How to diagnose a sub problem? Amp or driver?

[kurtlingle]

Hi everyone,

I'm wondering how to diagnose a previously (for 2.5 years) working sub, that is now on the "quiet" side?

I have the PA-120, and it's been pretty awesome in my setup. Now it really won't play very loud.

How do I know if the problem is the subs AMP or driver? (Course it could be an issue with the receiver, I guess).

How can I diagnose the problem? Suggestions would be helpful (or links). I did search this subwoofer forum, but there doesn't seem to be a diagnosing thread.

[Tom V.]

Originally Posted by kurtlingle

Hi everyone,

I'm wondering how to diagnose a previously (for 2.5 years) working sub, that is now on the "quiet" side?

I have the PA-120, and it's been pretty awesome in my setup. Now it really won't play very loud.

How do I know if the problem is the subs AMP or driver? (Course it could be an issue with the receiver, I guess).

How can I diagnose the problem? Suggestions would be helpful (or links). I did search this subwoofer forum, but there doesn't seem to be a diagnosing thread.

Double check all the basics first.

1)in receiver's speaker menu----all speakers set to small/80hz. Subwoofer set to On/Yes. Subwoofer/bass level control appropriately set.

2)On subwoofer-----crossover all the way up/bypassed. Gain appropriately set.

Sub cable connected to proper input/output on both ends.

Also, be sure the source deck(DVD/blu-ray) is still sending the full 5.1 or 7.1 signal to the receiver.

Tom V.
Power Sound Audio

[kurtlingle]

Tom,

Great advice. Yes, I've done that, but I will try again tonight/tomorrow.
I spent a good hour or 2 (few weeks ago) playing with the sub, and using the Yamaha test noise to see what was going on. I plan to run YPAO to see if maybe I did something wrong, but I'm pretty sure it's the sub. But I'll try one more time to confirm.

Originally Posted by Tom V.

Double check all the basics first.

1)in receiver's speaker menu----all speakers set to small/80hz. Subwoofer set to On/Yes. Subwoofer/bass level control appropriately set.

2)On subwoofer-----crossover all the way up/bypassed. Gain appropriately set.

Sub cable connected to proper input/output on both ends.

Also, be sure the source deck(DVD/blu-ray) is still sending the full 5.1 or 7.1 signal to the receiver.

Tom V.
Power Sound Audio

[Tom V.]

Originally Posted by kurtlingle

Tom,

Great advice. Yes, I've done that, but I will try again tonight/tomorrow.
I spent a good hour or 2 (few weeks ago) playing with the sub, and using the Yamaha test noise to see what was going on. I plan to run YPAO to see if maybe I did something wrong, but I'm pretty sure it's the sub. But I'll try one more time to confirm.

Source material (2 channel music or 5.1 film) doesn't make a difference---bass is very low with both? Sub placement hasn't changed?

If you have a separate deck (cd player, ipod, etc) you can try running the output straight into the sub. Start with the sub gain LOW. With a bassy song playing, slowly increase the sub gain. If the sub comes to life it indicates an issue upstream(cable, receiver setting, receiver) If the subwoofer barely produces bass, even at near max gain...it looks to be the sub.

Tom V.
Power Sound Audio

[kurtlingle]

Great idea Tom.

I'll try that tonight and see what happens.
At least I'll confirm it's the sub. Didn't get a chance to play with it over the weekend, but I'll try this tonight as I really want to figure out what is wrong. Thanks for the advice.

Originally Posted by Tom V.

Source material (2 channel music or 5.1 film) doesn't make a difference---bass is very low with both? Sub placement hasn't changed?

If you have a separate deck (cd player, ipod, etc) you can try running the output straight into the sub. Start with the sub gain LOW. With a bassy song playing, slowly increase the sub gain. If the sub comes to life it indicates an issue upstream(cable, receiver setting, receiver) If the subwoofer barely produces bass, even at near max gain...it looks to be the sub.

Tom V.
Power Sound Audio

[kurtlingle]

Ok,

So I played around with my sub and setup last night. The sub definitely works after ru-running YPAO (the Yamaha auto tuning with mic). I made sure the front speakers were set to small, and the crossover (in the rec. is set to 120). The crossover on the sub is set to 220 (all the way to the right). Volume on the sub is 7 (out of 10).

I'm still not sure if there is something wrong with the sub. I did get out my decibal meter and made sure all the speakers and sub were set to 75db (with my receiver set to +1). I had to turn the sub up in the receiver quite a bit (from +1 to like +7 or +8). So the sub can hit 75db.

I got out both "Kung fu Panda" (for the "skadoosh") and Dark Knight, but to both me and my son, it just doesn't seem to "shake the house" like it used to.

Is it possible, that the "low end" of the bass is not coming through? We just don't "feel it" like it used to be.

One piece of important info, that I left out, is that we had to (temporarily) move the system from one room to another. The older room was a bit shorter in length (smaller room is 16ft) and the new room is 29 feet. So perhaps this is why the sub sounds less intense? I guess I won't know until I move it back to the old room (once construction work is done).

I guess I didn't think about that factor - the sub had to be turned way up, compared to my other room. I guess thats why people get 2 subs (or more.

Originally Posted by Tom V.

Source material (2 channel music or 5.1 film) doesn't make a difference---bass is very low with both? Sub placement hasn't changed?

If you have a separate deck (cd player, ipod, etc) you can try running the output straight into the sub. Start with the sub gain LOW. With a bassy song playing, slowly increase the sub gain. If the sub comes to life it indicates an issue upstream(cable, receiver setting, receiver) If the subwoofer barely produces bass, even at near max gain...it looks to be the sub.

Tom V.
Power Sound Audio

[wormraper]

ahhhhhhhh, you changed room. room response is INCREDIBLY important in a subs performance. even a few inches can make a big difference. do the sub crawl for your new room..

put the sub at the listening position and play a loud test tone, crawl around on the floor on hands and knees. when you find the place in the room where you feel the most lfe response THAT is where you should put the sub.

add to the fact that the new room is 29 feet in lenght you've almost DOUBLED the volume of the room. your sub is running out of headroom fast.

[kurtlingle]

Yeah, that is probably it (I hope so).

The old room was 16x16 and the new one is 29x12.
It's really just 2 sides of a big basement, but the way it's split up by the stairs and the heater room in the middle, it's really 2 rooms (the kids play area, and home theater area).

I'm redoing the HT area, so the equipment move was to be a temporary move - but it's taken longer than expected. I guess I'll put up with it for now, and retest once it's back to it's proper area in the HT room.

Originally Posted by wormraper

ahhhhhhhh, you changed room. room response is INCREDIBLY important in a subs performance. even a few inches can make a big difference. do the sub crawl for your new room..

put the sub at the listening position and play a loud test tone, crawl around on the floor on hands and knees. when you find the place in the room where you feel the most lfe response THAT is where you should put the sub.

add to the fact that the new room is 29 feet in lenght you've almost DOUBLED the volume of the room. your sub is running out of headroom fast.