headunit shuts off when loud

[stilllearning]

Hey, I just installed a new headunit in my car. Everything works well, but when I turn it up loud it starts to cut out, then if I turn it up louder it will shut off and turn back on. I've seen that before when someone had to much draw on the switched 12 wire, but wondering what it might be? any ideas of what to do would be appreciated.
Thanks

[McCoolidge]

Where is the headunit getting power from?

[stilllearning]

Red to a violet/white wire and yellow to a red/green wire. both are fused with 7.5a fuses, but the headunit had an inline 20a fuse on the yellow wire.

[KenC]

my guess is you're clipping the amp and it's going into "protection" mode.

[NC325iC]

are you powering speakers directly?

if so could it be you have wrong resistance and are overheating you HU with volume up

[stilllearning]

Yeah, I bypassed the amp and am powering the speakers directly from the hu. Not quite sure what you mean by not enough resistance. Why would that effect it like that? What would I do to fix this?

[stilllearning]

Also figured Id try to add more that I noticed. So when I turn it on, it can be right away if I turn it up it will start to cut out a little. If I turn it up more it shuts off then turns right back on. I also noticed that have it about normal the lights on the hu kind of dim to the music when there are big hits and it cuts out and shuts off to the same beat. It really seems like the hu is drawing to much power. When I wired it up I use the two brown case ground wires for my ground. Is this not a very good ground?

[netcsk]

What speakers are you running?

[MikeE30325i]

It sounds like you are overpowering the deck and it automatically shuts it off to save it from being damages. amps have the same feature. good luck with finding the problem

[NC325iC]

what i meant by resistance:

all speakers have a given resistance (given in ohms, the symbol for ohms is a capital omega) usually speakers are like 2 or 4 ohms i believe
headunits and amps give power ratings in the number of watts they can put out at a given resistance. for example one of my amps can do like 360watts at 2 ohms (not fully sure on this but it doesnt matter), if you have a resistance that is not in the range of the headunit/amps capability to power you will start to over heat

for instance when i wired up my new sub about a year ago i wired the two voice coils in parallel (wired positive of the amp to one side of one coil, neg of that coil to pos of the next coil, neg of second coil to neg of amp) this setup put me at 1ohm and my amp can only handle 2 or 4 ohms. at 1 ohm the amp was flowing so much power out that it couldnt keep cool enough so the temp switch shut it off. to fix this i wired the sub in series, this made it a 4ohm setup which my amp handles easily, infact i have the gain all the way up with no distortion (which to me says i need a more powerful amp)

hope that helped some, and i hope it was all accurate

[stilllearning]

What speakers are you running?

They are some kenwood speakers that were in it when I bought it. The front was wired and I just cut into that, the rear was stock wiring, so I cut the two wires to the sub and ran new wires from the hu straight to the sub. the speakers sound fine, but could I have missed something that should have been wired in? also tried and if I turn the bass way down I can turn it louder. BTW by me saying it starts turning off when its loud, Loud is not very loud at all.

[smonkbmw]

LMFAO!!!!!!!!!! please tell me youre not running a subwoofer off the deck!!!

[stilllearning]

LMFAO!!!!!!!!!! please tell me youre not running a subwoofer off the deck!!!

No, the factory component setup. with sub and tweeter

[MikeE30325i]

LMFAO!!!!!!!!!! please tell me youre not running a subwoofer off the deck!!!

I am running a powered sub off of my deck ;)

hits like a bitch.

[smonkbmw]

ah ok, the stock component set then.

well a powered sub is obviously quite a bit different then a standard non powered sub.

i wonder if the stock speakers are a different ohm rating that is over heating the head unit.

im waiting for StereoInstaller to offer his input, to get to the bottom of all this.