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Crown PSA-2 power amp. Right after turning power on with volume controls all the way down, the amp continuosly thumps the woofers (alternating from the right to the left. This just started to happen. No prior problems. When the thumping is happening, I can see the cones retracting hard and the thumping is extremely loud. When the right side thumps, the right side standby light blinks and then goes off. Same for the left side. The IOC lights don't come on. This amp is part of a tri-amped system. It drives a pair of Klipsch KI-115"s. Thank you for any assistance you can provide. William.

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Hi! The thumping motion is usually caused by faulty cross-over voltage biasing. What this is is simple; Power amps of high wattage are usually constructed of two similar but opposite polarity amplifiers ;one drives the top (positive) part of the sinusoidal and the other drives the bottom.

The simple causes that need to be eliminated are

1) Earthing :-check earthing to ensure no earth loops
2) Check the Power fuses:- usually, the supply of power to only one part of the amplifier causes thumping motion. The power section in these designs have a positive and negative polarity eg.=80V-0V-(-) 80V
3) Disconnect the speakers and check the power supply Voltages across the output stage sumettry for more details visit
http://www.howtodothings.com/electronics/how-to-fix-your-guitar-amplifier

Posted on Dec 04, 2008

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How to use hk395 subwoofer without satellite speakers


System power is controlled by a switch on the right satellite speaker ON/OFF VOLUME control, therefore you would have to connect a separate switch to control power. However, you may be able to get a satisfactory result by turning the satellite volume control completely counter clockwise and adjusting the WOOFER VOLUME control to the desired level.

Jan 21, 2015 | Audio Players & Recorders

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(I think) our bass player plugged from the output on a powered desk in to the input of our JBL MPro 18" sub (MP418SP) powered by crown Amplifiers. Now the fault light is constantly flashing and...


I'm assuming you mean he plugged an amp output (meant for a speaker) into the input of one of the Crown amps powering the sub-woofer. Right? Crown amps have good protection circuits and are high quality units. Some models have internal fuses but you didn't list a model here. If they are fused (or some kind of breaker) you should be able to see those by opening the top cover (amp off and unplugged). It is unclear if you tried to use the amp again after this incident.
Some Crown amps have protection circuits that will reset themselves after the fault is removed. In this case, you should remove both inputs and output (speaker) and power it up. If the amp doesn't light any protection lights or indicators, then turn it off and connect a known good speaker (not the subwoofer) and a source you can control. Set a low volume and see how it goes. You can really try either approach first depending on what's easier.

Jan 28, 2011 | Audio Players & Recorders

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My subwoofer sometimes turns on and sometimes it don't. I've noticed that when i disconnect the power cord from the wall and connect it back the light/volume doesn't turn on. Also when i turn the amp too...


Subwoofers produce very high levels of vibration due to the intensity of their job. But the problem you are facing is a problem with the power pack. The power pack on the woofer is not supplying properly therefore the light/volume not coming on when the unit is unplugged and replugged. This also affects the woofer when you turn the amp to high because as a result of the power coming from the amp not being properly distributed instead of the power which flows into the woofer from the amp is not distributed accordingly it could blow the woofer so before it gets to that stage the unit shuts down.
All you have to do is get an expert to help you get and replace the power pack.
Hope this solution has been helpful?

Jan 01, 2011 | Infinity Modulus System

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The subwoofers still thump when i turn the volume all the way down. and they're not thumping the song it's kind of random thumping. I looked at the amp, the power wire looked like it was slightly pulled...


try running a wire from the ground to the shielding of the rca's. if that works you have a bad rca ground. you can either get the amp repaired or solder a wire onto the shield of the rca's.

Aug 20, 2010 | Car Audio & Video

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My sub woofer will stop working if i put the bass up to loud, ill have to turn my car off and on to get it to work again. What could be the problem?


Seems like your power amp for the sub woofer may be going into protect mode/thermal overload when you push the volume too much. Therefore it shuts down. I am surprised the speaker hasn't blown yet.

As far as turning car off/on to get it to work, it's as if your car is the power switch.

Amp and speakers may not be wired correctly, as you want to make sure your amp/speaker ohm measurements are within a specific range for the amp and speakers work together properly. You may have it wired for a 2 ohm load, and maybe your amp can't do 2 ohms all day long.

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YAMAHA AV receiver RX-V861 I have the message 'Vol-fix' appearing on Zone 2 and no sound. This was working fine until then


Setting the RX-V861 remote control to operate Zone 2:
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  2. Using the [NUMERICAL KEY PAD] on the remote and key in 9992, the [TRANSMIT INDICATOR] should flash.
Assigning the receivers internal amp for Zone 2:
  1. Set the remote control selector to [AMP]. (Located to the right of the volume buttons on the Remote.).
  2. Press the [SET MENU]button on the remote control.
  3. Arrow down to Manual Setup and press the Enter button on the remote control.
  4. Arrow to the [SOUND MENU] option and press the [ENTER] button on the remote control.
  5. Arrow to Speaker Set and press the [ENTER] button on the remote control.
  6. Arrow to the EXTRA SP ASSIGN and select ZONE2
  7. Press the [RETURN] button on the remote control to exit out and return to the Manual Setup.
NOTES: There is an option for setting the Maximum Volume and Initial Volume in the Zone Set menu.
  • Max Volume: This is an optional feature but isrecommended to prevent the accidental change in volume levels thatcould damage the speakers and receiver.
  • Initial Volume: This is also a great feature that would seamlessly start the volume level for the second or third zone at the desired level.
We do not recommend using any Speaker Selector boxes to enable more than the recommended number of speakers per terminal.
Controlling Zone 2 using the RX-V861 remote control:
  1. If the Main Zone on the receiver is on, press the [POWER BUTTON]down and while holding that button down press the [PHONO]/[**] button on the remote. The [TRANSMIT INDICATOR] will light up.
  2. You will not be able to use the following buttons on the remote: (Pressing any other button will cause the remote to exit Zone 2 mode. [POWER], [STANDBY], [VOLUME], [MUTE] and the [INPUT SELECTOR] buttons [DVD], [CD], etc.)

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There are the instructions as written straight from yamaha. If you need any further assistance please let me know.
Thank you,
Lee

Dec 13, 2009 | Audio Players & Recorders

1 Answer

Stereo makes a thump sound after a installed a mono amplifier, the noise comes from the subs it drives, its also present when i turn it off, just a single loud thump noise.


Are you turning of the amplifier first or the source of audio? Amps should be powered down first and then the source. If both are powered down at the same time make sure the volume is down or otherwise you will always get a thump. The opposite when you power up. The source and then the amp. Hope this helps.

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Amp not working properly


yes that is the cause sorry..i have done it before when i was younger a few times thats how i know..sorry man

Dec 05, 2008 | Car Audio & Video

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Do you know if my woofer is blown?


well if you hear a rattle sound its probably already blown...and the amp could be drawing too much power if the radio shuts off...make sure all your wiring is correct. also if your car is off and you turn it up it will most likely shut off cause the battery cant handle it. but as for the sub i think its blown. good luck

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Amps and sub-woofer not working


Enter into the Audio Setup mode(press and hold volume button for at least 1 second). Next, repeatedly push the volume button until the display shows "2 ZONE". Make sure this feature is turned off. Hold the volume button again for at least 1 second to leave Audio Setup mode.

Now you need to make sure the Subwoofer Output is turned on. Do this by holding down(AM position) on the control knob(toggle stick) for at least 1 second. Each time the button is pressed, the Subwoofer Output is turned ON/OFF. the display should show "SW ON".

Next, you can go into Audio Control mode(press but do not hold volume button). Keep pressing on the volume knob until "Sub-WLevel" is displayed. Here you can adjust the amount of gain for the Subwoofer ranging from -15 to +15.

I hope this fixes your problem with it.

Cheers

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