hello, I'm new here. My name is Patrick and with the ICEPower 125ASX2 I started to study power modules.
I'm not an electronic expert, but I'm not awkward either.
excuse my bad English.
The problem:
I have a 125ASX2 with Ghent RTX balancer for the BTL mode. It serves as a subwoofer power amplifier.
The preamplifier is always an AVR.
The problem is that the volume level is much too quiet.
Compared with 3 other submodules with less power, they play a lot louder.
even in stereo mode (to exclude an error with the ghent module) did not work. It has also been tested with different subwoofers (Mivoc 8 "/ 10" / 12 ")
what can I do? Where is the mistake?
My guess is that the preamp has too little power at the sub-output. However, I have heard that the ASX2 module only needs about 1.35V. Unfortunately, I do not know how much voltage my AVR outputs exactly. how can I measure that exactly?
But then I wonder why all the other modules have no problems with it.
I hope you can help me. Thank you.
I'm not an electronic expert, but I'm not awkward either.
excuse my bad English.
The problem:
I have a 125ASX2 with Ghent RTX balancer for the BTL mode. It serves as a subwoofer power amplifier.
The preamplifier is always an AVR.
The problem is that the volume level is much too quiet.
Compared with 3 other submodules with less power, they play a lot louder.
even in stereo mode (to exclude an error with the ghent module) did not work. It has also been tested with different subwoofers (Mivoc 8 "/ 10" / 12 ")
what can I do? Where is the mistake?
My guess is that the preamp has too little power at the sub-output. However, I have heard that the ASX2 module only needs about 1.35V. Unfortunately, I do not know how much voltage my AVR outputs exactly. how can I measure that exactly?
But then I wonder why all the other modules have no problems with it.
I hope you can help me. Thank you.
Hello and thanks.
Without the Ghent RTX module, I can only test in stereo mode. I have already done that. The result was again a quieter music output.
I measured a bit with a 50hz sine tone.
A Budytec 500 module has a voltage of 48 volts at about half the AVR volume (-35 dB).
Same scenario with the 125ASX BTL was 4.2 volts.
The AVR I can turn up to -12DB, from then distorted the signal in the 125ASX. The 125ASX2 comes only at about 30Volt output voltage in stereo mode. So far away from z.b. Budytec or other modules.
If the 125ASX2 is in stereo mode, the voltage at -35 dB at the AVR is 1.4 volts.
In stereo mode at -20DB it is 8.6 volts.
What I still noticed, at Buddytec My multimeter shows the 48V and the 50Hz. In the 125ASX2 BTL mode, I get the FQ not displayed clean, fluctuates in the khz area. In stereo mode, the 50hz could be measured again.
Without the Ghent RTX module, I can only test in stereo mode. I have already done that. The result was again a quieter music output.
I measured a bit with a 50hz sine tone.
A Budytec 500 module has a voltage of 48 volts at about half the AVR volume (-35 dB).
Same scenario with the 125ASX BTL was 4.2 volts.
The AVR I can turn up to -12DB, from then distorted the signal in the 125ASX. The 125ASX2 comes only at about 30Volt output voltage in stereo mode. So far away from z.b. Budytec or other modules.
If the 125ASX2 is in stereo mode, the voltage at -35 dB at the AVR is 1.4 volts.
In stereo mode at -20DB it is 8.6 volts.
What I still noticed, at Buddytec My multimeter shows the 48V and the 50Hz. In the 125ASX2 BTL mode, I get the FQ not displayed clean, fluctuates in the khz area. In stereo mode, the 50hz could be measured again.
Hello and thanks.
Without the Ghent RTX module, I can only test in stereo mode. I have already done that. The result was again a quieter music output.
I measured a bit with a 50hz sine tone.
A Budytec 500 module has a voltage of 48 volts at about half the AVR volume (-35 dB).
Same scenario with the 125ASX BTL was 4.2 volts.
The AVR I can turn up to -12DB, from then distorted the signal in the 125ASX. The 125ASX2 comes only at about 30Volt output voltage in stereo mode. So far away from z.b. Budytec or other modules.
If the 125ASX2 is in stereo mode, the voltage at -35 dB at the AVR is 1.4 volts.
In stereo mode at -20DB it is 8.6 volts.
What I still noticed, at Buddytec My multimeter shows the 48V and the 50Hz. In the 125ASX2 BTL mode, I get the FQ not displayed clean, fluctuates in the khz area. In stereo mode, the 50hz could be measured again.
Without the Ghent RTX module, I can only test in stereo mode. I have already done that. The result was again a quieter music output.
I measured a bit with a 50hz sine tone.
A Budytec 500 module has a voltage of 48 volts at about half the AVR volume (-35 dB).
Same scenario with the 125ASX BTL was 4.2 volts.
The AVR I can turn up to -12DB, from then distorted the signal in the 125ASX. The 125ASX2 comes only at about 30Volt output voltage in stereo mode. So far away from z.b. Budytec or other modules.
If the 125ASX2 is in stereo mode, the voltage at -35 dB at the AVR is 1.4 volts.
In stereo mode at -20DB it is 8.6 volts.
What I still noticed, at Buddytec My multimeter shows the 48V and the 50Hz. In the 125ASX2 BTL mode, I get the FQ not displayed clean, fluctuates in the khz area. In stereo mode, the 50hz could be measured again.
The supply voltage does not determine the volume, the gain does. The gain of the 125 may be lower, or the AVR output for subwoofer may be lower.
You can check by using the 125 module for any of the other channels. If the level is OK then, it's the AVR output that is too low for the woofer.
If the 125 is still low, probably the 125 has an issue.
Jan
You can check by using the 125 module for any of the other channels. If the level is OK then, it's the AVR output that is too low for the woofer.
If the 125 is still low, probably the 125 has an issue.
Jan
Thank you. Is not that the case, that a higher voltage at the amplifier output also brings a higher level with the same speaker?
I could also test the same with another module. For example, a 120Watt module is a lot louder than the 125er.
I can not translate correctly what I should test now.
I should test other pre-outs on AVR for the 125er?
What could that be a problem on the 125er?
How do I properly measure the voltage at the pre-out of the AR?
I could also test the same with another module. For example, a 120Watt module is a lot louder than the 125er.
I can not translate correctly what I should test now.
I should test other pre-outs on AVR for the 125er?
What could that be a problem on the 125er?
How do I properly measure the voltage at the pre-out of the AR?
Supplement.
Do I understand that correctly?
I could measure max 30Volt, before the signal became unclean (oscilloscope). Is that then now (very roughly) 30Volt / 4Ohm = 7.5A * 30Volt = 225Watt? Or you can not measure it that way?
would like to find out if the module is now too low amplified or the output voltage of 3 different AVRs is too low, which I have at home.
Do I understand that correctly?
I could measure max 30Volt, before the signal became unclean (oscilloscope). Is that then now (very roughly) 30Volt / 4Ohm = 7.5A * 30Volt = 225Watt? Or you can not measure it that way?
would like to find out if the module is now too low amplified or the output voltage of 3 different AVRs is too low, which I have at home.
IF you have an oscilloscope,please do this:
1) get some signal voltage source.
It can be as basic as a small transformer, pad output (say, 6 or 12VAC) to about 2 V RMS.
For example, use a 2k2>1k resistor network with a 6V transformer or 4k7/1k with a 12V one , then go to a volume potentiometer, 10k is fine.
2) slowly rise signal into amplifier until you see output clip.
Since you are checking a balanced BTL type output, you can´t put scope leads across the load, none of them is ground, but no big deal, just clip probe ground to ground, and check *one* speaker output terminal, when it starts clipping check the other is clipping about bthe same.
Once you just reach clipping, measure RMS voltage across the load with your multimeter and calculate power output.
And measure actual signal voltage fed to input to check sensitivity.
Please post both results.
3) IF not even 2V RMS is enough to drive your ICE moduke to clipping, either it or the "balancer" feeding it have a big problem.
But guessing is futile, please post actual measurements.
1) get some signal voltage source.
It can be as basic as a small transformer, pad output (say, 6 or 12VAC) to about 2 V RMS.
For example, use a 2k2>1k resistor network with a 6V transformer or 4k7/1k with a 12V one , then go to a volume potentiometer, 10k is fine.
2) slowly rise signal into amplifier until you see output clip.
Since you are checking a balanced BTL type output, you can´t put scope leads across the load, none of them is ground, but no big deal, just clip probe ground to ground, and check *one* speaker output terminal, when it starts clipping check the other is clipping about bthe same.
Once you just reach clipping, measure RMS voltage across the load with your multimeter and calculate power output.
And measure actual signal voltage fed to input to check sensitivity.
Please post both results.
3) IF not even 2V RMS is enough to drive your ICE moduke to clipping, either it or the "balancer" feeding it have a big problem.
But guessing is futile, please post actual measurements.
Thank you. Please remember, I'm still a beginner. yes, I have an oscilloscope, a very old one, it still has to learn it correctly.
Unfortunately, I do not quite understand what I should do now. I repeat.
Unfortunately I have no small AC source.
Can I also take a pre-out of the AVR?
I also do not understand that with the Resistance. For what exactly should be.
In my case with the 125ASX2 I also installed a potentiometer 10k (I had already disconnected)
Must / Should the subwoofer be connected during the test? Does the 125 ASX2 break without output at the output?
Can I also measure as follows?
AVR - PRE-Out Fairs
AVR - Pre-Out -> RCA connector -> 10k potentiometer -> Ghent RTX balancer -> 125ASX2 BTL mode.
Oscilloscope ground to housing of the 125ASX2 (the housing is not grounded) and signal tip to a pin speaker output.
Since the pre-out should output a constant voltage or passes through the input, I now have to slowly turn the potentiometer until the sine wave turns into a choppy signal. Right?
When the chopped signal is reached, measure with multimeter at the bridged speaker output. Does a subwoofer need to be connected?
Unfortunately, I do not quite understand what I should do now. I repeat.
Unfortunately I have no small AC source.
Can I also take a pre-out of the AVR?
I also do not understand that with the Resistance. For what exactly should be.
In my case with the 125ASX2 I also installed a potentiometer 10k (I had already disconnected)
Must / Should the subwoofer be connected during the test? Does the 125 ASX2 break without output at the output?
Can I also measure as follows?
AVR - PRE-Out Fairs
AVR - Pre-Out -> RCA connector -> 10k potentiometer -> Ghent RTX balancer -> 125ASX2 BTL mode.
Oscilloscope ground to housing of the 125ASX2 (the housing is not grounded) and signal tip to a pin speaker output.
Since the pre-out should output a constant voltage or passes through the input, I now have to slowly turn the potentiometer until the sine wave turns into a choppy signal. Right?
When the chopped signal is reached, measure with multimeter at the bridged speaker output. Does a subwoofer need to be connected?
Are You sure the balancer is correctly wired ? For BTL mode, You must invert one of the signals. Are you connecting AVR SUB RCA -- Balancer (one channel only) --- XLR Pin 1 Ground - Amp Ground. Pin 2 Left channel amp module. Pin3 Right channel amp module ?
Or are You connecting both balancer RCA ins to the sub out and then each XLR out to the Amp (Signals in phase in BTL cancel each other) ?
Check the AVR manual. There is presumably a setting in the menu for setting the sub out gain. I believe Your AVR outputs 300mV consumer level and The Icepower needs more, datasheet only mentions max input and not sensitivity.
Or are You connecting both balancer RCA ins to the sub out and then each XLR out to the Amp (Signals in phase in BTL cancel each other) ?
Check the AVR manual. There is presumably a setting in the menu for setting the sub out gain. I believe Your AVR outputs 300mV consumer level and The Icepower needs more, datasheet only mentions max input and not sensitivity.
Please post balancer schematic or wiring diagram.
We will first test it works right.
After that we´ll check the ICE module.
You will not connect speaker or any load until specifically asked to.
As of test signal: can your AVR play an MP3?
If so, download and save these for future use:
* https://www.mediacollege.com/audio/tone/files/100Hz_44100Hz_16bit_30sec.mp3
* https://www.mediacollege.com/audio/tone/files/250Hz_44100Hz_16bit_05sec.mp3
* https://www.mediacollege.com/audio/tone/files/440Hz_44100Hz_16bit_30sec.mp3
* https://www.mediacollege.com/audio/tone/files/1kHz_44100Hz_16bit_30sec.mp3
* https://www.mediacollege.com/audio/tone/files/10kHz_44100Hz_16bit_30sec.mp3
these are 30 second MP3s so for practical use you must set player to "loop" or "repeat one" or equivalent, so they provide continuous tone (with a small chirp every 3 seconds when restarting).
You´ll check their presence and health at different test points with the scope, so you will need to practice setting sensitivity and sweep so you have a clear stable image on screen.
We will first test it works right.
After that we´ll check the ICE module.
You will not connect speaker or any load until specifically asked to.
As of test signal: can your AVR play an MP3?
If so, download and save these for future use:
* https://www.mediacollege.com/audio/tone/files/100Hz_44100Hz_16bit_30sec.mp3
* https://www.mediacollege.com/audio/tone/files/250Hz_44100Hz_16bit_05sec.mp3
* https://www.mediacollege.com/audio/tone/files/440Hz_44100Hz_16bit_30sec.mp3
* https://www.mediacollege.com/audio/tone/files/1kHz_44100Hz_16bit_30sec.mp3
* https://www.mediacollege.com/audio/tone/files/10kHz_44100Hz_16bit_30sec.mp3
these are 30 second MP3s so for practical use you must set player to "loop" or "repeat one" or equivalent, so they provide continuous tone (with a small chirp every 3 seconds when restarting).
You´ll check their presence and health at different test points with the scope, so you will need to practice setting sensitivity and sweep so you have a clear stable image on screen.
Hello. Thanks for the answer. As far as I understand, should be connected properly.
AVR Sub Out (RCA) -> Signal + Ground in RTX Balancer -> Signal1 + Signal2 + Ground -> to ICE Module -> Speaker Output on ICE Channel1 + and Channel2 + -> Subwoofer.
I also used a PC directly as a source. same problem.
Even without the RTX balancer the same problem.
As far as I could find the manuals of all my AVRs nothing about the output voltage.
In another forum it was said that the ICE module needed about 1.3 volts for full power.
Another question. Why are all subwoofer power amplifier modules able to cope with so little voltage? An ICE module not? ^^
without the poti I also tested.
RTX Ghent +6db
ghentaudio --- RTX (unbalnced RCA to balanced XLR Converting) Module
@JMFahey:
Thank you. Would you please describe the construction in more detail? I do not want to make a mistake and am still new in the field.
What can I take as an ac source what can be found in the normal household? I can not think of anything. I only have DC devices so far.
test build
AVR Sub Out (RCA) -> Signal + Ground in RTX Balancer -> Signal1 + Signal2 + Ground -> to ICE Module -> Speaker Output on ICE Channel1 + and Channel2 + -> Subwoofer.
I also used a PC directly as a source. same problem.
Even without the RTX balancer the same problem.
As far as I could find the manuals of all my AVRs nothing about the output voltage.
In another forum it was said that the ICE module needed about 1.3 volts for full power.
Another question. Why are all subwoofer power amplifier modules able to cope with so little voltage? An ICE module not? ^^
without the poti I also tested.
RTX Ghent +6db
ghentaudio --- RTX (unbalnced RCA to balanced XLR Converting) Module
@JMFahey:
Thank you. Would you please describe the construction in more detail? I do not want to make a mistake and am still new in the field.
What can I take as an ac source what can be found in the normal household? I can not think of anything. I only have DC devices so far.
test build
Last edited:
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