Safe to underpower?

[MellowHype 10+ year member]

Ive just got myself an alpine type R 12", its the 1243d dual 4 ohm version. For now i have only got a 4 channel amp, with two spair channels. However, the amp i have, MRP-F600, can only give 150watts at 2ohms. Is this too little power and bad for the sub? Im going to be getting a new amp soon, but i want to know if i can use the MRP-F600 while im waiting for my new amp?

RMS Continuous Power (at 14.4 V, 20 - 20kHz)

• Per channel into 4 ohms (≤1% THD+N)

MRP-F600 ........................................... 100 W x 4

• Per channel into 2 ohms (≤1% THD+N)

MRP-F600 ........................................... 150 W x 4

• Briged 4 ohms (≤1% THD+N)

MRP-F600 ........................................... 300 W x 2.

They are the specs of the amp.

The sub will be going in a ported box, 2cubic ft at 32hz.

Thanks for any help.

Click to read more...

 

[DaveVT 10+ year member]

your not going to blow ANY sub from under powering. So yes, you can use it, just wont be very loud.

 

[pro-rabbit 5,000+ posts]

Here is the only issue that comes from lack of power when driving speakers.

If you crank everything up you will clip the signal and generate heat which will kill the speaker. If you keep the power clean there is absolutely no issue with "under powering" a speaker.

 

[MellowHype 10+ year member]

Here is the only issue that comes from lack of power when driving speakers.
If you crank everything up you will clip the signal and generate heat which will kill the speaker. If you keep the power clean there is absolutely no issue with "under powering" a speaker.

Ok makes sense, thanks for that.

Would setting correct gains for a 150watt speaker with a DMM be alright?

 

[zako 10+ year member]

If you don't ask the amplifier to provide more wattage than it can, it will not damage anything. The sonic difference between 300watts and 600watts is not huge, just 3dB. Type R is efficient subwoofer that should do fine on 300watts. Another thing is that a lot of Alpine amps are sort of underrated at 2ohms. The PDX amps are rated for the same wattage at 2 and 4ohms, but tests should they produce more power at 2ohms. If you want to be safe use DMM to set gains so that you never push the amplifier above 300watts. Frankly, for playing "SQ bass" (that is the bass guitar, bass drum, and other instrumental/acoustic bass) 300watts should be plenty. For rap and hip hop it should also fare well, just probably not at dance club levels.

 

[RangerDangerV2 5,000+ posts]

^^^ 3 db is quite a bit... that is almost as much as adding another driver in some situations...

 

[brynm 10+ year member]

Ok makes sense, thanks for that.
Would setting correct gains for a 150watt speaker with a DMM be alright?

Yes, a 150w 2ohm speaker.

As said, as long as you are sending a clean signal there is no way at all you can wreck a speaker by sending it less than the speaker was designed to handle in the situation. Think of it this way, if a speaker was wrecked when it was fed too little power what would happen when you turned your volume down? The problem comes from someone saying "I should be able to get more out of this speaker, I'll just turn the gains or bass boost right up" which ends up sending a clipped signal to the speaker.

 

[zako 10+ year member]

^^^ 3 db is quite a bit... that is almost as much as adding another driver in some situations...

3db means very little sonically. Try to change the subwoofer level by 3db if your stereo has this function and see what happens. And adding a second sub adds 3dB SPL ONLY if you do not double power. If you double the cone area AND power, then you will see 6dB increase in SPL.