What does Speaker Efficiency mean?

[drrocko]

HI. Just recently read a post that mentioned speaker efficiency. What does that mean and how would I use it to figure out what speaker amp combo to buy. Leaning toward a powered mixer i.e. Mackie 808. Does the more efficient speaker sound louder with less power? Is it a sound quality issue? Thanks.

[tlbonehead]

Originally posted by drrocko HI. Just recently read a post that mentioned speaker efficiency. What does that mean and how would I use it to figure out what speaker amp combo to buy. Leaning toward a powered mixer i.e. Mackie 808. Does the more efficient speaker sound louder with less power? Is it a sound quality issue? Thanks.

There's no secret or magic to it. Its exactly what you'd think the word means. The amount of final product (volume, in this case) you get out of x amount of input(wattage, in this case.)Ordinarily, it is measured at 1 watt/meter. Some also list a max, which is the DB level at the maximum power that the speaker is rated at.

[flanc]

Efficiency means a great deal. It is generally expressed as the amount of SPL (sound pressure level or how loud) a speaker can achieve measured at 1 meter of distance when powered with 1 watt of power.

 

You typically see speakers range from the low 90's to some that approach 110db. Industry experts argue that a percieved doubling in sound level occurs when DB levels increase by somewhere between 6 and 10 db. If you consider this, a speaker rated at 105 db of efficiency will be somewhere over 2 to 4 times louder than a speaker rated as 93db efficient.

 

This means a more efficient speaker will require less power to be equally as loud. To follow this further, you'll spend less money on amps with more efficient speakers; smaller/less amps draw less power which is really important to bar/club bands playing in power constrained venues.

[boseengineer]

While this is all true in theory, published sensitivity or efficiency numbers (big difference between the two !!) are close to being worthless since there is not standardized method that all manufacturers follow. There is so much variation in the different measurement methods that the numbers even for the same speaker are all over the place.

 

It would be a great data point to have, but unfortunately the numbers given by different manufacturers can simply not be compared.

[agedhorse]

What Boseengineer correctly points out is why reputation and real world performance experience with equipment is so important. Even though a Meyer speaker and a "no-name" speaker costing 1/10th as much may show the same sensitivity and power handling, my real world experience tells me that the "no name" box numbers are full of crap.

[yeahbuddy]

Efficiency is the ratio of total acoustic output relative to input power mesured in %. Distance and direction are IRRELEVANT to efficiency rating.

 

Sensitivity on the other hand, is a frequency and distance dependant measurement of output in dB SPL relative to a given input power measured directly in front of driver at a specified frequency and distance.

 

Contrary to popular belief, efficiency and sensitivity arent always directly proportional nor do they describe the same thing.

[flanc]

 

Originally posted by agedhorse What Boseengineer correctly points out is why reputation and real world performance experience with equipment is so important. Even though a Meyer speaker and a "no-name" speaker costing 1/10th as much may show the same sensitivity and power handling, my real world experience tells me that the "no name" box numbers are full of crap.

 

 

I stand by my original assertion that speaker efficiency is very important but yield to both of you (Agedhorse & Boseengineer) that there is a lack of consistency with how various manufacturers measure and report these numbers. At the end of the day, you should use your ears and common sense to mitigate any confusion that might arise from manufacturer (marketing) specs when comparing speakers. I'd probably go with some 97db efficient Meyer/Martin/EAW's over some 103db rated Gemini DJ Wonderblasters.

[dboomer]

 

Originally posted by boseengineer It would be a great data point to have, but unfortunately the numbers given by different manufacturers can simply not be compared.

 

 

So I think you have to assume the worst case where a manufacturer doesn't specify how measurements are made

 

Even when you compare apples to apples ... the published spec relies on the engineer making the measurement to make compromises. Not every frequency in the bandwidth is the same loudness. So does the stated number define the loudest point in the measurement or some average eyeballed by the engineer or ??

 

The most important thing to look for is whether the measurement is stated under anaechoic conditions or is it in half space (which will commonly add an extra 6 dB of output especially in the low end). If it doesn't say, assume it's a half space spec and subtract 6 dB from it.

 

The other cute trick, frequently performed by manufacturers who make quasi horn loaded bass enclosures, is to measure 1 meter from the speaker itself (which is up inside the box) instead of measuring from the front baffle of the speaker. As you can well imagine moving a foot closer to the speaker raises the "spec" number 4 dB or more as you are no longer really at 1 meter.

 

more info here:

http://peavey.com/support/technotes/concepts/THE_LOUDSPEAKER_SPEC_SHEET_GAME_2005.pdf

[drrocko]

Huh?

 

Sorry guys, but I think this is beyond my comprehension level. Let me ask this:

 

(I still haven't yet decided on a powered mixer vs passive mixer with powered speakers, or passive mixer, amp, passive speakers.) I'm ready to go out an listen to speakers and mixers, powered and passive.

 

If I like a speaker that is rated for 350w of power, how much power should I look for in an amp.

 

On the other hand, if I settle on say a Mackie 808 with 1200w of power (2 X 600 I think), and we use two main speakers (we already have powered monitors) is this too much power for those speakers (350w)?

 

My intuition tells me that I should find speakers I like first, then find an amp that best matches the speakers. But if I settle on the amp first (Mackie 808), then how do you properly match the speakers?

 

Thanks for zigging and zagging with me.

[flanc]

 

Originally posted by drrocko Huh? Sorry guys, but I think this is beyond my comprehension level. Let me ask this: (I still haven't yet decided on a powered mixer vs passive mixer with powered speakers, or passive mixer, amp, passive speakers.) I'm ready to go out an listen to speakers and mixers, powered and passive. If I like a speaker that is rated for 350w of power, how much power should I look for in an amp. On the other hand, if I settle on say a Mackie 808 with 1200w of power (2 X 600 I think), and we use two main speakers (we already have powered monitors) is this too much power for those speakers (350w)? My intuition tells me that I should find speakers I like first, then find an amp that best matches the speakers. But if I settle on the amp first (Mackie 808), then how do you properly match the speakers? Thanks for zigging and zagging with me.

 

 

The 600 X 2 watts are at 2ohms.....300watts (still hyped) per channel is the 8ohm rating.

[drrocko]

 

Originally posted by dboomer So I think you have to assume the worst case where a manufacturer doesn't specify how measurements are made Even when you compare apples to apples ... the published spec relies on the engineer making the measurement to make compromises. Not every frequency in the bandwidth is the same loudness. So does the stated number define the loudest point in the measurement or some average eyeballed by the engineer or ?? The most important thing to look for is whether the measurement is stated under anaechoic conditions or is it in half space (which will commonly add an extra 6 dB of output especially in the low end). If it doesn't say, assume it's a half space spec and subtract 6 dB from it. The other cute trick, frequently performed by manufacturers who make quasi horn loaded bass enclosures, is to measure 1 meter from the speaker itself (which is up inside the box) instead of measuring from the front baffle of the speaker. As you can well imagine moving a foot closer to the speaker raises the "spec" number 4 dB or more as you are no longer really at 1 meter. more info here: http://peavey.com/support/technotes/concepts/THE_LOUDSPEAKER_SPEC_SHEET_GAME_2005.pdf

 

 

Just got finished reading this. It seems from this article, there is no real standard for the arriving at the numbers the manufacturers are putting out there. So how does a small time guy like me get the best sound for his budget?

[tlbonehead]

Originally posted by drrocko Huh? Sorry guys, but I think this is beyond my comprehension level. Let me ask this: (I still haven't yet decided on a powered mixer vs passive mixer with powered speakers, or passive mixer, amp, passive speakers.) I'm ready to go out an listen to speakers and mixers, powered and passive. If I like a speaker that is rated for 350w of power, how much power should I look for in an amp. On the other hand, if I settle on say a Mackie 808 with 1200w of power (2 X 600 I think), and we use two main speakers (we already have powered monitors) is this too much power for those speakers (350w)? My intuition tells me that I should find speakers I like first, then find an amp that best matches the speakers. But if I settle on the amp first (Mackie 808), then how do you properly match the speakers? Thanks for zigging and zagging with me.

Depends on what speaker number you are using. Make sure you use the RMS rating of the speaker and not program or peak. Then get an amp that puts out about the same amount of power as the speaker's RMS rating. (Or less if you don't need that much volume) And of course,use the speakers' impedance so that you know to look for a power amp with that amount of power AT THAT IMPEDANCE.

[bazza54]

 

Even though a Meyer speaker and a "no-name" speaker costing 1/10th as much may show the same sensitivity and power handling, my real world experience tells me that the "no name" box numbers are full of crap.

 

 

Excuse me for asking, but did you have some traumatic experience with a no-name speaker earlier in your life? Why single some unspecified brand at the cheaper end of the market and compare it with one of the most expensive brands? Just because the quality of one is better than the other doesn

[agedhorse]

bazza54 - I was pointing out that some manufacturers claim things that are absolutely incorrect and when compared to a speaker (I used John Meyer's product because their performance is undisputed amongst most professionals across their entire product line) with known professional performance, the one with claimed (but false) numbers is going to stand out like a sore thumb.

 

Some of my customers have indeed purchased "great deal" - no name boxes, and also some "great deal" - boxes with brand names but in a quality line that is not representative of their professional offerings. In all cases their purchases were based on getting something greater than they actually paid for, and in all cases they were sorely dissapointed and in fact they ended up getting exactly what they paid for or less. Most bought the "super deal" speakers on the claims of specifications which were incorrect or grossly misleading.

 

All manufacturers do interpret their test results into marketing numbers in a variety of ways, and these methods vary between the different product lines as well. The more professional companies [in general] tend to be more real-world realistic with their numbers. Just a look at the auto sound industry will give you a bit of insight into how incorrect numbers sell speakers and amplifiers.

 

I'm getting the impression that I am becoming less popular here on this forum lately because some of you don't like my answers or comments. I come from a professional background and there IS a big difference between professional offerings and the non-professional "MI" offerings. There is a price difference commensurate with those differences. To claim otherwise is not fair to those here on the forum who are tryiong to learn and seperate hype from reality.

 

For me to ignore the facts (engineering and otherwise) behind this information would be unethical. Bad information is worse than no information. I (and a few others here who seem to get the similar negative comments for unpopular but correct answers) am offering informative and correct, to the best of my ability answers to subjects that are commonly misunderstood.

 

If you guys don't want accurate information, and want to perpetuate the bull{censored}, just let me know.

 

And to clarify, not everybody needs the professional offerings. In fact, the majority probably do not, BUT for them to think they are getting a professional quality with "professional specifications" when in fact they are getting something entirely different is just wrong IMO.

[drrocko]

In the final analysis, I guess it comes down to "how good does it sound?". I'll listen to as many boxes as I can and pick the ones that sounds best within our budget.

[nobrainer440]

 

Originally posted by bazza54 I think I am right in assuming that the dB measurement is simply a ratio based on a logarithmic scale. If that is the case there is no absolute dB figure. It is always referenced to another figure. By altering the reference value any final figure expressed in dB could be obtained.

 

 

I agree with some of your post, and I would say that most manufacturers doctor their specs a bit. Also, for comparison purposes, adding 6dB to the anechoic rating would give you the same comparison as subtracting 6dB from all the others.

 

dB is a relative measurement, BUT it is relative to a specific reference value. In the case of sensitivity, you are talking about dB SPL at 1 watt at 1 meter. dB SPL is a measurement relative to .00002 Pa of pressure. This would be 0dB. So if you say "this speaker is 6dB louder than that one," it is a relative measurement. But if you say "this speaker puts out 100dB SPL at 1 watt at 1 meter," you are talking about a specific pressure level at a specific power input and a specific distance.

 

Just wanted to put this on the record.

[fantasticsound]

Originally posted by agedhorse bazza54 - I was pointing out that some manufacturers claim things that are absolutely incorrect and when compared to a speaker (I used John Meyer's product because their performance is undisputed amongst most professionals across their entire product line) with known professional performance, the one with claimed (but false) numbers is going to stand out like a sore thumb... ...I'm getting the impression that I am becoming less popular here on this forum lately because some of you don't like my answers or comments. I come from a professional background and there IS a big difference between professional offerings and the non-professional "MI" offerings. There is a price difference commensurate with those differences. To claim otherwise is not fair to those here on the forum who are tryiong to learn and seperate hype from reality. For me to ignore the facts (engineering and otherwise) behind this information would be unethical. Bad information is worse than no information. I (and a few others here who seem to get the similar negative comments for unpopular but correct answers) am offering informative and correct, to the best of my ability answers to subjects that are commonly misunderstood. If you guys don't want accurate information, and want to perpetuate the bullshit, just let me know. And to clarify, not everybody needs the professional offerings. In fact, the majority probably do not, BUT for them to think they are getting a professional quality with "professional specifications" when in fact they are getting something entirely different is just wrong IMO.

 

Well, I for one hope you continue to contribute here. I know I'm not an engineer (in the strictest sense of the word) but I felt I had a pretty good grasp of the electrical concepts involved in audio. I've been "spanked" once or twice over some of those areas I thought I understood, by you and others, but even if I've been defensive about it, I still like ending up on the other side with a better understanding, even if my face is red and my "tail between my legs".

 

It has to be tough to walk into a cross section of the industry, from newbies to other professionals of every level and put your knowledge and opinions out there. It certainly isn't a meeting of only the best and the brightest. It's everybody. Newbies who've received bad information (and there's so much of that around) but believe the source and pros who think they've seen or heard it all when, in fact, they're only slightly less ignorant than the newbies. (Yeah, I'm probably closer than I'd like to admit to that second group. .) I don't envy you the desire to contribute in a place where you're likely going to be misunderstood by a large number of people, and dismissed by others for their own ego.

 

Try to remember there are those of us who really appreciate your contributions, even when they embarrass us. You have a wealth of information and experience I'll likely never have, even if I go back and study these issues in depth.

[agedhorse]

I was fortunate to have access to the (real) professional world and learn while the technologies were developing. It's important to pay this back to others who find themselves struggling to seperate the truth from the bullshit. It's tough enough when you have good information.

 

Oh, I don't mean to embarrass anyone. Most folks will stop and re-evaluate their original thoughts. Others on the other hand...

[fantasticsound]

And, to the point....

 

EV has long touted their sensitivity via their own reps and manufactuer's reps to MI retailers as one feature that customers can hear for themselves. They place the similarly sized EV that costs $500-$600 next to the cheap stuff from Yamaha, Peavey, etc. and invariably the first thing people notice is how loud the EV's sound in comparison, when all that's changed is the speaker. It's a real world difference they can hear. There are few quality differences that support the price difference in the minds of MI consumers.

[fantasticsound]

Originally posted by agedhorse I was fortunate to have access to the (real) professional world and learn while the technologies were developing. It's important to pay this back to others who find themselves struggling to seperate the truth from the bullshit. It's tough enough when you have good information. Oh, I don't mean to embarrass anyone. Most folks will stop and re-evaluate their original thoughts. Others on the other hand...

 

 

I didn't mean to suggest you meant to embarrass anyone. It's just a hazard when someone goes off, half-cocked, with bad or incomplete information. You're pretty even handed in how you approach people. Even those who continually try to bait you.

[flanc]

Originally posted by fantasticsound ..... Even those who continually try to bait you.

 

 

Yes there are folks here who engage in baiting...I'd say a few are master baiters.

[6Imzadi]

Originally posted by fantasticsound Well, I for one hope you continue to contribute here. I know I'm not an engineer (in the strictest sense of the word) but I felt I had a pretty good grasp of the electrical concepts involved in audio. I've been "spanked" once or twice over some of those areas I thought I understood, by you and others, but even if I've been defensive about it, I still like ending up on the other side with a better understanding, even if my face is red and my "tail between my legs".

I would have to agree with this as I have also been "spanked". Not that I didn't need it either. I think now, however, I have been humbled to the point of expanding my mind to take in the information given here then research it better.

 

Try to remember there are those of us who really appreciate your contributions, even when they embarrass us. You have a wealth of information and experience I'll likely never have, even if I go back and study these issues in depth.

 

HERE, HERE. I second this motion.

[agedhorse]

You will always learn more from your mistakes and embarrasments than you ever will from your successes. I have learned a lot over the years this way. They are good lessons if they force you to re-examine and learn.

 

A short story going back about 20+ years... I was showing horses in competivite western trail events and had successfully rehabbed a couple of well known performance horses who had been retired and not ridden for a few years. I had started riding and training one and was well prepared for this show when 2 days before the show he became ill. Rather than scratch out of the event, it was suggested by the horse's owner that maybe giving the other one a try was an option I hadn't considered. Since this horse hadn't been ridden in almost 3 years, taking him to a show was out of the question... or was it? Oh, he was a big, strong, stout cutting horse.

 

So, I hopped on and did some really quick tuning up the day before and figured what the hell could possibly happen? Get to the show (I was taking some other folks so I really couldn't abandon the idea totally anyhow) and saddle up. So far so good. Enter the course and do the first few obstacles almost dead-on perfect and I'm thinking I've got this thing nailed until the 4th obstacle where we are supposed to do a 360 degree turn on the hanuches and the horse's eyes roll back in his head and he starts spinning, his tounge hanging out of his mouth, squeeling some and really moving fast. I finally get him stopped and it's the first and only time I ever felt car-sick horseback. We finish up perfectly, but I hugely embarrased myself in front of my peers and learned that even though everything seemed A-OK, ALWAYS be prepared for the unexpected. Big lesson here, and fortunately nobody got hurt. It did change my riding style in that now I ride with much better balance.

 

Fast forward to this year, I was showing a very young, inexperienced but very (VERY) big horse at one of the largest horse expos on the west coast, and during the warm-up period with the arena full of other horses/riders a forklift goes by and drops a whole load of pipe scaffolding sections on the asphalt service road next to the arena. One hell of a clatter and the arena errupts in spooking horseflesh, some riders hit the dirt but because of the lesson I learned years before, and the corresponding change in my riding style, I knew without a doubt that I was not coming off... which in an arena full of spooking horses, the dirt is NOT where you want to be.

 

While an embarrasing lesson to learn, it got me to get my {censored} together which paid big dividends down the road.

[fantasticsound]

No doubt, Agedhorse! (To paraphrase a quote, 1,000 - 2,000lbs. of anything moving is dangerous! .)

[Al Poulin]

Originally posted by flanc Yes there are folks here who engage in baiting...I'd say a few are master baiters.

 

 

 

Now that's my kind of humour!