I was trying to set up my new Orion amp to let me crank my head unit (Panasonic) all the way before giving me distortion, so I set the gain to 0 and tried to adjust a little at a time until I could just start to get saturation at peak volume (the head unit's 40). However, what I got was distortion at very low output levels with the head unit just hitting 25. When I increase the output on the amp, I can get the head unit a whole lot louder and cleaner at 25, but then it goes into saturation beyond that. For now, the solution is to not turn the head unit above 25, and just adjust my amps to each other. That isn't the long-term solution I want though.
Does anyone have experience with this type of issue? Is it an amp issue, or the head unit?
Thanks,
Chris
Replies (12)
speakerman3 on 11/29/2004 22:36:45
The car is a 2000 Saturn SL2. I have been running it with a sub amp just fine for several months now, but when I added an amp for the main channels, I ran into the above problem where I couldn't adjust my amp gain without having distortion at a very low output level. My speakers are CDT Audio 6.5's, and they are not afraid of a little power.
I'm going to try hooking up some other amps of mine to see if the problem persists with any amplifier.
Thanks for any advice you can give me.
swez on 11/30/2004 08:45:20
There is a technique for matching HU output to the amp gain settings. It takes time and some patience, but you are on the right track. We have an FAQ that spells out the process for you:
http://www.clubknowledge.com/Car_Audio_FAQ/?t3
This notes the use of LOC's. If you have RCA's out of the HU, this section does not apply.
Good luck,
Swez
speakerman3 on 12/1/2004 20:34:12
I am using RCA's for the connection. I will update if I come across any revelations this weekend.
Thanks,
Chris
swez on 12/1/2004 20:43:31
Most HU's internal amps will begin to show signs of distortion at ~50% power of the HU. The RCA lines are low level and will not develop maximum output until the internal amps are very close to distortion values.
Do you know the RCA voltage ratings on this Panasonic HU? Model number may be helpful or a link to that HU. If the HU line voltages are low from this HU, this may be part of your noise problems. Most newer HU's offer 4.0 volt RCA's. If your's has less that that, there are some products (line driver or EQ) that can kick up the signal voltage supplied to your amps. This may be your best solution... depending on that HU design.
Finally, noise is often a problem with low voltage RCA's and high gain amps. The best way to get past that is to boost RCA output voltage and minimize noise on the system. That's primarily a need for adequate grounding of all components in the Audio Chain. That means HU,amps, processors and crossovers are all seeing the same ground potentials. The best way to get that, is to ground all devices to clean, paint free body grounds. If you get all those done correctly, the system noise will be minimal.
Comments?
Swez
speakerman3 on 12/2/2004 15:29:21
The head unit I have is a Panasonic PANCQC5310U, and has 2.5v RCA's which could be an issue. Also, the problem seems to show up at higher output levels from the HU, not the amp or speakers. Volume 25 (0-40 range) seems to be the threshold for usable output whether the amp is set with 0 gain, or 50% gain--probably even with 100% gain.
Thanks for your feedback. I will tinker with things this weekend to see if I can narrow the problem a little more.
Chris
swez on 12/2/2004 20:26:55
Good luck and let us know how you make out!
That 2.5 volts is usually enough power to drive most amps properly. Before you do any tweaking, make sure the HU is grounded to floor pan or firewall. That is often overlooked when HU's are installed. The harness ground often has so many other devices connected to it, "may" lose 'reference ground' and create unwanted noise.
Swez
speakerman3 on 12/10/2004 01:03:59
I have tried another amp (Lanzar Opti100) that will be used in my install, and it gave me the same results: great sound at good levels, but the HU output cannot go higher than 25 of 40 before I get distortion. I'm going to recheck the ground in the head unit as swez suggested, and if that doesn't do anything, I'll be looking for a new head unit to upgrade to in the future.
Thanks for all of your input. I will update again if anything changes this weekend.
swez on 12/10/2004 06:41:26
That's the main issue (normal) when using HU amps to driver internal speakers and a larger sub amp for bass. The HU will reach distortion values most would consider unacceptable by the time it hits ~ 50-60% of max power.
Personally, I believe the HU is fine and doing its job well. Amping the interior speakers may be cheaper and give superior results in this application. Can use a modest 2 channel for fronts only, or a good 4 channel for F&R speakers.
FYI: CD's have such a high level of audio saturation, it does not take a whole lot of pre-amplification to drive most HU's in severe distortion. This is normal! The goal is clean, pure and undistorted sound from your rig. It does not matter what the volume control # is to reach that goal. Outboard amps will deliver that, when the gain and EQ are optimized.
Swez
speakerman3 on 12/22/2004 02:55:42
Just as an update, I did find a new ground location for my head unit, and it did improve things, slightly, but noticeably. I readjusted my amp level to give me a little more play with volume control up front.
I also did some toying with my amps' onboard low-level and high-level crossovers and came up with a blend that is much less "strident" sounding than when using the head unit's built-in crossover.
Things are starting to come together. Now I just need to build a custom box for my Crystal Cmp15.
Thanks again.
Chris
ttocs on 12/22/2004 13:49:14
what are the bass, treble and loudness settings on the deck? Alot of people complain about bad sound when they have the loudness and bass up all the way. Loudness settings on decks are rarely anything more then a distortion switchs.......... Make sure you are making all adj on the amp with the EQ options on the deck off..
speakerman3 on 12/23/2004 16:12:34
I did check the system with everything flat. I do more adjusting with the subwoofer output level (adding a little oomph to older recordings, toning things down for particularly bass-heavy music) than with the head unit's eq. The HU does, however, have what I consider to be a very useable eq that isn't just a bass & treble "distortion" control like on many units.
Thanks again for all the good advice that helped me improve my system. I'm sure there are many tweaks yet to be made, but it is doing very well.
Chris
swez on 12/23/2004 18:17:55
Good report and great follow up efforts too. That's what happens when we climb the "audiophile" ladder. Our pickiness factor goes up several notches.
Swez
Does anyone have experience with this type of issue? Is it an amp issue, or the head unit?
Thanks,
Chris
Replies (12)
speakerman3 on 11/29/2004 22:36:45
The car is a 2000 Saturn SL2. I have been running it with a sub amp just fine for several months now, but when I added an amp for the main channels, I ran into the above problem where I couldn't adjust my amp gain without having distortion at a very low output level. My speakers are CDT Audio 6.5's, and they are not afraid of a little power.
I'm going to try hooking up some other amps of mine to see if the problem persists with any amplifier.
Thanks for any advice you can give me.
swez on 11/30/2004 08:45:20
There is a technique for matching HU output to the amp gain settings. It takes time and some patience, but you are on the right track. We have an FAQ that spells out the process for you:
http://www.clubknowledge.com/Car_Audio_FAQ/?t3
This notes the use of LOC's. If you have RCA's out of the HU, this section does not apply.
Good luck,
Swez
speakerman3 on 12/1/2004 20:34:12
I am using RCA's for the connection. I will update if I come across any revelations this weekend.
Thanks,
Chris
swez on 12/1/2004 20:43:31
Most HU's internal amps will begin to show signs of distortion at ~50% power of the HU. The RCA lines are low level and will not develop maximum output until the internal amps are very close to distortion values.
Do you know the RCA voltage ratings on this Panasonic HU? Model number may be helpful or a link to that HU. If the HU line voltages are low from this HU, this may be part of your noise problems. Most newer HU's offer 4.0 volt RCA's. If your's has less that that, there are some products (line driver or EQ) that can kick up the signal voltage supplied to your amps. This may be your best solution... depending on that HU design.
Finally, noise is often a problem with low voltage RCA's and high gain amps. The best way to get past that is to boost RCA output voltage and minimize noise on the system. That's primarily a need for adequate grounding of all components in the Audio Chain. That means HU,amps, processors and crossovers are all seeing the same ground potentials. The best way to get that, is to ground all devices to clean, paint free body grounds. If you get all those done correctly, the system noise will be minimal.
Comments?
Swez
speakerman3 on 12/2/2004 15:29:21
The head unit I have is a Panasonic PANCQC5310U, and has 2.5v RCA's which could be an issue. Also, the problem seems to show up at higher output levels from the HU, not the amp or speakers. Volume 25 (0-40 range) seems to be the threshold for usable output whether the amp is set with 0 gain, or 50% gain--probably even with 100% gain.
Thanks for your feedback. I will tinker with things this weekend to see if I can narrow the problem a little more.
Chris
swez on 12/2/2004 20:26:55
Good luck and let us know how you make out!
That 2.5 volts is usually enough power to drive most amps properly. Before you do any tweaking, make sure the HU is grounded to floor pan or firewall. That is often overlooked when HU's are installed. The harness ground often has so many other devices connected to it, "may" lose 'reference ground' and create unwanted noise.
Swez
speakerman3 on 12/10/2004 01:03:59
I have tried another amp (Lanzar Opti100) that will be used in my install, and it gave me the same results: great sound at good levels, but the HU output cannot go higher than 25 of 40 before I get distortion. I'm going to recheck the ground in the head unit as swez suggested, and if that doesn't do anything, I'll be looking for a new head unit to upgrade to in the future.
Thanks for all of your input. I will update again if anything changes this weekend.
swez on 12/10/2004 06:41:26
That's the main issue (normal) when using HU amps to driver internal speakers and a larger sub amp for bass. The HU will reach distortion values most would consider unacceptable by the time it hits ~ 50-60% of max power.
Personally, I believe the HU is fine and doing its job well. Amping the interior speakers may be cheaper and give superior results in this application. Can use a modest 2 channel for fronts only, or a good 4 channel for F&R speakers.
FYI: CD's have such a high level of audio saturation, it does not take a whole lot of pre-amplification to drive most HU's in severe distortion. This is normal! The goal is clean, pure and undistorted sound from your rig. It does not matter what the volume control # is to reach that goal. Outboard amps will deliver that, when the gain and EQ are optimized.
Swez
speakerman3 on 12/22/2004 02:55:42
Just as an update, I did find a new ground location for my head unit, and it did improve things, slightly, but noticeably. I readjusted my amp level to give me a little more play with volume control up front.
I also did some toying with my amps' onboard low-level and high-level crossovers and came up with a blend that is much less "strident" sounding than when using the head unit's built-in crossover.
Things are starting to come together. Now I just need to build a custom box for my Crystal Cmp15.
Thanks again.
Chris
ttocs on 12/22/2004 13:49:14
what are the bass, treble and loudness settings on the deck? Alot of people complain about bad sound when they have the loudness and bass up all the way. Loudness settings on decks are rarely anything more then a distortion switchs.......... Make sure you are making all adj on the amp with the EQ options on the deck off..
speakerman3 on 12/23/2004 16:12:34
I did check the system with everything flat. I do more adjusting with the subwoofer output level (adding a little oomph to older recordings, toning things down for particularly bass-heavy music) than with the head unit's eq. The HU does, however, have what I consider to be a very useable eq that isn't just a bass & treble "distortion" control like on many units.
Thanks again for all the good advice that helped me improve my system. I'm sure there are many tweaks yet to be made, but it is doing very well.
Chris
swez on 12/23/2004 18:17:55
Good report and great follow up efforts too. That's what happens when we climb the "audiophile" ladder. Our pickiness factor goes up several notches.
Swez
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