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| Thread ID: 145518 | 2017-11-22 03:35:00 | Panasonic stereo - question about speakers | BBCmicro (15761) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1442386 | 2017-11-27 00:57:00 | I read in an Audiophile magazine somewhere (waiting room sometime in my past, who knows) that most music is listened to at around 10W of power give or take. I read it again when researching if a 20W T-amp was going to be enough on the PC (it really is). I can really recommend these low power 12v amps for PC use. Similar to this one www.ebay.com.au w I got one for $60 NZ several years ago, connected a spare pair of Bookshelf speakers to it, and have been using it for PC sound ever since. It's loud enough to listen too around the house, has sound quality you wouldn't believe at the price, and takes up a tiny amount of space. Note I'm not vouching for that particular model or seller, I just did a quick search and picked one that looked like mine. I think the "T-class" may be a bit of a misnomer at least for some of them but who really cares. Before buying one I read a few reviews, including one by an audio technician who was comparing it to a $10k reference amp or something like that. I remember his stated disgust at the fact that within it's power range it was in the same league quality wise and may even have been better. Some power trivia for you for those interested, some of you will already know. 3dB = double /half the power and approximates the minimum volume step an average listener can make out Because of this a 100W amplifier is not twice as loud as a 50W one (1 3dB step), but rather you almost can't tell the difference. The 100W will have less distortion and sound cleaner at high volume in theory though - all else being even This explains why a 20W stereo amp is actually very loud, it's only 3 audible volume jumps behind a 160W stereo amp at max and probably more than half the audible volume. It also tells you that a 92 dB/W speaker is just barely louder than an 89 dB/W at the same input power level and if the difference is < 3dB you will likely not hear it. Volume dials are not linear. For a small to medium room, a true 20W RMS per channel amp is enough for most music listening. I tried a 10W for a while and it was pretty good too but occasionally I found myself wanting more or triggering the protection circuit and having it cut out. |
dugimodo (138) | ||
| 1442387 | 2017-11-27 03:30:00 | I agree with what Dugi has posted and would just add a couple of points. Impedance matching is important for maximum power transfer: Think along the lines of you filling a bottle with liquid through a funnel and the air keeps bubbling back. That is the liquid equivalent of what causes distortion. Be very sceptical of Frequency Response specifications: Having an amplifier rated flat from 16hz to 20Khz doesn’t mean a thing unless your Ears are, and I can guarantee they aren’t. An awful lot of people cant hear below about 30hz and above 10Khz, so, before you spend a lot of money get your hearing checked. As a matter of interest, remember that Middle C on a Piano is only 260 Hz, and the the whole range of a standard Piano is only 4Khz. Finally, read about Timbre, HERE (en.wikipedia.org) would be a good place to start. Good luck coming to a indisputable conclusion as to the correct Sound System. :) |
B.M. (505) | ||
| 1442388 | 2017-11-27 03:53:00 | ...... a indisputable conclusion as to the correct Sound System. :) To my mind, the correct sound system in what pleases and sounds good in your ears. I have a 6 year old SONY Android WALKMAN Z-1060 32GB and it sounds wonderful to me even with my beggared hearing. Ken :) |
kenj (9738) | ||
| 1442389 | 2017-11-27 08:34:00 | Yes that was the problem :) Thanks Too many volume controls in series - I missed the phone itself I hope the 30% distortion is in the speakers not the amplifier tweak'e although, with the low volumes I listen to these days it mightn't matter the distortion is made by the amp and distortion can kill speakers. distortion rating is often played with to make the amp spec seam better than it is. marketing BS. at low volumes its probably not much of an issue. |
tweak'e (69) | ||
| 1442390 | 2017-12-03 17:52:00 | This hifi system SC-UX100 is good. My uncle use this model. Good details. But distort at the very end with highest volume. | Eliza23 (17586) | ||
| 1442391 | 2017-12-03 19:35:00 | the distortion is made by the amp Yes I've just read in the manual "measured by spectrum analyser" Talking about marketing BS, what do you think of this "woofer": 8475 |
BBCmicro (15761) | ||
| 1442392 | 2017-12-03 21:10:00 | That's a Bluetooth speaker and a 2.5" woofer is absolutely a legitimate thing. Not one that you'd use with a home theatre obviously, but it's still a woofer. I have a Sony Bluetooth speaker with a similar sized woofer and it blows my mind how much Bass they actually get out of something that size. Not that it can compare with a full size stereo but many of these tiny speakers offer better sound than the giant Ghetto blasters of the 80's and 90's. I think the small end of the scale is where speaker technology has made the biggest improvements. |
dugimodo (138) | ||
| 1442393 | 2017-12-03 22:07:00 | Impedance matching is important for maximum power transfer: Not for modern 'solid state ' audio amps . Its not really even a thing :-) Sure VERY important for RF & valve amps . Modern transistor/mosfet based power amps would have output impedance of less than 1ohm, so hardly matched at all . And, IMPEDANCE of speaker varies greatly with freq, normal hifi speaker boxes may have impedance that STARTS at 6ohm and will easily double that or more with differnet audio freq . I agree on all the market BS with hifi . There was an expensive amp(cost thousands) that got very good reviews . Someone opened it up for a look . It was based around a generic power IC chip, the same as might be found in low end cheapies . It was very much a con job . |
1101 (13337) | ||
| 1442394 | 2017-12-03 23:07:00 | And, IMPEDANCE of speaker varies greatly with freq, normal hifi speaker boxes may have impedance that STARTS at 6ohm and will easily double that or more with differnet audio freq True - see plot for my B and W DM4 speakers My speakers came with measured frequency plots and they look impressive. The hardware is a 143mm woofer, 19mm high freq tweeter, and an "upper mid frequency" unit The manual doesn't state the diameter of the mid range unit but perhaps the NZ agent could help me? The agent, according to the manual, is Arnold and Wright at 210 Willis St Wellington. If they're no longer there I could contact the manufacturer, as the manual helpfully provides their telex address in England. They've also given a telegram address - Monex Worthing - but that might have been discontinued?? |
BBCmicro (15761) | ||
| 1442395 | 2017-12-04 22:12:00 | Valve audio amplifiers also had very low output impedance due to the use of negative feedback. For example the popular 10 watt Mullard amplifier using EL84s was 0.9 ohm into a 15 ohm load, and the 20 watt version using a pair of EL34 output valves was 0.3 ohm into 15 ohms, according to the "Mullard Circuits for Audio Amplifiers" book. 15 ohm speakers were commonly used in those days |
Terry Porritt (14) | ||
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