7 replies to this topic

[systemomega]

Hi guys, i have a question for you, i have 2 x 10" kicker CVR's in a sealed enclosure (i do know the enclosure is *slightly* smaller than the min required for these subs), they were being driven by a 1000w kenwood 2ch but were very sloppy and obviously not getting enough power. I just chucked in an 1800w kenwood monoblock on about half gain (anymore sounds worse) but it still sounds like crap. some songs sound great, but most of it is terrible. Would the box being that tiny bit too small be causing this? i was under the impression that these kickers would just about punch me though the windscreen!! I am not chasing a bass heavy doof doof system (i mainly listen to metal) and want better overall SQ and great intergration of high, mid and low range. i am also running no EQ and pass filters on the head unit, everything is tuned at the amps.

[kiwi]

What size is the box and what model Kenwood amp is that ? Any idea what the filter is set at.. ie is it adjustable ?

[Selfdestruktor]

What size enclosure have you got them in?

I'd be willing to bet money on the enclosure being way to small.

Edited by Selfdestruktor, 09 January 2007 - 11:09 AM.

[Juls]

I can see 2 problems immediatly that would be causing issues.


1. The boxes are 2 small.
2. The boxes are Flexing.


To fix this, your going to need to build uptimum sized boxes, around 10-20litres larger than current. the boxes must be built from at least 18mm MDF, and they must be braced like all hell to eliminate flex and vibration which leads to distortion.

Prefab boxes are all cheaply built with no bracing or anything, and flex like crazy.

Flex and Vibration on the Sub box panels = Distortion/Coughing from your subwoofer.

I've seen many so called "Custom built" boxes from reputable stores still be all flimsy and flexy,
you can't just slap a 25mm mdf box together and expect it to be stiff enough.

18mm MDF is plenty thick enough for almost all applications, if it is assembled and braced correctly, it will well and truly outperform a 25mm mdf enclosure without bracing.

Bracing means that all joints must have additional joint area added, (like a 20mm square down them glued and screwed) and all walls need to be joined together internally, how you brace depends on the design of the box, the main point where the subwoofer connects must be extremely solid.

Attached is a picture of a box I recently assembled. Over 230 Screws and 3 big bottles of glue used!!
weighs almost 20kgs on it's own!



 0_HPIM0012_25.jpg   21.92K   2 downloads  0_HPIM0022_25.jpg   23.1K   6 downloads
 HPIM0034.jpg   583.09K   4 downloads

Edited by Juls, 09 January 2007 - 01:11 PM.

[systemomega]

kiwi, on Jan 9 2007, 10:28 AM, said:

What size is the box and what model Kenwood amp is that ? Any idea what the filter is set at.. ie is it adjustable ?

the amp is a Kenwood KAC-9152D and i think the filter is set somewhere around 70-80 from memory....

hopefully a bigger box will solve this issue for me.....

[Pulse-R]

I hope you deadened the back of that base board... could be some distortion harmonics radiated back through the cone @100Hz (=muddy midbass).

[Juls]

Pulse-R, on Jan 9 2007, 01:18 PM, said:

I hope you deadened the back of that base board... could be some distortion harmonics radiated back through the cone @100Hz (=muddy midbass).

it's all deadened, as well as 10mm layer of open cell foam throughout the whole box.

[Pulse-R]

cool