2 subs 2 amps

[DTGFRESH]

i started with skar sub EVL 12inch 2 ohm sub and Skar RP 1500 amp. thats not enough bass for me so i want to add another 12 inch evl sub. my question: is it ok with hook a second amp up for the new sub? so i would have 2 evl subs in one box and run 2 amps one for each sub. 

[JohnP]

Here's what I see. 

 

Increasing the driver count increases the sound pressure level by virtue of the fact you are moving more air.   Adding a second amplifier of same exact kind doubles the current draw on your car's electrical system.  

 

To realize an  increase in sound pressure using two of a kind speakers:  They have to be acoustically in phase.   Meaning:  They both have to be moving air such that one's not pushing it out of the box while another  draws it in or speakers are not otherwise cancelling each other out to whatever degree.   

 

Putting two subs in one box can be a challenge because the idea is to get two drivers to operate as one.  This may not happen for variances in speaker manufacturing as well as box dimensions and port dimensions used .   In my opinion and having tried two drivers in one box:   The best is to partition the box into two separate chambers and do all the engineering for one box at a time.  

 

"Not Enough Bass" can have two meanings:   The sound pressure level is not to your tastes or the low frequency response is too low.   In other words you are not hearing frequencies below 100 Hz or lower at the intensity you otherwise would.   Perhaps a box redesign or modification would serve better than adding speakers, amps, and electrical load.

 

Are you using online, freeware, or some kind of box software to plot the frequency response curve of the box and design being used ?    Are you using a manufacturer's recommended sealed or ported design ?   The great thing about "boxware" is it's much easier to change the type of box and critical dimensions with a few keystrokes than it is to cut lumber and building materials. 

 

 

 

 

[CCole]

Quick and easy answer is yes you can hook up a second amp to the new sub. Are the subs dual voice coil 2ohm or single 2ohm. If they are single you may not need a second amplifier or you may want to step up to a single larger model. I.E. RP2000 and run at 1ohm.  Once you get to the 3000 watt RMS mark you need to seriously think about upgrading your charging system. Especially with Skar RP-series amplifier. Great amps but have a tendency to give up the ghost w/o the amperage needed.  

[1point21gigawatts]

Just gain and filter match the amps and there would be no problems. Them amps don’t have a phase control, so don’t worry about the phase. As long as your subwoofers aren’t wired out of phase and the polarity is the same then there no need to worry about phase issues. Meaning, as long as you aren’t twisting positive and negative wires together or hooking positive and negative wires to the wrong terminals then you are fine.

[1point21gigawatts]

8 hours ago, JohnP said:

Here's what I see. 

 

Increasing the driver count increases the sound pressure level by virtue of the fact you are moving more air.   Adding a second amplifier of same exact kind doubles the current draw on your car's electrical system.  

 

To realize an  increase in sound pressure using two of a kind speakers:  They have to be acoustically in phase.   Meaning:  They both have to be moving air such that one's not pushing it out of the box while another  draws it in or speakers are not otherwise cancelling each other out to whatever degree.   

 

Putting two subs in one box can be a challenge because the idea is to get two drivers to operate as one.  This may not happen for variances in speaker manufacturing as well as box dimensions and port dimensions used .   In my opinion and having tried two drivers in one box:   The best is to partition the box into two separate chambers and do all the engineering for one box at a time.  

 

"Not Enough Bass" can have two meanings:   The sound pressure level is not to your tastes or the low frequency response is too low.   In other words you are not hearing frequencies below 100 Hz or lower at the intensity you otherwise would.   Perhaps a box redesign or modification would serve better than adding speakers, amps, and electrical load.

 

Are you using online, freeware, or some kind of box software to plot the frequency response curve of the box and design being used ?    Are you using a manufacturer's recommended sealed or ported design ?   The great thing about "boxware" is it's much easier to change the type of box and critical dimensions with a few keystrokes than it is to cut lumber and building materials. 

 

 

 

 

Dude, I’ve been reading your posts and having to follow behind you to correct your falsehood. Even though you know valid information about car audio, you don’t know that much about car audio. Let me explain in one sentence. You learn information but don’t know how to apply it or correctly use it. No disrespect, but quit trying to help and teach about car audio when you have yet to learn enough to teach and help in car audio. Don’t take this the wrong way. But I had to say it. 

[JohnP]

One Point Two...

 

In multi speaker and amplifier setups in car, home, commercial and professional audio if multiple speakers are covering the same frequency range  for the objective of increased sound pressure level there's the risk of one speaker cancelling out another.  This can be quite easily noticed by turning up the volume  for one speaker and noticing a drop in overall volume level when the volume for another speaker is increased.   In this case the speakers are acoustically out of phase.     

 

I've seen this very thing happen in both my own system and when people came to me with the same exact problem with faded hopes of more volume for more speakers and amps.   Sometimes it's a simple as reversing the wires to the speaker, other times it involves changing the location of the  speakers relative to each other and other times it means using a fairly elaborate and expensive Digital Signal Processor (DSP) to see if delaying the material to one of the speakers causes them to get back into phase and stop cancelling each other out.  

 

One problem in some quite elaborate home systems I've dealt with:  The use of a DSP in things like echo, reverb, delay, and various and sundry sound effects programmed into the DSP can make the system sound much worse and in some cases it can make it sound better.   Of course worse and better are subjective to the listener.

 

Would you please discuss the issues of the thread and not me ?  Realize it or not in shifting the discussion to me you're saying more about yourself.   No disrespect intended.    If I'm wrong post your opinion as to what you think wrong, we can respectfully discuss it,   and hopefully we all as the forum can benefit.    Thank You. 

 

 

[1point21gigawatts]

52 minutes ago, JohnP said:

One Point Two...

 

In multi speaker and amplifier setups in car, home, commercial and professional audio if multiple speakers are covering the same frequency range  for the objective of increased sound pressure level there's the risk of one speaker cancelling out another.  This can be quite easily noticed by turning up the volume  for one speaker and noticing a drop in overall volume level when the volume for another speaker is increased.   In this case the speakers are acoustically out of phase.     

 

I've seen this very thing happen in both my own system and when people came to me with the same exact problem with faded hopes of more volume for more speakers and amps.   Sometimes it's a simple as reversing the wires to the speaker, other times it involves changing the location of the  speakers relative to each other and other times it means using a fairly elaborate and expensive Digital Signal Processor (DSP) to see if delaying the material to one of the speakers causes them to get back into phase and stop cancelling each other out.  

 

One problem in some quite elaborate home systems I've dealt with:  The use of a DSP in things like echo, reverb, delay, and various and sundry sound effects programmed into the DSP can make the system sound much worse and in some cases it can make it sound better.   Of course worse and better are subjective to the listener.

 

Would you please discuss the issues of the thread and not me ?  Realize it or not in shifting the discussion to me you're saying more about yourself.   No disrespect intended.    If I'm wrong post your opinion as to what you think wrong, we can respectfully discuss it,   and hopefully we all as the forum can benefit.    Thank You. 

 

 

You are incorrect. I posted facts. Not opinions. You posted falsehood. There would be NO PROBLEMS with phase even if he wired 100 of them amps on 100 of them subwoofers in the same enclosure, with no sections, as long as the gains and filters were matched and the subwoofers were all wired correctly. There’s no reason the subwoofer’s would be out of phase, play differently or cancel another subwoofer out. If the filters and gains are set differently then the subwoofers would play in the same direction (because the polarity in each subwoofer is the same) but the subwoofers would sound different because of the gains and crossover filters being different on each amp. They would not cancel each other out and they would be in phase correctly. There’s no phase switch or knob on that amp so we can cancel that option out. So in this case, the only way for them subwoofers to move opposite from each other and cancel each other out would be if he reversed the polarity on one subwoofer by wiring it out of phase.  Some stuff about car audio you kind of know, but it seems like most of the stuff about car audio, you don’t know. Just because you tuned something wrong or wired something wrong on your own dual amp setup and went out of phase doesn’t mean the next man would. When the crossover filters and gains aren’t matched on each amp the subwoofer do appear to move differently and this is true in a sense but the subwoofers are moving in the same direction but one might move more because of unmatched gains and then one subwoofer might not play at all and the other one would and make you think one was canceled out but that is just because the crossover filters are matched and one of the subwoofer’s didn’t play a frequency and the other subwoofer did. Most of what you say is false. So I’m gonna call you on your falsehood and let it be know and then I’m gonna correct it. When others that are knowledgeable about car audio read your falsehood, most of them are gonna call you out on it or just correct you. Either or. But you shouldn’t be confusing and overwhelming noobs like you did on this thread for no reason about something that wouldn’t happen as long as the amps are tuned correctly and the subwoofers are wired correctly. That’s not how you help somebody.