Hi all,

I just bought 2 new 10" Pioneer TS-W256C subwoofers to replace my old subs.

Now I've used them in the same box i had, running off the same (old) Kenwood Mono Bloc Amp.

My question is:

How can i tell if my subs are underpowered (apart from not enough bass)?

The bass sounds good at low to intermediate volumes, but when i turn up the volume, it sounds hollow and boxy. Is this an indication of underpowered subs?

The subs are rated at 800w each. Not sure how much power the amp is putting out, but its running at a 2ohm load.

one way to tell is when the subs start clipping from not getting enough power from the amp
they'll be fine at low volume but when you increase the volume you are asking the amp to put more power into the subs, which will then cause the amp to overwork itself which it will fry itself
oh and clipping is also a bad thing you could end up damaging the voice coils on the subs which mean they will be ****ed
my advice is to buy a proper amp to run the subs comfortabley with extra power to spare

If they sound hollow but aren't clipping, could be the wrong sized box for your subs.

If they sound hollow but aren't clipping, could be the wrong sized box for your subs.

They arent clipping, but the bass sounds great at lower volumes, its only when i turn things up, its seems the volume of the subs is not as progressive as the rest of the system.

I do have the amp turned all the way up, with bass emphasis switched on aswell. I also have to have the bass settings turned up on the head unit. Not good I think.

Hmm...

I'm going to re-measure the box...

The recommened enclosure size is 0.8 to 1.25 cubic feet.

My boxes are 0.992 each (this includes sub displacement). So the box size is not the issue.

Hmmm i had a similar problem with my dual setup, but i put that down to a crappy amp. But try swapping the polarity of ONE of the subs around (if you can on a monoblock).
May not do anything, but that's what i had and it solved my problem. Even just remove 1 sub and see if it makes a difference (ie. does the 1 sub go harder than the 2 combined).

Also just one last thing, are the 2 subs in the same box? Is the box seperated in the middle?

if you have the gains on max and the bass boost up you need a better amp with more power.

Turn the gains down, you are probably clipping the preamps.

Hmmm i had a similar problem with my dual setup, but i put that down to a crappy amp. But try swapping the polarity of ONE of the subs around (if you can on a monoblock).
May not do anything, but that's what i had and it solved my problem. Even just remove 1 sub and see if it makes a difference (ie. does the 1 sub go harder than the 2 combined).

Also just one last thing, are the 2 subs in the same box? Is the box seperated in the middle?

Yeh, this is the case if ur subs are cancelling each other out.

But mine are both running in the same phase, and in seperate boxes anyway.


if you have the gains on max and the bass boost up you need a better amp with more power.

Turn the gains down, you are probably clipping the preamps.

I have since turned down the gains, and it all sounds better. However, not enough grunt.

The lower end bass is good, but the punch is lacking now.

Time for some Amp shopping I think!

Thanks for your input guys.

I went out and bought the new Pioneer GM-7300 Monoblock Amp today.

Running like a million dollars now!

Pics coming soon!

Thanks again

good stuf!

leave the bass boost off too :)

good stuf!

leave the bass boost off too :)

Bass boost off what exactly? the headunit?!

Cause the amp has a +6 and +12db bass boost and i've got that ON.

http://img180.imageshack.us/img180/8971/cimg0977kt0.th.jpg (http://img180.imageshack.us/my.php?image=cimg0977kt0.jpg)

yeh turn it off at the amp.

if you want more bass just add more volume, bass boost is just a spike in your bass frequency, unless your response is lacking in that area its not what you want to hear as you want a nice flat response across the freq range.

Start with all EQ off and work your way from there, if you want more bass thats fine, just use the sub out volume (at the headunit)

yeh turn it off at the amp.

if you want more bass just add more volume, bass boost is just a spike in your bass frequency, unless your response is lacking in that area its not what you want to hear as you want a nice flat response across the freq range.

Start with all EQ off and work your way from there, if you want more bass thats fine, just use the sub out volume (at the headunit)

To me, i seem to believe two subs should really pack a punch! They ARE alot better with the new amp, and i dont really want to spend any more than i have already.

I'm not sure if it is really hitting its full potential. Maybe i need to hear other peoples cars with subs to really get an idea, and compare it.

Perhaps I'm expecting too much.

Anyone in the western subs of Melbourne willing to lend me their ears, or lemme hear their subs. Perhaps even try my subs in your car, or vice versa?

I don't know anyone else who I can really compare with.

what frequency are you lowpassing them at? is that all done at the amp or at the headunit? Do you know what slope the are on? eg 18 db/oct?

What are your mids crossed at?

what frequency are you lowpassing them at? is that all done at the amp or at the headunit? Do you know what slope the are on? eg 18 db/oct?

What are your mids crossed at?

The Amps LPF is set at about 120hz... the headunit's LPF is set to about 125hz... I cant go above that even if i wanted to.

Unfortunately the slope is not adjustable on the amp or headunit. On the headunit though, it doesnt look very steep.

Ahh no wonder it sounds bad...

bring your lowpass down to around 80 hz... at the headunit, (or the amp if the headunit cant do it...)

What are your splits playing down to?

(my subs playing 31hz down lol... but im stupid)