Originally Posted by shawnz28
I purchased an open box 12" a few months back which I am regretting and hoping someone here may have some ideas. A couple weeks after getting it I noticed some low level noise coming from the sub. It is not a hum or buzz and not constant and fluctuates. Best way I can think to describe it is if it's windy outside and air is getting through a cracked window or door. When I noticed this I emailed monoprice whom took 2 weeks to respond with an answer that was less than helpful and seemed the person did not understand the issue or question. During that time though I had messed with cables and settings and I can't recall exactly what I had done but I think I had found that I had the subwoofer always on and if I changed it to standby it seemed so stop happening. I honestly don't get to use this whole setup very often so time passes between uses. Anyway sometime later the problem has since recurred a couple times.
I have found that the input cable makes no difference when it happens, if I completely unplug from the receiver the noise is still there. I've tried more than one electrical circuit as well. I have noticed that adjusting the low pass filter will change the amount or what is coming out of the speaker when it is making this noise. The problem is not consistent and does not always occur. Typically unplugging the sub and letting it power down (unplugged the led flashs for a bit of time) and plugging it back in makes the problem go away.
I tried emailing monoprice again a while back for help on what could be wrong and they were quicker to respond this time but basically just said I was outside my 30/90-day window and to find a repair shop. I'm assuming at this point it's probably something on the amp going bad or faulty the curious if anyone has any ideas on what it could be or what I should be looking for. Doing some reading it sounded like it could be maybe a bad solder joint or even just a loose wire
So back on page 41 I reported this above issue with my 12" sub. Someone here pointed me to Hobie who was kind enough to take care of me and sent me a replacement openbox sub. The replacement sub arrived in early September and while I don't get many chances to listen to it for extended periods more than once a week at most it seemed to be behaving properly. Then on Nov 8th I found it started experiencing the noise again, I hoped it was a fluke but then two weeks later same thing.
Seems to only typically do it after listening a couple hours. I have to pull the plug or at minimum flip the power switch and let it power down, pulling the RCA has no impact. When I pull power it will continue until the light shuts off. Once I power it back on it is usually fine again at least for a while but then the other day when it happened if I pulled power and only waited a short time it seemed to happen again quick, I had to pull power and let it sit for a while.
I have tried contacting Hobie a handful of times about this 2nd sub and got one response a few weeks back asking about was it on a power strip or shared circuit. Informed that it was on a strip with a few other devices (not the TV or receiver) and that I have put both this sub and the prior on a circuit with no other AV equipment, or much else for that matter, and it has again happened.
One thing I should have done sooner was take a clip of the sound. I took this with my phone and sent to him as well last week. In-person the sound has more flutter or dynamic to it than the audio recording seems to have caught but it gives an idea.
Could I have just gotten a 2nd defective one? I think I saw someone here say they had parts now.... maybe I can just get a new amp for it sent if so.