Print Page | Close Window

Speaker RMS higher than Amp RMS

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=68739
Printed Date: May 23, 2024 at 11:08 AM


Topic: Speaker RMS higher than Amp RMS

Posted By: deeve
Subject: Speaker RMS higher than Amp RMS
Date Posted: December 19, 2005 at 4:13 PM

This may seem like a silly question to some, but I cannot seem to find an answer. How important is it to have a speaker RMS that is close to the AMP RMS. I understand wanting to not have the AMP be more powerful than the speakers, but what about the other way around. For example, the AMP is rated for 45 RMS and the speakers are like 75 or up RMS.

Would the speaker work better if the RMS is closer to the AMP?

Thanks!
DAve



Replies:

Posted By: greg_jobes
Date Posted: December 19, 2005 at 4:27 PM
The truth of the matter is that how much power you need is really based on the enclosure you put the sub in. A ported box would need less power then a sealed box to reach full excursion. But yes under powering a sub is not a problem, it just might not reach full excursion.




Posted By: youngone
Date Posted: December 19, 2005 at 4:30 PM
well if you have a amp as you mentioned you can have a problem with trying to push the amp to far to get the speaker to actually perform as you would like it to. but you will have a big problem when you try to do that and it is called clipping. it happens when you turn the gain up on the amp to get more out of the speakers. you cant do this. because you can only get a certain amount of clean power out of the amp before it starts to clip. this is what destroyed allot of speakers because people turn there gains to far up.
you can power any speaker with any amount of power as long as you do it safely in the speakers capability.

and to answer your question you can power you speakers with that amp you gust have to set your gains right.

if you have any questions gust post
Aaron

-------------
Want to know some good equipment- JL,Adire Audio,Mcintosh,Brax,Helix,Eclipse,JBL,RE,Dimoand Audio,Zapco, pritty much anything DYhon,Forbidden recommend
On the12volt you give some info and you get in




Posted By: deeve
Date Posted: December 19, 2005 at 4:30 PM
If it makes a difference I am more refering to front component speakers. I am not going to even get into subs at this point!

Dave




Posted By: DYohn
Date Posted: December 19, 2005 at 4:35 PM
To answer your question, if you are interested in the longest life for your system your speaker power HANDLING rating should always be higher than the amplifier power GENERATING rating.  The amp makes power and the speakers use it up, and about 80% to 90% of all amplifier power is turned into heat.  If the speakers are capable of handling more power than the amplifier can generate, you should never be able to burn up your speakers by turning it up too loud. The danger happens when the amplifier is more powerful than the speakers can handle (or the amplifier is adjusted incorrectly so that it is producing more than the rated output due to severe clipping.) 

-------------
Support the12volt.com




Posted By: deeve
Date Posted: December 19, 2005 at 4:58 PM
I hope I am not cross posting. I have another thread, but this topic seems kinda like a sidebar topic....

Ok, so to be specific on this. I think I understand what I am being told is that in order for the speakers to work well I need to overpower them a little, and if I have a speaker that is too far above the amp then I will "overwork" the amp and cause clipping to try and get the speakers to work. My amp stats below.

Pricewise/soundwise I am looking at some Alpines. Either SPS-171A or SPR-17LS. One has an RMS Of 50 and the other 70. To play it safe would it be smarter to go with the SPR's or will that cause me to have to turn the amp up too much?

MTX Thunder895
RMS Power measured at 12.5 Volts DC:
35 Watts RMS/Ch x 4 into 4 Ohms with less than 1% Thd+N
70 Watts RMS/Ch x 4 into 2 Ohms with less than 1% Thd+N
140 Watts RMS bridged x 2 into 4 Ohms with less than
1% Thd+N
• Subwoofer:
160 Watts RMS into 4 Ohms with less than 1% Thd+N
320 Watts RMS into 2 Ohms with less than 1% Thd+N
• Dynamic Power measured at 14.4 Volts DC Front and Rear:
50 Watts x 4 into a 4 Ohm load
100 Watts x 4 into a 2 Ohm load
200 Watts bridged x 2 into a 4 Ohm load
• Subwoofer:
245 Watts x 1 into a 4 Ohm load
490 Watts x 1 into a 2 Ohm load




Posted By: greg_jobes
Date Posted: December 19, 2005 at 5:16 PM
Well i think you will find that the speakers you are looking at are 4Ohm speakers. Which means the amp will only produce 35Wx4 Or 140WX2, i myself would not feel comfortable putting that much power to them speakers. The best thing you can do is match the RMS rating of the speakers to the RMS rating of the amp. What i think DYohn is saying is underpowering the speakers will not harm them, but if you crank the gain, or turn the Hu up to much you will drive the amp into clipping. Which will harm the speakers.




Posted By: DYohn
Date Posted: December 19, 2005 at 5:24 PM

deeve] wrote:

k, so to be specific on this. I think I understand what I am being told is that in order for the speakers to work well I need to overpower them a little, and if I have a speaker that is too far above the amp then I will "overwork" the amp and cause clipping to try and get the speakers to work.

No, that's BS.  In general you do not want to overpower car audio speakers unless you really know what you're doing.  And the only way a speaker can "overwork" an amp is if the impedance load is too low, and even then it's not "overworking" it, it's simply drawing too much current.

For a standard, every-day stereo system used by the average person, amplifier RMS power should be equal to or less than speaker handling RMS power.



-------------
Support the12volt.com




Posted By: DYohn
Date Posted: December 19, 2005 at 5:25 PM

greg_jobes wrote:

Well i think you will find that the speakers you are looking at are 4Ohm speakers. Which means the amp will only produce 35Wx4 Or 140WX2, i myself would not feel comfortable putting that much power to them speakers. The best thing you can do is match the RMS rating of the speakers to the RMS rating of the amp. What i think DYohn is saying is underpowering the speakers will not harm them, but if you crank the gain, or turn the Hu up to much you will drive the amp into clipping. Which will harm the speakers.

Yep.  Overpower is what harms speakers.  Clipping is one way to generate an overpower condition.



-------------
Support the12volt.com




Posted By: greg_jobes
Date Posted: December 19, 2005 at 5:25 PM
You might look into This Amp, it's a US Acustics 65Wx4, And it's at a good price.
I notice it's on backorder though.




Posted By: deeve
Date Posted: December 19, 2005 at 5:51 PM
I already have the amp, but I wish I knew about that one. I was just trying to get something that would cover my needs and I think the MTX will do that, for now ;) At this point I just want some good clean sound. See post https://www.the12volt.com/installbay/forum_posts.asp?tid=68587&PN=1

So I guess good speakers with an RMS a little higher than 35RMS is probably the way to go.




Posted By: youngone
Date Posted: December 19, 2005 at 7:19 PM
sounds good man you got the ideaposted_image roll with it

Aaron

-------------
Want to know some good equipment- JL,Adire Audio,Mcintosh,Brax,Helix,Eclipse,JBL,RE,Dimoand Audio,Zapco, pritty much anything DYhon,Forbidden recommend
On the12volt you give some info and you get in




Posted By: deeve
Date Posted: December 19, 2005 at 11:34 PM
Cheaper that way too! posted_image





Print Page | Close Window