Path: utzoo!utgpu!cunews!bnrgate!bigsur!bnr-rsc!mascot@bnr.ca From: mascot@bnr.ca (Scott Mason) Newsgroups: comp.sys.ibm.pc.hardware Subject: Re: Sound cards-sound blaster, adlib, roland.. Message-ID: <4481@bnr-rsc.UUCP> Date: 9 May 91 02:22:33 GMT References: <116g..m@rpi.edu> <41652@fmsrl7.UUCP> Sender: news@bnr-rsc.UUCP Distribution: comp Organization: Bell-Northern Research, Ottawa, Ontario, Canada Lines: 46 In article sigma@obee.ipl.rpi.edu (Kevin Martin) writes: > >I'm posting because I've got a question to go along with this. I bought >Realistic Minimus 2.5 speakers from Radio Shack. They're rated at 20 >watts, and sound fantastic. Turn up the Soundblaster and they can get >quite loud. Now, what I didn't realise when I bought the speakers was that >the Soundblaster drives 2w or 4w speakers. Like I said, it sounds great >with these 20w critters. > >Why does this work? I was worried I'd have to exchange them for smaller >speakers. Apart from this concern, I highly recommend these speakers. > The 4 Watt rating of the Soundblaster is the maximum electrical power that it can supply to the speakers and still achieve reasonable distortion levels. Normally this is an ``RMS'' value, which indicates that the ``average'' output can reach this level. It can be inflated by specifying it as a ``peak'' value instead, in which case the loudest output can reach this level. Note that this is at best a guideline unless the manufacturer specifies what they consider reasonable distortion. Also, you may not be able to achieve the ``average'' output level specified if your sound contains large peaks which amplifier cannot produce. However, unless you have the volume up high the output level will be below the maximum rating. The 20 Watt rating of your speakers indicates the maximum electrical power that they can receive without damage. Again the manufacturer may have meant peak or average input power. Note that this is not related to how loud the sound produced will be. This is determined by a separate parameter which gives the speaker's efficiently, typically by specifying how loud it is with a 1 watt average input. Efficiency does not scale directly - it is logarithmic. A speaker rated at 90dB at 1 watt will sound twice as loud as one rated at 87dB. A problem can occur if your amplifier is much too small to drive your speakers to the volume levels that you like. This is because the spectrum of a distorted signal is not at all like that of music and can damage speakers whose rating is intended for music. Probably more speakers are damaged by modest amplifiers producing lots of distortion than by powerful amplifiers which produce too much music power. In short, your arrangement is quite reasonable. --