The meaning of "Watts" on a hi fi help?

owsaboutthatthen

Can anyone tell me what PMPO watts are (in this case 50 x 2 output) and 5 watts x 2 RMS on a hi fi? I'm in the process of buying a new one and want decent sound but not overpowering. Does this sound decent or not?!

DatabaseError

long time since i looked into it, so, from (bad) memory, Peak Music Power Output is the kind of thing i'd expect on an amstrad stacker system from 1985, a nice, large, meaningless number. RMS is a real measurement of the power of the speakers, 5 watts (x2 speakers) is slightly more powerful than a fly's flatulence, you can still go 'loud' but the flatulence increases through the speakers. Your standard car radio will be a minimum of 25w x 4, and will sound best, to sane, non chavvy people, at a relatively low volume, maybe 1/3rd, at this volume none of the components are having to work very hard to output the music, so they can do a good job of it. my hifi (retired to the loft) had 80 watt RMS speakers, but i only played music at about 1/4 full volume, and it sounded great, 1/2 vol was way too loud. Best advice I can give is find your nearest Richer Sounds and ask advice there (and buy equipment), it may not look as pretty as the 5w thing you are looking at, but it will possibly cost less, and sound immeasurably better.

ManAtHome

Yep, listen before you buy - plenty of stuff goes loud, but some stuff starts distorting before other stuff. Would also recommend Richer Sounds - even though they have tiny shops, quite a few have listening "rooms", likely to be more realistic than in a warehouse type shop (slightly better than not listening at all...).

unrich

The normal way of measuring the power output of audio equipment is the Root Mean Square(RMS) of the sound output waves. Its a kind of average power.

PMPO is the peak measure of power output. Worthless. Only manufacurers seeking to hoodwink a prospective purchaser ever use PMPO.
In normal listening you will never hear the max PMPO output.

In normal listening you should never hear the full RMS as the sound will probably be distorting so badly you will not want it turned up that high.

Its a long time since I bought a separate but I think I bought a 50W (RMS) capable amp and never had it turned past about 20% on the volume.

2x 5W RMS (5W per stereo channel ) should be fine for a small/medium room and comfortable listening. If you ever have a party and want it turned up then it will probably distort like anything.

Any more help from an audophile?

A person I once worked with admitted he bought a house because the living room was the right shape for his audio setup.

+1 for Tonyhague and richer sounds.

DatabaseError

unrich wrote: »

A person I once worked with admitted he bought a house because the living room was the right shape for his audio setup.

Sounds like an old friend of mine, he did spend money on his hi-fi, but the sound /imaging was incredible, from 2 speakers and a record (remember them?) I could close my eyes and place each musician around me.

totalsolutions

Watts = Power
No.1 The more you have the bigger/better/more you have.
No.2 You pay for Power, see no.1, the more you pay in bills.
No.3 Power is the same in AC or DC circuits, a great leveller.
No.4 Pure power is hard to come by. The cleaner and more precise the more it costs.
No.5 True Power is measured in RMS

Note that sound levels are measured in decibels not watts

Fifer

Power has no real relationship with sound quality, only with how loud a particular speaker load can be driven (although a low power amp will tend to distort really horribly before a high power one). That said, any manufacturer who specifies PMPO rather than RMS is probably producing rubbish which is best avoided. It's a very misleading (and flattering) figure. RMS is the only meaningful power figure to quote.

A visit to Richer Sounds is probably a good idea. They sell a lot of good stuff at quite low prices and they don't carry really bad stuff, so you can't go to far worng.

meester

totalsolutions wrote: »

Watts = Power
No.1 The more you have the bigger/better/more you have.
No.2 You pay for Power, see no.1, the more you pay in bills.
No.3 Power is the same in AC or DC circuits, a great leveller.
No.4 Pure power is hard to come by. The cleaner and more precise the more it costs.
No.5 True Power is measured in RMS

Note that sound levels are measured in decibels not watts

The cost of power is not really significant relative to the cost of the appliance.

The OP should in any case forget the Argos wattage figures completely and read some reviews in a hi-fi mag and then go listen to some hi-fi in person in a hifi shop (quite possibly Richer Sounds).

Conor_3

owsaboutthatthen wrote: »

Can anyone tell me what PMPO watts are (in this case 50 x 2 output) and 5 watts x 2 RMS on a hi fi? I'm in the process of buying a new one and want decent sound but not overpowering. Does this sound decent or not?!

PMPO is the figure the manufacturers of cheap tat love to quote. It is a figure which is the maximum output a speaker can handle at a specific frequency for a specific amount of time (usually in seconds) before it blows itself to bits. Even though it's misleading, it's perfectly legal to quote it because technically it's correct.

The RMS value is the true indication of what they're rated at. Using the power output tells you nothing of how they'll sound. It'll not tell you how good the bass, mid or treble is. You can only do that by taking your favourite CD along and listening to it.

cheepnis

All of the above.
and for clarity, see...

http://www.webopedia.com/TERM/P/PMPO.html

Play loud for maximum sonority

owsaboutthatthen

meester wrote: »

The cost of power is not really significant relative to the cost of the appliance.

The OP should in any case forget the Argos wattage figures completely and read some reviews in a hi-fi mag and then go listen to some hi-fi in person in a hifi shop (quite possibly Richer Sounds).

I've been looking on ebay for hi-fi's and it is someone selling on there that has quoted the PMPO! Unfortunately I don't have a Richer Sounds local to me (think Prestwich is the nearest). However thanks for all your advice its been very informative indeed.