Which amp would be better

elocate

Just a quick question,
I was just curious as to what everybody though was the better of these two amps,

The MTX Audio Thunder 1004 or the
Rockford Fosgate Power 851X?

I realize there is a slight difference in power, mtx 125x4, rf 115x4, as well as a slight price difference.
I am looking to power 2 sets of polk/momo mm6's. I am only getting around 55 watts each now, and although it sounds great to me, they are still being overwhelmed by my 2 MM124's.

I don't necessarily need the most power, just the better quality sound and workmanship if there is a difference.
...also, if it matters, there won't be a huge amount of ventilation, so whichever one says cool longer, etc. that would be a plus as well. I apologize if these are dumb questions, I'm just not sure which amp to buy.

Thanks in advance.

elocate

I messed up on my earlier post,
I believe the Rockford Fosgate is 110x4, not 115.

Also, another reason I'm asking about either of these amps is because I'm looking for just one amp to power my front and rear speakers.

...and finally, some online sites throw certain things in your order when buying from them, 1. f caps being among them. From what little I know about them, i guess they make sense for you subs, but do they do anything for your door speakers? And if I get them included (for free) in my order, should I use them...or are they garbage? They must have a usefull purpose...

Sorry about the 20 questions...

PoweredByDodge

well... both of those amps are new models for 2k3 and rated at 14.4 volts...

if its rated 14.4 is probably over rated a bit... the old mtx 81000d's were rated 1500 x 1 at 14.4 and only put out 1350 - 1360 @ 13.8 (normal car running voltage you'll usually pull)... rockford used to rate their stuff at 13.8 or 13.6 i think... but now they're up t 14.4 too..

nobody's really seen the 1004 mtx yet... I went to circuit city the other day to talk to the dude there who i'm buddies with and see if he'd seen the 1k4 yet... he said they dont have it in yet but he'd seen/heard the scoop on it and basically the amp is not anything special... it will not push its rated power and it's got something like 0.3% thd which is pitiful for an amp for highs.

i had planned on swapping out my two 81000d's for two 1004's but after hearing that i wouldn't touch the amp.

mitek has been slowly going down in quality last few yrs... the Blue THunders were great... the original Thunder 1000D was a stud, cleaner, more efficient, higher damping... while the latest Thunder line has been higher distortion, lower damping, and lesser quality components... not much less.. but less.. logic might dictate the new thunders aren't gonna be anything special.

far as the fosgate... i really cant comment.. i'm nto a fosgate junkie and haven't seen the 851 nor heard much, so you'll have to rely on someone else for input on that..

in general.. i'd suggest another amp all together though.. i mean you'll spend like 6 - 7 hundred on either of those...

I think you might really want to consider using two amps... for a couple reasons...
1- if 1 amp dies... then you dont have to pay 600 for a whole new one.. u can simply pay 2 or 3 for one of the two.
2- clarity / output... most of those bigger amps really are not geared toward use on highs... they're aimed toward subwoofer use... least out of yoru mainstream brands... US Amps makes stuff that's 500 x 2 geared for highs...

the only 4 channel big 1000 watt amp i've liked was the Alphasonik ... its 125 x 4 at 4 ohms. its pricey like any other.

Just thinkin off the top of my head... if I had to buy new amps for my highs today.... i'd probably get two alpines...

Two alpine MRV-F340's -- bridged they're 130 x 2 ... they're not too big... and they're a WHOLE LOT cleaner than that mtx or RF amp. designed for highs and geared toward sound quality.

bout 300 each i think. so it'll run ya the same as the other two... but i'm betting you'll get a noticeably better performance out of them.

I'm running like 180 x 2 and 95 x 2 to my highs currently... JBL GT S and Q series.... they're pretty old but run like tanks... clean as heck. I'd reccomend the GTS 180x1 to you but you'd end up needing four of them...lol... i doubt you'd be to happy with that.

elocate

Thanks.
Everyone I seem to talk to seem to always be into Rockford fosgate. Im sure they are good but I dont want to get one just because everyone else seems to like them.

Any idea on the caps, worth it or not?

sntnsupermen131

i know more about rf than mtx
but rf are highly underrated
my 500 watt rf amp pushes out 810 watts
my 1000 watt rf amp pushes out 1200
mine are behind my backseat and dont have a lot of ventilation space but i havent had any problems
and i live in south tx where it can get REALLY HOT inside a car
but rf are sometimes known to overheat
i havent had any problems though
sites to look at to buy them
www.onlinecarstereo.com
www.carstereotime.com
www.sounddomain.com
as far as caps
a 1 farad rockford fosgate is like $100
and i would go ahead and install it if you get it free
they do help out
theyre controversial but for a small amp they work great
-Cody

elocate

one last question to anyone who wants to answer...

As far as 2 channel amps go, I know alpines are supposed to be good for mid's and highs (door speakers), but what about the new sony amps. they seem to be rated at pretty high rms and they are really inexpensive.

Are they crap? I havent heard anybody say anything about them. The particular amp I am thinking about is the Sony XM-2165GTX. I pasted the stats:

Sony's Xplod XM-2165GTX

Key Features:

165 watts RMS x 2 at 4 ohms
200 watts x 2 at 2 ohms
400 watts x 1 bridged output at 4 ohms
stereo or bridged mono output
4-ohm stable in bridged mode
Tri-Way capable
requires 8-gauge power and ground leads — wiring and hardware not included with amplifier
MOSFET power supply and output stages
50-300 Hz low-pass filter, 12 dB/octave
preamp- and speaker-level inputs
gold-plated connectors
selectable bass boost (10 dB) centered at 40 Hz
15-1/4"W x 2-1/4"H x 7-3/8"D
1-year warranty

sntnsupermen131

sony makes a lot of great products
tvs, playstation, cameras etc
car audio is not one of them
i cant recall anyone having something good to say about sony except theyre good for ppl who dont know what theyre doing and just want to get a start
but i dont even give them that
they look nice...
but they have no quality
every sony amp ive been in contact with has been underrated
break easily
the reason no one really talks about sony
is because if youre going to run quality speakers
especially momos
they dont even consider it an option
i have rockford fosgate powering my subs
i would look at them
they are really underrated
my 500w amp pushes out 810w
so you can get an a rf rated at 150 x2 at 2 ohms but in reality they will be pushing 200+ watts
-Cody

elocate

Thanks for the answer,
I was wondering why nobody spoke of them.
So whicj Fosgate would be best to power 2 Momo 12" Subs.

I am assuming not a mono amp, but possibly a 2 channel one, or maybe even a four channel one bridged?

sntnsupermen131

elocate,
i found a great deal for you
www.onlinecarstereo.com has the Rockford Fosgate 360.2 on sale for $259 with free shipping
plus, www.carstereotime.com will beat any competitors price by at least 5%
everything is brand new with full warranty
this amp is rated at 180w x 2 at 2 ohms rms
it will probably do 250-300w x 2 at 2 ohms
and it will sound a lot better than that sony amp
if carstererotime does the 5% thing from the top of my head it will be around 245
but i dont know how long the sale lasts so you might want to hurry
-Cody

elocate

What about if I wanted to push around 400-450 watts each,
then which amp

I was thinking about this amp, The rf power 851x
Any suggestions?

http://www.crutchfield.com/

sntnsupermen131

one more thing
theoretically
that amp is too small for 2 mm120s
itd be about right for 2 10 in momos
depends on your application
but i would really suggest getting a rf 500.2
the minimum 1 mm120 is supposed to be fed is 375 watts
the 360.2 only puts out maybe 300
but if you never(no really i mean never ever ever) want to push those subs hard
the 360 should be fine
but i think youd be happier with the 500.2
well id be happier anyway
check out those 2 website in my previous post for the 500.2
itll probably run you about $70 more
but theyll probaby have better sound quality
the reason i gave you the other amp was b/c i thought you had the 10s...dont know why...lol
but just to give you an idea about much youll save going to those websites:
the rf 360.2 retails at $490
its normal price at onlinecarstereo is 280 on sale for 260
the sony is retail at 200
it sales for 170 on onlinecarstereo
i have the same speakers you do
the mm6s and a pair of mm120s
i have the mm6s running off the 500.2 amp i was telling you about and i have the gain(pretty much another word for volume) turned down
my mm120s are run by a rf bd1000.1 which has 1200watts so im getting 600 to each mm120
thats the max they should be fed
375 is the minimum
-Cody

elocate

Thanks for the info.

One last question and i wont bother you anymore.

So I can get a mono amp, and power 2 12"subs properly?
I though mono amps were 1 channel, I'm guessing it's safe, but I figured ohm-wise it messed things up.
But I don't know a lot about this kind of stuff...

sntnsupermen131

yes mono amps are fine
my amp is a mono
and as far as the 851s goes
go for it
that amp will do awesome
-Cody

PoweredByDodge

Cody's right --- sony is a heap of scrap... although Grand Theft Auto VIce city rules!

but anyway...

*since u decided RF*
two momo 10's... i'd run off one of the two following amps.
1- 801X or 851X (400 x 2 and 450 x 2 respectively) - Class AB
2- BD1000.1 a grand, probably 1100+ x 1 at 2 ohms - Class D

two momo 12's... i'd run off...
1- TWO Power 551S amps (550 x 1 at 4 ohms each) class AB
2- BD1000.1

for the price overall and the power -- if you went with 2 12's i'd really do the mtx 81000d... i think its the best match price /power wise (350 on ebay). but the BD1000.1 is bascially the same... maybe 100 - 150 watts less overall power and a few bucks more, but same difference...

happy amping.

elocate

Thanks all..