why is my system not loud enough?

Ok so i have a Pioneer DEH-12E head unit and a Power Acoustiks CPT1-4000D Mono block amp with two Pioneer TS-W253R 10 inch subs and one TS-W303R 12 inch sub hooked up to it. I have 6-gauge power and ground wire with 12-gauge speaker wire hooked up also. Now my question is when i hook up my 12 only my decibel meter reads 118, but when i hook up the two 10's (in parallel) the spl only goes up to 120.4.  Why is this? My amp is 1 ohm stable also. I just dont understand why when i add two more subs it barely changes the spl.

The Amp is rated 1200 watts rms @ 4Ohms 1700 @ 2 Ohms and 2200 @ 1 ohm

dBs are a logarithmic measurement as opposed to linear.  It takes significant increases in air movement to made dBs go up.  I believe the old rule of thumb is if you double your power and your cone space you will only gain 3dB.

That being said and incrase of 2.4dB sounds about right for what you added (if not a little on the high side).

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Kevin Pierson

So what would be the best way to reach 140? Double my power?

Also i added a Alpine type R 12 and it went down to 119. I just cant understand why.  My setup is in the trunk of a 2006 Chevy cobalt with the back seats down and the subs are facing backward.  Ive seen one guy in a van that hit 140 with a single ten. Can someone explain this please??

Maybe you are choking your amp by making it try to supply all these subwoofers.
Anyway, you split the output between the subs anyway....
try upgrading to a better quality wire....like a 4 guage or add another amp along with your other one.

To go from 120 to 140 you will need to increase 20 db which is roughly 7 3db segments.

That would be you would need to double your power 7 times (and double your subs 7 times).

So, if you added around 152,000 watts to your current setup (plus another 381 subs) you should be around 140db.  Now, remember, this is just a rule of thumb, but it should be fairly close.

Much much much more goes in to an SPL number then just the type of sub and the RMS power of the amp pushing it. 

What is your box tuned at?  Is it sealed or ported?  What kind of voltage are you seeing when the bass hits?  How much energy is lost in vibration of your Cobalt?  Those are a few starter points.  If you didn't custom build your box for maximum output based on the params of your particular subs you most likely won't see great SPL numbers out of it.  The box construction is just as important, if not more, then the equipment you are running.

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Kevin Pierson

To go from 120 to 140 will be costly.  You may be better off getting a different vehicle.  What kind of vehicle do you have this equipment installed in?

WOw i didnt know so much went into it. I thought it was a little more simple then that lol. Well my cobalt rattles the trunk alot and no i dont have a custom built box but the boxs that they are in are the exact size for the subs. They are sealed also. I was hoping to start competeing but with a wife and being 19 and trying to get a house im gonna have to stick with what i got lol

120 dbSPL is MORE that sufficient for a daily driver.  In fact it will cause hearing loss if that level is sustained.  Unless you plan to go into competition it's not worth the money it would take to bump up 20db.  If what you want is to brag to your friends, do what I do:  lie. 

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Support the12volt.com

LOL! I had a customer said he was hitting 190.
LOL. I said I wanted to see it because the current world record is 183. LOL.

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Thats funny lol no i just really got into building systems so i thought i would try to compete. Yes me and some of my friends are competeing against each other and so far im in 2nd with 120.4 and my buddy has a 2004 ford sporttrac truck with two 12 inch kicker c something in a custom built box and he is hitting 120.6 just a fun hobby i was gonna run with but aint got the money lol

im curious to know HOW exactly are you measuring your spl?
I had a guy come in after we upgraded his system and said his spl was the same.
Turns out while the system was noticeably louder, he was using his Ipod with an spl app to measure.
It capped at 130. I had to get the termlab on it.

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I bought a schoshe spl meter online for forty bucks. It seems to work good and accurate.

Which way are your woofers firing?

I got the twelve laying on its back facing the top of the trunk and the two tens are sitting right where my seats fold down facing the trunk. I have moved them around a bit and that seems to be the loudest i can get them.

Can you face them all to the rear of the trunk, prefferably about 10 inches from the rear of the trunk.

Its not wide enough. My two 10's only leave enough room for half of my 12 to fit and if i put the tens 10 inches away from the rear trunk then my 12 behind them it dont work. I moved my subs around for three hours today and the way i have them set up is the best so far

What is the ohm rating of each sub? How do you have it wired right now?

I know you said money was tight, but I would try to replace the 12 with another 10 and make one box to hold all three of them and place them across the back of the truck like I Am An Idiot suggested. You may have to put some slight angles on the box to fit them all in there but it can be done.

I am also skeptical that your amp is putting out the power you claim it is with only a single 6awg wire powering it. What size is the inline fuse at the battery?

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Kevin Pierson

My subs are rated at 4 ohms each and i have them wired up in parallel( the exact way it tells me to under sub wiring on this site). Now i gave you the specs of the amp but im not sure my amp is putting out what it says, or maybe your right and my wire is to small. The fuse is 80 and my amp has 4 30's which equals 120. is that bad??

https://www.poweracoustik.com/pa2006/product_AUDIO_amp_crypt.htm    

You can see my amp here. It is the 4000D mono block

https://www.pioneerelectronics.com/PUSA/Products/CarAudioVideo/Subwoofers/Champion/TS-W303R

This is the 12 inch sub. I have two tens just like it rated at 200 rms each and 4 ohms

So you have 750wrms of subs and you're putting out around 1900wrms?

With an 80A fuse at 14.4vdc and 90% amp efficiency you are sitting right around 1036 watts.  This is assuming you are pulling 80A through the fuse and your battery voltage is steady at 14.4 (both of which probably isn't true) and that you have a very efficient amp (which probably isn't the case). 

My guess is the amp is probably putting out closer to 800-900 wrms or so but that is just a guess. 

With that kind of guesstimated current draw your 6awg actually should be sufficient for what you are doing. 

Like I said before, if it were my car I would ditch the 12, buy another 4 ohm 10" sub and build a custom box to house all three subs.  If you want more output (SPL) I would port the box (if those subs respond well to a ported box).  If you want a deeper, cleaner bass a sealed box would be the preferred route.

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Kevin Pierson

I figured i was getting the amount of amps i needed to. I might do that get me another 10 though but i like the way my bass is hitting man. It hits hard and tight sounds real nice. It makes my whole damn car shake lol

18sbb] wrote:

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My subs are rated at 4 ohms each and i have them wired up in parallel( the exact way it tells me to under sub wiring on this site). Now i gave you the specs of the amp but im not sure my amp is putting out what it says, or maybe your right and my wire is to small. The fuse is 80 and my amp has 4 30's which equals 120. is that bad??

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no, that just means that you're not taxing your amp to its capacity because the 80A fuse isn't blown yet. but the bad news is that you amp is more like a 1000W amp. if that amp gives you any more than that it's probably pure distortion.

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