Disadvantages to powering 60w RMS speakers with 50w RMS (per channel) amp - Ford Mustang Forum
 
LinkBack Thread Tools
post #1 of 10 (permalink) Old 04-17-2013 Thread Starter
Banned
V6 Member
S197 Member
 
AlbertaEthan's Avatar
 
Joined: Jan 2012
Location: Calgary
Posts: 293
 
Disadvantages to powering 60w RMS speakers with 50w RMS (per channel) amp

The title pretty much says it all. I'm trying to put together a basic audio system in my car and replaced the door speakers a while ago. I'm currently running speakers that are rated at 60w RMS at 4 ohms but was able to pick up an Alpine MRP-F300 really cheap that only works at 50w RMS at 4 ohms. Is there any disadvantage to slightly under-powering the speakers?

AlbertaEthan is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old 04-19-2013
PONY Member
V6 Member
S197 Member
 
mtu245's Avatar
 
Joined: Oct 2011
Location: Vancouver
Posts: 556
 
Hey,

The only disadvantage is over working the amplifier. Your speakers will somewhat ask for 60 watts rms when you turn up the volume. However, your amp can only provide 50 watts rms. So if you have the volume turned up more than often you may be making your amplifier work too hard and might burn it out eventually. Also when an amp is being pushed to its limits it can sometimes distort or send ''dirty'' power to your speakers.

Good rule of thumb is to have 20-25% more power on the amp so it never has to work maxed out. So if your amp put out 70-80 watts rms it would match a bit better. Having said all this most people run speakers off an aftermet deck, and those have like 14-20 watts rms to each speaker. So you should be ok. Just don't turn the gain knob or boost too high on the amp. And keep an eye on how hot to the touch it gets after using it.

Sent from my Sony Tablet S using AutoGuide.Com Free App


2011 Kona Blue MT82 V6 Mustang Pony Package 3:31 Gear Ratio, Interior Upgrade Pkg, Security & Shaker500/Sync
Mods (in order of installed): AM Bama SCT SF3 Tuner w/ 87 Hybrid Tune, Airaid CAI, Hurst Billet Plus 2 Short Throw Shifter, Lethal O/R H Pipe w/ Stock Exhaust, Blacked-Out Tints on Rear Windows, Full Ceramic Tint on Front Windows, Metra Touchscreen Dash Adaptor, Single DIN Head Unit, 6.5'' Component Speakers Fronts, Stock Rear Speakers, 10'' Sealed Subwoofer, 4ch. and 1ch Amplifier. LED licence plate lights, LED interior dome lights, FRPP/Dynamic shocks and struts, SR Performance lowering springs, GT500 Strut Mounts, BMR Adjustable Panhard Bar, BMR LCA's, BMR Relocation Brackets. Rear Seat Delete.
mtu245 is offline  
post #3 of 10 (permalink) Old 04-19-2013
SHELBY GT 350 Member
 
Strange Mud's Avatar
 
Joined: Apr 2011
Location: small town CT
Posts: 5,387
         
+1. Speakers are more apt to be blown by underpowering rather than over powered, it's the distortion/clipping that does them in. But with what you have unless you play it on 9 of 10 on a volume level you should be fine.

2012 V6 traded in for a 2017 VW GTI.
Strange Mud is offline  
 
post #4 of 10 (permalink) Old 04-19-2013 Thread Starter
Banned
V6 Member
S197 Member
 
AlbertaEthan's Avatar
 
Joined: Jan 2012
Location: Calgary
Posts: 293
 
Thanks guys. I'm really just looking for better quality. I couldn't care less about how loud the system will be
AlbertaEthan is offline  
post #5 of 10 (permalink) Old 04-25-2013
Sean Reilly
Guest
 
Sean Reilly's Avatar
 
Posts: n/a
As stated, the quality will be better !
post #6 of 10 (permalink) Old 04-27-2013
Apprentice
 
iScream's Avatar
 
Joined: Mar 2013
Location: Middle
Posts: 106
 
Quote:
Originally Posted by mtu245 View Post
Hey,

The only disadvantage is over working the amplifier. Your speakers will somewhat ask for 60 watts rms when you turn up the volume. However, your amp can only provide 50 watts rms. So if you have the volume turned up more than often you may be making your amplifier work too hard and might burn it out eventually.
Sorry but that just isn't even close to being correct.

The load a speaker places on your amplifier is determined by the impedance rating, not the max RMS power rating. A 4 Ohm speaker rated at 500 Watts RMS will not place any more load on your 50 Watt amp than a 4 Ohm speaker rated for 50 Watts RMS. And a speaker with 60, or 100, or 1000 watt, power handling will not make your 50 Watt amp get a single degree warmer than a 50 Watt speaker, if the impedance is the same.

You're correct about most people these days running amps that are rated at higher output than their speakers are capable of handling. There is some truth to speakers being damaged by over driven amp but that is also something people who sell amps love to say, so they can sell you a more expensive amp.

The fact is that, if you run a quality amp, which is capable of driving the impedance load of your speakers, and set your gains properly, your 60 watt speakers and 50 watt amp will give you great sound for years.
iScream is offline  
post #7 of 10 (permalink) Old 05-04-2013
PONY Member
V6 Member
S197 Member
 
mtu245's Avatar
 
Joined: Oct 2011
Location: Vancouver
Posts: 556
 
Quote:
Originally Posted by iScream View Post
Sorry but that just isn't even close to being correct.

The load a speaker places on your amplifier is determined by the impedance rating, not the max RMS power rating. A 4 Ohm speaker rated at 500 Watts RMS will not place any more load on your 50 Watt amp than a 4 Ohm speaker rated for 50 Watts RMS. And a speaker with 60, or 100, or 1000 watt, power handling will not make your 50 Watt amp get a single degree warmer than a 50 Watt speaker, if the impedance is the same.

You're correct about most people these days running amps that are rated at higher output than their speakers are capable of handling. There is some truth to speakers being damaged by over driven amp but that is also something people who sell amps love to say, so they can sell you a more expensive amp.

The fact is that, if you run a quality amp, which is capable of driving the impedance load of your speakers, and set your gains properly, your 60 watt speakers and 50 watt amp will give you great sound for years.
Thanks for the correction! Its a hobby for me. I try to help when I can, and its great when soneone can teach me something new.

Btw how did this work out AlbertaEthan?

Sent from AutoGuide.com Free App

2011 Kona Blue MT82 V6 Mustang Pony Package 3:31 Gear Ratio, Interior Upgrade Pkg, Security & Shaker500/Sync
Mods (in order of installed): AM Bama SCT SF3 Tuner w/ 87 Hybrid Tune, Airaid CAI, Hurst Billet Plus 2 Short Throw Shifter, Lethal O/R H Pipe w/ Stock Exhaust, Blacked-Out Tints on Rear Windows, Full Ceramic Tint on Front Windows, Metra Touchscreen Dash Adaptor, Single DIN Head Unit, 6.5'' Component Speakers Fronts, Stock Rear Speakers, 10'' Sealed Subwoofer, 4ch. and 1ch Amplifier. LED licence plate lights, LED interior dome lights, FRPP/Dynamic shocks and struts, SR Performance lowering springs, GT500 Strut Mounts, BMR Adjustable Panhard Bar, BMR LCA's, BMR Relocation Brackets. Rear Seat Delete.
mtu245 is offline  
post #8 of 10 (permalink) Old 05-05-2013 Thread Starter
Banned
V6 Member
S197 Member
 
AlbertaEthan's Avatar
 
Joined: Jan 2012
Location: Calgary
Posts: 293
 
Quote:
Originally Posted by mtu245 View Post
Thanks for the correction! Its a hobby for me. I try to help when I can, and its great when soneone can teach me something new.

Btw how did this work out AlbertaEthan?

Sent from AutoGuide.com Free App
So far so good! I put everything in last weekend and it's a huge improvement over stock. The rear speakers were easier to put in than most people think. I didn't need to take apart much of the trim in the back. You only have to remove a couple pushpins and then the rear tray is flexible enough to pop right out. At this point, I've had no issues running the speakers with the lower RMS amp
AlbertaEthan is offline  
post #9 of 10 (permalink) Old 05-28-2013
Rookie
 
bgrinder90's Avatar
 
Joined: May 2013
Location: Cheektowaga, NY
Posts: 13
 
You're not going to notice major problems (assuming you don't push everything to the max for extended periods of time). You generally want an amp to provide an amount of power that falls between your RMS and Peak handling ratings.

It's a common misconception that under-powering a speaker is safer for it.. Theoretically it sounds to be correct, because it sounds like you couldn't blow a speaker when you're providing it with less power than it's designed to handle.. There is a lot more that goes into it though, if you drive the system hard, the amp will clip, a clipped signal will cause the amp to push high-voltage DC current through the speakers' voice coils, which will burn them out in a hurry.
bgrinder90 is offline  
PONY Member
 
Midnight21's Avatar
 
Joined: Feb 2013
Location: Atlanta
Posts: 356
 
as far as sub goes, I just installed one 12" 4ohm with 300watt peak and supplied power to it with a "D" class mono amp that has 200watt RMS so it would be clean and have room to play. It absolutely rocks my hatchback when i turn it up. Very clean crip and I only have the gain on a 30% turn with 70% left on the amp. Never cuts off and BOOMS when I need it!!! Got a ported slimline light box from best buy to house the 12" and I just laid it down facing upward behind in the middle of the fold down seats.

'90 lx hatch - Midnight Metallic
-Milled/Ported - Gt40p_Cobra Intake - "Ecam" -280rwhp_319rwtrq- w/ AC climate control
Custom Tune Chip with all bolt on's, including electric fan. pulleys - 5spd - 3:55 gears
High Velocity Stage Down - 83mm Pro-M, 73mm bbk tube, 65mm TB
...daily driven and pinching ponies ain't cheap.
Little oil pump shafting and lifter tappin' ass in
Midnight21 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Mustang Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a VALID email address for yourself, otherwise you will not receive the necessary confirmation email needed to confirm, validate and activate your new AFM member account.

Failure to provide a VALID email address, will result in the cancellation of your new AFM member account registration.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
 


Search Engine Friendly URLs by vBSEO 3.6.1