Bridged mode keeps cutting off...no fuses blown

[31337hxr 10+ year member]

hello, guys i just tried to bridged my subs but it seems as though it gets cut off if i turned it too loud......it appears that no fuses are blown but it gets cut off after i put the volume about half way up.

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[MikeofTulsa Moderator]

might try turning the gain down a little, go to a bigger gauge wire for your power and ground, a little more information would be helpful....like what kind of amp, and all the specs....good luck

 

[31337hxr 10+ year member]

I found out why it cuts off! The "over-current" light keeps coming on if the volume is increased to "20/40" ...if it's 15/40 its fine.

it's being bridged but the over-current light comes on only when its bridged! anyone know how to solve this problem??!!?

thanks!

 

[MikeofTulsa Moderator]

what size power and ground wire are you using and how many watts is your amp putting out??? and how is everything wired....sounds like either your amp is running at to low of an load or your wire's are not big enough to supply the power that your amp is wanting.....good luck

 

[audiocraze 10+ year member]

maybe your amp cant take the power

 

[SuckMikeHawk23 10+ year member]

i think what goddyd said was right, my first guess would be that the ohms of ur subs are wired to where they are too low for the amp. wire it differently, try to wire it to 4 ohms and if it doesnt work, then it might be the power wire problem.

 

[31337hxr 10+ year member]

The amplifier is a Sony XM-1502 760watt amplifier and the two subwoofers are the Infinity kappe perfect 12.1 Single voice coil 4-ohm subwoofer.

The subs are BRIDGED. Positive of both speakers are connected to the positive terminal of the R side of the amp, and the negatives of both speakers are connected to the NEGATIVE on the Left channel of the amp.

thus, when the volume increases, the over-current light comes on.

this amp is suppose to do the following specs:

760W max power (380W x2 @2O )

150W x2 into 4O , 20-20kHz, at 0.04% THD

190W x2 into 2O , 20-20kHz, at 0.01% THD

380W x1 into 4O , 20-20kHz, at 0.01% THD

So actually, i'm trying to push 380 watts into both subs simultaneously! The types of amp wiring cable i'm using are:

1 RCA Interconnect high definition audio cable shielded w/Built in remote wire 25ft Right Angle

2 Red Power Wire 20ft 4Gauge

3 Blue/Purple Ground Wire 4ft 4Gauge

4 OFC Speaker Cable 35ft 12Gauge

5 Blue remote turn on wire 20ft 16Gauge

6 Water Resistant Inline Fuse Holder AGU type 4Gauge

7 Agu Fuse 80Amp Gold plated

8 Gold ring terminal 1 4Gauge

9 Split loom for cable protection and organization 6ft 4Guage

Black Color

also using 40 amp fuse for battery and 40 amp fuse for amplifier.

my head unit is a pioneer deh-p4400 but i guess that doesn't matter. the subs and amp works fine in 2 channel mode but it's less power.

Hope this help! thanks

 

[F16Fxer4real 10+ year member]

Goddy was right, right now you're amp is seeing a 1 ohm load which it doesn't like. You have two 4 ohm speakers "bridged" giving the amp a 2 ohm load but the amp itself is bridged yielding a 1 ohm load. I don't believe that Sony can handle that in bridged mode. Your best bet would be to run the speakers in series. ( amp positive to one speaker positive, that speaker negative to the other speaker positive, and finally that speaker negative to the bridged amp negative) Then it will see a 4 ohm load bridged and run just fine.

 

[31337hxr 10+ year member]

So if I bridge it in series like you said, then it'll still become 4-ohm load but bridged. Thus it will still give me the 380-watts I need in both subwoofers and thus will be more power than using 1 channel per amp which is 190watts?

thanks!

 

[31337hxr 10+ year member]

so in series mode, do i get more power still ? or will 1 sub be weaker since voltage is decreased? but doesn't current stay the same?

but voltage decreases, so would the 2nd sub get less power?

thanks!

 

[audiolife 5,000+ posts]

speakers are reactive meaning they change impedence depending what they are playing (from .1 of ohms to 100s of ohms) your amp is going into thermal shut down or is the "offset" light popping on? either way its causeing it to shut down if its thermal get a fan and change it to series .......................or get different amp like a jbl 1200.1 or 600.1 wont kill your bank either

 

[stones 10+ year member]

OK , the problem you have here is a piece of shiitte amp, SONY claims that the 760 will handle a 2ohm mono load, but the truth is that this amp is extremelly sensitive to reactive loads, this amp has caused thousands of headaches for thousands of people because of its "over current" curcuitry, I personally reccomend that you use that amp to power your front speakers and purchase SONY"S 1000watt class D amp that performs flawlessly under any condition (it will do almost 900 watts rms into a 2ohm mono load). The bottom line is that the 760 will not handle "sub" dutie worth a crap. The amp you have is not junk, its just not suited to powering subwoofers that well.

 

[audiolife 5,000+ posts]

it will go below 2 ohms just not nominally and if on a beefffffy sub that gets down n acts like a heavy reactant it suffers...thats why we put those on 1 sub or a pair of punch z 8 ohmers

 

[31337hxr 10+ year member]

if i series-bridged it....accordiing to this diagram here:

WOuld each sub get exactly the 380watts bridged mode or will the subs evenly divide that power and each sub gets 190watts ?

thanks!

 

[audiolife 5,000+ posts]

to put it simply its the only way your amp will run your subs without causeing it to destroy itself.... to make it work to its peak you could get a transformer to set the impedence.....but by the time you did that you could have gotten a better amp. alot better