Matt Riley Posted April 9, 2012 Share Posted April 9, 2012 Hi guys, I'm after some advice about my monitoring setup - I've got some RCF Monitor 55s (rated at 175W @ 8 ohms) I picked up cheap a couple of years ago which work surprisingly well as general speakers for video editing and garageband recording. The only current issue is I'm using a slightly temperamental old 60w RMS Acoustic Research amp I had knocking around to power them. The time has come for me to look at alternatives. Ideally the replacement would be compact, and powerful enough for listening at reasonable levels. I've initially been looking at the FiiO A1 although am concerned that 14w per channel might not quite be enough in this case! Link to comment Share on other sites More sharing options...
brainwave-generator Posted April 9, 2012 Share Posted April 9, 2012 Hi guys, I'm after some advice about my monitoring setup - I've got some RCF Monitor 55s (rated at 175W @ 8 ohms) I picked up cheap a couple of years ago which work surprisingly well as general speakers for video editing and garageband recording. The only current issue is I'm using a slightly temperamental old 60w RMS Acoustic Research amp I had knocking around to power them. The time has come for me to look at alternatives. Ideally the replacement would be compact, and powerful enough for listening at reasonable levels. I've initially been looking at the FiiO A1 although am concerned that 14w per channel might not quite be enough in this case! No you really want to have more power per speaker than they are rated for. Under powering them like that is likely to damage them. Really it depends on what your budget is. GIve us an idea? Link to comment Share on other sites More sharing options...
mackerr Posted April 9, 2012 Share Posted April 9, 2012 No you really want to have more power per speaker than they are rated for. Under powering them like that is likely to damage them. This is a fallacy. Mac Link to comment Share on other sites More sharing options...
brainwave-generator Posted April 9, 2012 Share Posted April 9, 2012 No you really want to have more power per speaker than they are rated for. Under powering them like that is likely to damage them. This is a fallacy. Mac It is not a fallacy. It is a simple fact that if you drive a low powered amp to it's max it is far more likely to damage a speaker than if you run a high powered amp well inside it's confines. Link to comment Share on other sites More sharing options...
Brian Posted April 9, 2012 Share Posted April 9, 2012 It is a simple fact...Actually it's a very complicated fact. It really depends on how under-rated the amp is, how over-driven it is and how over-optimistic the speaker's specs are. Link to comment Share on other sites More sharing options...
Matt Riley Posted April 9, 2012 Author Share Posted April 9, 2012 It all depends on how loud you want the speaker to go - as long as the amp isn't clipping when the speaker is at the loudest desired volume then everything's fine! At the moment the AR amp which is quite optimistically rated at 60w is more than fine for my needs - I'm only looking for a maximum of say 90-95 db(a) from the box. Really it depends on what your budget is. GIve us an idea?Lets say under £200, although the lower the better otherwise it will be more cost effective to just sell the RCFs and buy a set of KRK Rokits. Link to comment Share on other sites More sharing options...
mackerr Posted April 9, 2012 Share Posted April 9, 2012 No you really want to have more power per speaker than they are rated for. Under powering them like that is likely to damage them. This is a fallacy. Mac It is not a fallacy. It is a simple fact that if you drive a low powered amp to it's max it is far more likely to damage a speaker than if you run a high powered amp well inside it's confines. In discussions on other forums with some pretty smart loudspeaker designers this has been discounted as a cause of speaker damage repeatedly. There are 2 mechanisms for damage to speakers, over excursion, and heat. Since the small amp is below the rated power of the speaker over excursion is out of the picture. For heat to be an issue the long term power output has to be above the speaker's rated power. While the heating power of the amp will be above it's rated power with a heavily clipped signal, it will only be a maximum of twice the rated power, and then only with very hard clipping. With the OP's 60W amp he might get 120W of heat, which should make any speaker with a long term rating above 120W safe from heat damage. On the other hand, an amp with a power rating at or above the rating of the speaker may be able to damage the speaker both in terms of over excursion, and heat. It is still recommended to use an amp at or above the rating of the speaker, but not for reasons of damage control, but to get the full benefit of the speaker's capabilities without driving the amp into distortion, which is something we should be striving for. In either case we should be trying to avoid distortion unless we are talking about guitar amps. Clipping an amp is bad because it causes distortion, not because it damages speakers, and an amp is only too small if it can't get your speakers loud enough without going into clipping. Mac Link to comment Share on other sites More sharing options...
ramdram Posted April 9, 2012 Share Posted April 9, 2012 I would be interested to know mackerr's reasoning on the amp v speaker power. As for this "simple" fact, Brian says it is a very complicated fact. Indeed it is an extremely complicated fact. Were "you" to google up any gen on the subject then be hopeful your math is up to it. Your best bet I would suggest is to look for a tech' paper from a speaker manufacturer. I'm almost certain they must have some idea... Once armed with the correct info you would be better able to do the selection thing. Link to comment Share on other sites More sharing options...
dbuckley Posted April 9, 2012 Share Posted April 9, 2012 Mac is (as ever) spot on with his description. I suspect that where this story comes from is that if you take a box (say a disco box) with a 12 inch cone driver (say rated at 100W) and a small horn (say rated at 10W) and feed it from a clipped 50W amp then a lot of the output from the amp will be higher order harmonics which the crossover in the box will feed to the horn. The horn cant take that much power and thus dies. Why is the horn rated at such a low power compared to the 12 incher? For each octave the frequency goes up, you need about half the power to achieve the same SPL. So a low power horn matches a higher powered low frequency driver. On ordinary full range programme matrerial that just fine. Put 50W of screeching synth into that horn it'll probably die too. This is why hifi speakers dont make good studio monitors; their tweeters have very low power ratings. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.