In need of basic help/knowledge


J_Vegas

CarAudio.com Newbie
May 30, 2020
1
0
Lincoln California
So the most i have ever done with any thing related to car audio was plug in my pioneer headunit and plug in my door speakers. Basically the wiring for both of those where already done. I used to have a powered small sub in the back but that was stolen....
Im trying to replace it with a new better subwoofer setup the basic idea is two tens under the backseat i found a box with the correct mounting depth for the skar audio subs i would like to get now i mainly need help with what wires to buy and how to find a good amp for the subwoofers. Ill post the information for the subs and amp i was considering below. Any help is appreciated like i said this is my first real step into car audio so if im missing any necessary information i will try to fill it in as best as i can

Amplifier power rating information
Rockville dB25 2800 Watt/1400w RMS 2 Channel Amplifier
  • Rockville dB25 2800Watt/1400Watt RMS Class AB 2 Ohm Car Stereo Amplifier With Optical Coupler Technology
  • CEA Compliant Power Ratings (Rated at less than 1 % distortion) (Use these CEA ratings when matching and comparing with other CEA compliant brands such as Kicker, Rockford Fosgate, etc)
  • o 2 Ohm: 350 Watts x 2 Channel <1% THD+N
  • o 4 Ohm: 230 Watts x 2 Channel <1% THD+N
  • o 4 Ohm: Bridged: 700 Watts x 1 Channel
  • RMS Power Ratings: (Use these RMS ratings when comparing with great brands such as Hifonics, Earthquake, Soundstream, etc)
  • o 2 Ohm: 700 Watts x 2 Channel
  • o 4 Ohm: 460 Watts x 2 Channel
  • o 4 Ohm:Bridged: 1400 Watts x 1 Channel

Subwoofer(s) power rating information
Skar Audio SDR-10 D4 10"
  • 10-Inch Dual 4-ohm Car Subwoofer
  • Peak Power: 1,200 Watts | RMS Power: 600 watts
  • 2.5" 4-Layer High Temperature Copper voice Coil
  • High Roll Foam Surround and Competition Grade Pressed Paper Cone
  • Frequency Response Range: 28 Hz - 300 Hz | Sensitivity: 82.5 dB
  • High Flux Ferrite Motor | Advanced Air Flow Cooling Design
 

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Popwarhomie

SHAMPOO IS BETTERRR
10+ year member
Jan 22, 2010
7,752
1,021
FL
You want a mono block amp. Not a two or four channel for subwoofers.
 

1aespinoza

Junior Member
May 22, 2013
387
114
Pharr, Texas
Like Popwarhomie said, one channel amps are great for subs. They use less energy, run cooler, and tend to have a smaller footprint. But at 700 watts rms, I do not think it be critical to save energy by way of a class D amp. I personally prefer class a/b for subs for they sound musical and tend to be more violent on the bass notes. That being said, this seems like a great setup. Class a/b coupled to 2.5" voice coils will give good frequency extension. Those subs play to the edge of 300hz so you will be able to blend them seamlessly to your front stage. For wiring kits look into Skyhigh Car Audio. They have all copper kits at great prices.
 

THATpurpleKUSH

Smoke weed everyday
10+ year member
Sep 30, 2009
7,798
626
Slums of the Shaolin
Like Popwarhomie said, one channel amps are great for subs. They use less energy, run cooler, and tend to have a smaller footprint. But at 700 watts rms, I do not think it be critical to save energy by way of a class D amp. I personally prefer class a/b for subs for they sound musical and tend to be more violent on the bass notes. That being said, this seems like a great setup. Class a/b coupled to 2.5" voice coils will give good frequency extension. Those subs play to the edge of 300hz so you will be able to blend them seamlessly to your front stage. For wiring kits look into Skyhigh Car Audio. They have all copper kits at great prices.
Some false information to clear up here....


Amplifier class and size of voice coils have absolutely NOTHING to do with frequnecy extension.

Class AB amps these days are cheap chinese current hogs unless you get into the real high dollar stuff. Modern technology has enabled d class amps to sound as good as the old ab amps of the past. D class is the way go these days for efficiency and packaging.
 
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1aespinoza

Junior Member
May 22, 2013
387
114
Pharr, Texas
Amplifier class and size of voice coils have absolutely NOTHING to do with frequnecy extension.
I am basing this off the specifications of the sellers info. It says the sub can play up to 300hz, so 160hz is not far fetched. Imo 160hz is a bit into the vocal range, so seamless integration into the front stage is very doable. Also, 2.5 inch voice coils are more efficient than bigger sizes and thus play better with less. As for class D amps sounding great on vocals, I agree. I have had an class D xd200/2 for 7 months and am blown away at how much better it sounds (vocal wise) than my Orion 375.2 that it replaced.
 

THATpurpleKUSH

Smoke weed everyday
10+ year member
Sep 30, 2009
7,798
626
Slums of the Shaolin
I am basing this off the specifications of the sellers info. It says the sub can play up to 300hz, so 160hz is not far fetched. Imo 160hz is a bit into the vocal range, so seamless integration into the front stage is very doable. Also, 2.5 inch voice coils are more efficient than bigger sizes and thus play better with less. As for class D amps sounding great on vocals, I agree. I have had an class D xd200/2 for 7 months and am blown away at how much better it sounds (vocal wise) than my Orion 375.2 that it replaced.

You are still blindly assuming. There is more to efficiency than the size of a voice coil. What about the type of suspension that coil is attached to? Motor force? Enclosure design? You cannot sit there and the blindly assume when you don't understand how all the pieces of the puzzle work together.

If you have ever measured your own theile small parameters, you would know that manuafcturer posted specs are wildly off most of the time and there are many variables that can affect the outcome of those numbers hence the manufacturer can sway the numbers one way or another.

You shouldnt be crossing a sub above 100hz. If you are you are doing your midrange setup completely wrong.
 

1aespinoza

Junior Member
May 22, 2013
387
114
Pharr, Texas
You are still blindly assuming. There is more to efficiency than the size of a voice coil. What about the type of suspension that coil is attached to? Motor force? Enclosure design? You cannot sit there and the blindly assume when you don't understand how all the pieces of the puzzle work together.

If you have ever measured your own theile small parameters, you would know that manuafcturer posted specs are wildly off most of the time and there are many variables that can affect the outcome of those numbers hence the manufacturer can sway the numbers one way or another.

You shouldnt be crossing a sub above 100hz. If you are you are doing your midrange setup completely wrong.
You are right, I am assuming 100%. I have zero knowledge of how to use much less apply tsps unless I have access to a box design program. However, I have never seen a sub with a 2.5" voice coil have an rms of 1kw or more. The highest rms I have seen is 700 watts on a set of Oz Audio 15" Matrix Elites. The specs sheet says they are able to be used in ib, sealed, and even ported. But they have none the less very soft parts. SAS basically banked on 2.5" voice coils, and their efficiency on those tubes is phenomenal. But then again, it goes back to what you said, speaker and box design. So yeah, that is where I extrapolated that 2.5" vcs have a higher efficiency than other sizes. And in regards to running subs over 100hz, I am guilty as charged. I had a universal volume with frequency (250hz max)knob running to a 275g4. It was pushing two Fosgate 12" t0 subs and sounded great to my ear. I thought they were playing up to 250hz, but someone here told me it was probably less because of roll off. Now about that I am unversed so I take the word of those smarter than me at face value.
 

THATpurpleKUSH

Smoke weed everyday
10+ year member
Sep 30, 2009
7,798
626
Slums of the Shaolin
You are right, I am assuming 100%. I have zero knowledge of how to use much less apply tsps unless I have access to a box design program. However, I have never seen a sub with a 2.5" voice coil have an rms of 1kw or more. The highest rms I have seen is 700 watts on a set of Oz Audio 15" Matrix Elites. The specs sheet says they are able to be used in ib, sealed, and even ported. But they have none the less very soft parts. SAS basically banked on 2.5" voice coils, and their efficiency on those tubes is phenomenal. But then again, it goes back to what you said, speaker and box design. So yeah, that is where I extrapolated that 2.5" vcs have a higher efficiency than other sizes. And in regards to running subs over 100hz, I am guilty as charged. I had a universal volume with frequency (250hz max)knob running to a 275g4. It was pushing two Fosgate 12" t0 subs and sounded great to my ear. I thought they were playing up to 250hz, but someone here told me it was probably less because of roll off. Now about that I am unversed so I take the word of those smarter than me at face value.

It's fine to lack knowledge and experience. We all start somewhere.


But to blindly assume things you don't know and understand is just plain ignorance and then to continue spreading that and trying to justify your own bullshit reasoning is a detriment to this sport and that's what really irks me and will trigger me to stand up and speak out.

If you knew you were wrong about something then why did you say it and then try to justify it?
 

1aespinoza

Junior Member
May 22, 2013
387
114
Pharr, Texas
If you knew you were wrong about something then why did you say it and then try to justify it?
I never said I was wrong. I showed you examples of common logic and yet you keep saying I am bullshitting. Yet you still have not provided any empirical evidence in any if your indignant rants. If you are irked then educate, show me your knowledge. I may not be a genius but I am smarter than your average bear.
 
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jt4x4

CarAudio.com Enthusiast
Jul 22, 2019
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20
ND
It's fine to lack knowledge and experience. We all start somewhere.


But to blindly assume things you don't know and understand is just plain ignorance and then to continue spreading that and trying to justify your own bullshit reasoning is a detriment to this sport and that's what really irks me and will trigger me to stand up and speak out.

If you knew you were wrong about something then why did you say it and then try to justify it?
He said he was assuming, then he told you his basis. Can't you let it be at that? There's theory and there's practice, and they don't always align. He went off theory based on his own personal experience. We're all here to learn. Nobody knows everything, and everybody has been wrong before. Why do you always have to turn it into an argument? Well, not always; you selectively turn things into arguments, but hopefully you understand the sentiment.

- Joe
 

THATpurpleKUSH

Smoke weed everyday
10+ year member
Sep 30, 2009
7,798
626
Slums of the Shaolin
I never said I was wrong. I showed you examples of common logic and yet you keep saying I am bullshitting. Yet you still have not provided any empirical evidence in any if your indignant rants. If you are irked then educate, show me your knowledge. I may not be a genius but I am smarter than your average bear.
I already said what needed to be said in first post addressing the misinformation.

Its not my job to spoon feed noobs information. There are plenty of resources out there to find the information one might seek.
 

1aespinoza

Junior Member
May 22, 2013
387
114
Pharr, Texas
Heres your empirical evidence:

Thank you. I have been searching online on versus of vc sizes. Only thing most agree on is that a bigger vc dissipates heat better, enabling higher power handling. This link below gives a great synopsis of vc and cone characteristics. Now on to learn me sum edumacation!
 

THATpurpleKUSH

Smoke weed everyday
10+ year member
Sep 30, 2009
7,798
626
Slums of the Shaolin
Thank you. I have been searching online on versus of vc sizes. Only thing most agree on is that a bigger vc dissipates heat better, enabling higher power handling. This link below gives a great synopsis of vc and cone characteristics. Now on to learn me sum edumacation!
Correct about increased surface area dissipating heat better.

Winding width, flat or round wire, number of layers, former material and wire material will all affect efficiency. And thats not even getting into motor and suspension design.
 

Slo_Ride

Regulator
10+ year member
Oct 15, 2005
24,699
1,563
ATLANTA
He said he was assuming, then he told you his basis. Can't you let it be at that? There's theory and there's practice, and they don't always align. He went off theory based on his own personal experience. We're all here to learn. Nobody knows everything, and everybody has been wrong before. Why do you always have to turn it into an argument? Well, not always; you selectively turn things into arguments, but hopefully you understand the sentiment.

- Joe
He's a total douche bro. Easily the most punchable guy here, but that's his troll and for some dumb reason he enjoys it.
 
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jt4x4

CarAudio.com Enthusiast
Jul 22, 2019
80
20
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He's a total douche bro. Easily the most punchable guy here, but that's his troll and for some dumb reason he enjoys it.
I suppose no one would strive to be popular on the internet if they could do it in real life.
 

1aespinoza

Junior Member
May 22, 2013
387
114
Pharr, Texas
Can you get a DVC 2 ohm sub and then run a two channel amp at two ohms. One channel for each voice coil? Sorry, if this is the wrong section.
Yes. That is how I was running a pair of d4 Fosgates with a two channel Orion 275g4. Sounded BEAST.... until it popped a few mosfets. One side of the power input plugs came loose and starved the mosfets. I am now running them with a US Amps 500a. Not as powerful but sounds sweet.
 

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