Differentwith professional guitarists, hobbyist and advanced learner have a fewer chanceto play at bigger stage .Certainly ,they might play at a smaller venue, or practiceat home . So how many power of amp is good for them?
1.
The relationship between powerand loudness
Letus start from discussing relationship between power and loudness. The unit of measure loudness most common is the decibel
(dB), the dB is a unit of measure for sound intensity or level. It is alogarithmic scale developed to express wide ranging quantities on a simplescale. Because it is logarithmic, it can be a little bit confusing. As anexample, a doubling of volume is not equal to twice the number of dB. The chartbelow will help you to better understand the dB and how it relates to what youhear, and what is happening throughout your system as volume levels change. Butfirst, we need to look at the other end of the equation.
Power,
in this discussion, refers to watts. Power defined is the rate at whichenergy is converted or dissipated, as in the case of an amplifier driving aloudspeaker. It is important in our discussion in defining the generalrelationship.
A simple chart will help to understand therelationship of the terms we have introduced: Looking at the chart, and starting at the left, wecan see than an increase of 3dB results in a
voltage increase1.4 times the original, a doubling of power, and yields only a subjectiveincrease in loudness only 1.23 times the original. To get a doubling ofloudness, it is important to note that an increase of 10dB is necessary. And toreproduce that volume through our loudspeakers, note that we require
ten times
more power from the amplifier! The chart below is relationship between power withloud 100 watts is 1.23 as loud as 50 watts.
80 watts is 1.1562 as loud as 50 watts.
60 watts is 1.0578 as loud as 50 watts.
40 watts is 94% as loud as 50 watts.
30 watts is 86% as loud as 50 watts.
25 watts is 81% as loud as 50 watts.
22 watts is 78% as loud as 50 watts.
20 watts is 76% as loud as 50 watts.
18 watts is 74% as loud as 50 watts.
15 watts is 70% as loud as 50 watts.
12 watts is 65% as loud as 50 watts.
10 watts is 62% as loud as 50 watts.
9 watts is 60% as loud as 50 watts.
8 watts is 56% as loud as 50 watts.
7 watts is 55% as loud as 50 watts.
6 watts is 53% as loud as 50 watts.
5 watts is 50% as loud as 50 watts.
4 watts is 47% as loud as 50 watts.
3 watts is 43% as loud as 50 watts.
2 watts is 38% as loud as 50 watts.
1 watt is 31% as loud as 50 watts.
3/4 watt is 28% as loud as 50 watts.
1/2 watt is 25% as loud as 50 watts.
1/4 watt is 20% as loud as 50 watts.
1/10 watt is 15% as loud as 50 watts.
50mW is 13% as loud as 50 watts
20mW is 10% as loud as 50 watts.
10mW is 8% as loud as 50 watts.
5mW is 6% as loud as 50 watts.
Sowe can know
- All other things being equal, a 100-watt amp will be just perceptibly louder than a 50-watt amp. It takes about a ten-fold increase in power to double perceived volume. That's right, you'd need a 500-watt amp to be "twice as loud" as your buddy's 50-watt amp. Even more thought-provoking is the fact that a 50-watt amp will only be perceived as a little bit louder than a 15-watt amp driving the same cabinet!
- All other things are almost never equal. There are so many variables controlling sound pressure level (SPL) and perceived volume that it is quite common for a small amp to sound louder than a much more powerful amp.
- The initial purchase price of a 100-watt amp will be significantly higher than a 30-watt amp with similar features.
- It will cost you signficantly more to re-tube a 100-watt amp.
- If you are driving a 30- or 50-watt amp hard enough to require frequent re-tubing, chances are very good that you will also drive the 100-watt amp hard enough to require frequent re tubing (at significantly higher cost).
2.
Does hobbyist need 100w amp?
Below arerelationship between hearing and volume:
50dB-60dB volume ofelectric guitar without power.
70dB-80dB thevolume of watching TV and wood guitar
80-90dB Volume ofsolid guitar amp, this volume don't noise your neighbor on day.
90dB-100dB Thevolume of ROCK ,you can start feeling cool ,although it still need moreheadroom. It is only one fifth of full volume of 30w-50w amp damaging yourhearing. Not face to speaker.
100dB-110dB Thevolume is very cool. half of volume of 50w amp, good headroom, damaged hearingserious .
110dB-120dB It islimit of amp.
Within a few years hearing of player will be permanentlydamaged.
- There is absolutely
no
venue that
requires
a larger amp and cabinet than one suitable for use as a stage monitor – provided that the members of the band don't get into a juvenile competition to outdo each other. Need more feedback? Fine, move closer to the amp, for crying out loud! Typically, a really good 30-watt rig with a suitable cab is ample! Depending on the composition of your band and the variety of venues you play, an even smaller rig mic'ed to the PA and then pumped to stage monitors may be even better.
Note that while a good 30-watt rig has ample volume you may end up having to buy a more powerful rig to get other desired features. - At a small venue, a 15 to 30 watt amp can be placed behind the band in a traditional position and used without a mic. In this position the rig serves as a monitor for the guitarist and as the primary amplification for the guitar.
- At a medium venue, the small rig can be placed in front of and facing the guitarist as a monitor, and be mic'ed and run through the band's PA. The band's PA speakers are placed along the front of the stage and facing out. This arrangement allows the sound to be balanced at the mixer and allows the band to flood a medium to large venue without damaging their hearing.
- At a large to giant venue, that same small rig can be arranged much as described above but now the band's mixer feeds the house PA. This is the only way to reach the back of the room without dangerous SPLs near the stage at a large venue and
would be required no matter how powerful a rig the guitarist has. - Smaller equipment takes up less space on cramped stages.
- The money you save by purchasing a smaller amp can fund a nice power conditioner to protect your equipment and clean up power line noise – the conditioner will cost less too since now you don't need one that will handle a billion watts.
- If the band members will agree not to compete,
all
of them can recognize significant savings by not having to purchase unnecessary equipment. - Your band is far more likely to be called back for a repeat engagement if you provide a well-balanced, easily managed performance than if you are just obnoxiously and uncontrollably loud.
- Many guitarists already have the monster amp – it isn't necessary to get rid of it. You can use an attenuator (see the attenuator myth) and perhaps a smaller cab.
3.
How about amp which power is within 10w?
Itdepend on whatsound you want. If you like clean sound, No problem, one 5w combowhich has smaller speaker is good for you.But if you want distortion sound(manypeople want it). It is different.
Thereare fours components in total guitar amp syetem.
#1 preamp tube distortion( which let soundhard ,more metal), #2 power tube distortion( which let sound warm ) #3 speakerdistortion ( I like regard it as No-Line of speaker)#4 the physical movement ofair that your speakers produce at high volumes.
When the power of amp issmaller such as 5w.It is difficult to obtain more distortion from power tube. At same time, because the capacity of power tube issmaller, the distortion of preamp is limited . The power push coil of speakeris too smaller . The response of speaker will became bad.
4.
What is the best combination of amp for hobbyists ?
Wehave discussed 100w and 5w guitar amp , know disadvantages of two kind of amp.
What is good choice for hobbyist?
One amp, which power is within 50w , is good selection.At same time combination 50w amp with one attenuator will help you more. |
发表于 2012-10-29 07:56:34
好吧。。那末就接受现实，好在我不大有时间弹琴。。。。
15瓦玩过，金属疲软不刚正，中频偏多，但是弹清音比较好听，50瓦6L6后级管的比较适合干金属
