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Topic: How much power in a power amp? |
Tim Sheinman
From:
Brighton, UK
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Posted 30 Aug 2014 11:11 am |
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How powerful should my power amp be to run a 300w 15" speaker at 4ohm?
Need it be 300w also or can it be significantly less?
Tim |
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b0b
From:
Cloverdale, CA, USA
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Posted 30 Aug 2014 11:36 am
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You didn't say what brand/model of speaker, but generally...
300 watts is the power handling capacity. You don't want to go over 300 watts. Lower powered amps will work fine, but you won't get the best sound of the speaker once you get below 20 watts or so. It's designed to push high volume sound. Amps in the 25-250 watt range should work very well.
A race car doesn't perform well at 10 MPH.
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-𝕓𝕆𝕓- (admin) - Robert P. Lee - Recordings - Breathe - D6th - Video |
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Tim Sheinman
From:
Brighton, UK
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Posted 30 Aug 2014 2:55 pm
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| Thanks, its a telonics neo 4ohms |
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Jon Light (deceased)
From:
Saugerties, NY
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Posted 30 Aug 2014 3:03 pm
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| My Milkman Creamer came with a Telonics 15". It's a 20 watt amp, + or -. It works brilliantly. |
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Tim Marcus
From:
San Francisco, CA
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Posted 30 Aug 2014 3:04 pm
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Pretty sure the Telonics Neo speakers are rated for 500W RMS
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Milkmansound.com |
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Tim Sheinman
From:
Brighton, UK
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Posted 31 Aug 2014 2:26 am
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| The website says the power handling capacity is 300w |
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Jay Ganz
From:
Out Behind The Barn
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Posted 31 Aug 2014 8:38 am
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I've been using a tiny 1 lb. 500 watt power amp with my Telonics Neo for the last 6 months with no problem whatsoever.
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Straight Ahead 500 watt mini~power amp |
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b0b
From:
Cloverdale, CA, USA
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Posted 31 Aug 2014 9:40 am
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I have no experience with the new-fangled neodymium magnet speakers. That will change when I get my Milkman.  With more traditional hi-powered speakers (EVM, JBL, Black Widow, etc.), a very low powered amp doesn't move the heavy cone well enough to get the normal frequency response. The speaker works - no harm done - but it doesn't sound like it should.
It's also worth noting that 500 watts is just a little bit more headroom than 300 watts. I think it's logarithmic - 300 watts is twice as loud as 30 watts. Something like that. 500 watts isn't much different from 300 watts.
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-𝕓𝕆𝕓- (admin) - Robert P. Lee - Recordings - Breathe - D6th - Video |
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Paddy Long
From:
Christchurch, New Zealand
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Posted 31 Aug 2014 7:02 pm
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The new Telonics TCA-500 Combo amp is 500 watts so I guess the speakers must be rated for at least that ?
_________________
14'Zumsteel Hybrid D10 9+9
08'Zumsteel Hybrid D10 9+9
94' Franklin Stereo D10 9+8
Telonics, Peterson, Steelers Choice, Benado, Lexicon, Red Dirt Cases. |
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Eugene Cole
From:
near Washington Grove, MD, USA
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Posted 1 Sep 2014 6:06 am
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Tim; this may fall in to the more than you wanted to know bin. And I'll keep my comments pretty brief and not too detailed: but enough to convey the concepts.
I want to point out that different power amps are rated with different reference standards. RMS, PMP, CMP, et cetera. I'll spare you the nuances of the differences here-in.
But some amps use a standard like PMP which is essentially peak output power which really means the maximum power the amp can (when connected to its dedicated power supply) put out for only a few thousandths of a second (and usually at a high level of distortion) before the amp is starved and can not continue to maintain its output level.
Other amps are rated for how much power they can put out continuously at a very low distortion level. Amps of this type are the ones which (most) Steel players want to own and are the most likely to keep forever (or for as long as they can). These amps also can usually put out a great deal more power than they are rated at; albeit at a higher lever of distortion.
| b0b wrote: |
You didn't say what brand/model of speaker, but generally...
300 watts is the power handling capacity. You don't want to go over 300 watts. Lower powered amps will work fine, but you won't get the best sound of the speaker once you get below 20 watts or so. It's designed to push high volume sound. Amps in the 25-250 watt range should work very well. |
Bob probably asked his "brand/model of speaker" question in part to ascertain the efficiency of the speaker. The efficiency of the speaker (as it is mounted) also makes a difference. Speaker specifications of give a Decibel output level which is measured at some fixed distance from the speaker at a particular frequency and drive level. Something like 1 watt at 1 meter at 1000 hertz would be an example of this type of specification.
So an old pair of Tannoy HiFi speakers (high efficiency) being driven with 80 watts would be painful to be close to. A Black Widow 1502 driven with 80 watts would be comfortable to be around.
I hope that this gives you an understanding of the distinct nuances of how amps are rated in very different ways.
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Sierra U14 8+5 my copedent, 1972 MSA D10 8+4, and nothing in the Bank. 8^) |
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