[BRKGBAD]

*Editing for privacy*

[cengell]

Well BRKGBAD, here's the truth... How important is the audio sound?? The better sound quality the more it will cost you. To get a very good sound with good bass and clean mids and highs, I went with the GM-650 unit $850 just for that and what that does takes the raw audio from the head unit and makes line level output that you can then run to a DSP like the JL Twek D8 $300 and then output to a 5 channel Alpine amp $650 ish and then a 1200 watt Rockford Fosgate mono amp $240 for the subs, and then you must replace all of the GM factory poor sound speakers! This is want I did. But the important thing is is you want very high SQ this is what I did, but if the sound quality is not that $$ to you then the LCi7 with new speakers and you will need a new amp. Ok why is this needed because GM and Bose is a locked in system, that is the head unit sends digital signals to the GM amp then outputs to the speakers, and some did not know is the Bose audio changes sound freq to the different speakers at different sound levels! That sucks if you want to take lets say the back speakers because they are not full range because Bose made it special. The way I did and others that got a unit to take the raw full freq sound from the great head unit and then handle it like the old days. Bottom line is how much $$ do you want to invest for what level of sound quality. What I wanted was loud but not deflating but clean with very good bass but I have a convertible and made my own dual 12 sub woofer box. look more here and you will find high end $15K-$20K to the LCi7 as that's what I want going to use until I found out I would need to take the speaker level from the door speakers to get near full range lows to highs and I went to the $10K setup.Christopher Check out https://pac-audio.com/catalog/amppro...faces/ap4-gm61 GO STEELERS!!

[Vtor_ZL1]

There's video on youtube of guy in white? 6th gen that redoes entire autdio system.. prob answers most of your questions.

[KirkH]

I have the AmpPro 4, like cengell linked. I haven't installed it but the instructions make it look simple and cleared up all the stuff I didn't understand.

[BRKGBAD]

*Editing for privacy*

[KirkH]

Originally Posted by BRKGBAD

So if I go with the Amp Pro 4, what else do I need to get a system up and running? Do I also need some type of DSP?

I dont think so. I can post the instructions when I get home later.

[JoeCarSeller]

You don't need a DSP. It gives clean outputs to RCA's that go to your amp. You can use a DSP with TOS link also which is a digital output with better sound quality. The install instructions are on the pac audio website and look super easy. I also purchased the amp connector pig tails for $50 to keep install clean and simple.

[drfeelgood]

Need is subjective lol . No, you definitely don't need a DSP, but I need a DSP on all of my installs, because without it, the staging sounds like crap. It's all about what your ears like, but in terms of simply hooking up the system, you do not need a DSP

[KirkH]

Originally Posted by drfeelgood

Need is subjective lol . No, you definitely don't need a DSP, but I need a DSP on all of my installs, because without it, the staging sounds like crap. It's all about what your ears like, but in terms of simply hooking up the system, you do not need a DSP

Could you please explain what you mean by staging and where the dsp goes in your system? Thanks! (I am just learning all this stereo install stuff.)

[drfeelgood]

Originally Posted by KirkH

Could you please explain what you mean by staging and where the dsp goes in your system? Thanks! (I am just learning all this stereo install stuff.)

No problem, I'll try

STAGING:

when you listen to music, the frequencies from each speaker are hitting your ears at different times. Even if its milliseconds, the ear can actually hear the difference. In most setups, and to most ears, it sounds like very faint echoes. That is what an inaccurate sound stage sounds like. The car is already a HORRIBLE environment for sound reproduction and staging. Reflections are happening everywhere, and its hard to get it perfect. But with a digital sound processor(DSP) with digital time alignment (DTA), you can try.

With DTA, you can measure the distance of each speaker to the center of your listening reference, let's say your reference is 5 inches in front of your nose. Measure each speaker's distance to that point, and you input that distance into a time-alignment setup, which will delay the sound from closer speakers so that each speaker's frequencies will hit the reference point at the same time.

Now that is just distance, you also have to adjust for volume differences from the sources as well, such as tweeters reflecting off of the windshield vs tweeters firing "on axis" directly at your ears, etc. Remember, these are powered by difference channels, possibly from different amplifiers, so the power going to each speaker may be different. A perfectly tuned system will take all of this into consideration, and make adjustments so that the sound arriving to your reference point is perfect, or as perfect as can be in a vehicle.

Lastly, you can play with frequencies from different speakers, and set your crossover point on your midbass/midrange, thus bringing vocals either up in your listening field (sound stage) or lower. For example, a simple passive crossover setup may use a 24db butterworth slope at 2500 Hz as the crossover point between the midbass/midrange and the tweeter.

But, in an active setup, you can adjust the crossover point. Lowering that crossover point will remove frequencies from the midbass, bringing your sound stage up. Increasing the crossover point, say to 5k, will play more frequencies through the midbass, thus lowering your sound stage.

DSP location:

The flow of info goes as follows: Headunit > AmpPro4 > DSP/DTA > Amplifier(s) > Drivers (speakers)

[KirkH]

Originally Posted by drfeelgood

No problem, I'll try

STAGING:

when you listen to music, the frequencies from each speaker are hitting your ears at different times. Even if its milliseconds, the ear can actually hear the difference. In most setups, and to most ears, it sounds like very faint echoes. That is what an inaccurate sound stage sounds like. The car is already a HORRIBLE environment for sound reproduction and staging. Reflections are happening everywhere, and its hard to get it perfect. But with a digital sound processor(DSP) with digital time alignment (DTA), you can try.

With DTA, you can measure the distance of each speaker to the center of your listening reference, let's say your reference is 5 inches in front of your nose. Measure each speaker's distance to that point, and you input that distance into a time-alignment setup, which will delay the sound from closer speakers so that each speaker's frequencies will hit the reference point at the same time.

Now that is just distance, you also have to adjust for volume differences from the sources as well, such as tweeters reflecting off of the windshield vs tweeters firing "on axis" directly at your ears, etc. Remember, these are powered by difference channels, possibly from different amplifiers, so the power going to each speaker may be different. A perfectly tuned system will take all of this into consideration, and make adjustments so that the sound arriving to your reference point is perfect, or as perfect as can be in a vehicle.

Lastly, you can play with frequencies from different speakers, and set your crossover point on your midbass/midrange, thus bringing vocals either up in your listening field (sound stage) or lower. For example, a simple passive crossover setup may use a 24db butterworth slope at 2500 Hz as the crossover point between the midbass/midrange and the tweeter.

But, in an active setup, you can adjust the crossover point. Lowering that crossover point will remove frequencies from the midbass, bringing your sound stage up. Increasing the crossover point, say to 5k, will play more frequencies through the midbass, thus lowering your sound stage.

DSP location:

The flow of info goes as follows: Headunit > AmpPro4 > DSP/DTA > Amplifier(s) > Drivers (speakers)

Awesome thanks! Im out of town right now but I will have some questions I am sure when I can really dig into this.

[JaxChris]

To the OP's original question -- what do you lose if you just hook up a LC7i to speaker level inputs?

Well, you don't get a flat signal. You're getting the post processed signal from the factory amplifier, which has high and low roll-off on the rear channels. This means you'll want something like the Fix86 instead of the LC7i. It does a better job of correcting the rolloff of the factory processors, has more adjustability and offers a PC software interface to keep the size of the unit in the car down to something more manageable.

Using the Fix or LC will also sum your bluetooth calls and chimes. You don't want those playing full blast on all of your speakers. Nor do you want it sending ANC signals to your amplifiers.

Instead of NAVtv, get the PAC AmpPro or Axxess DSP-MOST for much less. They get the pre-processed signal from the radio and the car system bus, so it can ignore the ANC signal, reduce the chime volume and play calls on only the channels you want.

Both the PAC and Axxess modules are the same price or cheaper than the Fix or LC units and do the job properly for today's integrated technology vehicles.

If your car uses a CAN bus instead of a dedicated MOST bus for multimedia, then I would suggest the Rockford DSR1 (if you want built-in DSP) or the Maestro AR (if you want external DSP). The DSR1 is 250$ and the AR is 100$. Because CAN bus is relatively old and royalty free, they don't charge nearly the same price as the MOST bus modules that have been around for a long time.

Sadly I wish there was a GM compatible version of the Audison bit DMI, because that thing is tiny and just gives you an optical output to your choice of DSP. But it is also now overpriced for the market at 600-700$ just for essentially the interface without without real DSP functions, just source volume control of each channel on the MOST bus (which is where it really shines, since you can control relative volume of different sources, which an external DSP is unable to differentiate).