVTV unit, but if the head unit does not send any frequencies above say 15kHz, then all of those frequencies will not be available for the NAVTV, DSP, and amplifiers to use use.

 

The real question is, what are the usable frequencies provided by the head unit.  Someone with an O-scope will have to answer that one.  Once that is known, then on to the next step.

[Ecroofing01]

Do not buy the NAVTv unit. It doesn’t not work. Or it will work temporarily then shut off. You can’t use Toslink with out static. Do not believe their claims of it being resolved. I ended up taking out my new JL amp with processor because the thing would never work as it should. They screwed me and my installer. They knew well that there’s an issue but had us chasing our tail. The last straw was it completely turned off after the update. Some guys are adding a switch to restart to unit. If you think that is acceptable, go ahead. I now have all new speakers ran by the Bose amp and a JL 10 that has its own. It’s sounds much better than stock but not as good as a properly tuned stereo. When the NAV unit worked my radio was awesome some it was always short lived. I have Hertz door speakers with components and Audison dash speakers. Having tweakers in the back helps a lot. Also having a bass controller helps. If I were you, I’d wait until someone comes out with something better and stick with the Bose amp for everything but the sub. 

 read through this and you will see everyone is having issues. I’d like to ring Bob’s neck at NAVTv because he’s such a liar. Good luck!

[Wakezilla]

On 7/26/2020 at 12:19 AM, Cesar Ramirez said:

I recently installed two audio control amplifiers (D.4-800 and LC-800) coupled with infinity kappa CSX 90 and CSX 60 component system for the highs and (2) P3 15” subs for the lows. 
 

I’m having trouble getting a frequency ranges from 15 kHz to 35 kHz from the factory radio to the amp.
 

We double checked the wiring coming in from all the inputs from the Bose system and everything checks out.

 

I am very disappointed with the way my new system sounds. Do any of you guys know what’s the fix on this?

 

Long story short my tweeters sound like ******.

Mine is much simpler.. .and sounds amazing.

 

View this post -- https://www.gm-trucks.com/forums/topic/220921-factory-subwoofer/page/12/?tab=comments#comment-2325899

[Wakezilla]

here's the correct link: 

 

[blyent]

I have the 2020 High Country with Bose system.  This is what I've done.

 

My initial plan was just to add a subwoofer.  So I bought a T-harness from LLJ Customs.  I had a local box builder build me a sealed box for a single sub 12" sub.  I had him wrap it in black vinyl to match the black leather seats.  I put in a JL Audio 12w3 in the box.  I powered the sub with a Rockford Fosgate Prime R500XD1 mono amp.  I paid $100 for the box, $150 for the sub (used), and $148 for the amp on Amazon.

 

I wired it up and it was everything I wanted for bass.  However, there are absolutely no tweets in the factory system.  Their is a 2.75" midrange in the dash and 6x9 mid bass speakers in the front doors.  The sound is very underwhelming.

 

So, I set out to upgrade the front speakers.  I have some old Boston Acoustics Pro series 3 way compenent speakers (6.5" mid bass, 4.5" mid range, ~1.5" tweeter).  These speakers I've had a long time and they sound amazing.  Anyway the 4.5" wouldn't fit in the dash without some major modifications so I bought some kenwoods off of crutchfield that would fit and thought I'd just use that one instead of the 4.5" mid range from the boston set.  I bought an Audio Control D-4.800 4 channel amp with dsp integrated to power the new speakers.  I thought I could purchase the 6 channel T harness from LLJ Customs for this for about $50.  However, after researching this, the T harness is not what I needed.  I would need the Loop back harness that costs roughly $300. 

 

In continuing with the research I found that alot of people had issues with the door chimes being super loud after adding an amp and replacing the front speakers.  I didn't want that.  So, I started playing around with the system.

 

I put a pair of coaxial speakers in the door powered by the bose amp.  That was god awful.  Apparently the only signal it sends to the door speakers in mid bass.  Nothing else came out of the coaxial speakers.  So then I used a posi tap connector to grab the signal from the dash speakers.  Out of the coaxial speakers came nothing but tweeters.  So I knew I could get tweeter and mid range from the dash speakers.  I then took the tweeters from the boston seperates and hooked them up to the posi taps ( not directly though, I still had the signal going through the passive crossover that came with the bostons).  If your able to follow I've got the factory 6x9's in the front door, I've got kenwood 2.75" mid range in the dash,  and I've got boston tweeters tapped into the line going to the kenwoods.

 

It actually sounded really good.  Not as good as if the full set of Bostons were  powered by an aftermarket amp but surprisingly good.

 

After hearing all of the issues with loud door chimes and also the navtv unit.  I'm not sure its worth the effort of going with an aftermarket amp for the the front speakers.  I'd definetely recommend trying out what I did on your truck and seeing if you like that.  The LLJ Customs 2 channel T harness for $35 plus shipping is what I ordered.  I didn't add an LOC or anything just used the high level input to the amp.

 

For cost comparison this is what I spent.

 

Custom box for 12" sub - $100

JL Audio 12w3 used - $150

Rockford Fosgate Prime 500w mono amp - $148

Kenwood Excelon KFC-X2C 2.75" dash speakers - $70

Amp Wiring Kit off Amazon - $35

posi taps from Amazon - $7

speaker wire from walmart - $13

I already had the Boston Tweeters and passive crossover.