Amp Help/Suggestions

I just put subs in my truck, though at about mid volume on a harder hitting bass song the amp cuts out. I have a Kenwood KAC 8105D 1000 Watts Class D Mono Amplifier running (2) Alpine Type R 1043's. The two subs are currently wired at 2ohms. Any suggestions why the amps cutting out? Is it just too small of an amp for these subs, or should I try running them at 4 ohms rather than 2 ohms? Any suggestions will be appreciated. Anyone else running these subs and if so what amp are you using. Thanks

 

The problem is, you are trying to run a mono chan amp with 2 subs...

 

does it still cut out with the gain turned down? is the amp hot?

 

From this I assume you mean the two voice coils are wired in parallel, producing a 2-Ohm load for each sub.

Then there are two ways for the subs to be wired up: 1) in series so amp sees a 4-Ohm load, or 2) in parallel so amp sees a 1-Ohm load.

If you are wired to the amp as in #2 above, then you are shutting down due to overload protection. The amp is designed to handle a 4- or 2-Ohm load, but not the 1-Ohm load you would experience with choice #2.

 

He can also fun a series on the speakers if they are DVC and a parallel from the speakers to the amp resulting in a 2 ohm load to the amp.

 

No, you cant. Series on the subs + Parallel to amp = 4ohm final load. A Dual 4 sub can only be wired to 2 or 8 ohm. 2 of these can only be wired to 1 or 4 ohm (or 16, but not realistic). No way to get a 2 ohm load from a pair of D4 subs.

http://www.the12volt.com/caraudio/woofer_configurations.asp?Q=2&I=42#results

 

Tuchè, I was thinking about my old D2 IDMAX set-up.

 

I'm starting to wonder if I wired it wrong where I'm getting 1ohm at the amp. Id think the amp is big enough. It cuts out roughly half volume. Can anyone post a image of how it should be wired for best results. And yes there 4ohm dual voice coil subs.

 

One place for an ilustration is at the12volt.com

http://www.the12volt.com/caraudio/woofer_configurations.asp?Q=2&I=42

you need to be wired as 4-Ohms given the amp/subs combo

for some reason when I checked back the link fails. type in "dual voice coil two wiring" wiring in google and select the12volt.com hyperlink.

JL also has some drawings

http://mobile.jlaudio.com/support_pages.php?page_id=161

 

honestly, i wouldnt have mixed and matched companies. i would get an alpine amp to match the subs, much better and more reliable because they are techniqually made for each other

 

Nope. Your sub does not have any idea what company in china made the parts that are soldered to the board inside the metal case.

On the other side of that, your amp has no idea what build house wound the coil, pressed out the cone, or molded the surround.

Brands are unimportant in any situation, beyond getting quality gear the puts out the power/functions as an air piston properly.

I suspect lbridges hit it on the head, and the subs are wired to 1 ohm, and the amp is going into protect. Wire those suckers to 4 ohm and you should be golden

 

Fail. He can run 1, 2 , 3 or more subs from a single amp. Number of subs is 100% irrelevant.

 

Fail. They are in NO WAY techincally made for one another. THere is NO truth to this statement AT ALL.


As stated above the guy is running a 1 Ohm load. Thats the problem. He needs to run a 4 Ohm load and cut his power by a ton or get 2 Ohm dual voice coil subs and run em at 2 Ohms total.

YOU CANT RUN A 2 OHM STABLE AMP AT 1 OHM.

 

Thought this bore further explanation since it appears:

A. The original poster may have had dual 4 Ohm subs, wired to 2 Ohms each, and then run at 1 Ohm together, resulting in his amp shutting down by going into protection.

B. Someone I corrected saw fit to IM me, laugh at me, then try to explain why I am a Moron and would continue to spread misinformation.

With that I will go through the IM and my response...

OK, I will start slow. Lets start by defining bridging. In simplest terms bridging is done on and can only be done on a two channel amp. You cant bridge a mono amp. (well you could but it would take a second MONO amp... lets not go there) It is impossible by definition with a single MONO amp. Discussion of bridging a mono amp is like talking about blinker fluid... it is not reality and does not exist. Bridging is when you use a + terminal from one channel of a 2 channel amp and the - terminal from another channel of a 2 CHANNEL AMP. You are running the power of two seperate amps in opposite phase. No amount of configuring subs constitutes BRIDGING of an amp. Bridging an amp is not altering the impedance load on an amp. It strictly refferes to combining the power of TWO amplifier channels and ONLY this. This seems to be what you are implying (bridgining an be done via subwoofer wiring) which is just not reality or true. So while I cant "learn to read" as a "moron", you would do well to learn A. What bridging is. B. Not to correct people who are trying to educate you. C. Understand that wiring subs in parallel or series or any combination there of does NOT constitute BRIDGING an amp.

Now that said... You can run an infinite number of speakers or voice coils on a mono amp... for example, lets say its a 4 or 2 Ohm stable amp. You can run subs with dual voice coils... lets say 4 Ohms. Wire those to a 2 Ohm load then run 2 subs, thus wired into a 4 Ohm load. Then wire another two, identically wired subs, into a total 2 Ohm load. None of this has anything to do with BRIDGING... which cant be done since we only have one channel to work with... now we have a 2 Ohm load with 4 dual 4 Ohm voice coil subs and this will work perfectly fine. Nothing is or can be bridged. I hope this helps.

So... the original poster either ran 2 2 Ohm subs into 1 Ohm, OR he ran 2 Dual 4 Ohm Subs into a 1 Ohm load.

He cannot run 2 subs that are at 2 Ohms, into a 4 Ohm load as he describes. THis implies he probably mistakenly ran a 1 Ohm load.

 

I can tell you know the methodology, but I think you have a typo in the above (or I need reading lessons)

 

you guys are dumb if you honestly think that companies dont make their own amps for their own subs. thats completely ignorant in every way. i know for a fact that JL and Alpine make their amps to run with their subs. that in mind, i had a JL 12 inch w7 with an alpine amp and it sounded good because the amp is very solid, but they fact that it was an alpine made the sound quality worse. i then got a JL amp for it and it sounded much better and hit much cleaner. the companies like kenwood and those lower brands say they are running a certain amount of wattage when really, they are actually pushing out a much lower amount on average. nicer companies like JL and alpine are true to their word and make their amps and subs for quality, and ultimately for their own products. so like i said, if you have an alpine sub, get an alpine amp for better quality. they arent techniqually made for each other, but the same technology goes into the same ones so they work best with each other. you have a nice sub and i think you could definately upgrade the amp, not saying its bad, but i think you would be better off with an alpine amp at least, if not a JL

 

answered earlier...

I will allow that companies *may* make an amp designed around their subs - using your example, lets take JL Audio. They rate their W3 subs at 300w(optimum), so using a 250/1 is perfect for a single, or a 500/1 for a pair. A W6 is rated for around 400w (optimum) so you run a single on a 500/1 or a pair on a 1000/1. These are for matching *power ratings* but that is all.

I know you probably heard this stuff from a manager or something at your local audio shop, but it doesnt make it true.

And for the record, while a lot of people consider JL and Alpine to be "high quality" and other things "low quality", there is a lot to be said on the subject online. Do some research, and you will find that many of your "lower" brands put out rated clean power, but marketing and up-sells from shops tell you otherwise.

Your reading assignment for the day -

http://www.diymobileaudio.com/forum...ogma/93755-all-amps-sound-same-watt-watt.html

http://www.diymobileaudio.com/forum...level-matched-amps-head-units-sound-same.html

http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/86892-audiophile-banana.html

 

So are you guys saying that if I have (2) 4ohm DVC subs I can not get them down to 2ohms at the amp? I've viewed the links provided above and it looks like I can only do 4ohms by the time I get to the amp.

http://images.the12volt.com/12voltimages/2_4ohm_dvc_4ohm.gif

 

this is a huge myth.

http://www.diymobileaudio.com/forum...ry-dogma/98693-myth-matching-brands-best.html

and you should always buy your tires from the Toyota dealer, they're always better there.

 

Correct. you have the option of 1, 4, or 16 ohm wiring with 2 4ohm DVC subs.