Which amp should I use for my front components? Old School

[SR20det 10+ year member]

Which amplifier should I use, MTX Thunder 250 (1999 USA) or Kenwood KAC-642 (1991 Japan) for my components? I currently own both and am just looking to put one of them to use in my new car. The equipment…

Head unit: JVC KD-AVX2

Front speakers: 4” MTX Components (Old School 1998/1999 USA) can handle 75rms

Rear speakers: 6.5” Infinity Kappa coaxials

Subwoofer: JL 10w7

Sub amp: Kenwood KAC-X810d

I plan on running either the MTX or Kenwood amp for the front components and using HU power for the rear fill. The amp’s specs are pretty similar and they are both older, underrated amps. They are also about the same size, give or take an inch on either dimension. Although the MTX is about a pound or so heavier.

Here are the manufacturer specs.

MTX Thunder 250 (25amp fuse)

Signal to noise ratio 110db

RMS Power measured at 12.5 Volts DC:

25 Watts x 2 into a 4 Ohm load with less than 0.05% THD+N

50 Watts x 2 into a 2 Ohm load with less than 0.1% THD+N

100 Watts bridged into a 4 Ohm load with less than 0.1% THD+N

Dynamic Power (IHF-202 Std) measured at 14.4 Volts DC

55 Watts x 2 into a 4 Ohm load

100 Watts x 2 into a 2 Ohm load

200 Watts bridged into a 4 Ohm load

Kenwood KAC-642 (15amp fuse)

Max power 90 Watts x 2 in 4 Ohm load

Rated Power 45 Watts x 2 in 4 Ohm load (0.8% THD)

Signal to Noise Ratio 100db

I don’t have birth sheets for either amp but other owners have stated 50-55x2 is typical. Which one should I use for my front components? Thanks in advance

-Jon

Click to read more...

 

[Louisiana_CRX 5,000+ posts]

Go with the MTX ...I have several of the older MTX amps.....including a Thunder 250 if its the bluish gray colored one . They are good solid amps

 

[SR20det 10+ year member]

The MTX is the black and gold one. (black wrinkle finish, bright gold MTX logo).

I just got it this morning, it was 20shipped. I received it this morn and thru it on the test bench this afternoon, works great just had scratchy gain pots.

On the test bench with an ipod-to-rca connection the Kenwood undoubtedly sounded better. Although it isn't fair to judge based off the super-low voltage input. I was just making sure it was a fully working amp, since it was sold as-is.

 

[Louisiana_CRX 5,000+ posts]

most likely some tuner cleaner will fix the scratchy gains....that was a really good deal on that amp...but since you have both and they are both compact it should be easy to do a listen test in your vehicle . I've had some of the Black with Gold logo MTX's also...They were all very similar