Perfectly said. But it will keep going on like a zombie that never dies. LOL.
What is the sweet spot for WPC?
- Thread starter Taketheflame
- Start date
Perfectly said. But it will keep going on like a zombie that never dies. LOL.
50nstillhifi
Super Member
There was once an audio theorem.. more power provides increased "dynamic headroom", an element most audio enthusiasts prefer. I am not sure if this is sound (pardon the pun) reasoning given most listened material is now digitally enhanced or delivered.
spicer
Lunatic Member
Assuming the same sound quality of the amp... same sonic signature... same whatever... more power is always good. Like power available from a throttle... car, airplane, fighter jet, rocket ship... the more power available the better from the drivers, cockpit position. No longer use them, no longer have a big room, but for years I had Altec 19s, known for efficiency... and they sounded fine with a Marantz 2235... open, airy... using it right up to the point where power compression is first detectable, back it off just a little and the combination breathes full bodied sound into the room... however, put in a 2325, 125 watts per, and it is another ball game... at least twice... more actually... as 'loud' before any hint of power compression, and, this might be opinion, but it seems to sound better, more authority, then the 2235 at 35 watts per at it's comfortable limit. What ever that means... I don't know... kind of afraid to say, but this is my experience with almost any speaker. Now... if we're comparing a 'lousy' higher wattage amp to a 'good sounding' amp of lesser wattage... the lesser wattage wins every time unless we are talking booze and drug fueled listening, and it still loses but nobody cares except the neighbors...
foobarz
Active Member
The sweet spot in wpc is enough to avoid ever clipping with your speakers, up to their nominal input power, and also enough headroom wpc up to and beyond the speaker's max music/dynamic input power. If/when the amp runs out of power and clips, that is when it is most likely that the speakers will be destroyed (by the clipping). For example, I have 6ohm speakers with 150W nominal input power and 250W music input power handling. My amp was selected for them as a match because it can deliver 195Wpc RMS into 6ohms and up to 315Wpc dynamic/music power. The amplifier will not clip within the speaker's power handling. If you do manage to really exceed the speaker power handling without clipping, then the speakers will still be damaged from excessive power input (not from clipping). The trouble is that an under-powered amp that can deliver say 125Wpc RMS with a small amount of dynamic headroom may clip within the speaker's power rating and still damage the speakers anyhow from the clipping. The clipped signal is like a powerful DC current and also a sudden loss of speaker diaphragm/cone control - the diaphragm undergoes a powerful shearing etc. when control is suddenly lost at high power by clipping. This can just break at cone or dome driver apart or burn up the voice coils ... something like that. The amp needs to be powerful enough to deliver power without ever clipping for the speaker connected - my opinion.
Holy crap, why do you always pick fights and twist words into things that were never said???
It's this simple, if you are trying to recreate the front row of any loud concert, or blasting volume to the limits, more power is a very good idea, probably even a "must have" to prevent exposing speakers to harsh clipping.
If you are not trying to blast maximum SPL (which most aren't), and have even modestly efficient speakers (which most do), and even a mildly reflective room (which almost all do), you likely do not need more power beyond 30ish WPC. There is nothing ever wrong with getting more power than you need, but unless you like feeding money into a shredder, you probably don't need more power (more likely, that upgrade money would be better spent getting a better quality amp than simply a more powerful amp (and usually even better spent upgrading speakers or adding a sub rather than changing the amp
)).For those contemplating getting a more powerful amplifier to get better bass, or better sound quality, out of an existing pair of speakers at normal volume levels -- which is a topic frequently discussed on AK -- I personally think that advising them to get a more powerful amplifier of the same quality level is not a good investment to solve that problem because -- at normal volume levels -- the amp they have isn't being stressed. I say that based upon the principles of how current flow works, which I outlined in a prior post, quoted again below for your convenience. The theory below also correlates with my decades of experience with many amps/receivers.
I want to be clear that I don't discount anyone's experience that a more powerful amp sounded better to them at in-limit volumes -- it could be other differences within the two amps -- and vintage amps vary by sample depending on the health of the internal components. There are many reasons it could sound better independent of maximum power output level. Psychology can also be a factor, though I tend to believe the direct experiences of seasoned audio persons. Whatever the case, the current flow physics make it unlikely that simply increasing power output will improve bass, or any other aspect of the sound, at reasonable volume levels. The design and internal components used in any amp makes more of a sound quality difference than maximum power output (when used at volumes volume levels within operational limits).
I never even remotely suggested that smaller amps sound better than larger amps. That is you twisting words to invent something I never said. Power level and sound quality have no inherent relationship at all. Any differences favoring the sound quality of higher power or lower power amps is due to design differences and internal component choices made by the manufacturer for each brand and model of amp. That said, for any fixed dollar amount, you can buy a higher quality amp by targeting modest power levels than you can if you target only high power amps. Please don't twist this -- that's not me saying small amps are better, that's just basic economics (I know you are still going to twist it anyway).
For the record, the post you quoted is below . I never suggested small amps sound better. In fact, I said pick the higher power amp if everything else is equal. Have fun with your word-twisting invented arguments -- I have zero tolerance for it.
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Frbock
Active Member
Well, if my basic trig still still works, the square inches are still Pi*d times the number of speakers.
1 12 in speaker is 37.68 sq in
2 8 in speakers is 50.24 sq in
Back in the 70s Dynaco built the A50 with 2 10 in woofers instead of 1 15 for a simple reason, the total mass of the speaker cones was less. Similar surface area.
z-adamson
Addicted Member
A 12in woofer has a cone area of about 113 square inches
A 8in woofer has a cone area of about 50 square inches
Its radius squared multiplied by pi.
Not pi multiplied by diameter
I don't think your "basic trig still still works"...
RTally
Speaker addict
I see a couple errors.
First, when referring to speaker size, we normally are referring to the frame size, not the cone diameter. A typical 12" speaker has a cone with a 9.25" diameter. A typical 8" speaker has a cone diameter of 6". This diameter ignores the slight amount that the surround contributes to the sound emitting surface of the driver. Check out any web page that sells surround foam and you can find the cone diameter specs for most sizes and brands of drivers.
Second, Geometry rules, more so than trig. The area of a circle is pi times the radius squared.
12" driver area = 3.14 * 9.25/2 * 9.25/2 = 67.2 sq. in.
8" driver area = 3.14 * 6/2 * 6/2 = 28.3 sq. in.
So, two 8" drivers have 56.6 sq. in. of cone area, which is less than a 12" driver that has 67.2 sq. in.
In this case, I think the area of the cone defined by the mouth of the cone is pertinent, which is reflected by the above calculations. Although, I can see a case being made to compare the surface areas of the right conical frustum of the cones.
z-adamson
Addicted Member
Understood....as long as you compare cone diameter to cone diameter OR frame diameter to frame diameter, the result should be the same, as far as which has more area.
Be it one 12 vs two 8s or one 9.25 vs two 6s.
The math yields the same result as long as you are consistent....right?
If you go by frame size, two 8s comes to 88% of the single 12. If you go by your cone measurements, the two 8s (or 6s) comes to 84% of the single 12 (or 9.25). So, pretty close, even though we all know that the frame isn't what really counts.
RTally
Speaker addict
As I noted in another comment earlier in this thread:
Math counts or matters or . . . something.
Precision matters. If you are going to the effort to calculate something, do it correctly or don't bother wasting time.
Accuracy matters. Being off by 4% when doing a basic calculation is sloppy and inaccurate, particularly when it is no more trouble to use the correct dimensions.
z-adamson
Addicted Member
What if you used the correct dimensions then added in the area of the surrounds? That would surley reduce the discrepancy. Additionally, my 12s (JBL2213H) come out to 9.5in. HPM100 woofers commonly referred to as 12s come out to 9 7/8in. So even to call 12s a 9.25in cone could be a stretch. But for the sake of generalizing and in the non-scientific conversational context of "two of this size woofer is more area than one of that size woofer"....using basket size does tell the tale. Right?
RTally
Speaker addict
As for the surrounds, they contribute very little to the generation of sound waves as they transition from the cone edge to the stationary frame through the roll. If you think otherwise, please explain.
You can make all the excuses you want, but when comparing the radiating surfaces of drivers, it is cone area that matters, not frame size. If you want to compare two specific drivers, have at it, but if you want to make general statements, then at least start with the correct premise, frame size is irrelevant.
I am reminded of the time NASA lost a $125 million Mars probe because, for one calculation, they failed to convert between metric and Imperial system values. It seems like it should have been close enough, but accuracy matters, no matter what we do. I bet they learned from their mistake. Hmmm.
Wrong. Completely wrong. Area is pi x radius x radius or pi r squared. So 2 x (16pi) = 32 pi. pi x 6 x 6 = 36 pi... Simple math. You described circumference and not surface area...
z-adamson
Addicted Member
I get the preference for accuracy. If, for example someone says "Two 8in JBL LE8 woofers have more cone area than a single 12in JBL 123a woofer!!" Then of course it would make sense to measure the cone area. But on the other hand if someone like @botrytis says "Two 8in woofers have more cone area than a single 12in woofer!"...there are no exact values to go by. Even to call a 12in woofer a 9.25in cone is a guess that will not lead to an accurate calculation. No matter how you calculate it, the 12 comes out bigger and yet accurate, driver specific numbers are not available other than frame size. Or you can average out the radiating cone area for all drivers of a given frame size. You still get the same outcome as to which has more area.