Auto off/on mod?

[98falstaff]

Hi everyone, I hate to ask for help on my first post but here we go. My receiver is a Yamaha RXV 557 and my sub is a Cerwin Vega CL5612S. These are upgrades from a smaller Yamaha and smaller Cerwin sub. Had the same problem with them too. Problem is that I have to turn up the volume extremely loud to get the light to go from red to green, when I go back to normal listening levels it goes back to red after a little while and I lose the sub, usually when there is talking parts during the show and no big bass in the program. I have all speakers set to small, sub set to on. Have adjusted LFE levels and have tried every level and combination on all concerned parameters. Seems like the sub signal is not enough to keep it on at lower volume levels. Is there some mod that can be done to bypass the auto fuction and leave the sub amp on all the time? If there is this is what I would like to do. This sub and the old one both stayed on longer when they were new but gradually the time on periods got shorter. What signal from the receiver tells the auto to stay on? I don't think it is the reciever. This is very frustrating and I would like to have the sub to work. Thanks in advance for any help.

 

[Adam]

Welcome to the forum!

One trick to help with that issue is to increase the subwoofer output level on the receiver (and correspondingly decrease the subwoofer volume setting on the sub itself to keep the overall volume the same). The auto-power sensor is using the audio signal coming from the receiver to determine if the sub should be on or off. If the audio signal is lower than the threshold of the sensor, then the sensor will act like there isn't a signal and shut the sub off after a set amount of time. By increasing the subwoofer output level on the receiver, the signal being sent to the sub is higher and has a better chance of exceeding the threshold for the sensor.

I'll check on your sub now to see if you can bypass that feature. Is there an "On" setting?

 

[98falstaff]

Correction to my first post. The model is a Cerwin Vega CLSC 12S. Sorry.

 

[fredk]

What Adam wrote. I am using a Behringer 1024 to EQ my sub, so I was able to monitor the input signal and set it so that it reaches just below clipping on the loudest movie scenes. Where others with my exact same sub have had problems with auto on, I have none at all.

 

[Lordoftherings]

If you set the Auto to OFF, your sub should be ON all the time.

 

[98falstaff]

Thanks for your input guys. I think I will just buy a new sub with on, off, and the auto on/off. I have tried everything you can think of. There seems to a lot of similar issues out there. So it's either the AVR signal too low (even at maximum settings) or the auto sensor level is too high. Both setups were with Yamaha AVR's and Cerwin Vega subs.

 

[98falstaff]

Jumper installed, Problem solved. Took the amp out of sub, took it to work and looked it over good. Found a 12V relay on one of the circuit boards, the only relay in there. Looked up the relay on internet for coil and contact pin locations. Removed upper board for access to lower board. Traced contacts to speaker output. Powered up amp and green LED came on, Took voltage tests. Waited for LED to turn fron green to red. Verified contacts opened. Powered down. Soldered jumper wire across normally open relay contacts and reassembled. Took amp home and installed in sub cabinet and hooked up to system. Got normal bass out of sub, green light on, all cool. Waited for timer or low bass signal to auto off. Red LED came on and still had sub sound, which is exactly what I was trying to do. Now output to sub speaker is on all the time, awsome. Mission accomplished! The relay is a Goodsky UDH-SH-112D. Thanks again for all input.