# Elemental Designs A2-300 Subwoofer Issue



## rton20s (Feb 14, 2011)

OK, I've had an A2-300 (active 200w RMS 12" ported subwoofer) from Elemental Designs since May of 2010. Despite having to replace both the subwoofer (broken tensile lead) and the amp (blown capactitor) I have been pleased with the subwoofer overall. 

Recently I had noticed a low hum from the subwoofer when it was on. I wasn't even sure it was the subwoofer at first, but I confirmed by feeling the cone vibration. This was intermittent and fairly quiet, so I never really attempted to do anything about it. 

Then there was this morning...

I was still in bed, fast asleep, when I was startled awake by the entire house started shaking. I thought a huge piece of construction equipment must have been operating right in front of our house. Nope. The wife comes running in from the kitchen in a panic and says... "It's the subwoofer!" I jumped out of bed, ran to the living room and shut off the subwoofer. She followed up with, "All I did was turn off the kitchen light!" 

So, none of the other home theater setup was on. Not the TV, not the receiver, nothing. The subwoofer shouldn't have been receiving any signal whatsoever to even get turned on. I'm not sure what about turning off the kitchen light (adjacent open kitchen) triggered the issue, but I think it is probably a 60 Hz hum from the house wiring. 

Any idea what in the amp could have failed to cause this? 

I plan to "test" the subwoofer again this afternoon to see if it behaves the same way when I turn it on. Both with and without the RCAs connected. 

Anyone have any other thoughts or advice? 

I'll end up having to pull them amp and send it out for repair/upgrade.  Probably to daveds50 since I believe he did repairs for eD and has a photo of the LT.200, LT.300 and LT.500 on his FB page.


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## win1 (Sep 27, 2008)

Sub'd want to see where this leads


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## rton20s (Feb 14, 2011)

It might not lead anywhere, I don't think there is very much traffic in this sub-forum. 

I will report back what I find though.


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## diy.phil (May 23, 2011)

Sometimes it may be a cable/connector issue. If we touch the RCA-type cable/connectors and it stops, then it's the cable (try a different pair of RCA-type cable that grips the RCA-type/phono connector tight/good). Or the issue may be something in the amp's board or the source/component.


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## 4thseason (Mar 31, 2013)

Well it's certainly impossible to troubleshoot via the "net", but I'd say sure it's possible that switching on a light in another room on the same circuit could cause a surge, or drop in voltage.


That causing something in the subwoofers sensing circuit to see the change and caused it to fail, most likely something was already not right and it was going to fail. 


Just an odd timing thing


If your home theater doesn't have a line conditioner on it - that wouldn't have likely saved it. Doubtful that switching on the light is the root cause.

That said it's always a plus to have your theater on it's own circuit in the house and have it conditioned. 


Electronics at their root are pretty fragile, well one's not made to milspec. So this actually isn't even that uncommon just that your failure caused a noise. 


_I would definitely test whats coming out of your wall_. I've seen similar situations kill computers, and it happens more often than you think. 

People in general don't make a consideration on reliability of stuff like they used to. In a time where we change our cell phones 3 times a year and cars almost as often, reliability is usually an afterthought.

My work partner John has gone through, I swear, like 9 phones in the last 12 months.


Now that I've said all that- I still don't have any better idea as to what failed in your amplifier. We, are as 12-volt enthusiast pay more attention than most since our hobby requires parts built to a work in demanding conditions. 

So your question here isn't much a surprise where many would have just localized the bad seed and ordered a new one. 


I rarely buy things I don't pour hours into researching so rarely do I get "lemons". My amplifiers in my theater for instance are nearly 30 years old Yamaha's, and I bought a new Volvo 5 years ago and put 170,000 miles on it...


Ummmm- what were we talking about?? LOL

B~


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## rton20s (Feb 14, 2011)

Thanks for the responses. When I get home, I plan to try the following...

1. Unplug the existing RCA and power up turn the power switch back on. 

If issue persists, it is probably time to contact a pro. 

If issue does not persist...

2. Turn amp off, plug in existing rca, turn amp on. 

If issue does not persist, leave things as is for now, but keep an eye on it. (How should I test my outlet, and what should I be looking for?) 

If issue does persist...

3. Turn off amp, swap RCA for different RCA. 

If issue does not persist, leave things as is for now, but keep an eye on it. 

If issue does persist...

4. It might be time to reconsider the in-wall cabling. 

This is what is currently in use (all from monoprice)...
Pioneer VSX-1019AH-K > 6ft High-quality Coaxial Audio/Video RCA CL2 Rated Cable - RG6/U 75ohm (for S/PDIF, Digital Coax, Subwoofer & Composite Video) - Monoprice.com > 3-Gang 7.1 Surround Sound Distribution Wall Plate w/ HDMI® - Monoprice.com > 50ft High-quality Coaxial Audio/Video RCA CL2 Rated Cable - RG6/U 75ohm (for S/PDIF, Digital Coax, Subwoofer & Composite Video) - Monoprice.com > Keystone Jack - Modular RCA w/White Center (White) - Monoprice.com > 6ft High-quality Coaxial Audio/Video RCA CL2 Rated Cable - RG6/U 75ohm (for S/PDIF, Digital Coax, Subwoofer & Composite Video) - Monoprice.com > Elemental Designs A2-300 (LT.200)

I just really don't want to have to spend any time on this. I have my car audio install to work on this weekend!


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## rton20s (Feb 14, 2011)

Well, I never could get the subwoofer to repeat the same exact issue. It does still have a very low level hum (assuming 60 Hz from the power connection). For now, I am powering the subwoofer down when not in use, just to be safe.


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## bottom3 (Jul 30, 2007)

The hum is prob wiring, you can use a two prong adapter on the amp to ck and see if it goes away, but I can't advise leaving the amp pluged up without the third ground. I'm guessing the wife got some static feed back, always leave the source on and mute it, or turn everything off. I leave all my equipment on 24/7, one amp has been on over 10 years minus power outages.


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## rton20s (Feb 14, 2011)

I actually had a 2 prong adapter in place previously. (This was actually under the advice of Elemental Designs, which I didn't necessarily agree with.) It has now been removed. 

The amp to the subwoofer had previously been left on 24/7 for about 8 years. With this issue, I have gone to shutting the subwoofer amp off when not in use.


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