ok this is one for the resident audiophiles

i have recently acquired a pair of B&W DM4 speakers and although they're older than i am (!) they've been looked after ok, so they sound pretty good.. (my girlfriends dad was gonna chuck them )

anyways i have nothing to run them off. i was thinking of plugging them into my off-the-shelf 5yr old panasonic stereo but its rated at 120watts (im guessing 60w per channel, we lost the manual - it just says 120watts on the back).. from what i can gather from my trawls of the net the B&W's are only rated at handling 10 - 30 watts each (taken from the original manual)

i first assumed i couldnt do this, cos the higher power would kill the speakers, but after having a look around the net, there are sites saying that it would be ok to do, i just wouldnt want to turn it up to full volume..

anyone know much about this? care to help out?

also maybe suggestions in case i cant use the stereo? maybe try get an el-cheapo amp off ebay or summin or nuffin?

A larger amp is fine - good even - just don't turn it up too much. The definition of "too much" in this instance is a harsh sounding distortion. Avoid this & you should have no problems. Also, if the amp says 120 watts on the back then that would most likely be its power consumption rather than its output. It's probably more like 30-40 watts per channel.

The danger is underpowered amps and large speakers. If a low powered amp is turned up too loud it it output direct current when it clips and probably burn out the speaker coils.

I would not bother with that Panasonic amp. From your description of its power consumption. it RMS output would be likely in its teens. I bet you can easily lift it with one hand. Chuck it.

LOL!

The good ol' "if it's heavier, it's better" audiophile test (it works too!).

B&W's hey they simply are the finest loudspeaker you can get, dont worry about thier age. My fathers had a pair of B&W 801's near on 20 years and I can attest they are the best speaker ive ever heard .

Yeah dont use that panasonic thing. There is a decent DSE (Disck Smith brand) 2 channel amp that is quite decent and good value for money from what I've heard. I think they cost about $80 new. No fancy stuff though.

Matt.

yeah i'd heard B&W's were sposed to be decent speakers so i jumped at the chance to grab them when i heard they were being chucked. also when i got them the heavier=better theory was on my mind then cos these are pretty heavy for their size

with the panasonic, i cant find the exact manual but looking online at ones that have similar model numbers they all have RMS outputs of 60 - 100 watts per channel.. its just a basic stereo - 5cd changer/twin cassette/am-fm tuner but it goes alright..

my parents also have a sony stereo of similar specs that outputs 100w per channel.. would i wanna use them with that?

B&W have been the monitor speaker of choice at abbey rd studios in london for some 20+ years.
Thats where the beatles that liverpool combo recorded for our younger posters.
oh and where star wars music was recorded..

Ok. First and foremost nothing can be taken for granted, specs are constantly misstated or misinterpreted usually on purpose. (so say the 180watt powered speakers plugged into my computer at work - they are about 2" across).

You will not destroy a speaker by using to powerful an amp - just keep the volume down to a level that the speaker can handle and it will be fine (and 20 watts is a pretty decent amount for a car - don't worry - most 200 watt home stereos are in the 15-40watt range).

vicmeldrew, the turning up a small amp thing is a fallacy. Any amp no matter what size can clip and destroy a speaker, speaker size has nothing to do with it, nor has amp size. Whatever system you have, if you hear distortion through a speaker then turn down the amp because you are clipping and that can destory speakers.

You are however more likely to turn up a small amp to the point of clipping, this is where the get more than enough mentality comes into it.

PS. B&W might have been the monitors of choice at Abbey road for 20+ years, but both starwars and the beatles were a little earlier than that.

Gack, how could you suggest he buy some Dick Slop garbage to use as hi-fi?!?!?

The good thing about quality speakers is that you can enjoy them even at lower volume levels for many types of music. Depending on the amp, you are more likely to find that the amp isn't good enough for the speakers.

What will help is going to a good hi-fi shop (not a brand-name shop, as they most often don't know what they are doing) and get some better than basic cable to connect the amp to the speakers with (and other components to the amp). That will make a big difference, as the lower the quality of physical metal audio has to be transmitted through, the lower the quality of the sound.

Small amps have been known to blow up even quite high powered speakers because a clipping amp produces far more energy in the high end (square waves contain lots of high frequencies) than what any music could ever contain. The result is blown high frequency drivers. Very small amps can blow up high powered HF drivers without difficulty if driven to clipping.

Large amps can also blow up small speakers too - by "poling" or clipping the speakers themselves. This is more likely to affect low frequency drivers. Either way, this stuff only happen if things get put of hand.

ok so if im listening to music and theres no distortion that i can hear then im not hurting the speakers and all is well?

thinking i'l give em a go on my 'rents sony

methinks i also might goto a specialist hifi shop and score some good speaker wire, thanks for the tip curra. how expensive is it?

Hey audio peoples... and Gurgle...

Would he have to worry about impedence at all? The ohms?

I can remember my dad talking about it once when I was hooking up some old speakers to my amp... hmm...

Of course he would, he just didn't ask about it so I assumed that it was ok.

Soulman, you basically repeated exactly what I said. My comment was that it wasn't only small amps that did it - any amp can blow up any speaker if turned up to high.

You are less likely to turn up a bigger amp to high though - better to have to much power than not enough.

funny how those Krell 2 x 50 Watt amps weigh about 60 kilos versus something bought from Aldi that is rated to deliver 7 x 100 Watts that weighs about 5 kg.

And just for what it is worth (although this has mostly been covered):

B&W's rock.
The bigger the amp the better... within reason.
*Listen* when you are listening... (although tests show most people have trouble picking up harmonic distortion below about 10% levels... over excursion of the cones of the speaker are easier to pick up... the speaker tends to 'fart' at first, then goes 'crack' when it finally hits the back plate or jumps from the gap)
Small amps DO kill more speakers than large amps do. (having worked for both a car audio importer and a large multinational Pro Audio company that also does hi-fi I can tell you this is definitely the case... as has been pointed out it is to do with the square waves that are introduced in amplifier clipping and the extreme amounts of high-frequency energy that this creates. I've seen about 10 times the amount of burnt voice coils as opposed bent voice coil formers - not a perfect test of what 'killed' a speaker but a reasonable guide.)