Buying Speakers on eBay: RMS vs MAX

This guide is to help people who are looking to buy speakers on eBay. It will explain the difference between RMS and MAX values, what they mean, and why it is important that you concentrate on the RMS value of the speaker and how to match it to an amplifier if necessary. The guide is aimed at people who are not familiar with these values.
First of all, the most important thing to think about if you are buying your first set of speakers is what kind of audience you will be producing sound for. If you are running a mobile disco for smaller venues of up to 150 people you could get away with using a small 300w RMS speaker and amplifier system. For larger venues of up to 400 people you would ideally need at least a 1000w RMS system. If you will only be using your speakers to play background music for wedding receptions and will not need loud music then a 500w RMS system would be adequate for up to 500 people allowing for a little quiet talking through microphones too.
If you are a home user and are looking for speakers to hook up to your PC for playing some MP3s then 25-50w is plenty enough. This is just a rough idea on wattages of speakers and should not be seen as concrete specifications. The main aim of this guide is to explain the difference between RMS and Max/Programme values when buying speakers from eBay.
Ok, quite simply the RMS value of a speaker is the wattage (w) that it can handle continuously for hours on end. What many people dont realise is that many sellers on eBay claim that their speakers are 300w Max, but these speakers will not run at 300w for hours on end. The Max value of a speaker is what the speaker can handle intermittently, for example the punch of the bass, which of course is not continuous.
If you are looking for a system that has a total of 1000w, then two 500w RMS speakers will be fine matched up with an appropriate amplifier. Two speakers that are rated at 500w Max however, will not. Usually, a speakers RMS rating is half that of the Max rating and so as you can see, the system would be reduced down to only 500w RMS power.
Please remember that the RMS value is the Continuous amount of wattage that the speakers can handle over long periods of time, the MAX and PROGRAMME values are only what the speaker can handle for very short periods of time, usually for a couple of seconds at a time.
If in doubt, or if the RMS value is not displayed, use the Ask a Seller a Question Button to ask the seller what the RMS value is, it is your right to know!
Please view my other guide on how to match an amplifier to your speakers!