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View Full Version : How many watts is my SR getting?



Jak3
06-20-2009, 10:09 PM
Ya i just got a new 12"dvc SR and i got it hooked up to my previous 6x9 amp (Hifonics TXi4008) until my new amp arives, im wondering how many watts im actually giving this sub because the stats for the amp are:

2- channel
# RMS Power Rating:
* 4 ohms: 100 watts x 2 chan.
* 2 ohms: 200 watts x 2 chan.
* Bridged, 4 ohms: 400 watts x 1 chan.

I currently have the sub wired to 2 ohms and i have it bridge on the amp.. it cant work at 4 ohms (Bridged, 4 ohms: 400 watts x 1 chan) right since its wired at 2 ohms? so am i only putting 200 watts in the sub or what?

http://www.sonicelectronix.com/item_11201_Hifonics+TXi+4008.html

http://www.sonicelectronix.com/item_7113_Polk+Audio+SR124-DVC.html

exalted512
06-20-2009, 10:53 PM
If you have the sub bridged at 2 ohms, I'm surprised that amp hasnt shut off on you yet. Its not designed for that.
-Cody

Jak3
06-20-2009, 10:56 PM
so do i just wire the sub regular to the amp, one channel positive/negative? leave the second channel open?>

Ii doesnt seem to effect anything soundwise hooking it up this way, the amp is working fine, has never quit working... am i risking damage?

Toxis
06-20-2009, 11:49 PM
You need to get a different amp. You risk destroying the amp and eventually the sub.

Jak3
06-21-2009, 12:00 AM
i dont see how that would destroy anything please explain?

nguyendot
06-21-2009, 01:09 AM
You are running a lower impedance (higher load) than the amp can safely handle/is designed for.

You will overheat it and possibly destroy the amp from overloading it, as well as the sub as it is connected to it.

Your best bet is to wire each voice coil to each channel of the amp and run it at 200w rms. You should not bridge the amp at 2 ohms. Your other option is to get a 2nd subwoofer and wire it in series with this one the same way to get 4 ohms and then you can extract the full power from the amp.

Jak3
06-21-2009, 11:51 AM
i dont see anything in the stats about 8 ohms stable?

if i wire the sub to 8 ohms and bridge it wont that still be the wrong load?

http://www.the12volt.com/12voltimages/1_4ohm_dvc_8ohm.gif

arun1963
06-21-2009, 12:20 PM
Your amp has to be stable at the impedence your speaker offers.

The SR 124dvc has two voice coils. If you hook these coils in parallel it would present a 2 ohm load to your amp. At 2 ohms your amp puts out 2x200watts as per the birth sheet. Frankly I dont know how accurate this is. Lets assume for a min that this is accurate.

Now if you were to bridge the 2 channels how much do you think you're getting? 200+200? Wrong. Typically when u bridge channels you get combined output x amps efficiency. Typically class ab amps exhibit 60-75% efficiency. I would rate your amp close to the 60 mark. Hence the sr's would be seeing 400x0.6=240 watts rms. Way, way to low for the SR's.

Cody is right you would clip and blow the amp running it this way.....get a good 600watt rms @ 2 ohm mono amp. ;)

nguyendot
06-21-2009, 12:25 PM
No one said to bridge 8 ohms. Also, if an amp is stable at a certain impedance, it will definitely be stable at a higher one because it is easier on the amp.

I stated to run it one voice coil to one channel of the amp, which will be 4 ohms each channel which it is rated to do.

exalted512
06-21-2009, 02:24 PM
Even easier than running one coil to each channel is just taking what you have now, and instead of bridging it, just put it on one channel. You'll get 200 watts to the sub that way. Which for that amp, I would bet itd be closer to 125 watts.
-Cody

Jak3
06-21-2009, 02:36 PM
No one said to bridge 8 ohms. Also, if an amp is stable at a certain impedance, it will definitely be stable at a higher one because it is easier on the amp.

I stated to run it one voice coil to one channel of the amp, which will be 4 ohms each channel which it is rated to do.

i dont get it lol

Jak3
06-21-2009, 02:39 PM
ya i guess ill wait till i get a better amp, crutchfields specs on those subs say 100-700 watts rms so i figured since im gonna be breakin em in for a while anyway 100-200 watts rms would be safe, since i gotta pull the sub out of the box to re wire it to 8 ohms i think im just gonna leave it as is and just go without the sub for a few weeks.

Screwing that sub in is nerve reckoning lol

nguyendot
06-21-2009, 03:15 PM
It sounds like your box only has one set of terminals so you have to bridge the sub to get it to work. Just leave it at 2 ohms and attach it to only one channel of your amp like exalted512 said. It'll give you 200wrms and run the sub fine. Don't bridge the amp at 2 ohms or you'll kill it. 8 ohms will give you almost no power.

Jak3
06-22-2009, 04:11 PM
ya i was thinking about this.. i guess ill just do that for now, awesome, great, gnarly.

Jak3
06-30-2009, 10:02 PM
Just wanna let everyone know i got a kicker 750.1 amp powering my SR now, all i can say is wow.

This one SR is twice as powerful as 2 boston acoustic G5s i had a couple months ago.

royalty
07-01-2009, 09:18 PM
Yeah those SRs are beasts....what is the wattage on your kicker?

Jak3
07-08-2009, 04:02 PM
750 watts but im pretty sure the amp puts out around 850-900rms, got it used for 130 bucks, almost mint condition.
Dont know what the birthsheet states.