Hey guys, I have a weird problem...
Last night I finally got around to setting my zx950's gains.
The 500 section reached my target voltage pretty easily
But the 450 section was a little odd. I got 20~21 AC volts (a little more then 100w) with all my gains and bass boost at the lowest setting. I was trying to find 17v ac.
Here's some other info that may help...
HU 5v (set at 7/8 volume)
PLD1 (set until peak LED lit up and backed down)
AC four.1 (gains and volume set about 1/2 way)
I apologize if I can't get back to you guys about this soon, I'm at school and this is the only chance that I have to ask this.
Setting gains with DMM
Setting gains with DMM
Last edited by vin78 on Thu Sep 13, 2007 10:10 am, edited 1 time in total.
You should set the gains on your other devices with a multimeter as well. The exact same principles work for RCAs as work for amps.
Take your + lead, connect it to the RCA center, and connect the - lead to the RCA shield. When playing 60Hz test tones, you can then adjust your PLD to exactly 8 volts on each channel, then do the same on the AC. Once you do that, you will only really need to put your gains at the lowest setting on the amps.
Take your + lead, connect it to the RCA center, and connect the - lead to the RCA shield. When playing 60Hz test tones, you can then adjust your PLD to exactly 8 volts on each channel, then do the same on the AC. Once you do that, you will only really need to put your gains at the lowest setting on the amps.
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fuzzysnuggleduck
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That's exactly what Tom helped me out with when he was in Vancouver and the system sounds GREAT.stipud wrote:You should set the gains on your other devices with a multimeter as well. The exact same principles work for RCAs as work for amps.
Take your + lead, connect it to the RCA center, and connect the - lead to the RCA shield. When playing 60Hz test tones, you can then adjust your PLD to exactly 8 volts on each channel, then do the same on the AC. Once you do that, you will only really need to put your gains at the lowest setting on the amps.
My gains on the amps are at the lowest setting because the amps are seeing nice high (for M series) input voltage. They don't run too hot anymore either.
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dedlyjedly
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You really don't want to worry about making certain that your line driver is outputting max voltage because that is likely more than the amplifier you're driving can handle. The point is to maximize signal input to the amp without causing the amp to clip the output so you really want to meter the amp's outputs while adjusting processors further "upstream."
The only reasons I think you'd ever bother to take a reading at the rca outputs of the individual processors is to ensure that they're not outputting a clipped signal (but the PLD1 has a peak led for this reason), or when you're running the signal into another processor that has a max input voltage. I thought you might to level match left/right independent controls (sld44 or tld's) but even that can be accounted for by metering the amp's output channels while making adjustments.
The only reasons I think you'd ever bother to take a reading at the rca outputs of the individual processors is to ensure that they're not outputting a clipped signal (but the PLD1 has a peak led for this reason), or when you're running the signal into another processor that has a max input voltage. I thought you might to level match left/right independent controls (sld44 or tld's) but even that can be accounted for by metering the amp's output channels while making adjustments.
OK guys, I made some adjustments last night and here's what I found.
My HU has 2.5v ac with the volume set at 7/8
The LPL would not make 8v unless it is set to max, I only can set it to around ~4 - 4.5v ac to avoid the clip LED
As far as the AC EQ, I was able to send 8v ac downstream to the amps easily without the "peak" led flickering. I double checked the voltage at the rca at the amps and it was a little high, so I simply lowered the gain on the AC a little to about 7.7/8 v
I tried this with 50hz, 60hz and 75hz test tones.
Also, while I was at it I went ahead and set my amp's internal xovers, it was a bitch to say the least.
I ran test tones for my crossover points....60hz LP, 60 and 250hz BP and 250hz HP.
There was no way I could set the voltage correctly. For example, for the high pass I ran a 250hz test tone thinking that I would get peak voltage once I hit 250hz and the voltage would drop once I get pass 250hz...far from truth, the higher I set the crossover, the higher the AC voltage.
It seems that voltage depends on frequency.
As of now, my xovers are set by ear. Are there any better ways to set the xovers? The crossover markings on the ZX amps are poop. I basically set it by eye, then went from there. I was getting a retarded amount of voltage (50+ volts) when the HP was set to 600hz which was fully clockwise. I was afraid my DMM was going to fry.
Again, I was getting around 25v ac on the each of the 450 channel, far from my 17v target, once I set the xovers by ear.
It sounds like hit of distortion when I listen to music at high levels, but not passing 7/8 on my HU
Should I just lower the levels on the processors?
thanks for the help fellas!
My HU has 2.5v ac with the volume set at 7/8
The LPL would not make 8v unless it is set to max, I only can set it to around ~4 - 4.5v ac to avoid the clip LED
As far as the AC EQ, I was able to send 8v ac downstream to the amps easily without the "peak" led flickering. I double checked the voltage at the rca at the amps and it was a little high, so I simply lowered the gain on the AC a little to about 7.7/8 v
I tried this with 50hz, 60hz and 75hz test tones.
Also, while I was at it I went ahead and set my amp's internal xovers, it was a bitch to say the least.
I ran test tones for my crossover points....60hz LP, 60 and 250hz BP and 250hz HP.
There was no way I could set the voltage correctly. For example, for the high pass I ran a 250hz test tone thinking that I would get peak voltage once I hit 250hz and the voltage would drop once I get pass 250hz...far from truth, the higher I set the crossover, the higher the AC voltage.
It seems that voltage depends on frequency.
As of now, my xovers are set by ear. Are there any better ways to set the xovers? The crossover markings on the ZX amps are poop. I basically set it by eye, then went from there. I was getting a retarded amount of voltage (50+ volts) when the HP was set to 600hz which was fully clockwise. I was afraid my DMM was going to fry.
Again, I was getting around 25v ac on the each of the 450 channel, far from my 17v target, once I set the xovers by ear.
It sounds like hit of distortion when I listen to music at high levels, but not passing 7/8 on my HU
Should I just lower the levels on the processors?
thanks for the help fellas!
Last edited by vin78 on Fri Sep 14, 2007 8:00 pm, edited 1 time in total.
It's possible the PLD was clipping early because the HU was clipping a bit. I had the same issue with my Saab, so I redid my Audiocontrol gains with the headunit at 2/3 volume instead of 3/4. Sounds LOTS better now, I can get lots more volume before distortion, and it solved all of my headlight blinking.
Unless you have a "True RMS" DMM, you can't measure at any frequency tone other than 60Hz. You will simply have to set your crossovers by ear, which is probably the best way anyways...
Unless you have a "True RMS" DMM, you can't measure at any frequency tone other than 60Hz. You will simply have to set your crossovers by ear, which is probably the best way anyways...
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fuzzysnuggleduck
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We have a Fluke DMM at work that claims to be True RMS... I should borrow it.stipud wrote:It's possible the PLD was clipping early because the HU was clipping a bit. I had the same issue with my Saab, so I redid my Audiocontrol gains with the headunit at 2/3 volume instead of 3/4. Sounds LOTS better now, I can get lots more volume before distortion, and it solved all of my headlight blinking.
Unless you have a "True RMS" DMM, you can't measure at any frequency tone other than 60Hz. You will simply have to set your crossovers by ear, which is probably the best way anyways...
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HoseHead
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When I bought my car:
- Alpine HU volume set to 40%
- AC Four.1i gains set to about 40%
- Each PG AX406 I/P (F &R) set to about 50%
- Each PG AX406 O/P (LP,BP,HP) set to about 50%
- FAS gains (both MQ430 and MS2125) set to about 85%
Extended power listening on the initial ride home (one hour or more) the FAS would go thermal. I thought I pooched it. The FAS, of course, recovered and all is good for another 20 minutes or so then the process repeats. I get home and internet research finds you clowns. Read, read and read some more. The original installer had a theory of "crank the amp, man". Wrong.
Set gains sequencing through each processor in the signal path. Processors do not generate significant heat when set high. The greater the CLEAN signal amplitude you can deliver to your final component (amp), the less amp gain required resulting in more dynamic sound and less work for your amp = cooler operation, less stress and extended life. Also, once all I/P's and O/P's are optimized, any further setting adjustments will affect all remaining components down stream.
Set up now:
- HU volume set at 75%
- AC Four.1i set to about 90%
- PG AX406 I/P (F &R) set to about 65%
- PG AX406 O/P (LP,BP,HP) set to about 75%
- FAS (MQ 430 - BP from 406) gains set to about 35%
- FAS (MS2125 - LP from 406) gains set to about 30%
- 406 HP goes to Alpine 3315 now - Gain is about 45% - This amp was NOT in the original configuration.
Resulting sound is FAR superior and the FAS only gets mildly warm to the touch. I did not use any instruments other than my noggin receptors and clip LED's if the component is so equipped. I'll DMM it all this winter during the system rebuild (cosmetics only).
I learned most of this from all you large foreheads. Regret the novel
- Alpine HU volume set to 40%
- AC Four.1i gains set to about 40%
- Each PG AX406 I/P (F &R) set to about 50%
- Each PG AX406 O/P (LP,BP,HP) set to about 50%
- FAS gains (both MQ430 and MS2125) set to about 85%
Extended power listening on the initial ride home (one hour or more) the FAS would go thermal. I thought I pooched it. The FAS, of course, recovered and all is good for another 20 minutes or so then the process repeats. I get home and internet research finds you clowns. Read, read and read some more. The original installer had a theory of "crank the amp, man". Wrong.
Set gains sequencing through each processor in the signal path. Processors do not generate significant heat when set high. The greater the CLEAN signal amplitude you can deliver to your final component (amp), the less amp gain required resulting in more dynamic sound and less work for your amp = cooler operation, less stress and extended life. Also, once all I/P's and O/P's are optimized, any further setting adjustments will affect all remaining components down stream.
Set up now:
- HU volume set at 75%
- AC Four.1i set to about 90%
- PG AX406 I/P (F &R) set to about 65%
- PG AX406 O/P (LP,BP,HP) set to about 75%
- FAS (MQ 430 - BP from 406) gains set to about 35%
- FAS (MS2125 - LP from 406) gains set to about 30%
- 406 HP goes to Alpine 3315 now - Gain is about 45% - This amp was NOT in the original configuration.
Resulting sound is FAR superior and the FAS only gets mildly warm to the touch. I did not use any instruments other than my noggin receptors and clip LED's if the component is so equipped. I'll DMM it all this winter during the system rebuild (cosmetics only).
I learned most of this from all you large foreheads. Regret the novel
The only stupid question is the one not asked .......
Thanks for a very learning thread.
I installed a SLD44 yesterday and started some gain tuning with DMM. I set the output from the SLD44 to my RSD1200.1 to 8V with my Alpine deck on 25\35 on the volume.Then i set the gain on the amp also to 8V. But how about the LPL44 then? I set the LPL to max but what happens when i turn it down? Does the amp need 8V for full output with the LPL44 set to max and if the LPL is turned down to f.ex 50% then the amp will need like 16V to produce full output?
No big deal because it sounds great with high voltage input but i`m the typr that just need to know every little detail
Or am i just missing something relevant here?
Thanks
I installed a SLD44 yesterday and started some gain tuning with DMM. I set the output from the SLD44 to my RSD1200.1 to 8V with my Alpine deck on 25\35 on the volume.Then i set the gain on the amp also to 8V. But how about the LPL44 then? I set the LPL to max but what happens when i turn it down? Does the amp need 8V for full output with the LPL44 set to max and if the LPL is turned down to f.ex 50% then the amp will need like 16V to produce full output?
No big deal because it sounds great with high voltage input but i`m the typr that just need to know every little detail
Or am i just missing something relevant here?
Thanks
The LPL is a volume attenuator, so you are correct... it will only produce full volume at 100% on the LPL if your gains are set properly.
What some of us do, however, is set your gains on the amp a little higher, and use the LPL to reduce the volume from that point. This lets you add a bit more bass to songs that don't have a strong bassline, but you have to be VERY careful with the LPL. If you turn it up all the way on a very bassy song you will easily make the amplifier clip again.
What some of us do, however, is set your gains on the amp a little higher, and use the LPL to reduce the volume from that point. This lets you add a bit more bass to songs that don't have a strong bassline, but you have to be VERY careful with the LPL. If you turn it up all the way on a very bassy song you will easily make the amplifier clip again.
I did a little cheating too, i set the output to 8 Volts with the Sub-Level on my Alpine deck set to +8dB but it goes up to +15dB so i can boost a little if needed.
Is the basscube to be set between the SLD44 and the Amp? If so, should i send 8 Volts into the Basscube? Will the signal be over 8 Volts if i use the boost knob on the Cube or isn`t the Boost lifting the voltage of the signal?
Is the basscube to be set between the SLD44 and the Amp? If so, should i send 8 Volts into the Basscube? Will the signal be over 8 Volts if i use the boost knob on the Cube or isn`t the Boost lifting the voltage of the signal?