Mobile Audio Discussion

**davidburn** · **02-24-09, 05:38 AM**

I realise this is mainly for home audio but Mike P is a genius with Sub's so here we go...

Currently have 2 x 12" KFC-xw1225db in a 80 lt box tuned to 25 hz in a Custom VY commodore. I wanted to take away the box and turn in into an IB setup? Spec's for Sub are as follow...

Z. 4+4 ohms
Re. 3.1+3.1
Levc. 4.7
Sd. 0.0312
BL. 17.9
Vas. 113lt
Mms. 126 ?? (12.6)
Fs. 24 Hz
Qms. 6.06
Qes. 0.37
Qts. 0.35
Xmas 9mm
Peak Power. 1200 w
RMS Power 300 w
Sensitivity 93 db
Displacement 0.15 cu-ft

Currently have a mono block amp running the Sub's.

Kenwood Excelon KAC-X811D ( Im sure its set to 1 ohm )

The current setup was done by Autobarn and its no good!, will the IB setup work well or any idea's on a new box?. I spend a huge amount of money for this setup 3 yrs ago and no good. Any help would be great. I modeled the sub's in win isd and it came up with 120 lt for 1 sub?.

Any help would be great. Thanks in advance.

Im not sure but I think the boot is about 450 lts.

**Mike P.** · **02-24-09, 02:17 PM**

Quote:

The current setup was done by Autobarn and its no good!

What do you mean by "no good"? Not enough bass or is it boomy sounding?

**davidburn** · **02-24-09, 02:55 PM**

some bass is good, but other is no good. I want to knock the side's out of the box and go free to air? xmax is a little low.

**davidburn** · **02-24-09, 03:14 PM**

The bass is very flat, it seems the sub's are reaching xmax before there is any real noise, I had 1 12" older sub that was bolted strait to the back of the seat that sound better than 2 of these $350 au kedwood subs. The guy's that put it in dont know what went wrong, I havent been happy with the setup since it was done. Any thought's on how it will sound with the boot as the box?. I really cant change the box size, unfurtunatly the sound isn't great but it looks awsome.

**Mike P.** · **02-24-09, 04:56 PM**

The KFC-XW1225db sub is not designed for an IB setup. With its limited Xmax of 9 mm it will reach its limits with very little power. The 80 liter box they are in was built according to the manufacturers recommendation of 40 liters each for a ported application.

http://inform3.kenwoodusa.com/manuals%5CKFC-XW1205dB.pdf

Check the subs to make sure they are both properly wired for the amp you have. If possible try a different amp, maybe it's the KAC-X811D that is the problem.

**davidburn** · **02-26-09, 07:00 AM**

I will be pulling out the sub's on sunday to double check that the sub's are wired to 2 ohm's each, giving 1 ohm load on the amplifier, and will go with kenwoods recomended tuning which is 37 - 38 hz in 40 lt box for each sub. The Amp should put out 900 watt's rms at 1 ohm. Any thought on the amplifier setting's??. Crossover, Sub sonic filter, Bass boost, there is to many setting's and i think that is half the problem...

Kenwood Excelon KAC-X811D, This amp has way to many setting's.

Thanks in advance.

**Purefire9** · **03-04-09, 05:02 PM**

It is quite possible that you box is too small!
A program like WINisd is more truthful than manufacturer specifications.
When in WINisd, in the "box" tab, the "box shape" button, click on the "optimum" button to get the size of the box needed and try it out! It might just be your solution!

**Pinhead-227** · **03-04-09, 06:38 PM**

I would double-check to make sure the subs are in phase with each other.

**davidburn** · **03-05-09, 02:27 PM**

I changed the tuning from 25 hz up to 37 hz as per kenwoods recommendation, and it Ok. When im bored one day ill still knock the sides out of the box and see how it sounds.
Thanks for the replys

**nando79** · **10-09-09, 01:43 PM**

Hello. Hey DavidBurns are you interested in selling that amp. I've been looking for a KAC-X811D. I could be reached at 781-420-3215. Thanks...

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