Will amp due or should i still... Glass/fishy/john

 

New member
Username: Rsoares28

Scarborough, Ontario Canada

Post Number: 10
Registered: Sep-04
i just bought this amp Alpine MRP-M350 Mono Amplifier:

200 watts RMS x 1 at 4 ohms
350 watts RMS x 1 at 2 ohms
requires 8-gauge power and ground leads -- wiring and hardware not included with amplifier
MOSFET power supply
low-pass crossover, 50-200 Hz, 24 dB/octave
15 Hz subsonic filter
variable Bass EQ bass boost (0-12 dB at 50 Hz)
preamp- and speaker-level inputs
blue power LED
extra-large gold-plated terminals
9-3/16"W x 2-7/16"H x 9-9/16"D

do you guys think this will do, it's 200 watts rms @4ohm for my alpine 4 ohm svc type R, or should i go for something like maybe the jbl 180.2 which is 360 rms bridged.... i remember you guys telling me that a 2 channel amp does it's best work bridged and a mono amp does it's best work in 2 ohms.... oviously i can't bring the alpine down to 2 ohms so would the jbl be a better match?
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 4809
Registered: Dec-03
if you want alpine, get the MRD-500 for that sub.
you want to feed a type R about 350-500 wRMS.
depending on the type of box that is.
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 4810
Registered: Dec-03
that JBL would do the trick too, and it's a class AB amp.
more heat, but much cleaner on distortion.
 

Bronze Member
Username: Rsoares28

Scarborough, Ontario Canada

Post Number: 11
Registered: Sep-04
thanks for the advice guys..... so i installed the alpine for now, to be really honest i don't really hear or feel that much of a difference... the kenwood i was using was only giving the type R 100w rms, this new alpine i bought is giving it 200w rms and it has a bass eq..... i think maybe i don't have all the settings right..... i have the gain 3/4 up and same with the bass eq, i also have a mtx crossover that has an output level for the lpf, i also have that 3/4 up.... is that ok or should change it???
 

Bronze Member
Username: Rsoares28

Scarborough, Ontario Canada

Post Number: 12
Registered: Sep-04
another question, this amp says it has subsonic filter but i can't seem to find it.... every website i check the specs on says it has it but where is it on the amp?
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 4926
Registered: Dec-03
the subsonic filter is probably jsut built in.
nothing to set.
frequencies below 20Hz or so are just filtered out.

as for a difference, you won't really notice much of one.
remember double the power is still only a gain on average of +3dB.
double the volume is +10dB, which actually requires an increase in power on the order of ten times.

example:
100 watts = 90dB
200 watts = 93dB (noticeable but not drastic)
1,000 watts = 100dB (twice the original volume)

this is why every dB makes such a big difference to SPL competitors. Sometimes half a decibel can mean a lot of work to achieve.
 

Bronze Member
Username: Rsoares28

Scarborough, Ontario Canada

Post Number: 13
Registered: Sep-04
thanks for that info glass, but can you answer the question i posed in post maybe 3 up? oh yeah and my box is a sealed enclosure with one port.
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 4936
Registered: Dec-03
with the external mtx XO, you can set that LPF to full up.
that's just an attenuator to reduce the level if the subs are overpowering the rest of teh system.
it's not like the amplifier's gain which balances teh amp's input stage to the line voltage.

 

Bronze Member
Username: Rsoares28

Scarborough, Ontario Canada

Post Number: 14
Registered: Sep-04
thanks glass i will change that, and what about the alpine amp gain and the bass eg, i have them both set at 3/4 up it won't blow the sub right?
 

Gold Member
Username: Glasswolf

NorthWest, Michigan USA

Post Number: 4940
Registered: Dec-03
the gain, ideally, should be set to match input voltage.
that'd be done using an o-scope.
otherwise you just need to set it by ear and avoid distortion and clipping.

bass EQ.. that's your call.
I prefer to leave those things set flat/off to avoid clipping as well.
if I have any EQ changes to do, I use an external parametric or 1/3 octave unit, like alpine's 3401 or 3402, audiocontrol's EQL or EQT, or orion's DEQ30
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