Subwoofer box tuning, cabin gain, power requirements, etc.

I am trying to design my sub box for my truck. I have (4) 8" DD608 D4 subs, which are rated at 300-600 RMS each. I'm assuming I can wire them series parallel down to 1 ohm. I believe I need a 3.25^ft box, with a 52sq" x 20" long vent, which should tune it to 35-40Hz, according to DD website.

I will also be running a 3-way active front stage with about 500 watts or so.

My truck is a 2014 Chevy Silverado Crew Cab, if that helps with my questions.

My questions are:

Will cabin gain come into play, such that I need to figure it in before I build my box? If so, how do I do that?

Can I manipulate the box tune to go lower, and should I, if I can?

What size amp, or amps would you guys recommend for the subs? (One big amp, or 2 smaller ones)

What will I need as far as extra battery or upgraded alternator requirements, if any? (I have done a big 3 upgrade with 1/0)

Any ideas on the best way to attach an MDF amp rack to the back wall of a truck without drilling any holes in the cabin?

As always, thank you for your assistance, and your patience with my ignorance!!!

Bobby K.

WinISD will help you, if you can find bassbox pro is a good one too..

What are you looking at each sub getting power wise realistically?

Attaching permanent, epoxy a piece of MDF or metal to the back wall with preset holes pre-tapped or with nutserts.

Upgrading alternator, hmm what is the output of the one you have in it now? are you building a SPL monster?

Thanks for the reply! I was thinking an amp or amps that put me at 2k-3k so there is headroom with the subs. I'm wanting to have excellent SQ, but I am a closet bass head, and would like the option of thump when the mood strikes Thanks for the epoxy idea. My alternator is whatever a 6 cyl Chevy has, I just wasn't sure if I need to upgrade, since I'm looking at being between 2k-3k total power when complete.

add a second battery, forget the alternator for now.

2k should be good. I can recommend two amps Soundigital Amps:
SD1600.1D 1600W @ 12.6v 1ohm or 1800W @ 14.4V @ 1ohm
SD2000.1D 2000W @ 12.6V 1ohm or 2400W @ 14.4v @ 1ohm

I know there's others out there but recommending soundigital amps..

Quote:

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Originally Posted by AccordUno

add a second battery, forget the alternator for now.

2k should be good. I can recommend two amps Soundigital Amps:
SD1600.1D 1600W @ 12.6v 1ohm or 1800W @ 14.4V @ 1ohm
SD2000.1D 2000W @ 12.6V 1ohm or 2400W @ 14.4v @ 1ohm

I know there's others out there but recommending soundigital amps..

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Adding a second battery will only be useful if using the audio with the engine off. While the engine is running, a second battery is an increased load on the existing alternator. Looking at what the OP is looking to run, I dont see why a bigger alternator or an extra battery would be needed. Stock alternators on large trucks are plenty big. My puney stock alternator and battery in my impreza handled the 3 amplifiers (JBL 5001, JBL 1004, and a PPI 4ch - cant remember which one) just fine.

Thank you guys for the input! I won't be doing much demoing with the truck turned off, unless I can actually make one of the GTG's, so I'm hoping the stock alternator can handle it. So, from what I understand, while the truck is running, the voltage will be around 14.4. Is that the number I should focus on when looking at amp statistics? Should I run a digital voltage meter somewhere within sight to ensure it doesn't drop below a certain number?

I am not sure about your alternators output, but I know that GM has these trucks set up to run at 13.8 volts, all the way up to 15.8 volts.
I was shocked the first time I saw my voltage gauge reading so far over 14 volts, and I put a meter on it.
I then asked on some GM forums and was told that these new trucks will do that.

So 99% of the time, they will be in that range. But they can at times fall as low as 12.4 volts while running with no load. The BCM can basically turn the alternator off if it feels that the battery has reached full charge, and the system load is low enough such as not having the HVAC system and infotainment system on.

This is less common in this generation of the truck, but in the last one you would see the voltage gauge drop all the time. I have an 07 that did that. Was vary unnerving to see that thing sit at just over 12 volts for more then 45 min at times. But my truck had a second battery installed in it as well. So that might have had something to do with it.



To find out what alternator you have look in glove compartment at option list, it should start with a K

K09 Alternator, 140 amps
K60 Alternator, 100 amps
K62 Alternator, 105 amps
K65 Alternator, dual, 105 amps each
K68 Generator, 105 AMP
K76 Alternator, dual, 125 amps each
K99 Alternator, 85 amps
KD9 Alternator, dual, 145 amps each
KG3 Alternator, 145 amps
KG4 Alternator, 150 amps
KG7 Alternator, 125 amps
KG8 Generator 130 Amp
KG9 Generator, 140 Amp
KW1 Alternator, 160 amps
KW2 Generator, 124 Amp
KW5 Alternator, 220 amps
KW7 Alternator, 170 amps
KW8 Alternator, 155 amps
KXB Dual Generator, 100 Amp
KXB Alternator – Dual 100 AMP
KY1 Generator, Hybrid motor

hope this helps...

I do have a KG4 number, so I'll assume it's 150 amps. Will that do everything I need it to do, without running an SPL monster?

Quote:

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Originally Posted by beak81champ

I do have a KG4 number, so I'll assume it's 150 amps. Will that do everything I need it to do, without running an SPL monster?

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more than enough.

i wouldn't tune above 35 unless competing (i say with my 38hz tuning)