yoha Posted November 27, 2004 Share Posted November 27, 2004 Hi folks, i just got the RW-12 sub and my sub keep on "dying" on me. In other words, everytime i listen to music / watch movies, i need to set the switch @ the back of the subwoofer to "on" so that it will start producing bass even though it is on "auto" which i read should turn on (light indicator turns green). Then if i change it to "auto", the indicator light stays on green which is good. But after a few minutes, it returns to "stand by" again(light indicator becomes red) and not producing anything and now i need to turn the switch to "on" again and so on. Anyone has experienced something like this on your sub? btw, i set the sub vol to half. I connect the sub to my Denon AVR-3805 via LFE channel, phase is @ 90*, Lowpass: 85 Hz. Thanks for any suggestion and help Best Regards, Yoha Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted November 27, 2004 Share Posted November 27, 2004 It sounds like it is not receiving a signal. When you manually switch the sub on do you get sound from the sub or does the green light just come on? Do you have the sub turned on in the receiver? I used to have an RW-12 and it was not very sensitive to turning on. I had to turn the volume way up to "wake up" the sub and then turn it back down. It never went "back to sleep" once it was on though. If all else looks OK, you might try turning up the gain in the receiver and down on the sub proportionally. Carl Quote Link to comment Share on other sites More sharing options...
yoha Posted November 28, 2004 Author Share Posted November 28, 2004 CECAA850, True, the volume needs to be turned up for the signal to be detected by te sub which i think make sense. if there is no need for the sub to produce bass(ex. volume is low), why should it fire. 1 more thing, since you used to have the rw-12 as well, i have questions regarding the phase and lowpass knobs. what are they? how can i set them? right now it is set by default by klipsch to 0* for phase and 40Hz for lowpass. any suggestions? thanks Best Regards, Yohannes Quote Link to comment Share on other sites More sharing options...
DrWho Posted November 28, 2004 Share Posted November 28, 2004 The lowpass frequency is the frequency below which the sub starts to make sound. If you are connecting your sub to the LFE send on your reciever, then you should use the reciever's options to select the crossover frequency and then turn the dial on your sub to the highest value (so that it doesn't interfere with your reciever). There is also very little information below 40Hz anyway, so perhaps that helps explain your auto power issues. The phase knob is a tool for helping you integrate your sub with your mains. When two audio signals are 180degrees out of phase, they completely cancel each other out. The easiest way to set the phase without special testing equipment is to flip the + and - cables on your main speakers. This will effectively put your mains 180degrees out of phase. Then while playing bass heavy music, have a friend turn the phase knob on the sub while you sit in the main listening position until the bass sounds the quietest. Then flip the + and - cables on your mains back to their normal position and your sub will now be in phase with your mains. Quote Link to comment Share on other sites More sharing options...
ironwoods Posted November 28, 2004 Share Posted November 28, 2004 ---------------- On 11/28/2004 5:19:20 AM DrWho wrote: The easiest way to set the phase without special testing equipment is to flip the + and - cables on your main speakers. This will effectively put your mains 180degrees out of phase. Then while playing bass heavy music, have a friend turn the phase knob on the sub while you sit in the main listening position until the bass sounds the quietest. Then flip the + and - cables on your mains back to their normal position and your sub will now be in phase with your mains. ---------------- Hi, I must ask, and I wonder why you recommends, to flip the wires on the mains, when the same thing can be accomplished by just listening to which position on the sub's phase switch yields *more* bass? I only wish to make it easier for the laziest of the couch potatoe forum members. Yoha, if you're using the LFE input on the sub, this by-passes it's internal x-over, and relies on the settings in your Denon's bass management menu. However it it not clear as to what this is set at. Is it 85hz? I would try about 100 or even higher. Experiment.... you won't break anything at low to moderate volumes. Quote Link to comment Share on other sites More sharing options...
DrWho Posted November 29, 2004 Share Posted November 29, 2004 ---------------- On 11/28/2004 7:45:08 AM ironwoods wrote: Hi, I must ask, and I wonder why you recommends, to flip the wires on the mains, when the same thing can be accomplished by just listening to which position on the sub's phase switch yields *more* bass? I only wish to make it easier for the laziest of the couch potatoe forum members. Yoha, if you're using the LFE input on the sub, this by-passes it's internal x-over, and relies on the settings in your Denon's bass management menu. However it it not clear as to what this is set at. Is it 85hz? I would try about 100 or even higher. Experiment.... you won't break anything at low to moderate volumes. ---------------- Simple Answer: It's easier to hear a 20dB change in volume than a 6dB change. Say you've got two speakers A and B each playing an 80Hz tone. When in phase, there is a 3dB INCREASE in volume. If the speakers are close enough to each other and the listener is close enough, you might measure an increase as large as 6dB. If speaker A and B are 180 degrees out of phase, then you will measure a TOTAL volume of 0dB. Notice the difference between increase and total. Because our rooms and systems are not ideal, you will most likely only measure a 20dB decrease in volume. A difference of 3dB is equivalent to a doubling of power. However, it usually requires up to a 6dB change to be heard as a doubling of volume. It follows then that you can choose between a difference of 10 times louder versus twice as loud. Another thing to keep in mind, which is probably more important is the fact that these changes in volume don't happen at just one single frequency; there is a bell shaped curve surrounding the target frequency. That means that a larger change in volume is also going to affect more frequencies. This is important when you consider the fact that the bass in music is spread throughout the frequency range. For example, a kick drum can have information from 30Hz up to 1kHz all at the same time. The more of this we alter, the more accurate our attenuation should become. So I guess when it comes down to it, it really is "easier for the laziest of the couch potatoe forum members" to listen for the more drastic change when going for the best calibration without buying extra measuring equipment If you're really that lazy, I think some subs will have a 180 degree phase switch as well as a phase knob. In which case you can just flip the switch, attenuate, then flip it back. And for the lazy DIY guy, I don't think it'd be too difficult to build a line level phase switcher that could be put between the sub and the reciever. An even more lazy DIY guy will make the switch and phase knob remote controlled Quote Link to comment Share on other sites More sharing options...
ironwoods Posted November 29, 2004 Share Posted November 29, 2004 Hey, I'm in phase with you now. Thank you for the in-depth splainer. Just thinking about all those DIY endeavers, has got me searching for the nearest couch. Quote Link to comment Share on other sites More sharing options...
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