# Volume on amp- problems!



## faithandfame (Jan 25, 2003)

My subs are perfectly fine. But, in the past week or so my amp volume starts to just go up and down at competely random times. Is there something wrong with my amp?


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## SuperSentra4203 (Dec 17, 2002)

Difinately sounds like it. I'd go to a local audio shop and have it checked out. First off, i'd check the input cables. The ends may be bad or loose.


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## faithandfame (Jan 25, 2003)

I check all of my wiring, and every wire is connected properly. How do I know if I have a bad amp?


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## ImportCarTuner (Jun 9, 2002)

faithandfame said:


> *How do I know if I have a bad amp? *


 Take it to your local audio shop and ask them to bench-test the amp.


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## faithandfame (Jan 25, 2003)

What does that test do?


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## faithandfame (Jan 25, 2003)

Would my subs not work at all if my amp was blown?


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## sno (Oct 4, 2002)

it may not be a completely blown amp, maybe just one of the capacitors in the amp went, which could be causing a power loss to your subs.


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## faithandfame (Jan 25, 2003)

I have heard that you can get a amp redone, is it worth doing that? Or would it be better to get a new amp? All that I have right now is the MTX Audio Thunder 4250D which is a 350-watt mono amp. Nothing real great- but I am looking into getting a 1000-watt Kenwood amp.


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## SuperSentra4203 (Dec 17, 2002)

If you want to get a 1000W Kenwood amp, spend the cash and get the Class D eXcelon amp. As for the fried amp. Probably transistors going out. They build up too much heat, and it will cut the amps output.


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## ImportCarTuner (Jun 9, 2002)

faithandfame said:


> *What does that test do? *


 Basically tests to see if there is proper current flowing into the left and right channels of the amp.


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## SuperSentra4203 (Dec 17, 2002)

And power consumption and output.


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## SentraStyleEMW (Aug 15, 2002)

faithandfame said:


> *I have heard that you can get a amp redone, is it worth doing that? Or would it be better to get a new amp? All that I have right now is the MTX Audio Thunder 4250D which is a 350-watt mono amp. Nothing real great- but I am looking into getting a 1000-watt Kenwood amp. *


Actually...your 350 watt MTX amp will probably outperform the 1000 watt kenwood amp. That 1000 watt rating on the Kenwood is Peak power which it will never deliver unless being struck by lightning (LOL). The RMS rating on that 1000 watt Kenwood amp is closer to 350 x 1 at 4 Ohms. Stick with the MTX...it is more powerfull and pulls less current than the Kenwood.


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## SuperSentra4203 (Dec 17, 2002)

That's why I gave her advice to get the Kenwood eXcelon Class D amp. Runs about $650. over 1200 watts peak at 1 ohm. Runs somewhere around 500 watts RMS.
As for the 1000W Kenwood. Remember, that amp is more than capable of running 2 ohm stable. That is where you can get the near 1000W peak output.


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## SentraStyleEMW (Aug 15, 2002)

SuperSentra4203 said:


> *That's why I gave her advice to get the Kenwood eXcelon Class D amp. Runs about $650. over 1200 watts peak at 1 ohm. Runs somewhere around 500 watts RMS.
> As for the 1000W Kenwood. Remember, that amp is more than capable of running 2 ohm stable. That is where you can get the near 1000W peak output. *


Yeah...2 Ohm stereo. You try running that amp at 2 Ohms mono and you'll have yourself a nice little paper weight.


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## SuperSentra4203 (Dec 17, 2002)

Not quite. My friend had one. Use a good cooling fan, and don't run it hard as hell all the time, it'll hold up. IMO, it's a great amp for it's price, but i'll never waste my money on an amp unless it's a Class D and is 1 ohn mono stable.
Also, try an Infinity Kappa 102A. Had one, excellant amp, but good luck finding one.


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## faithandfame (Jan 25, 2003)

I was trying to stay with an all Kenwood theme for my car... I was looking at getting the Kenwood KAC-849, 4 channel, 600 watt amp, the specs on it are:
RMS: 50 X 4
Peak Power Output: 100 X 4
Power at 2 ohms: 75 X 4
Bridged Power: 150 X 2

The MTX 4250D that I am currently running has the following specs:
RMS: 125 X 1
Peak Power Output: 200 X 1
Power at 2 ohms: 250 X 1

I currently have the MTX amp hooked up to two 12' MTX T4124A and the specs on those are:
RMS: 50-200
Peak Power Output: 400

I am looking into getting two 12' Kenwood KFC-XW1225dB and the specs on those are:
RMS: 25-600
Peak Power Output: 1200

So going from the MTX setup to the Kenwood setup. Good idea or not?


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## ImportCarTuner (Jun 9, 2002)

I say go with the Kenwood set-up. But get the KAC-929 amp instead of getting the KAC-849 amp. If you're going to be using the amp to power your subs, then you're better off buying the two channel amp (KAC-929) rather than the four channel amp (KAC-849). Plus they're both about the same price.


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## SuperSentra4203 (Dec 17, 2002)

IMO, go with Kenwood. My HU was awsome, and my cheap ass subs hit harder and clearer than others. If you have the cash, I can't encourage you enough to go with the eXcelon Class D mono amp, since you'll be running eXcelon seried subs anyway.


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## ccroaddog (Jun 20, 2002)

if u wanna go with the kenwood set up it would be nice and yes excelon is a lot better. the kac929 is around 400 watts rms at 4 ohm and the 4250d is at least 325 at 2 ohms at 12 volts. mtx is know that if you push 14 volts plus u can get at max 30% more ( i have proof). I dont know if u bought the amp brand new but mtx comes with a 3 year warrnety so dont get a new one just send yours out


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## faithandfame (Jan 25, 2003)

I had my entire system installed at Circuit City, yeah, don't kill me for doing that but I have no idea on how to install all of that stuff. Anyways, everytime I start to go up there to see what they can do about my amp, my amp is competely fine. The volume doesn't change rapidly at all. It's so strange... So, I have no clue if it's the wiring, amp, subs, no clue... Also, what do I have to do to get 30% more power to my MTX's?


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## HuMMerMan (Jan 22, 2003)

importcartuner said:


> * But get the KAC-929 amp instead of getting the KAC-849 amp. . *


I can personally vouch for the KAC-929. Ive had mine for just about a year, no problems at all. Benched at 451wrms X1 @ 4ohms @ 14.4v - Book says 460wrms. So a tiny bit overrated. The cooling fan is a bit noisy, but you wont hear it unless the system is on and nothing is playing. Otherwise its great, adjustible x-over, solid as he**, mine has taken alot of punishment in my b12.

Been running at 2ohms for almost 4months, without any problems yet either. Great for 1 or 2 subs. Not a powerhouse by any means, not as nice as the excelon series, and that 1000w sticker on the front annoys me, but its a well rounded 2ch amp.


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## ccroaddog (Jun 20, 2002)

> _... Also, what do I have to do to get 30% more power to my MTX's? [/B]_


_ 

run 4 gauge wire to a cap and there u go. 14.4 and 30% more power.... my 81000d is rated at 1000 watts rms at 2 ohm but at 14.4 it was tested and signed by mtx at 1299 rms at 2 ohm so thats almost 30 %_


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## faithandfame (Jan 25, 2003)

Really? Damn... sounds good. Any recommendations on what kind of cap to get?


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## SuperSentra4203 (Dec 17, 2002)

Monster Audio. I use their products for all my wiring. Won't use anything else besides Streetwires for my power wires.


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## ccroaddog (Jun 20, 2002)

SuperSentra4203 said:


> *Monster Audio. I use their products for all my wiring. Won't use anything else besides Streetwires for my power wires. *


if u plan on doing anything at circuit city u better hurry cause they are dropping Monster cable and picking up metra's Tsumi stuff. it may happen within a monthor two


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## SuperSentra4203 (Dec 17, 2002)

Why are they dropping Monster? Looks like i'll be ordering my wires for now on.


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## omega (Jun 27, 2002)

No No People, don't just order the wires, Best Buy carries Monster cables , oh and that monster cap from them with the digital top and the 24 volt surge will run you 200 bucks.


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## ccroaddog (Jun 20, 2002)

i could swear that best buy carries rockford or "lightning audio" wires


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## omega (Jun 27, 2002)

well as the supervisor or the car audio department at Best Buy I can tell you that we carry Rockford Fosgate power and RCAs as well as Monster Cable RCAs, and one of there 4 AWG amp kits and their one farad cap.


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## ccroaddog (Jun 20, 2002)

as a circuit city roadshop sales person and installer we dropped dynomat and monster car audio to pick up Metra'a tsunami havent seen it yet but i saw a display at Hot import nights and the stuff looks ok.....i dont think the quality would be as the 401 monster rca's but hell people wany cheap shit


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## omega (Jun 27, 2002)

your telling me, I can't tell you how many people will try to save a buck and go with cheap quality jensen RCAs and then wonder why they have distortion and blown subs. I guess these are the same guys that go to home depot for their power wire


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## SuperSentra4203 (Dec 17, 2002)

Our Best Buy doens't carry much Monster Audio at all, mainly Fosgate. As for cheap RCA's, I invested in a set of Monster which ran me about $75 and had no feedback or distortion with my subs, even though I ran it right next to the power and ground cables.


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## ccroaddog (Jun 20, 2002)

thats why i got 401 4ch set and 401 2ch set (m series cost too much). It was funny one guy came in thinking his rca's where picking up rpm wine so he bought some mirco monster rca's... and the problem got a lot worse ....turns out the deck was sending out a bad signal, he has really suprised how much better the rca's where...


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