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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Lounge => Topic started by: Danijel Foler on December 25, 2013, 01:46:10 PM
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hello
Manufacturers of the PA speakers in most cases spec amp to have 2x RMS speaker rating. So, if speaker have 500W amp need to have 1000W. I can confirm that this formula work fantastic and no speaker and amp ever overheating or work with clipping. In this way amp and spekaer work with 50% load. Even for bass you can use 4x RMS rating because peaks. But, 99% active speakers have amps 0.5-1x RMS rating. Why is that??? How large 1kw 18" driver can be driven with 500w-1000w amp? Cant be.
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The simple answer is they aren't underpowered.
You need to research the different between driving loudspeakers full range and multi-way. Most powered speakers are mulit-way, and dialed in far better than passive speakers.
It isn't apples to apples.
JR
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The other thing to consider is the potential for damage with higher rated amps vs the minimal increase in output. By using a smaller amp inside the box, it makes it more idiot resistant. It's difficult to explain to some people that they blew their speakers, even with the gain controls at less than maximum.
When it comes to powered speakers, just pay attention to the output levels. The number of watts inside is truly meaningless for anything other than bragging rights.
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There is no simple answer. Sometimes it is price sensitive for a particular target market.
Another factor is that many people belive that they can simply turn up the level as high as they want and not tear up the loudspeaker-distortion and compression be damned.
So by using a smaller amp-there is less possibility of damaging the drivers-but it can still happen.
Limiters only work to a certain extent. They offer a "measure" of protection-but do not guarantee it.
I like to think of it as airbags for your car. They offer some protection but if you driver you car off a cliff the air bags are not likely to do much for you.
They "assume" normal precautions are taken when driving. Just like limiters-they "assume" the operator is paying proper attention to what is going on.
Sadly in many cases that is not the case and most people operating sound systems simply do not have a clue.
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Manufacturers of the PA speakers in most cases spec amp to have 2x RMS speaker rating. So, if speaker have 500W amp need to have 1000W.
That may be recommended for many situations but that 500W (continuous) power rating is not what the speaker "needs" nor does having less than 1,000W make it "underpowered". Whether a speaker has sufficient power is a function of the application, if a speaker gets loud enough for the use with just a fraction of the rated power then it is not "underpowered", while the speaker power rating defines how much power the speaker can handle rather than how much it needs.
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I like to think of it as airbags for your car. They offer some protection but if you driver you car off a cliff the air bags are not likely to do much
I really like this analogy. Also somewhat related is that if you actually listen to your speakers, you don't need limiters. Unfortunately, most of my customer don't...
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The speakers are designed and the correct power for the speakers is installed. If the company is honest with their specs and states 130db SPL, then what do you care if it's a 5 watt amp or a 5000 watt amp as long as the cabinet reaches the design goal without self destructing? All too often time and thought is wasted on a non issue, and this is one of them.
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The speakers are designed and the correct power for the speakers is installed. If the company is honest with their specs and states 130db SPL, then what do you care if it's a 5 watt amp or a 5000 watt amp as long as the cabinet reaches the design goal without self destructing? All too often time and thought is wasted on a non issue, and this is one of them.
The problem is that if a loudspeaker is rated for max of 130dB, then people expect to play music and put an SPL meter in front of it and read 130dB.
This sounds like a good idea-but 130dB is the peak. If you say that "average" music has a 10dB crest factor (most has more than that) then the typical meter (that has a slow response time (even though it say "fast" will read around 120dB. So they keep pushing it trying to get to the "rated" 130dB. Higher dynamic range material would produce lower average readings.
With a meter that can actually respond to the peaks-they would read the rated 130dB peaks.
Things are not always as simple as people would like them to be.
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I agree, so rate the cabinet at 125db. Regardless the point is simple. Who gives a fuck about the amplifier rating as long as the cabinets work as advertised.
ps- Merry Christmas.
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I agree, so rate the cabinet at 125db. Regardless the point is simple. Who gives a fuck about the amplifier rating as long as the cabinets work as advertised.
ps- Merry Christmas.
But the cabinet can actually produce 130dB-just not in the way most people would like to measure it.
Another example might be saying your car gets 80 mpg. yet somebody else can only get 30 mpg out of the same model/year. Well they are measuring it during normal day to day driving, you you got your 80mpg doing down a long mountain.
Your mileage was correct-just not measured how other think it should be.
There are some products out there that state max outputs just like that-with a "special test tone" or such. Yes the cabinet can produce the max output stated-just not under normal conditions. The result is that the actual measured and rated peaks are close to 20dB different.
Of course if you rate the cabinets at how the "average person" measures with an "average meter", then there will be others who don't and guess which products people buy? The one that is rated higher. Unless they can compare side by side-and THEN the differences quickly rise to the surface.
But most people don't have that opportunity.
The whole problem is that music is dynamic-so there are all sorts of different numbers that could be "presented" with the same test results. It all depends on what the person stating the numbers is trying to do.
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What products is the OP even talking about? How often do we know the drivers and their ratings in powered speakers?
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The problem is that if a loudspeaker is rated for max of 130dB, then people expect to play music and put an SPL meter in front of it and read 130dB.
This sounds like a good idea-but 130dB is the peak. If you say that "average" music has a 10dB crest factor (most has more than that) then the typical meter (that has a slow response time (even though it say "fast" will read around 120dB. So they keep pushing it trying to get to the "rated" 130dB. Higher dynamic range material would produce lower average readings.
With a meter that can actually respond to the peaks-they would read the rated 130dB peaks.
Things are not always as simple as people would like them to be.
+1,
Also, even if the speaker does make the continuous SPL rating listed, there is nothing that says it sounds good at that SPL.
IME, the big difference between less expensive speakers, and more pro level gear is that the more pro level gear sounds good all the way up to where it clips (and even then in most cases).
Less expensive boxes tend to sound good at lower volumes, but not so much when they are forced to get really loud.
.... and all that assumes that the SPL readings are actually done the same way.
To answer the OP's question.... active speakers are very likely powered perfectly for the amp and driver installed. If anything, the amps installed are much bigger than they need to be (especially for the HF driver) and are digitally limited. The larger amps are only used because it is less expensive to use the exact same amp for HF and LF on all their speaker lines.
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If anything, the amps installed are much bigger than they need to be (especially for the HF driver) and are digitally limited. The larger amps are only used because it is less expensive to use the exact same amp for HF and LF on all their speaker lines.
I wouldn't bet big money on that. powered speaker designers can use higher impedance drivers for high-mid and low impedance drivers for LF, so same voltage power amp makes more appropriate power for the passbands.
Talking about power in the context of loudspeakers is just a convenient hook that consumers think they understand.
JR
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hello
Manufacturers of the PA speakers in most cases spec amp to have 2x RMS speaker rating. So, if speaker have 500W amp need to have 1000W. I can confirm that this formula work fantastic and no speaker and amp ever overheating or work with clipping. In this way amp and spekaer work with 50% load. Even for bass you can use 4x RMS rating because peaks. But, 99% active speakers have amps 0.5-1x RMS rating. Why is that??? How large 1kw 18" driver can be driven with 500w-1000w amp? Cant be.
It's my understanding that an amp rated at 500 w RMS can put out more than that for short periods of time without clipping, and thus matches the speaker specs perfectly. In my mind the only reason for an amp 2xrms of speaker, is to make sure that it doesn't clip at maximum volume. I generally see amplifier manufacturers claim that a speaker needs an amplifier with 2-4xrms (wonder why? more sales). Where as a lot of speaker manufacturers say the amp can match rms. I'm sure that a powered speaker is about perfectly matched with it's amp. One thing I don't understand is for example the QSC K series, the amplifier supplies up to 500 watts to the woofer, and up to 500 watts to the horn. This seems like overkill for the horn, as I've never seen one that can handle that much power. And if it could it would be so much louder than the woofer...
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It's my understanding that an amp rated at 500 w RMS can put out more than that for short periods of time without clipping, and thus matches the speaker specs perfectly.
not likely
In my mind the only reason for an amp 2xrms of speaker, is to make sure that it doesn't clip at maximum volume. I generally see amplifier manufacturers claim that a speaker needs an amplifier with 2-4xrms (wonder why? more sales). Where as a lot of speaker manufacturers say the amp can match rms. I'm sure that a powered speaker is about perfectly matched with it's amp. One thing I don't understand is for example the QSC K series, the amplifier supplies up to 500 watts to the woofer, and up to 500 watts to the horn. This seems like overkill for the horn, as I've never seen one that can handle that much power. And if it could it would be so much louder than the woofer...
Think about it: a speaker with two (presumably identical) 500W amplifiers (into 2 ohms)
woofer: 2 ohms
tweeter (horn) 8 ohms
net result: marketing voodoo
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And that's why you eliminate all the bullshit by 1) choosing a quality, known and respected brand of your choice, and then 2) listening to the cabinet under real life conditions before you buy it.
I've never placed much importance on numbers that relate to SPL unless I was looking at them myself. What concerns me more is the right cabinet doing the job I want it to do. don't care about anything else. If I size my amps in relation to the boxes I'm powering and they do the job without being damaged, then I'm happy, and the customer is happy. In the end I don't get paid to design and engineer the cabinet. I get paid to make it sound good.
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It's my understanding that an amp rated at 500 w RMS can put out more than that for short periods of time without clipping, and thus matches the speaker specs perfectly.
In the old days-when amps were measured using continuous sine waves- you could get "a tad" bit more power when measuring a short pulse.
But with todays amplifiers-(class D and others) they can only produce a short pulse-and that is the rating of the amplifier.
Why in the world would a manufacturer rate an amplifier for 500 watts when it can actually put out 1000 watts? They would be shooting themselves in the foot.
I would argue that in most cases if an amplifier can deliver 500 watts-that is THE MOST it can do on a very short duration signal. And depending on how things are "measured/calculated", 500 watts is probably VERY gracious.
I WOULD NOT expect or assume that the amp could produce any more power than that.
In most of todays amps the power the amp can produce continuously is around 6dB less than the peak power. Yet you almost NEVER see the continuous rating-ONLY the peak rating.
And that will be my stance until somebody proves me wrong.
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Yet you almost NEVER see the continuous rating-ONLY the peak rating.
Because the sales department only want to see the highest number possible.
Steve.
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In most of todays amps the power the amp can produce continuously is around 6dB less than the peak power. Yet you almost NEVER see the continuous rating-ONLY the peak rating.
And that will be my stance until somebody proves me wrong.
I have written about this before too... It cost more money "and" makes the amp a worse match for how speakers consume power to make amps full continuous power. For the last few decades amp makers backed off 24x7 power output because consumers were unwilling to pay for it, and spent their money buying reduced term output amps.
Now with class D efficiency the duty cycle calculus is a little different, but I prefer to leave amp/driver selection to the speaker engineers. The market will work out what is a value or not.
"You can't fool all the people all the time."
JR
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I don't like powered speakers for a number of reasons John, but that's another discussion. Your last statement though is spot on and probably what I've been trying to say.
There are plenty of people being paid to design these boxes and I'll leave it up to them to match the components. If the design is good, then everyone's happy and the box sells. If the design is faulted then just like you said, it won't take long for the market to work it out.
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I don't like powered speakers for a number of reasons John, but that's another discussion.
After 15 years at Peavey and getting to know several excellent loudspeaker and amp designers (and many consumers). i really like the opportunity to have that decision made by people who understand more about the drivers and amps than simple rules of thumb.
The potential today with cheap DSP and Class D amps, makes the potential for even higher performance and reliability available. I know more than average about the technology and know that I can't do a better job than these engineers that do it for a living.
Your last statement though is spot on and probably what I've been trying to say.
There are plenty of people being paid to design these boxes and I'll leave it up to them to match the components. If the design is good, then everyone's happy and the box sells. If the design is faulted then just like you said, it won't take long for the market to work it out.
Rather than good design or bad, I suspect this comes down to expensive vs cheap boxes designed to meet a lower price point using cheaper components and construction methods. That said even with sharp pencil design I suspect powered cabinets to spank non-powered systems all else equal because of the design engineer involvement.
JR
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I'm confused, I though amps gave RMS rating not peak power ratings. When I read the specs it says RMS or sometimes continuous. For example the QSC powered speakers say 1000W continous. I thought it was only car amplifiers which boasted their max transient output.
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I'm confused, I though amps gave RMS rating not peak power ratings. When I read the specs it says RMS or sometimes continuous. For example the QSC powered speakers say 1000W continous. I thought it was only car amplifiers which boasted their max transient output.
Back in the Ye Olde Dayz, there was this thing called "dynamic headroom". It was the ability to squeeze the last bit of current from the PSU filter caps and apply it to the output transistors. How much more you could get for a few milliseconds (before you ran out of either current or output stage gain) varied from around 1.0dB or so to as little as zero.
These days, there is almost no such thing due to value engineering.
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I'm confused, I though amps gave RMS rating not peak power ratings. I thought it was only car amplifiers which boasted their max transient output.
Times have changed and amp designs have changed with it. IMO the "RMS" amplifier design was never a very efficient use of resources as music was always a much more dynamic signal than a pure sinewave. But it's also ironic that while current amplifier designs have moved towards a more dynamic output with less constant current capacity popular music recordings are more compressed than ever before and there are now music types with sustained synth notes that require an amplifier be capable of sustaining high currents and voltages. So maybe we will see the market segmenting into two types with heavy iron sub amps built like they were in the old days and lightweight digital amps for everything else.
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Back in the Ye Olde Dayz, there was this thing called "dynamic headroom". It was the ability to squeeze the last bit of current from the PSU filter caps and apply it to the output transistors. How much more you could get for a few milliseconds (before you ran out of either current or output stage gain) varied from around 1.0dB or so to as little as zero.
These days, there is almost no such thing due to value engineering.
Not to confuse the OP even more, back in the '70s there was consideration (by the IHF IIRC) of a dynamic headroom spec, mostly in the context of reproducing wide dynamic range classical music (Like 1812 overture with cannon or mortar explosions). This was before the trick amp topologies like Class G/H were popular so peak vs continuos sine wave power was mostly a matter of transformer/power supply "regulation" ( regulation means how much the voltage sags under continuous current vs. no load voltage due to winding resistance) and power supply reservoir cap sizing that affects ripple voltage and clipping under power. The FTC even got involved with voltage sag after the transformer gets hot (temperature coefficient of copper wire increases resistance with increased temp causing more internal losses) adding a thermal preconditioning step before measuring rated output power.
These metrics like dynamic headroom and overly dynamic recordings did not gain much currency with consumers so faded away. FWIW modern amps with PFC and regulated supplies will not suffer regulation or temperature sag while a smart amp may reduce voltage in response to difficult local conditions.
Back in the late '80s I designed a small bedroom studio monitor amp for Peavey (AMR) that was a nominal 35W amp, but was capable of 2x the voltage output transiently, so 4x the peak output power... In practice that 4x power deteriorated quickly, so i specified it as something like 100W for X mSec, 60W for 15 seconds (limited on purpose to not overheat the amp), then 35W for 24x7. This was a kick-ass little amp, but the technology did not scale up to higher power points cost effectively, so that was the first and last model in that series.
This is an interesting (perhaps) diversion, but loudspeaker design and mating with appropriate amplification involves multiple variables beyond this simple discussion.
JR
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Regarding your thread topic:
They isn't...
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This is an interesting (perhaps) diversion, but loudspeaker design and mating with appropriate amplification involves multiple variables beyond this simple discussion.
JR
"The truth is rarely pure and never simple. Life would be tedious if it were either, and modern audio systems a complete impossibility." - Oscar "not a sound guy" Wilde, with topical satire
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Regarding your thread topic:
They isn't...
He means them's not.
Steve.
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Regarding your thread topic:
They isn't...
Ha! ;D An alternative answer is "it aren't."
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Danijel Foler, please excuse these guys. They probably don't realize you are in Croatia.
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hello
Manufacturers of the PA speakers in most cases spec amp to have 2x RMS speaker rating. So, if speaker have 500W amp need to have 1000W. I can confirm that this formula work fantastic and no speaker and amp ever overheating or work with clipping. In this way amp and spekaer work with 50% load. Even for bass you can use 4x RMS rating because peaks. But, 99% active speakers have amps 0.5-1x RMS rating. Why is that??? How large 1kw 18" driver can be driven with 500w-1000w amp? Cant be.
I used to go with this formula, until I started custom building bass guitar cabs. Not many woofers can handle more than its 1x RMS power at bass frequencies without exceeding Xmax, and sound like flutters. Running transducers beyond Xmax can damage woofer physically, while clipping @ the amp or mixer simply sends square wave to transducers and make it heat up quicker - more of a problem for compression driver than woofer. When powered speakers bi-amp the HF and LF separately, clipping @ LF amp won't transfer the clipping to the HF amp section.
Having said that, I don't know which powered speakers uses amplifier w/ power half of woofer's RMS rating. Most of what I came across are 1x to 1.5x (QSC, JBL...).
Now putting my business hat on. A powered speaker with amplifier RMS power 2x that of transducer's RMS rating can end up in transducer premature physical failure (low frequency especially) without user-induced clipping: most likely oem responsibility. On the other hand, a powered speaker with amplifier RMS power 1x to 1.5x that of transducer's RMS rating, if damaged by user's excessive clipping signal inputs: most likely user responsibility.
This I believe is the reason why we don't see powered speaker with amplifier having 2x woofer's RMS rating. Not saying what's right or wrong, just trying to rationalize the situation.
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Danijel Foler, please excuse these guys. They probably don't realize you are in Croatia.
I wasn't making fun of his command of the English language. I was making fun of his topic.
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here is one rare example in which amps have 2x rms speaker ratings:
http://www.rcf.it/products/touring-and-theatre/tts56-a
Why I ask question about under powered active speakers? Before some time I have PA for rent, mostly dj playback EDM (techno/trance). Here is picture:
(http://imageshack.us/scaled/thumb/527/img1106hd5.jpg) (http://imageshack.us/photo/my-images/527/img1106hd5.jpg/)
(http://imageshack.us/scaled/thumb/515/img1100sp4.jpg) (http://imageshack.us/photo/my-images/515/img1100sp4.jpg/)
This RCF ESW1018 subs have 600W RMS but crest factor 2.5x, which is 1500W program and 6000W peak (L18S800 driver). My Peavey CS4000 is bridged for two subs and this is clear 1600W per sub 20hz-20khz. I can put this amps to clip and woofer I think can even use 4x RMS power. Never to much woofer excursion, never amp overheating, never into clip of course, all day all night, clean power...
If I have for this subs only 600W RMS, this system cant work to maximum potential and amp will non-stop overworking. Someone have comparison with car. Is it strange that 7.0L V8 in Corvette Z06 can have better mpg than some 1L city car???? No, because V8 will work with 20% instead 100%.
I think that for money I can build better passive system with 2x or more RMS than with active speakers. In this way all components have needed headroom for playback without problems.
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Danijel Foler, please excuse these guys. They probably don't realize you are in Croatia.
Good point.
My friends who have English as a second or third language like to have their mistakes corrected for them so they can learn.
Unfortunately, we didn't do that.
I apologise.
Steve.
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I think that for money I can build better passive system with 2x or more RMS than with active speakers. In this way all components have needed headroom for playback without problems.
Given that your comparison is to a box that cost $10,000 to $11,000 USD, I should hope so.
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My experience is at the bottom end of the market. Down here I think passive+amp sounds better than powered. The amps in economical powered speakers are spec'd by the guys in marketting not engineering.
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Another practice aspect of powered speaker is cooling. Until until recently, powered speakers cannot get too much wattage in the integrated amplifier because there are no huge fans to cool: most of them rely on passive cooling or tiny fans. Passive speakers use racked amplifiers that have much more airflow since noise is not as much a factor - can be stowed away elsewhere.
With Class D amplifiers more prevalent now, powered speakers can pack more wattage without overheating.
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Another practice aspect of powered speaker is cooling. Until until recently, powered speakers cannot get too much wattage in the integrated amplifier because there are no huge fans to cool: most of them rely on passive cooling or tiny fans. Passive speakers use racked amplifiers that have much more airflow since noise is not as much a factor - can be stowed away elsewhere.
With Class D amplifiers more prevalent now, powered speakers can pack more wattage without overheating.
While temperature may be a minor consideration the larger benefit from class D and switching supplies is the lower size and weight and more importantly lower cost, at least lower cost for modern class D. Consumers have some difficultly grasping a fair price comparison between powered speakers and passive speakers + amp(s), + crossovers. Even though the complete package could be a better value it appears to be higher priced than buying passive speakers
JR
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Another practice aspect of powered speaker is cooling. Until until recently, powered speakers cannot get too much wattage in the integrated amplifier because there are no huge fans to cool: most of them rely on passive cooling or tiny fans. Passive speakers use racked amplifiers that have much more airflow since noise is not as much a factor - can be stowed away elsewhere.
Which also leads to how cooling, loading, response, etc. of the driver in a particular box can affect the resulting power handling capability and just looking at the woofer driver rating of a powered speaker does not tell the whole story.
A powered speaker is typically a system of DSP, amplifier, driver(s), cabinet and sometimes preamp. Manufacturers make decisions in the design of that system to optimize various performance and reliability characteristics. They may decide to compromise some aspects in order to focus on others.
This RCF ESW1018 subs have 600W RMS but crest factor 2.5x, which is 1500W program and 6000W peak (L18S800 driver). My Peavey CS4000 is bridged for two subs and this is clear 1600W per sub 20hz-20khz. I can put this amps to clip and woofer I think can even use 4x RMS power. Never to much woofer excursion, never amp overheating, never into clip of course, all day all night, clean power...
Where did you get those numbers and the 2.5X crest factor for your driver? Look at the General Specifications in http://www.lautsprechershop.de/pdf/rcf/l18s800.pdf (http://www.lautsprechershop.de/pdf/rcf/l18s800.pdf), as far as I can tell the power rating for the driver noted is 700W Continuous and 1400W Program. They don't identify a Peak rating but I'd assume 2800W. If the drivers were rated 600W with a 2.5X crest factor then the peak rating would be just 1500W, not 6000W, with probably a 1050W Program rating. If you want to run 3200W into each sub then go for it, I'm sure your parts supplier will love you.
Also look at the response associated with the bare driver and those poiwer ratings. To get a relatively flat response down to 40 or 50Hz you're apparently looking at the cabinet and processing having to add something like 8 to 10dB of low frequency boost to the driver response. What might that do to the power the driver can handle?
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Consumers have some difficultly grasping a fair price comparison between powered speakers and passive speakers + amp(s), + crossovers. Even though the complete package could be a better value it appears to be higher priced than buying passive speakers.
When I buy speakers I go to a store with about $x. When I listen to $x powered and passive speakers the $x passives sound so much better.
Of course I should be comparing $x passives to $2x powered, but I already have the amp channels. And I didn't walk into the store planning to spend $2x. :-)
... but I do hate carrying too much gear at setup/teardown.
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When I buy speakers I go to a store with about $x. When I listen to $x powered and passive speakers the $x passives sound so much better.
Of course I should be comparing $x passives to $2x powered, but I already have the amp channels. And I didn't walk into the store planning to spend $2x. :-)
... but I do hate carrying too much gear at setup/teardown.
IMO you can't really compare $x passive with $x active without factoring in the cost of new amps for the passive. For example:
Active
JBL PRX 715 = $949 x2 = $1,898
Total = $1,898
Passive
JBL PRX415 = $549 x2 = $1,098
Crown X4000 Power amp(1000w@8 ohms per channel) = $649
Total = $1,747
All prices taken from Musicians Friend.
It should be noted that, according to the specs, the 715 is rated at 136dB peak and the 415 is rated at 128dB peak. Therefore I don't know how fair a comparison this is as the 715 is rated higher than the 415 though I think they are close enough for comparison. I also suspect, from other reading other forum posts(not personal experience), that the 715s sound much better than the 415 because of the internal bi-amping and DSP.
Anyway I also see that it makes sense to buy passive if you already have a significant investment in power amps, so I see where you're coming from.
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At the risk of repeating myself, any good powered cabinet will have an active crossover and use separate amps per driver. Perhaps a simplified passive crossover between mid and high. So add a crossover and perhaps more channels of amps.
JR
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I wasn't claiming my comparision made perfect sense. Evolutionary step-at-a-time purchases can lead to odd outcomes.
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At the risk of repeating myself, any good powered cabinet will have an active crossover and use separate amps per driver. Perhaps a simplified passive crossover between mid and high. So add a crossover and perhaps more channels of amps.
Also consider that with a powered speaker the speaker processing not limited to the signal flow, virtual processing devices and allowed settings defined by others as you are with an unpowered speaker and external digital speaker processor. A powered speaker designer can freely incorporate any signal processing they feel may be appropriate. And you don't even have to think about the processing settings or investing any of your own effort in determining them.
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Also consider that with a powered speaker the speaker processing not limited to the signal flow, virtual processing devices and allowed settings defined by others as you are with an unpowered speaker and external digital speaker processor. A powered speaker designer can freely incorporate any signal processing they feel may be appropriate. And you don't even have to think about the processing settings or investing any of your own effort in determining them.
Yup, this is an old theme from me, but another useful factor in favor of properly engineered powered speakers is that smart driver protection can be engineered in. While perhaps not necessary a designer could even directly measure driver temperature rise, and dynamically tweak internal limiting wrt actual conditions.
I know I can't do a better job than the full time speaker designers. YMMV Of course cheap powered speakers are just like cheap passives.... cheap.
JR
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I know I can't do a better job than the full time speaker designers. YMMV Of course cheap powered speakers are just like cheap passives.... cheap.
+1
Better design is better design.
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IMO you can't really compare $x passive with $x active without factoring in the cost of new amps for the passive. For example:
Active
JBL PRX 715 = $949 x2 = $1,898
Total = $1,898
Passive
JBL PRX415 = $549 x2 = $1,098
Crown X4000 Power amp(1000w@8 ohms per channel) = $649
Total = $1,747
All prices taken from Musicians Friend.
It should be noted that, according to the specs, the 715 is rated at 136dB peak and the 415 is rated at 128dB peak. Therefore I don't know how fair a comparison this is as the 715 is rated higher than the 415 though I think they are close enough for comparison. I also suspect, from other reading other forum posts(not personal experience), that the 715s sound much better than the 415 because of the internal bi-amping and DSP.
Anyway I also see that it makes sense to buy passive if you already have a significant investment in power amps, so I see where you're coming from.
Those boxes also make use of completely different 15's and HF drivers than the other, and are nowhere near alike soundwise, or even the price of the raw components themselves.