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Discussion Starter · #1 ·
Hi. My Pioneer PRO-111FD TV came with a pair of un-powered speakers. Here is a screen shot of their specifications:




With my limited knowledge of speakers and amplifiers, I know there is a Peak Output and then RMS output. The amplifier I'm looking at gives this info:

◎ Power Input: DC 12V 2A RECOMMENDED

◎ P.M.P.O: 2 X 180 W ( Peak Music Power Out)

◎ R.M.S: 2 X 18 W ( Root Mean Square ),

◎ Impedance: 4 - 8 oh.

◎ Signal /Noise Rasio: 100 dB

◎ T.H.D: 0.05 %

◎ Audio signal Input Method: RCA input (back panel), Mp3 Input(Back panel)



My main question: is that wattage quoted on the speakers RMS or PMPO? So is it RMS 2 x 18W (because I have two speakers) or the PMPO is 2 x 18W? If the speakers are 2x18W RMS, then I'm golden, right? If the speakers are 2x18W PMPO, then this receiver is too powerful for my needs, right?


And, say, another receiver says this:

Output Power: 200W + 200W

Input Power: 12V 6A DC

Input Sensitivity: 200mv

Input Impedance: 47K

Speaker Impedance: 4ohm to 16ohm

Frequency Reponse: 20Hz to 20KHz

Min. THD: 100dB



Is there a way for me to figure out the RMS for this other reciever? Some magical math formula? Or does that not matter because the speakers are quoted in PMPO and this receiver is also too powerful?


Sorry for all the questions; don't want to ruin my last good pair of speakers.


~Ibrahim~


P.S. I'm plugging these speakers into my computer, hence the amplifier.
 

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Speakers aren't generally rated in PMPO. Amp sometimes are (and it's meaningless.)


You have some leeway, so I would consider an amp of up to 30 watts to be pretty safe. Of course more can be used, you just need to be careful. Hooking up a 100 watt channel receiver to it means you have a real risk of damaging the speaker due to to much power.


I was going to recommend a Sonic Impact amplifier, but they seem to be out of stock, and used units are going for high prices.
 

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Discussion Starter · #3 ·
Sweetness, thank you. I'll get the one with 2 x 18W RMS which should match the speakers perfectly.


Amazingly, it was only $20 on eBay? It looks legitimate, so I think I should be all right. It has the specifications of the first amplifier specs I posted.


Thanks, mate!
Hopefully I'll remember to post back how it works out or if I kill my speakers.



~Ibrahim~
 

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You really need to know the sensitivity of the speakers as well as their nominal impedance. If the speakers are 90 dB sensitive or higher the 18 watts @ 8 ohms will be okay for normal TV listening, as opposed to serious surround sound dynamics. This calculator may help:

http://www.crownaudio.com/apps_htm/d...ct-pwr-req.htm


As an example, assume a listening distance of 4 metres (12+ feet); SPL of 80 (loud for a TV); speaker sensitivity of 90 dB; and amplifier headroom of 1 dB (likely) - that gives an amp requirement of just 2 watts, but you will need 10 times that for 90 dB SPL or dynamic sounds, and 20 watts would then be required. Most amps will double their RMS continuous output for peak (very brief) output requirements, so you should be okay if your speakers are 90 dB sensitive or better.
 

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Discussion Starter · #5 ·
Darnation....I don't know the sensitivity and Pioneer is scarce on any details.



I don't really need "stunning" sound, just decent. I mean, if music sounds even OK, I'll be happy. Speaker sensitivity: this is the same as speaker efficiency, no? I'm still learning stuff on speakers.


The way you've written, the increase of watts is also logarithmic? So I need ten times the watts for 10^10 louder sound?


I mean, since they are Pioneer speakers, I'll judge them to be pretty good quality. Sensitivity is measured at what watt level? One watt?


Sorry for all the questions: since I'm here, I thought I'd learn a thing or two.



~Ibrahim~
 

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if the speakers came in the new box with the tv then they should just plug into the tv. does the tv have an audio out on the back ?
 

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just checked your tv comes with detachable side speakers and a built in digital amp read your manuel... i thought that sounded off.
 

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Discussion Starter · #8 ·
Thanks for the reply,



Right. They are designed to work with the TV, but I have surround sound for it. And I need speakers for my computer (which does NOT have an amplifier built-in), so I thought I'd use these.


~Ibrahim~
 
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