Poor bass on my new sub+amp

[ps2cho 10+ year member]

you can get polfill at walmart in the arts and craft section lol. but it will only make the box act like its a little bigger i would just seal it up first and see how it sounds

Well once it is sealed it will be horrible getting it undone. I just spent a little time reading some posts on other forums and most people said for small, or irregular sized boxes, it does help with performance so I think I will go ahead and use poly fill.

One question about it though....do you fill the entire thing or just line the walls with it?

 

[BobbyDD 10+ year member]

Well once it is sealed it will be horrible getting it undone. I just spent a little time reading some posts on other forums and most people said for small, or irregular sized boxes, it does help with performance so I think I will go ahead and use poly fill.
One question about it though....do you fill the entire thing or just line the walls with it?

You won't need to take the box back apart, just take the speakers out if you want to add some.

 

[Ku-sama]

Ok what happened is this: I was so frustrated and was about to go to bestbuy to get them to fix it....I put everything back in place and started the car up -- SOUND!!!
BUT it was only coming from the right speakers and when I moved my transmission to drive, the left came on. I knew the problem was in the center console near the fader.

So I took everything apart and moved some cables around and it works again!!

No clue how that happened as I didn't touch anything in the center console...possibly when I was taking out the headunit I may have pulled a cable out of place or something where it was awkward.

VERY Happy to have everything back in order. Will seal the box up today/tomorrow.

As for sealing it up, do you guys recommend putting anything on the inside of the box? I heard there are scenario's where they put like padding or sound dampening material's inside the box. Should I do something like that or just glue it together and apply the sealant?

Thanks to everybody for your help! Sorry I am terrible at this LOL. First time mistakes and won't make anything I have done again now!

told you something was just shorting

You won't need to take the box back apart, just take the speakers out if you want to add some.

X2

 

[wolfman1966 10+ year member]

well, Im back...glad to hear that the amp/subs are working and sound better. I told you bridging them would give them more power. Glad you were able to get everything working right.. NOW ...seal that box and put the polyfill in it. IF the polyfill doesn't make it sound better, you can always take it out....later dude.

 

[ps2cho 10+ year member]

well, Im back...glad to hear that the amp/subs are working and sound better. I told you bridging them would give them more power. Glad you were able to get everything working right.. NOW ...seal that box and put the polyfill in it. IF the polyfill doesn't make it sound better, you can always take it out....later dude.

Ok box SEALED! we used wood glue and liquid nails all around the box to fill any possible gaps then put polyfill inside each chambre.

Can't wait til tomorrow to test it now //content.invisioncic.com/y282845/emoticons/greedy.gif.5a53e6246569d7ab79867170f3b06629.gif Will leave it with the garage open so lots of air to let it dry.

I'll let you guys know how it sounds for my cheapest of cheap amp+sub!

 

[XanderMoser 10+ year member]

Well, I'm glad you've solved most of your problems and are getting some bass.

I just have one concern though. You have 2 subwoofers in parallel. I'm assuming that they are 4 ohms each, which makes a 2 ohm load. And you're hooking them up to your amp in bridged mode. That is showing each channel a 1 ohm load. I don't believe your amp is 1 ohm stable. So if it overheats at moderate volumes, this is the reason. If it overheats it will probably shut itself off before it gets damaged, so you will know. Just a heads up.

Good luck with everything. I like how you built your box to fit into the back of the seat, are you going to finish the box with carpet?

 

[luvinthebass 5,000+ posts]

Ok box SEALED! we used wood glue and liquid nails all around the box to fill any possible gaps then put polyfill inside each chambre.
Can't wait til tomorrow to test it now //content.invisioncic.com/y282845/emoticons/greedy.gif.5a53e6246569d7ab79867170f3b06629.gif Will leave it with the garage open so lots of air to let it dry.

I'll let you guys know how it sounds for my cheapest of cheap amp+sub!

i once had a Dual amp the 460.2 model of 2004, did okay powering my 12'' pioneer, i think they're chinese made or japan made, but not bad for the price.

good luck on it

 

[wolfman1966 10+ year member]

.
I just have one concern though. You have 2 subwoofers in parallel. I'm assuming that they are 4 ohms each, which makes a 2 ohm load. And you're hooking them up to your amp in bridged mode. That is showing each channel a 1 ohm load. I don't believe your amp is 1 ohm stable. So if it overheats at moderate volumes, this is the reason. If it overheats it will probably shut itself off before it gets damaged, so you will know. Just a heads up.

Xander, wrong....if an amp is bridged, it is bridged to ONE channel internally, therefore in this case, the one channel is seeing a 2ohm load and since the amp is bridgeable, and stable at 2ohms, everything should be fine.

i posted the specs for that amp already but

100wattsX2channels@4ohms

145wattsX2channels@2ohms

290watts brigdged....which is one channel...showing 2ohms in this case

 

[XanderMoser 10+ year member]

Xander, wrong....if an amp is bridged, it is bridged to ONE channel internally, therefore in this case, the one channel is seeing a 2ohm load and since the amp is bridgeable, and stable at 2ohms, everything should be fine.

I am not trying to argue. I just always thought that each channel saw half of the total ohm load. That is why you say an amp is "4 ohm stable mono" and "2 ohm stable stereo", because they mean the same thing.

For most modern bridgeable 2 channel amps, the left positive and the right negative terminals are the speaker outputs. And they are 180 degrees out of phase naturally, one being + and the other being -. So when you hook up one load to these terminals, it is getting the full power from channel 1 in the + direction and the full power of channel 2 in the - direction. So it is getting twice as much power as if it hooked up to one channel. Both channels are pushing. So each channel is "seeing" half of the total impedance load.

That is how I always saw it. But I could be wrong, and always like to learn, so please enlighten me.

And to the OP, I still would highly suggest taking a DMM and measuring your total impedance of your subwoofers before even turning your amp on. Because I can't find any info on the nominal impedance of those subs...weird...

 

[XanderMoser 10+ year member]

i posted the specs for that amp already but

100wattsX2channels@4ohms

145wattsX2channels@2ohms

290watts brigdged....which is one channel...showing 2ohms in this case

Add up 145 watts and 145 watts. You get 290 watts

Add up 2 ohms and 2 ohms. You get 4 ohms

That's 290 watts at 4 ohms.

You can't just add up the power that each channel can make at 2 ohms and expect to get that amount of power while bridged, running at an impedance that each channel is supposed to see individually.

 

[wolfman1966 10+ year member]

Add up 145 watts and 145 watts. You get 290 wattsAdd up 2 ohms and 2 ohms. You get 4 ohms

That's 290 watts at 4 ohms.

You can't just add up the power that each channel can make at 2 ohms and expect to get that amount of power while bridged, running at an impedance that each channel is supposed to see individually.

I didn't just add the power together, thats the specs for the amp. I forget where I got them now, but it supposedly does run 290 watts....as for the ohm thing , I don't think it specified what ohms it runs at bridged....let me do a little reasearch.

 

[wolfman1966 10+ year member]

well, I can't find anything that says what ohms it is when bridged...I've only been really into this for 2years, and still don't completely understand how the ohms thing works, maybe someone else can help out. I'm going to forward a link to some of my car audio buddies, hopefully they can take a look at this thread and help.

 

[XanderMoser 10+ year member]

I didn't just add the power together, thats the specs for the amp. I forget where I got them now, but it supposedly does run 290 watts....as for the ohm thing , I don't think it specified what ohms it runs at bridged....let me do a little reasearch.

Sorry, I didn't word that very well. I realize you were quoting specs, I didn't think you were making them up.

What I meant was, if you add up the rms ratings of an amp of each channel at 2 ohms, you should get the rms ratings of the amp in bridged mode at 4 ohms. Check some amp specs, it should usually work out.

I have been into audio for about 3 years. Started in home theater, only been serious in car audio for about 4 months...mostly because I had no car before, haha. But my dad has been designing and building speakers for about 20 years, and I've learned a ton from him. And I work as a tech, setting up and running full concert systems for bands. There are a lot of similarities in the basics of home, pro, and car audio. It's cool to be able to learn in one section and use that knowledge in other things. So hopefully we can all learn something from this.

 

[XanderMoser 10+ year member]

I say this too much, but you can really learn a lot from this site. It's probably one of the most reliable places to learn stuff from:

http://www.bcae1.com

 

[ps2cho 10+ year member]

Well, I'm glad you've solved most of your problems and are getting some bass.
I just have one concern though. You have 2 subwoofers in parallel. I'm assuming that they are 4 ohms each, which makes a 2 ohm load. And you're hooking them up to your amp in bridged mode. That is showing each channel a 1 ohm load. I don't believe your amp is 1 ohm stable. So if it overheats at moderate volumes, this is the reason. If it overheats it will probably shut itself off before it gets damaged, so you will know. Just a heads up.

Good luck with everything. I like how you built your box to fit into the back of the seat, are you going to finish the box with carpet?

Ok lets assume that it IS running at 1 ohm....can this be a fire risk or anything? And if it I just run it like that, and it doesn't overheat, everything should be fine right?

As for finishing the box off, yes I will apply some carpet. I really want to find some to match my floor, but I don't think it will be possible finding it cheap so I might just go with black.

I looked in the manual it says Normal Impedence: 4 ohms.