There's better amps for the money
Written: Aug 16 '01 (Updated Oct 02 '01)
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Pros: Small size, class D, good value and SPL/SQ
Cons: Terrible technical service, use "only" 1/0 wire, LP crossover frequency not marked.
The Bottom Line: Good amount of power and clean enough, but with poor technical service. Other amps should given more consideration.
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| kyo77's Full Review: MTX Thunder 81000D Car Amp |
First the negative of this amp. If your amp ever needs technical servicing, they will swap the board inside the amp and if that doesn't fix the amp, they will tell you it's your fault. Of course they don't know anything about you, but it must be your fault that their amp doesn't work. Be prepared to spend money for shipping and wait to get it back; if it even works when you get it back.
The mtx8100d is the "updated" version of the popular mtx1000d, and they're almost identical. They both use an EBC port. The mtx8100d calls it the "EBC2" which is really the same as the original EBC. The are both about the same size and have the same features. One of the only differences is the mtx8100d has a metal top on it, most likely for better heat dissipation/looks. The EBC is a $25 accessory that I think is a must have for anyone that owns this amp. It allows you to vary the bass boost, with up to 18db centered at 40Hz from your dash. It's a black box with single knob adjustment that kind of works like a volume control, but it is varying the boost, not gain and also not, of course, "volume." This amp comes with an MTX T-shirt, and a performance certificate that rates your specific amps performance in 4 and 2 ohm modes tested at 12.5 volts direct current. The performance certificate rates the amp for: 1. Four ohm THD+N, 2. Signal to noise ratio, 3. Max power at 2 % THD+N (at 4ohm), 4. Two Ohm THD+N, 5. Max power at 2% THD+N (at 2ohms). The last spec. for my amp was rated over 1,200 watts with less than 1% THD+N and that's at 12.5 volts.
Main amplifiers specs:
S/N greater than 99dB A-weighted
Max. input 8Vrms
Variable bass boost (0-18dB) centered at 40Hz
Crossover variable from 40-200Hz, 24dB/octave low
pass (non-defeatable)
2 Ohm minimum impedance
Fuse size 150A (not included)
RMS power at 12.5 V:
500 watts x1 at four ohms with less than 2%
THD
1000 watts x1 at four ohms with less than
2% THD
RMS power at 14.4 V:
850 watts x1 at four ohms
1500 watts x1 at four ohms
Size: 15.4"x9.75"x2"
The manual states, "Thunder 8100d- 1/0 gauge only." Yes this amp has 1/0 inputs for power and ground, which is nice. Not many amps have those size inputs. But for some people, this means you need to upgrade your old 4 or 2 gauge power wire and buy new 1/0 for power and ground. Considering 1/0 power wire isn't cheap (6 to 9 dollars/foot) this should be taken into consideration. You could use cheaper welding wire instead, but the hassle for some and price should be thought out. Being the manual abiding citizen that I am, I used 1/0 wire, but others might be able to get away with using 2gauge. I didn't see any reason to skimp on the wire size, so I followed the manuals instructions. Also, it requires a 150amp fuse. These fuses are NOT cheap, as far as fuses go, at around $12 to $17 a piece. Of course, you need a distribution block/fuse block(s) that can handle 1/0 wire and the ($10+ a pop) blade type fuses.
Most importantly, this thing can suck some serious current. Even though it is a class "D" amp, it is more efficient (of course) than class A, A/B, but don't let that jargon fool you. This amp at 2 ohms will draw a lot of amps no matter what class it is. If you have an 80amp or less alternator, DO NOT run this thing in 2 ohms, you will regret it. Yes it will work for awhile. But then, imagine yourself driving down the road, the music gets quieter, and you turn up the volume. You notice the battery gauge is low. It is too late. R.I.P. alternator. You will have to upgrade your alternator, just adding caps won't help. It needs probably at least a 120amp minimum alternator at 2ohms, and that might even be pushing it. 2 ohms is the minimum impedence for this amp. That means that you can run four eight ohm subs, or two four ohm subs at most to get the 2ohm min. load. But just to be sure, always check the ohm load with a digital multimeter than can me bought at radio shack for about $18. You can also use this handy device to make sure your cars voltage isn't dropping too low e.g. less than 12V, among other uses.
One drawback for some is that there still is no labeled LP crossover for this amp. You have to use your ears or an external crossover. I use my HU for the LP crossover, so it isn't much of a bother for me. This is kind of a surprise, because a lot of customers complained about the previous version, the mtx1000d, for not having this feature. The crossover point is a non-defeatable 40-200Hz, at a 24dB per octave slope (which means it is strictly a mono subwoofer amplifier, as it is not designed to play frequencies over 200Hz).
Probably the most annoying thing with this amp is the fact I had to return my amp twice. The first time, my amp was emitting large amounts of distortion right outta the box, and the second time, it just didn't wanna work after a week while I was breaking in my subs, low volume and gain. I don't know if it is just bad luck or what, but if I have to return my amp for a third time (knock on wood) I'll update this review. And even though it's under warranty, you have to pay shipping charges for a 15-20lb amp which can cost an easy $25 for ground. But they pay shipping back.
This is an easy to install, high power subwoofer amplifer that has a good size/output power capability, however the added expenses of 2 or 1/0 power and ground wire, expensive distribution block(s)/fuse block(s), fuses and a decent output alternator (120amp min.) all required to make this amplifier run at its optimum level makes this amplifer not for everybody.
*For the price there are much better amplifiers to consider from companies like PPI, Kicker, Orion, US amps, Phoenix Gold, a/d/s. Anyone that thinks that MTX is better than those brands is probably a newbie to car audio, so believe them with a grain of salt.
Also, if you paid less than $550 for this amp, you bought it from an unauthorized MTX dealer, and you're not getting the MTX factory warranty which probably doesn't matter. They don't help you much anyway.
Recommended:
No
Amount Paid (US$): 575
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Epinions.com ID: kyo77
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Reviews written: 4
Trusted by: 0 members
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