Underwhelming output from sub

[grampi50]

I completed the sub build project of a sealed enclosure with an HO 12" Dayton sub. The amp is the SPA500DSP. The first thing I noticed after connecting the sub is that I had to turn the volume on the amp all the way up to get any decent amount of output. This was a bit puzzling to me because my previous sub (using a cheap, 15" MTX car audio sub and a PE 250 watt plate amp in a sealed enclosure) was never turned up above half volume, and it played a lot louder than this one does. The only thing I can figure is the preamp out signal I'm using for the amp's input (which is coming from a sound bar) has a low voltage. With the amp's volume turned all the way up, and the sub out volume control turned almost all the way up, I'm getting okay output when listening to music, and a little better output when watching movies. I feel like I have the best sounding settings on the DSP parameters, I'm just not that impressed with the output. The sub doesn't distort no matter where I have the controls set, so I'm wondering if the input signal needs to be a higher level. Is there any way to boost the preamp signal? Is this not the the fix? Maybe I'm just expecting too much from a 12? I would've thought this 12 (which is a much better sub than my previous MTX), with double the power I had on my MTX would be at least as loud. Any ideas?

[billfitzmaurice]

The source should be the LFE/Sub output of your AVR.

[Chris Roemer]

Yup. I would not drive your higher-than-mid-end setup w/the output from a cheap soundbar.

[djg]

Are you aware of the high/low input level switch on the plate amp?

[grampi50]

The source should be the LFE/Sub output of your AVR.

It is.

[grampi50]

Yup. I would not drive your higher-than-mid-end setup w/the output from a cheap soundbar.

Unfortunately, that's my only input source...

[billfitzmaurice]

The sub signal source can't be both the LFE/Sub output of the AVR and the soundbar. It's got to be one or the other. There should be no connection between the sound bar and the sub. The AVR should have the ability to set the drive levels to the soundbar and sub independently.

[grampi50]

Are you aware of the high/low input level switch on the plate amp?

Yes I am, and it's set correctly.

[Steve Lee]

Is there some easy way to take an output voltage measurement of the sound-bar output with some fixed frequency sent to it?

[craigk]

Are the drivers wired correctly

[Chris Roemer]

just measure across the lines w/a DMM. Play a 40Hz tone if you like (or whatever's appropriate).

[grampi50]

Are the drivers wired correctly

It's one SCV sub, and yes.

[grampi50]

I'm gonna try this device:

[djg]

Could you give details of your system, it may clarify the situation. Do you have just a soundbar (and new sub), or other components such as a home theater receiver, other speakers besides the soundbar (and new sub)?

[grampi50]

Could you give details of your system, it may clarify the situation. Do you have just a soundbar (and new sub), or other components such as a home theater receiver, other speakers besides the soundbar (and new sub)?

I have just a sound bar and the sub. I didn't want one of the sound bars that come with a sub because those subs are small and not powerful enough for a large living room, which is what I have. So I bought a sound bar that has a preamp sub out so I could connect my own sub. I see the link I posted in my last post disappeared for some reason, so I'll post it again.

[billfitzmaurice]

The source should be the LFE/Sub output of your AVR.

It is.

I have just a sound bar and the sub.

Which is it? The first piece of gear you need for a home theater install, other than a TV, is an AVR. If you don't have one that's the source of the problem.

the link I posted in my last post disappeared for some reason,

Posting links to other retailers is not allowed.