Standby mode on ULS-15—why use it?

[JerryMeeker]

I have owned my four ULS-15 subs for at least five years and am still very pleased with their performance. Lately, I have noticed that one of the subs requires a stronger signal than the other three to “wake up” from standby mode. All four subs are meticulously gain-matched, so I would expect all four to wake up simultaneously. I even devised a test using REW in which I isolated each sub and sent a pink noise test signal, gradually raising the level of the signal until the sub woke up. For three of the subs, this occurred with a signal of -45dB, and the fourth sub required -43dB. Not a lot of difference, but when I am listening to music at reasonable levels, the fourth sub can remain asleep for quite a while.

So I decided to run another test to see whether leaving all four subs in an “always on” state actually used a significantly different amount of power. I have a power measuring device called a “Kill-A-Watt”, which measures the power consumption of an attached device over time. I plugged it into one of the subs and measured two 12-hour periods, one with the sub in the always-on state, and one with the sub in Sleep mode. Given the cost of electricity in my area, which is $0.08/KWh, the cost of running a ULS-15 with no load is approximately $1/mo. The cost for the sub running awake or asleep was almost exactly the same, indicating that I could easily solve my problem by simply setting the subs to “always on”, and not worry about power consumption.

So, anyone see a downside to running the subs always-on? Anyone else do this?

[Kevin_Hsu]

There is no downside to running the sub always on. Feel free to do that. It's a very efficient amp such that it only pulls more watts if the sub is actually try to output bass material.

[JerryMeeker]

Originally Posted by Kevin_Hsu

There is no downside to running the sub always on. Feel free to do that. It's a very efficient amp such that it only pulls more watts if the sub is actually try to output bass material.

Thanks for the quick response, Kevin. That is what I will do then. And you know I would never try to generate excessive bass material...