15" subs under rear seat?

[mjscharlotte]

Hey guys,
I have a 2017 1500 Crew Cab Limited. I have (2) Tezla 1.5 subwoofers (12") under the rear seat mounted in a Fox Accoustics box and hooked up to a SoundDigital 1600.1 amplifier which is 800rms. I want to get more bass and am wondering if anyone has mounted (2) 15" subwoofers under the rear seat and if so, what box are you using?

 

[maxiderm]

You have two 12s with an 800 watt amp and you want more bass??? lol, jk. I don't think it's physically possible to add 15s under the seat. There doesn't seem to be enough room down there. I mean, you can try custom fabricating your own box, but even then the depth of a 15 inch sub is still likely so much that I can't imagine anything would fit.

 

[G-Ride990]

The 800 watts is your problem if you want more volume. Mo powah!!

Which fox box do you have? Dual 12 vented? Might not be enough airspace, tuned to the wrong frequency for the subs or a host of other issues. My dual Kicker 12s absolutely rip with 800 watts in my dual 12 vented foxbox.

EDIT: You have Tezla 1.5 12in woofers with only ONE 800 watt amp? The RMS of those subs are 1000 watts each. You need more amp man!

 

[BWL]

Not sure what the minimum airspace requirement is for the Tezla's, but that may be the issue. As mentioned before upping the power will add spl, but if you don't have the airspace it will never sound good. Vented needs more airspace generally so most settle for sealed under the seat. I'd say it's hard to crack the 140s with the limited airspace. Couple sundown SA12s and a 1500w+ RMS amp is probably the loudest set up you'd fit. Doesn't sound like you're doing an SQ build. 15s are a huge jump in airspace requirement that just doesn't exist under there.

 

[WY-Dave]

Box:

DODGE RAM QUAD & CREW CAB 2-12" OR 2-10" VENTED

RAM QUAD AND CREW CAB DQC-212-V Fits * 3rd & 4th gen "2002-2018" 1500, 2500 & 3500 * 5th gen "2019-up" 2500 & 3500 Does NOT fit 1500s * 2019-UP "CLASSIC" 1500, 2500 & 3500 2-12" VENTED SUB BOX 10" subs can be used with the 12 to 10 adapters in the product options. SUB SIZE: 12"SUB HOLE SIZE...

www.foxacoustics.com

INTERNAL AIR VOLUME: 1.55 FT3 PER SUB. Pretty decent, Should find out from Tezla what their recommended volume is.

AMP:

12" 1000w RMS Subwoofer 1.5K Series by Tezla Audio

Shop 12" 1000w RMS Subwoofer 1.5K Series by Tezla Audio at the Guaranteed lowest allowed price of 559.99 with 20+ yrs of the best customer service, only at the SSA STORE

store.soundsolutionsaudio.com

Looks like the 12s are rated 1000wRMS. The thing to remember that with high power speakers is that they require "umph" to get them going. And #2, amps deliver clean power up to about 85% of their rating. Along with that, voltage supply to the amp is critical also.

Right now the specs are not making any sense but for example. You can see with just a 1.8v difference there is a 269wrms difference.
1600.1D 2Ω
Power @ 12.6V @ 4Ω: 1 x 880 W RMS
Power @ 14.4V @ 4Ω: 1 x 1149 W RMS

Did you upgrade the alternator or install a CAP? If not, you are probably starving the amps on the hits.
Current Draw (Music): 87A
Current Draw (Max): 174A

SPEAKER:

SounDigital USA 1600.1D EVO

soundigitalusa.com

What version of speaker do you have dual 4Ω or dual 2Ω voice coils? Are the coils in parallel or series? And are the 2 speakers themselves in series or parallel? For instance

(double values for 4Ω voice coils)
2Ω voice coils in parallel will give you a 1Ω load, then if you parallel both speakers it's a .5Ω load.
2Ω voice coils in series will give you a 4Ω load, then series both speakers it's a 8Ω load.
2Ω voice coils in series will give you a 4Ω load, then parallel both speakers it's a 2Ω load.
2Ω voice coils in parallel will give you a 4Ω load, then series both speakers it's a 2Ω load.

and just for fun
1 2Ω voice coil in series (4Ω) series'd with a 2Ω voice coil in parallel (1Ω) will give you a .8Ω load.
1 2Ω voice coil in series (4Ω) parallel'd with a 2Ω voice coil in parallel (1Ω) will give you a 5Ω load.

Great info site:https://www.the12volt.com/caraudio/boxcalcs.asp#par

I have no idea of your background with car audio and I hope I am not offending you in any way. But when I worked at HiFiFoFum in St. Louis and Metro Audio Dynamics in Omaha, I would see guys (and gals) come in with hopes and dreams of boom, but go bust.


This was my single 15" Alpine. IIRC it hit 118db (1.6 ft3)


This was my dual ported Treo 12" (134db@ dbDragRaces). IIRC, 2.3ft3. I don't have a completed system pic and this was before I put the amps in.


Proof that, in this case, size don't matter. It's just alot of design and planning.

Oh yeah, this is what it was in.

 

[mjscharlotte]

The 800 watts is your problem if you want more volume. Mo powah!!

Which fox box do you have? Dual 12 vented? Might not be enough airspace, tuned to the wrong frequency for the subs or a host of other issues. My dual Kicker 12s absolutely rip with 800 watts in my dual 12 vented foxbox.

EDIT: You have Tezla 1.5 12in woofers with only ONE 800 watt amp? The RMS of those subs are 1000 watts each. You need more amp man!

I have the Foxbox dual vented box. I have a SoundDigital 1600.1 amp so I have 800w RMS going each subwoofer. - I can go to a bigger amp but not sure an extra 200w per sub will make that much of a difference. Don't get me wrong - it's hard but if I can get more bass - why not.

 

[mjscharlotte]

Box:

DODGE RAM QUAD & CREW CAB 2-12" OR 2-10" VENTED

RAM QUAD AND CREW CAB DQC-212-V Fits * 3rd & 4th gen "2002-2018" 1500, 2500 & 3500 * 5th gen "2019-up" 2500 & 3500 Does NOT fit 1500s * 2019-UP "CLASSIC" 1500, 2500 & 3500 2-12" VENTED SUB BOX 10" subs can be used with the 12 to 10 adapters in the product options. SUB SIZE: 12"SUB HOLE SIZE...

www.foxacoustics.com

INTERNAL AIR VOLUME: 1.55 FT3 PER SUB. Pretty decent, Should find out from Tezla what their recommended volume is.

AMP:

12" 1000w RMS Subwoofer 1.5K Series by Tezla Audio

Shop 12" 1000w RMS Subwoofer 1.5K Series by Tezla Audio at the Guaranteed lowest allowed price of 559.99 with 20+ yrs of the best customer service, only at the SSA STORE

store.soundsolutionsaudio.com

Looks like the 12s are rated 1000wRMS. The thing to remember that with high power speakers is that they require "umph" to get them going. And #2, amps deliver clean power up to about 85% of their rating. Along with that, voltage supply to the amp is critical also.

Right now the specs are not making any sense but for example. You can see with just a 1.8v difference there is a 269wrms difference.
1600.1D 2Ω
Power @ 12.6V @ 4Ω: 1 x 880 W RMS
Power @ 14.4V @ 4Ω: 1 x 1149 W RMS

Did you upgrade the alternator or install a CAP? If not, you are probably starving the amps on the hits.
Current Draw (Music): 87A
Current Draw (Max): 174A

SPEAKER:

SounDigital USA 1600.1D EVO

soundigitalusa.com

What version of speaker do you have dual 4Ω or dual 2Ω voice coils? Are the coils in parallel or series? And are the 2 speakers themselves in series or parallel? For instance

(double values for 4Ω voice coils)
2Ω voice coils in parallel will give you a 1Ω load, then if you parallel both speakers it's a .5Ω load.
2Ω voice coils in series will give you a 4Ω load, then series both speakers it's a 8Ω load.
2Ω voice coils in series will give you a 4Ω load, then parallel both speakers it's a 2Ω load.
2Ω voice coils in parallel will give you a 4Ω load, then series both speakers it's a 2Ω load.

and just for fun
1 2Ω voice coil in series (4Ω) series'd with a 2Ω voice coil in parallel (1Ω) will give you a .8Ω load.
1 2Ω voice coil in series (4Ω) parallel'd with a 2Ω voice coil in parallel (1Ω) will give you a 5Ω load.

Great info site:https://www.the12volt.com/caraudio/boxcalcs.asp#par

I have no idea of your background with car audio and I hope I am not offending you in any way. But when I worked at HiFiFoFum in St. Louis and Metro Audio Dynamics in Omaha, I would see guys (and gals) come in with hopes and dreams of boom, but go bust.


This was my single 15" Alpine. IIRC it hit 118db (1.6 ft3)
View attachment 468168

This was my dual ported Treo 12" (134db@ dbDragRaces). IIRC, 2.3ft3. I don't have a completed system pic and this was before I put the amps in.
View attachment 468169

Proof that, in this case, size don't matter. It's just alot of design and planning.

Oh yeah, this is what it was in.
View attachment 468170

LOL - my background is negligible at best. I know brands and a little about installation and that is about the extent. You're not offending me at all - I am learning alot. I misspoke about my subs - I have the Tezla 1.0 not the 1.5's. I just texted the installer that I used to get some more info about what ohm, series or parallel etc..I haven't upgraded the alternator and don't have a CAP. I have the original 160amp alternator. Thank you for the help and all the information. When I get the other information I can let you know and maybe you can offer some assistance of what I can do.

 

[G-Ride990]

I have the Foxbox dual vented box. I have a SoundDigital 1600.1 amp so I have 800w RMS going each subwoofer. - I can go to a bigger amp but not sure an extra 200w per sub will make that much of a difference. Don't get me wrong - it's hard but if I can get more bass - why not.

Ah gotcha, yeah if you are running 800 watts RMS each then you are good there. Depending on how they are wired of course.

Is your truck all dynomatted? Or does it rattle like crazy? That might help some too if not.

 

[mjscharlotte]

Ah gotcha, yeah if you are running 800 watts RMS each then you are good there. Depending on how they are wired of course.

Is your truck all dynomatted? Or does it rattle like crazy? That might help some too if not.

My doors/dash and rear floorboard are all dynomatted.