Audio issue - Mids/Highs cut out when giving Jeep more skinny pedal
08-14-2014, 08:19 PM
#51
JK Freak
Thread Starter
Basically, the -5 idea is very close to 4-1 gain overlap method I was mentioning earlier. 4-1 gain is a 6db headroom "perfect world" kind of setting. It would allow the equipment to reproduce the the full dynamics of the recording while minimizing clipping. This is not the absolute ideal for signal to noise, but it is a happy medium between maximum dynamic range, useable sensitivity, and low noise floor. 1-1 would have 0 db dynamics, 2-1 would have 3 db dynamic range, 3-1 would be 4.5db , and 4-1 would be 6db. Note that for an increase of 3 db that DOUBLE the power is required. 6db would be quadruple the power. So a 4-1 gain overlap would have a 100 watt amp running at 25 watts with the HU outputting a non clipped signal referenced to "0"db. (0 db would be the standard full RMS resolution of the source signal...CD, iPod, whatever). This would allow the dynamic range of the source material to be output from the source unit and allow 4x the power in reserve for transient peaks in the recording without clipping. The downside, for the average listener, is a perceived reduction in power from the system as most listeners are not normally aware of 5% distortion. All of the above, of course, is dependent on the build quality and design of the equipment. Some amps, regardless of how well they are integrated into the system, are just higher in distortion. Class D switching amps (very common in mono amps nowadays) come to mind here. Also this why the Mosconi amps, Focal amps, etc are "underrated". They assume a 4-1 gain overlap and usually RMS power is about 1/4 of max useable power. It helps to really understand real useable power is available and makes it easier to select amps to power quality speakers with. Most high end speakers can handle 4x the power for SHORT transient peaks in music and 2x the power thermally( more than a short peak).
08-15-2014, 04:05 AM
#52
The voltage reading vary depending on the amount of power the head unit or amp is capable of supplying. Could be less than a volt to hundreds of volts.
Secondly, since music is highly dynamic, the voltage will vary wildly with the music. A sine wave is really what is needed. (Test tones).
Secondly, since music is highly dynamic, the voltage will vary wildly with the music. A sine wave is really what is needed. (Test tones).
08-15-2014, 04:11 AM
#53
By "clipping" I mean the tops and bottoms of the sine wave as displayed on a o-scope will be flat(clipped off) instead of a smooth arc. Anything other than a smooth peak and dip would be distortion of the original signal. A smooth peak and dip would translate, in a perfect world, to a smooth accurate motion of the speaker moving in and out corresponding to the oak and dip. The erratic image of a sine wave would also mean the erratic movement of the speaker.
Of course, like previously stated, this is pointless if the speaker and equipment are not capable of reproducing the signals accurately.
Of course, like previously stated, this is pointless if the speaker and equipment are not capable of reproducing the signals accurately.
08-15-2014, 04:15 AM
#54
Sad too. My Jeep is at the house. Rolling with the new wife in the hybrid Lexus to save gas and haul ass!
08-15-2014, 05:28 PM
#55
JK Newbie
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I believe the "harness" that was used is the culprit as well as tying into the CAN-Bus. Exactly how, what and why was the CAN-Bus tapped for this? Since the only symptom described is sound output, I'd focus on the harness. Are the power connections to the amps ran in series or parallel. What type of circuit protection is being used? Are relays being used for for the control switches? Not sure if I read one of the threads right, but was this an issue with the previous system? What components or connections like the grounds were reused.
08-17-2014, 09:54 AM
#56
I'm writing a big giant kinda introduction to audio system tuning. And ways to compensate for the Jeep. Also about the advantages of the same Jeep vs a "regular" car. It's gonna take me a bit. Traveling to Colorado and back to Dallas over the next few days. Sad too. My Jeep is at the house. Rolling with the new wife in the hybrid Lexus to save gas and haul ass! <img src="https://www.jk-forum.com/forums/attachment.php?attachmentid=571237"/>
08-18-2014, 10:29 PM
#57
JK Freak
Thread Starter
I believe the "harness" that was used is the culprit as well as tying into the CAN-Bus. Exactly how, what and why was the CAN-Bus tapped for this? Since the only symptom described is sound output, I'd focus on the harness. Are the power connections to the amps ran in series or parallel. What type of circuit protection is being used? Are relays being used for for the control switches? Not sure if I read one of the threads right, but was this an issue with the previous system? What components or connections like the grounds were reused.
08-24-2014, 06:25 AM
#58
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The harness used was to provide a 12vdc power source for the deck I was told. I may have misspoken about tapping into the can bus. The "Remote" wire from the deck supplies voltage to signal the amps to turn on when the deck is on. No other switches or relays were installed.
09-17-2014, 09:53 PM
#59
JK Freak
Thread Starter
Finally able to update the thread. We ended up replacing all amps. Went with a Pioneer GM D8604 for miss and highs and a kicker kx400.1 for the subs. mids and highs remain Cedarslink and my 2 10" CVT's are still under the seats. Sound is amazing for the headache I had. Crisp and clear mids and highs and just the right amount of power for the bass... Thanks for all the tips and advice!