Question regarding appropriate amp to push a Rockford P2D2

NickBaragona · 12-12-2012, 06:51 PM

I currently have the Rockford Fosgate PBR300X1.

PUNCH Amplifiers - PBR300X1 - Rockford Fosgate®

I am new to this, but am I correct that with a 2ohm sub, this amp only pushes 150 watts at it? If the P2D2 is 300watts RMS and 600watts max, should I get an amp that's more powerful?

RonRizz · 12-13-2012, 07:51 AM

p2d2 is dual 2 ohm coils. One ohm load at amp=300 watts. good match.

NickBaragona · 12-13-2012, 08:34 AM

Thanks, I was asking because my sub is no longer working and may be blown. Would my amp power a P3D2 sufficiently if I decided to upgrade?

RonRizz · 12-13-2012, 09:06 AM

the P3d2 10 inch i would say yes. The p3d2 12 steps up power handling to 600rms, I would give it more than what you have.

NickBaragona · 12-13-2012, 09:32 AM

Forgot to mention I do have a 10''. I believe the P3D2 10 is 500rms.

SouthArk370Z · 12-13-2012, 10:53 AM

Quote:

Originally Posted by NickBaragona

Thanks, I was asking because my sub is no longer working and may be blown. Would my amp power a P3D2 sufficiently if I decided to upgrade?

It's easy to check bass and sub coils with an ohmmeter. Isolate the driver, set the ohmmeter on ~10 ohm scale (most drivers are 8 ohm or less), and place the meter probes across the driver terminals. If your drivers are 1-4 ohms, use a scale just above that number. Should read close to nominal impedance or infinity. Much above/below nominal and you have a problem*. Infinity = blown.
Don't try this with tweeters or mid-ranges unless you know what you are doing - you can burn out a coil.

*Keep in mind that your meter will be reading DC resistance and speakers/drivers are an inductive load. Impedance and resistance are not exactly the same so your reading my be a little off. If the reading is just a little off, try comparing with a few more drivers. If all read close to the same, you should be OK.

90 ST · 12-13-2012, 10:56 AM

If you want to go up to a P3D2 sub you need more power, the PBR300x1 you have makes about 315 measured at 1 ohm, not enough to run a P3, properly. and IMO it's not enough to run your P2, but i like to have extra power on tap. i run a P1000-1 on 2 P3SD2-10's.

RonRizz · 12-13-2012, 12:27 PM

more power never hurts.
I would typically chose my sub amp at or slightly above the subs rms rating; not to say that the sub would not work well with less, depending onn your setup.

SouthArk370Z · 12-13-2012, 01:21 PM

Don't get too obsessed with matching speaker and amplifier watts. Unless your speakers sound crappy at low volume, "underdriving" them just means they're not getting as loud as possible. Bass/sub drivers are, as a rule-of-thumb, more forgiving of high-power transients than tweeter and mid-ranges, so if your amp has twice the power your subs are rated for, it shouldn't be a problem unless you keep it cranked all the way up. Just make sure you don't over-stress the surrounds or bottom out the coil.

Also keep in mind that you will never get true, audiophile-grade, high-fidelity sound in a car, especially one as small as a 370Z. But it doesn't really matter since everybody's perception of sound is different. Make it sound they way you like.

Edit:
BTW, in an audio system, the transducers will have a much greater effect on fidelity than the amplifiers. Most modern amps do a very good job, so, unless you're using a microphone or other physical input, spend most of your effort and money on speakers. The right enclosure makes a big difference the lower the frequency the speaker puts out, so choose your sub enclosure carefully.

NickBaragona · 12-13-2012, 04:11 PM

When I turn my car on, there is a constant thumping noise coming from the sub. Could this be a wiring issue, or is it more likely that the sub is damaged? I didn't think my tiny PBR300X1 could blow a P2D2-10 lol.

SouthArk370Z · 12-13-2012, 04:52 PM

Quote:

Originally Posted by NickBaragona

When I turn my car on, there is a constant thumping noise coming from the sub. Could this be a wiring issue, or is it more likely that the sub is damaged? I didn't think my tiny PBR300X1 could blow a P2D2-10 lol.

Drivers only do what the amp tells them to do, so it's probably not the sub.

Does the volume of the thump change with the HU volume knob? If so, then the sub amp is probably OK.
Does the frequency of the thump change with engine speed. If so, then suspect ignition interference.
Check power at the amps and pre-amps, starting with the sub amp and working my way to the HU. Might be some weird fluctuations.
Could be a signal grounding problem. Ground shields at one end only.

Edit: double-check speaker wiring. It may be the auto-protection circuit kicking in.

NickBaragona · 12-13-2012, 05:26 PM

It's def not the HU, I unhooked the input at the amp and it still thumps. I agree that it may be a grounding issue.

SouthArk370Z · 12-13-2012, 05:36 PM

Without being able to put hands on, my top guess is that you have a dual-coil sub driver, each coil 1Ω, you have them in parallel for a net impedance of 0.5Ω, causing the amp's protection to kick in. Just a guess.

NickBaragona · 12-13-2012, 05:48 PM

Well it was working fine for a year, a local shop did the install in '11.

SouthArk370Z · 12-13-2012, 05:56 PM

Ah. I thought you were re-wiring the whole thing. nvm

12-12-2012, 06:51 PM	#1 (permalink)
NickBaragona Enthusiast Member Join Date: Jun 2011 Location: Maryland Posts: 353 Drives: 40th 370Z Rep Power: 13	Question regarding appropriate amp to push a Rockford P2D2 I currently have the Rockford Fosgate PBR300X1. PUNCH Amplifiers - PBR300X1 - Rockford Fosgate® I am new to this, but am I correct that with a 2ohm sub, this amp only pushes 150 watts at it? If the P2D2 is 300watts RMS and 600watts max, should I get an amp that's more powerful? __________________ 20%Sides&Rear 55%Windshield l Rockford Fosgate Amp & P2D2 l Stillen CAI l F.I. CBE & LTH l GTR Start Button l

12-13-2012, 07:51 AM	#2 (permalink)
RonRizz A True Z Fanatic Join Date: Aug 2011 Location: Pine grove, Pa Posts: 2,134 Drives: 2 feet, 3 pedals Rep Power: 6774	p2d2 is dual 2 ohm coils. One ohm load at amp=300 watts. good match. __________________ P99rs Head Unit--- Amps- 2 Pioneer Prs800d --- Zapco ST1000MX---Zapco ST-4XSQ---- SI BM mk5 Subs---SI TM65v2 Midbass--- SI M3 mids--- SI M25 xbl2 tweeters ----- 2016 MECA street class 3rd place at world finals

12-13-2012, 08:34 AM	#3 (permalink)
NickBaragona Enthusiast Member Join Date: Jun 2011 Location: Maryland Posts: 353 Drives: 40th 370Z Rep Power: 13	Thanks, I was asking because my sub is no longer working and may be blown. Would my amp power a P3D2 sufficiently if I decided to upgrade? __________________ 20%Sides&Rear 55%Windshield l Rockford Fosgate Amp & P2D2 l Stillen CAI l F.I. CBE & LTH l GTR Start Button l

12-13-2012, 09:06 AM	#4 (permalink)
RonRizz A True Z Fanatic Join Date: Aug 2011 Location: Pine grove, Pa Posts: 2,134 Drives: 2 feet, 3 pedals Rep Power: 6774	the P3d2 10 inch i would say yes. The p3d2 12 steps up power handling to 600rms, I would give it more than what you have. __________________ P99rs Head Unit--- Amps- 2 Pioneer Prs800d --- Zapco ST1000MX---Zapco ST-4XSQ---- SI BM mk5 Subs---SI TM65v2 Midbass--- SI M3 mids--- SI M25 xbl2 tweeters ----- 2016 MECA street class 3rd place at world finals

12-13-2012, 09:32 AM	#5 (permalink)
NickBaragona Enthusiast Member Join Date: Jun 2011 Location: Maryland Posts: 353 Drives: 40th 370Z Rep Power: 13	Forgot to mention I do have a 10''. I believe the P3D2 10 is 500rms. __________________ 20%Sides&Rear 55%Windshield l Rockford Fosgate Amp & P2D2 l Stillen CAI l F.I. CBE & LTH l GTR Start Button l

12-13-2012, 10:56 AM	#7 (permalink)
90 ST A True Z Fanatic Join Date: May 2010 Location: Calgary Posts: 1,861 Drives: 90 and 15 GMC Sierra Rep Power: 421	If you want to go up to a P3D2 sub you need more power, the PBR300x1 you have makes about 315 measured at 1 ohm, not enough to run a P3, properly. and IMO it's not enough to run your P2, but i like to have extra power on tap. i run a P1000-1 on 2 P3SD2-10's. Last edited by 90 ST; 12-13-2012 at 11:00 AM.

12-13-2012, 12:27 PM	#8 (permalink)
RonRizz A True Z Fanatic Join Date: Aug 2011 Location: Pine grove, Pa Posts: 2,134 Drives: 2 feet, 3 pedals Rep Power: 6774	more power never hurts. I would typically chose my sub amp at or slightly above the subs rms rating; not to say that the sub would not work well with less, depending onn your setup. __________________ P99rs Head Unit--- Amps- 2 Pioneer Prs800d --- Zapco ST1000MX---Zapco ST-4XSQ---- SI BM mk5 Subs---SI TM65v2 Midbass--- SI M3 mids--- SI M25 xbl2 tweeters ----- 2016 MECA street class 3rd place at world finals

12-13-2012, 01:21 PM	#9 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324197	Don't get too obsessed with matching speaker and amplifier watts. Unless your speakers sound crappy at low volume, "underdriving" them just means they're not getting as loud as possible. Bass/sub drivers are, as a rule-of-thumb, more forgiving of high-power transients than tweeter and mid-ranges, so if your amp has twice the power your subs are rated for, it shouldn't be a problem unless you keep it cranked all the way up. Just make sure you don't over-stress the surrounds or bottom out the coil. Also keep in mind that you will never get true, audiophile-grade, high-fidelity sound in a car, especially one as small as a 370Z. But it doesn't really matter since everybody's perception of sound is different. Make it sound they way you like. Edit: BTW, in an audio system, the transducers will have a much greater effect on fidelity than the amplifiers. Most modern amps do a very good job, so, unless you're using a microphone or other physical input, spend most of your effort and money on speakers. The right enclosure makes a big difference the lower the frequency the speaker puts out, so choose your sub enclosure carefully. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma Last edited by SouthArk370Z; 12-13-2012 at 01:33 PM.

12-13-2012, 04:11 PM	#10 (permalink)
NickBaragona Enthusiast Member Join Date: Jun 2011 Location: Maryland Posts: 353 Drives: 40th 370Z Rep Power: 13	When I turn my car on, there is a constant thumping noise coming from the sub. Could this be a wiring issue, or is it more likely that the sub is damaged? I didn't think my tiny PBR300X1 could blow a P2D2-10 lol. __________________ 20%Sides&Rear 55%Windshield l Rockford Fosgate Amp & P2D2 l Stillen CAI l F.I. CBE & LTH l GTR Start Button l

12-13-2012, 05:26 PM	#12 (permalink)
NickBaragona Enthusiast Member Join Date: Jun 2011 Location: Maryland Posts: 353 Drives: 40th 370Z Rep Power: 13	It's def not the HU, I unhooked the input at the amp and it still thumps. I agree that it may be a grounding issue. __________________ 20%Sides&Rear 55%Windshield l Rockford Fosgate Amp & P2D2 l Stillen CAI l F.I. CBE & LTH l GTR Start Button l

12-13-2012, 05:36 PM	#13 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324197	Without being able to put hands on, my top guess is that you have a dual-coil sub driver, each coil 1Ω, you have them in parallel for a net impedance of 0.5Ω, causing the amp's protection to kick in. Just a guess. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

12-13-2012, 05:48 PM	#14 (permalink)
NickBaragona Enthusiast Member Join Date: Jun 2011 Location: Maryland Posts: 353 Drives: 40th 370Z Rep Power: 13	Well it was working fine for a year, a local shop did the install in '11. __________________ 20%Sides&Rear 55%Windshield l Rockford Fosgate Amp & P2D2 l Stillen CAI l F.I. CBE & LTH l GTR Start Button l

12-13-2012, 05:56 PM	#15 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324197	Ah. I thought you were re-wiring the whole thing. nvm __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

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