Probs w/ MTX...time to upgrade?

unrealii

I have an MTX Thunder 5400X 5 channel amplifier. It is almost 3 years old. It had failed 1 month after i installed it in my ford taurus. Last year I sold the taurus and now the mtx is in my maxima. I like the sq from the amp, but it is starting to fall appart. I am pretty sure these have always been bad, I just never needed to use these features when it was in my taurus. First, my cross overs are bad, I get high pitched noise from the high pass filter. Second, my sub woofer pulsates when I inititally turn the amp on or when there is no signal going to the sub channel. It also pulsates when I adjust the gain or if I press the knob side ways. I have a good guys warranty, I dont know if they are going to make me live without a car stereo for a while (ie ship it to the repair center in AZ) or let me use the $250 I spent on the amp towards another amp.

Right now I have the following configuration:
hu: Eclipse cd8454
speakers: polk audio, db6510, db5510, db3000 tweeters, 2 cross overs
sub: image dynamics idq 10

Amp Configuration:
-channels 1 & 2, provide power to the polk crossover which splits the signal to the tweeters (in the front) and 5.5" speakers in rear doors of the car. (using the cross over settings on my hu, I can turn off rear fill whenever I deem it necessary ;-) )
-channels 3 & 4 provide power to the front 6.5" speakers.
-5 - directly to sub

I really doubt good guys will let me use the $250 I spent on the mtx towards another amp, but I just looked on ebay and a 5400x just went for $180. Ofcourse I will sell it after it is repaired. Anywhoo, here are the options I am considering. I am looking at jl because I hear they are very well built and I am not in the mood to be taking my trunk appart.

1-keep the mtx...even if it means going for 2-3 weeks without audio
2-upgrade to jl audio 500/5 to run my entire system
3-upgrade to jl audio e6450 (I am running 6 speakers...why not give em a channel each?) & a mono class d amp (probably the e1400d)

I know two amps are better than 1, but if I go with 2, then I will probably end up spending an extra $100 in wiring and mounting parts to mount these things. Right now I have a 4ga power wire...I am hopeing that should be good enough if I go with either option 2 or 3.

Thanks in advance. I would like to keep costs to a minimum, but not sacrifice durability or quality at the same time. If anyone knows any good authorized retailers online or local to orange county CA, please let me know. Hopefully after this, I quit molesting my car.

Here's a reference post to my problems with my crossovers:
http://clubpolk.polkaudio.com/forum/showthread.php?s=&threadid=23493#post243438

MacLeod

If youre able to afford the JL 500/5, get it. Thats as high end as you can get.

1996blackmax

Hey unrealii,

I replied earlier to your post at Maxima.org . Small world .

If you want to go high end here it is, ARC Audio 5150-XXK:

http://www.arcaudio.com/arc-05/amplifiers/xxk_5150.htm


If you are going to spend some coin go with the good stuff. I plan on using their amps when I get my Armada.

unrealii

Thanks for the replies.

I'll look more into the 500/5. Only thing is that I wish all 4 channels had the same amount of power. Looks like a very nice amp though.

I'll check out that arc amp too. Thanks for the replies on the org. I saw your equipment list and was like, this guy has good taste

unrealii

Just called up a local shop that I have bought stuff from before. If I sell my mtx on ebay, it will probably cost me about $330 to upgrade to that 5 channel arc. Only thing I am worried about is that if my eclipse 8v preouts would be too much for this amp.

1996blackmax

Originally posted by unrealii
Thanks for the replies.

I'll check out that arc amp too. Thanks for the replies on the org. I saw your equipment list and was like, this guy has good taste

Thanks.

QUOTE]Originally posted by unrealii
Just called up a local shop that I have bought stuff from before. If I sell my mtx on ebay, it will probably cost me about $330 to upgrade to that 5 channel arc. Only thing I am worried about is that if my eclipse 8v preouts would be too much for this amp. [/QUOTE]

That will not be a problem. I actually spoke to a guy over at ARC Audio. He said that input voltage rating is from a sine wave and not music, and that it will take a good amount of juice to get to the 2.5V because it is 2.5V RMS. In other words, no problem . I also asked him if I should just leave the gains all the way down or adjust them as I would normally. He said to adjust them as I normally would.

exalted512

thats the first time ive heard that the RMS is at a sin wave and not music...
dont waste your money on JL. The reason the JL has different power for the channels is because its meant to be used as rear fill and you should not power your front speakers with the same amount of power as you do your rears because it will pull your soundstage behind you. Its actually a really good idea, if it wasnt for their outrageous price it would be a very good amp.

you can get much better amps for the same amount of money than JL. Arc is a good brand. Look at www.speedsound.com for USAmps, theres not much better than that
-Cody

MacLeod

OK, right this down cause it probably wont happen again for a while.

Ready? I agree with Cody. :eek:

The JL having less power to the rears is a good idea cause it keeps your soundstage in the front.

I also agree that there is better out there for the $900 that the JL retails for.

This Kicker is one of my favorite 5 channels out. Tons of power and built very well, not to mention a lot cheaper than the JL and the Arc and I bet you wouldnt be able to tell the difference.

This Crossfire is another one I highly recommend. Same thing, tons of clean power and excellent build quality.

exalted512

yea, thats going in the sig in a few days
-Cody

MacLeod

Great! I had a feeling Id not live this down for a while!

unrealii

I would think the less power would mean that you could run a bi amp configuration and run the channels with less power through the tweeters. Either way, that jl is priced too high.

Thanks for the suggestions Cody. I got a really good price on the arc audio amp from my local retailer. Its actually very close in price to those two you have posted.

Damn, I feel special that I created this thread

MacLeod

Originally posted by unrealii
I would think the less power would mean that you could run a bi amp configuration and run the channels with less power through the tweeters.

Nah. Youll want them to be the same power and then you adjust their output thru the seperate gains.

neomagus00

true... more power also means less chance for distortion, which is the real tweeter-killer.

unrealii

Ah...guess I can cross that amp off the list. I am pretty sure I will go with the arc.

MacLeod

Why not check out the Polk C400.4?

Its only a 4 channel but its got a sweet **** crossover. You could skip the passive unit you have now and use the one on the amp. Youll have the ability for a lot more fine tuning that way.

unrealii

You know what? I dont know why I haven't looked at polk. Right now I am prefering one amp for simplicity and cost reasons. However, I would liek to go with whatever is best for long term. I jsut called a few shops, a combination of the 4 channel and either of the other two amps will be about $150 more than the ARC 5 channel. They also had some JL amps and I could get the 6 channel JL and the 1800d for about $200 more than than what I would be paying for the ARC.

Dammit, I dont know what to do now...two amps "seems" much better than one, but I would like to go with a very high end company.

Some good news. MTX no longer services the model I have...meaning GG cannot send it to them to repair. Hopefully their installer will be in the shop tomorrow to confirm that my amp is indeed bad before I have to rip it out. This gives me more leverage to get a refund

Ok...I think I am the king of stupid ideas, but I just got one. I'm looking at the specs of the ARC Audio 4150-XXK ( http://www.arcaudio.com/arc-05/pdf/xxk_amp.pdf ) and I am wondering if I could just use that 4 channel amp to power my system. Run the front speakers through the cross overs to channels 1 & 2 on the amp, then run my sub from channels 3 & 4. I have a DVC sub at 4ohm wired at 2. This amp isn't 2ohm stable, so can I run channels 3 & 4 to each coil on the sub?

MacLeod

If you have a sub with dual 4 ohm voice coils then yes, youd have to run one channel to each coil.

Dont misunderestimate (W) that Polk. Id put it up against that Arc anyday. Its extremely well built, makes much more than its rated power cleanly and has one of the best crossover networks on the market. Thats all you can ask of an amp.

I also recommend sticking with the bi-amping idea. Im a big time believer in that. You will always be able to get the best SQ from bi-amping as opposed to straight wiring.

My MM6's are bi-amped and I guarantee ya, you couldnt duplicate their sound by straightwiring.

If youre still wanting a 5 channel I stand by my recommendations of the Crossfire or Kicker. Both are extremely powerful and reasonably priced.

unrealii

Yeah, I am still looking at the polks. I'll call up polk tomorrow to get some exact specifications. I like that feature with the auto eq for momo. I am not sure if those settings will be ideal for my db's.

I like the high dampening factor ( > 2000 ) on the Arc 4150 amp. I will also look into the kicker.

I do plan to bi-amp in the future. Buying a 4 channel (wheter it would be polk, arc, etc) means I can use that to biamp in the future, then buy a sub amp. Right now I am looking for something good that can run my system for the time being. I just graduated college and my job doesnt start for 3 weeks. I am a bit torn since I have no income as of yet, but I want to get most of this taken care of before I start my job.

My only problem now is that if I have multiple amps, I cannot mount both hidden at the top of my trunk. Need to find some spot to hide the other...

MacLeod

The damping factor is irrelevant. Anything above about 30 is going to ok. You wont be able to tell the difference.

It sounds like a 5 channel is your best bet and will be the most practical. Flip a coin. There wont be much difference between the Kicker, Crossfire or the Arc. All are excellent.

1996blackmax

Originally posted by unrealii

Dammit, I dont know what to do now...two amps "seems" much better than one, but I would like to go with a very high end company.

That would be ARC Audio's XXK series . I really like Kicker and I have owned many of their products over the years. You can see in my sig that I still use their stuff, but I would not put Kicker's current amps at the same level as ARC. The ARC amps are a Zeff design (engineering team of Robert Zeff), as were the older Zapco amplifiers. These boys are in a higher class.

unrealii you should shoot Don (Pearl96Max)a PM over at the org, he carries ARC and he should be able to help you out with any questions regarding these amps.

unrealii

Yeah, I have been talking to Don. He has been very helpful in answering my questions.

I am pretty sure I want to run two amps, whether being Arc, polk or whatever. If one goes bad I dont want my entire system to go down. It sucks listening to music with an ipod & $10 portable speakers

Fry's electronics advertised the c300.2 for a really good price. I plan to pick one of those up to run my sub, then this leaves more funding open for me to get the arc 4150 to biamp the fronts. I am going to wire my rears to directly to the head unit. I called eclipse and they said it would be ok do that and use the rca's.

MacLeod

Ick.

I dont like powering anything with the head unit. For one its very dirty power and 2, its hard to adjust its output to your fronts so you end up pulling your soundstage to the rear more and dirtying up the detail.

The best way is to go without rear speakers altogether but if you want the rears then I suggest using the amp for all 4. Or you could get that JL Audio 6 channel. Bi-amp the fronts and use channels 5 & 6 on the rears.

unrealii

Yeah, you are right. No speakers powered by the unit. I dont think I can afford to bi-amp them either because I need to have a rear fill.

Ok, I have sorta been letting this go out of hand by not deciding on how much I truely would like to spend. Finally, I have set a max limit of $550. For that much, I can get the following

*1 Arc Audio 5150-XXK

*1 Kicker KX700.5

*1 C300.2 & (one of the following)
-1 Polk C400.4 OR
-2 Polk C300.2 (Yes, that's 3 amps total) OR
-1 JL e6450 (yes this one is 6 channel) OR
-1 Eclipse EA4000 (its a new model...already forgot the specs from what the shop told me)
-1 Arc Audio 4050-XXK

The C300.2 has been advertised at a local retailer for a good price. That is why it is in all of my combinations. I will be running each coil of my sub to each channel. I know its an A/B amp...I hope that is ok to use with a sub.

unrealii

Earlier today, I was really excited about the possibility of 3 amps (3 C300.2), however now the more I think about it, its going to get ugly trying to install all of those. If I have more than one amp, or one that is longer than 17", I cannot install it at the top of my trunk (and out of the way) like how I had my old mtx.



Now I think I am leaning towards the arc 5150.

MacLeod

If you want 2 amps, get the Polk 400.4 and the 300.2.

If you want a 5 channel, get the Kicker as its more powerful.

No need for 3 amps.

unrealii

Just picked up c300.2 for $150. The shop was trying to convince me to buy two more since that is what I had told them I would have done yesterday...lol

Good news...parents just gave me some $$$ for graduation. I can go up $50 on my max amp price. Not 100% sure if I am going to keep this c300.2, but the price was so good, I had to pick one up just incase I decide to use it or I will return it.

MacLeod

Why would you not keep it? Its a damn fine amp and as good as anything else you can find.

And for $150 you wont find a better deal.

exalted512

Originally posted by MacLeod


No need for 3 amps.

is 4 ok?
-Cody

MacLeod

Originally posted by exalted512
is 4 ok?
-Cody

Only for you!

unrealii

Picked up an eclipse PA5532. The c300.2 goes back to the store tomorrow.

Thanks for the help. Unfortunatly, it got to the point where this was stressing me out and I decided to go with my cheapest amp option I saw which happened to be the eclipse pa5532. I paid $375 for it. I could have probably found a kicker for the same price, but I am more familiar with eclipse as a company, so I guess this is good. I wired it up, this thing sounds great. The sub channel is rated the same as my old mtx, but it blows it away. Makes me wonder if it has been broken all this time.

1996blackmax

I'm glad you found something that you liked. In the end that is all that matters .