Sub Question

[TommyBoy24 10+ year member]

Okay, I am looking at adding some thump to my system and I am trying to determine what subs and amp I will need. Lets say I am going to install 2 subs with ratings of 300W RMS, 600W max and 4 ohm resistance. What is the formula to determine the power (RMS) that the amp will have to supply? Would I be looking for an amp which is 300W RMS @ 2ohms? How would I wire this, 1 sub per channel on a 2 channel amp and if I wired this like this, would I be interested in RMS values at 4 ohms since that is all the channel sees? If I was to bridge the amp and wire this in series (one big loop) what values of RMS should I look for? Thanks for your help

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[TommyBoy24 10+ year member]

Lets say Sony Xplods with 150W RMS and 600W max, how do I calculate the values for the amp? Thanks Again

 

[TommyBoy24 10+ year member]

Okay, model number XS-L1035. Max input = 600W, Rated Input = 150W, Impedance = 4ohms. Could you explain how to wire it, one sub to each channel of an amp or everything in series? Thanks again

 

[TommyBoy24 10+ year member]

In reguard to "Basically wire the positive terminals on the subs to the positive terminal on the box and the negative terminals on the subs to the negative terminal on the box ...

After that, buy an amplifier that puts out about 250 RMS into 2 ohms mono"

2 things:

I should wire the positive and negative of one sub to one output on the amp and the positive and negative of the other amp to the other channel of the amp OR should I put both positive terminals to the positive on the amp and both negative terminals to the negative on the amp?

Could you explain the 2 ohms mono and could this mono be acomplished by bridging a bridgable 2 channel amp?

Thanks again

 

[TommyBoy24 10+ year member]

Also, how did you come about the 250 RMS value? Thanks again

 

[TommyBoy24 10+ year member]

One more thing, how did you come about the 2 ohm value? Thanks again for all of your help

 

[TommyBoy24 10+ year member]

To start, thanks for the help but I am still a little confused, I understand how to wire it but I still don't understand how you got the value of 250 RMS for the amp. I am wondering how you got this value so I can calculate it for different subs instead of posting on the message board every time my mind changes. I am looking at the Profile Baja BA400 amp, it's ratings are:

Output power @ 4ohm = 2 x 200w

RMS power @ 4ohm = 2 x 100w

RMS power @ 2ohm = 2 x 150w

Bridged RMS @ 4ohm = 1 x300w

This is all that is listed for the amp, no 2ohm mono loading

You showed earlier that I would have 2 ohms, could I just add a 2 ohm inductor to get to a 4 ohm value? How would I make this amp work? Thanks again

 

[TommyBoy24 10+ year member]

"The only way you could get that amplifier to work would be to run it @ 8 ohms mono, which would be 200 RMS (rated) ... Unfortunately, the Profile amps are overrated by a good 5-10%, so you're looking at 180-190 RMS of actual power into that load ... "

So to get the RMS needed you add the RMS values of both subs?

Could you explain the 8 ohms thing and why I would need to run at that, earlier you said 2 ohms?

Thanks, again

 

[TommyBoy24 10+ year member]

From the info I gave you how did you determine the amp could do anything in 8ohms? Thanks again

 

[soundgy45 10+ year member]

I'd try to stick with either 2 or 4 ohms. 1 ohm if ur comfortable with wiring diagrams.