[Paradoxex]

Greetings,


Recently I received an eDesign A2-300, and I'm quit happy with the sub. I finally have it placed in a place that coalesces WAF and acoustics, and I have it dialed in, so to speak.


That said, it's now located near field, which places it on a different circuit than my receiver. This introduced a nasty 60mhz hum into my system. I used a cheater plug for a couple days, but I did not want to rely on this for a permanent solution.


So I bought one of these:

PAC SNI1 Noise Isolator

(Can't post URLs yet, sorry)


And I plugged it into the receiver's pre-amp, and the subwoofer cable into the device's left output. I left the right output empty.


The ground hum is gone, but the subwoofer's output sounds, possibly logically, as if it has been halved. Clearly that's not going to fly.


If I buy a Y-adapter to connect both outputs back into my subwoofer cable, will that restore the lost volume and sensitivity?


Surely it cannot be that hard to have both no ground hum and normal spl from my subwoofer...

 

[tony123]

I went through the same process and did turn up the subwoofer channel in my processor about 4db to compensate. You should still be able to calibrate your system to balanced levels.

 

[Paradoxex]

I feel like I'm having to turn it up much higher than that for comparable output. I'm not running the sub overly hot, but I am bothered nonetheless.


Is only using one of the two rca outputs on the noise isolator not to blame for making the sub quieter? I guess I figured that using a Y-cable to cover both outputs might fix the problem. Is this not true?

 

[jackbuzz]

It should return it to the previous level (or close) or you could do as tony123 has said, just turn it up/recalibrate to match other speakers level.

 

[DonH50]

Some subs do double the gain if both inputs are used so you could try the Y cable after the isolator. However, turning up the gain will work just fine if there's enough range to do the level caibration. There is very little downside to just turning up the gain, especially in a sub, and that is the easiest solution.

 

[brandonnash]

I'm not familiar with the isolator you used, but a few years back I picked up a ground loop isolator and it did get rid of the ground loop but apparently its intended purpose was to be used in line with a turntable. It included some sort of RIAA eq that was supposed to take out some harsh frequencies that are supposedly induced by a turntable. It makes little or no sense to me but it screwed with the sound horribly. The level was way down and whatever eq was built in the module portion of the rca cable just wrecked the sound. Nothing sounded correct. Not saying this is what you have but I would check the package or instruction book to make sure the RIAA didn't fudge with your sound.

 

[Sahak94]

These GLIs use transformers. The bandwidth is limited and a drop of 3 to 6dB < 100Hz is common in the less expensive GLIs. I suspect that's why you noticed a decrease in the level.

 

[DonH50]

Personally, I would just use the cheater plug...