Good Subwoofer gone bad, the graph.

[zhimbo]

Might be interesting to some, and maybe even folks can diagnose the issue, who knows.

So, I've moved my home theater setup twice recently, and as it seems to be in a more or less permanent home now, I got serious about dialing everything in.

But I was having trouble. One of my trusty SVS PC12-NSD subwoofers just...seemed off. Really quiet, too. As part of my detective work I took some ultra near-field measurements in REW. Ultra near as in I actually put the mic directly under the down-firing driver on the sub's base.

With all the room effects taken out, the first one measured like a perfect dream of a subwoofer. That's an *unsmoothed* measurement in orange. Wow.

For that, the sub had the gain at about 10 to 10:30 position on the dial.

The other sub...My initial measurement was too quiet for a proper reading in REW, even with the mic that close; I ended up cranking the gain up to the 3 o'clock position, almost the whole way, just to get comparable SPL.

And look at that curve. Ugh. Same model sub, clearly not in good shape.

All the crossovers and connections are fine. It's just time to say goodbye. New sub time!

 

[ParleyW]

Might be interesting to some, and maybe even folks can diagnose the issue, who knows.

So, I've moved my home theater setup twice recently, and as it seems to be in a more or less permanent home now, I got serious about dialing everything in.

But I was having trouble. One of my trusty SVS PC12-NSD subwoofers just...seemed off. Really quiet, too. As part of my detective work I took some ultra near-field measurements in REW. Ultra near as in I actually put the mic directly under the down-firing driver on the sub's base.

With all the room effects taken out, the first one measured like a perfect dream of a subwoofer. That's an *unsmoothed* measurement in orange. Wow.

For that, the sub had the gain at about 10 to 10:30 position on the dial.

The other sub...My initial measurement was too quiet for a proper reading in REW, even with the mic that close; I ended up cranking the gain up to the 3 o'clock position, almost the whole way, just to get comparable SPL.

And look at that curve. Ugh. Same model sub, clearly not in good shape.

All the crossovers and connections are fine. It's just time to say goodbye. New sub time!View attachment 55577

I’ve found after playing with dozens of powered subs (rip and replace amps over and over), I’ve gone to passive subs (converting powered to passive), then choosing an outstanding external amp ( I own three RBH SA-400). My performance is always consistent now with no need to tweak anything.