Horrible audio quality!

[xKingdom]

Hi everyone,

I added some 6.5” DS-18 speakers to my 2008 Avalanche LS. The guy before me had some crappy speakers in there so I thought that’s why my audio was so poor. The speakers helped but it’s still quite grainy. Does anyone have any ideas what the issue could be? I’m not a huge audio guy but the audio distortion at high volumes is just absurd. Do I need a new head unit? From my understanding the LS package doesn’t have an external amp. I have an amp from a 2008 LTZ could I swap that in? Let me know what you think. I don’t want any crazy setup with subs or anything I just want some decent door speaker audio.

 

[EXT4ME]

I am not an automobile audio expert, by any stretch of the imagination.

However, my degree is in electronics, so I do understand how circuits work.

With that being said, I believe I understand that the factory speakers in these trucks have an very low impedance.

Much lower than run of the mill car speakers.

I have heard the impedance of these factory speakers are 2 OHMS, where the impedance of the DS-18 speakers you mention appear to be 4 OHM speakers.

While these numbers appear to be small, they can actually have great effect on a stereo system output.

The higher the ohm rating, the more the speaker resists the incoming signal or sound.

The more a speaker resists, the more power is required to produce the same level of sound.

As the sound system reaches higher power output levels, the more likely it is for distortion to occur.

If the factory audio system is designed to work with the 2 OHM speakers, then the 4 OHM speakers will be doubling the resistance in the output circuit.

Perhaps someone better learned in car audio can better explain.

 

[redheadedrod]

To tired to respond right now but you have to match the speakers to what the system puts out. Also cheap speakers are just to make noise, not music. The normal head unit doesn't put out a lot of power.

Does your truck have a center console?

Having the amplifier or not can be an option beyond the trim level, so don't assume you don't have an amplifier... I believe even in the 2007+ if you have the center console you have the BOSE amplifier. You should be able to look on the option sheet (In glove compartment in the 1st gen, assume same place in 2nd gen) Look up the codes on the option sheet and find the one for the radio. That will tell you which options you have.

 

[xKingdom]

To tired to respond right now but you have to match the speakers to what the system puts out. Also cheap speakers are just to make noise, not music. The normal head unit doesn't put out a lot of power.

Does your truck have a center console?

Having the amplifier or not can be an option beyond the trim level, so don't assume you don't have an amplifier... I believe even in the 2007+ if you have the center console you have the BOSE amplifier. You should be able to look on the option sheet (In glove compartment in the 1st gen, assume same place in 2nd gen) Look up the codes on the option sheet and find the one for the radio. That will tell you which options you have.

I had a flip up center console, so I do not believe I have one. Like I said I know just about nothing about audio. My alternator is finally starting to die so I might upgrade to a higher output alternator as well as hear unit.

 

[2004Slickside]

The RPO code of UQA indicates an external amplifier for the 2008 Avalanche. If you don't have that RPO code, then no external amp. Sounds like your amp is either bad in your head unit or as the external amp, whichever you have. Junkyard head units are dirt cheap, but you need to reset the security with a scanner during install. There's an online resource someone here posted for used stuff. That's what I used when I replaced the head unit in my 2006 G6 GTP with one from 2008 (to gain a wired auxiliary in). I imagine you could also get the Bose amp if you like. Good luck.

See attached.

 

[redheadedrod]

You likely just don't have speakers that match the amplifier in the radio. The radio amplifier is very low wattage. If you throw an aftermarket speaker in the door and run it off the factory deck it will sound horrible as there is not enough power to drive the speakers. Easiest thing to do is get a new headunit and an amplifier to run your speakers. You MAY be able to run the speakers directly off the head unit as most have around 40watts of sound per channel. But again, you needs speakers that match what you are running or they will sound like crap. I have seen factory speakers from GM at 2 , 3 and 6 ohm. If you are replacing a 2 or 3 ohm speaker with a 4 ohm speaker it will have a lower output than the factory speakers.

Lower Ohm is a higher load on the amplifier and more power will go to the speakers (Most aftermarket amps will induce more noise when you go below 4 ohm. ). Higher OHM speakers are less load on the amplifiers and will not have as much power going to them. Most aftermarket amplifiers are designed around 4 ohms and so will the speakers. OEM a lot of times will use a lower OHM speaker to get a little more power out of the amplifier as long as it is designed to run the lower OHM.

 

[xKingdom]

You likely just don't have speakers that match the amplifier in the radio. The radio amplifier is very low wattage. If you throw an aftermarket speaker in the door and run it off the factory deck it will sound horrible as there is not enough power to drive the speakers. Easiest thing to do is get a new headunit and an amplifier to run your speakers. You MAY be able to run the speakers directly off the head unit as most have around 40watts of sound per channel. But again, you needs speakers that match what you are running or they will sound like crap. I have seen factory speakers from GM at 2 , 3 and 6 ohm. If you are replacing a 2 or 3 ohm speaker with a 4 ohm speaker it will have a lower output than the factory speakers.

Lower Ohm is a higher load on the amplifier and more power will go to the speakers (Most aftermarket amps will induce more noise when you go below 4 ohm. ). Higher OHM speakers are less load on the amplifiers and will not have as much power going to them. Most aftermarket amplifiers are designed around 4 ohms and so will the speakers. OEM a lot of times will use a lower OHM speaker to get a little more power out of the amplifier as long as it is designed to run the lower OHM.

I put some DS-18 4 ohm speakers in. I’ll check tonight to see if I have an external amp, but last time I checked under my center console I didn’t have one.