Why does my subs/amp turn off?

 

New member
Username: Mjjava

Bellevue, NE USA

Post Number: 1
Registered: May-05
Could someone please help me? I have a 600 watt KAC-729s amp with 2 12 450W IMPP subs and when I really crank it up the amp turn off, but then comes back on after a few secs, but I have to turn down the volume to stop the amp from turning on or off. The subs are wired with both pos connected to the left pos on the amp, and both negs on the sub are connected to the right neg on the amp. Please help. Everything sounds great but when I crank it up and it sounds great, it only last for a few intermittent secons. Thanks for all your help.
 

Bronze Member
Username: Mixneffect

Orangevale, Ca. USA

Post Number: 82
Registered: Apr-05
Your amp is clipping.

It then goes in safe mode and shutts off so you will not blow it up.

You amp probably cannot handle the load you are giving it. reduce the load and keep the volume down.
 

Silver Member
Username: Lbeckner

Tulsa, Ok Usa

Post Number: 392
Registered: Oct-04
Yeah. Or your not getting enuf power to the amp. Check the ground connections and the battery connections. Most likely you have to big of a load on the amplifier. What ohms are you voice coils?
 

New member
Username: Mjjava

Bellevue, NE USA

Post Number: 2
Registered: May-05
The subs are 4 ohms and the amp is 2 ohms stable. When I had then running parallel it would hit like no other, and then the amp would turn off. Also, there is no distortion in the speakers when it turn off. I thought clipping was that. Today I hooked up the subs directly to each channel instead of being parallel, and not it doesn't turn off. But it doesn't drop as hard. Thanks for all your help.
 

Bronze Member
Username: Mixneffect

Orangevale, Ca. USA

Post Number: 83
Registered: Apr-05
yeah, its safe to say that your amp is definetly not 2 ohm stable.

Engineers are lazy and they dont actually test stuff out. They just round off and/or guestimate.

This is what we get nowadays, people that dont give 100% anymore. I have seen alot of crap that said this and that, and when it came down to it, it didnt even do half of what it claimed.

Sorry to hear you got taken, but it happens to all of us man.
 

Bronze Member
Username: Mixneffect

Orangevale, Ca. USA

Post Number: 84
Registered: Apr-05
Clipping is hard to define because;

It started out when audio stuff was legit (70's & 80's). Back then it was either regular store stuff or extremely high end. The regular stuff was very cheap and weak. The extremely high end was EXTREMELY HIGH END. So when an amp was overstressed it was said to be clipping because it started to disrupt for a second or so, but it kept going as soon as it caught up, and if you kept the amp at that level and load it would eventually fry. Well engineers decided they would protect their equipment with extra circuitry (such as the one your amp has).

Now, dont get me wrong. There are audio equipment out there that can produce stable symmetrical power from off to peak, without any mechanical or audible errors. These extreme high end equipment also have a hefty price.

Just because there is no audible distortion doesn't mean that your amp is not clipping.
 

New member
Username: Mjjava

Bellevue, NE USA

Post Number: 3
Registered: May-05
So, basically I want to get my car stero to really thump, but the equipment that I have now makes it to where I cannot play it for the reason that I bought it. So, if I do want a system, that does what I want, what would be the best solution?
 

Gold Member
Username: Fishy

Tamarac Ft.Laud, FL USA

Post Number: 1231
Registered: Sep-04
Your amp may be 2 ohms stable stereo, but very few 2 channel amps are 2 ohms stable bridged.

Rewire you subs for an 8 ohm mono load or run them in stereo. I'd suggest the latter as wiring subs in series is often discouraged.

http://www.jlaudio.com/tutorials/wiring/index.html

For a future upgrade your best bet would be to find a 600-1000w, 2 ohm stable monoblock, although a new pair of subs(8 ohm, dual 4 ohm voice coils) or a single "supersub"(4 ohm, dual 2 ohm, dual 8 ohm voice coils) is also an option.

Unless you use only one sub you're limited to about 300 watts output with what you have.

-Fishy
 

New member
Username: Mjjava

Bellevue, NE USA

Post Number: 4
Registered: May-05
Thanks for all the info. I went and looked at the link above and it shows that I had mine running like the diagram of 2 SVC drivers with voice coils in parallel. Is that right. Because when I have it like that is when it turns off. Now I have one channel(left) going soley to the left driver, and the right channel going directly to the right driver. I'm a little confused. Sorry for my ignorance on this issue.
 

Anonymous
 
could be ur ground wire run with bigger wire i had a amp doing that when i first got into the loud systems and i was run 8ga. and needed to be running 4ga. wire and the amp stop cuttin off at high vol.
 

Gold Member
Username: Fishy

Tamarac Ft.Laud, FL USA

Post Number: 1242
Registered: Sep-04
Now I have one channel(left) going soley to the left driver, and the right channel going directly to the right driver.

Thats the way I'd recommend hooking them up. If this is your amp

http://shop.store.yahoo.com/discave/kac728s.html

then you'll be getting 100w rms to each sub which isn't a whole lot but unfortunately thats what you're limited to. Thats really only a 300 watt amp. I'm not exactly sure whether the 450 watt rating for those Pioneers is RMS or MAX so I cant really recommend a specific amp to replace the Kenwood. If you could provide the exact model number for those subs that would help.

-Fishy
 

New member
Username: Mjjava

Bellevue, NE USA

Post Number: 5
Registered: May-05
This is the info I found on my subs:

450 WATTS max, 20 WATT NOMINAL POWER, IMPEDANCE 4 OHMS, IMPP Composite Cone Woofer, Dual-Layer Urethane Surround, High-Energy Strontium Magnet, 4-Layer, Long Voice Coil, Aluminum Voice Coil Bobbin, Conex Damper with Damper Ring, Projected Pole Yoke with Vented Pole, Bumped Backplate, Molded Gasket
 

Gold Member
Username: Fishy

Tamarac Ft.Laud, FL USA

Post Number: 1257
Registered: Sep-04
450 watts max? Eeek, I hate max ratings. 450 watts max could mean anything from 100 to 250 watts rms.

I'd just stick with what you have(Kenwood in stereo, 100x2) and upgrade amp AND subs when your ready and use the Kenwood to power your mids and highs.

-Fishy
 

AudioFreq
Unregistered guest
guessing Fishy??
100-250 watts?? in whos' book? lol
Ahhh I see 'Gold status' is about the # of posts you have made, only. sorry

450 watts peak - 318.15 watts RMS no matter how you slice it.

http://www.allexperts.com/displayexpert.asp?Expert=63518
 

Silver Member
Username: Southernrebel

Monroe, Louisiana USA

Post Number: 779
Registered: Mar-04
AudioFreq,

Yes, i agree that a TRUE max power rating of 450w would yeild 318.15wrms (.707 of the max rating). But lower end car audio manufacturers pull "max ratings" out of their @$$.

Amps made by such companies as BOSS will claim "1500watts max" which SHOULD be ~1060.5wrms, but in actuality their amps will only produce ~500wrms. Such amps will also have low build quality and high failure rates.
 

Silver Member
Username: Iamduff_87

Michigan America!

Post Number: 338
Registered: May-04
yes many many low end companies, like BOSS stated by marshall, overrate their MAX rating by sometimes up to 3x or 4x the RMS. even Rockford has been doing this. they rate their amps at about 3x thier RMS not 1.3x or w/e .707 would come out to be.
 

AudioFreq
Unregistered guest
Obviously :D
But to me, it sounds like they are simply telling the real output stage rating accurately now [rather than what it is biased to use of that total array].
Even though, it would not hurt to get a speaker that handles 325, imho. heh

Good reason to not buy stuff like that, but it is a buzzword deal out there, these days. :S

ZED made amps NEVER hurt in the long run.
 

AudioFreq
Unregistered guest
I might also add this one (since the obvious/immediate fix seemed to elude so many here , somehow).

regardless of the volume setting, reduce the amp level..
 

New member
Username: Mjjava

Bellevue, NE USA

Post Number: 6
Registered: May-05
Thanks for all the information again. So, since I am running those Pioneer subs what size amp would give me the best sound? I'm not trying to be too cheap but I don't want too high end either. Also, is ported better than sealed?
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