"Power hungry" speakers

Hi folks, can you please explain to me why certain speakers so demanding with regard to amplifier power? I'm not talking about some notoriously-difficult-to-drive Apogees or some old Thiel models, but about speakers like the Sonus Faber Extrema's. These speakers do not belong to the realm of the less-than-1-Ohm-impedance-drop speakers, but need high powered amplifiers if you want to make them sing. Even 300 Watts wouldn't be enough! What is this for some ridiculous statement (or is this a fact?). What is the explanation for this phenomenon? I do not know much about physics, but I wonder what is happening with those Watts inside the speakers: will they be converted into warmth or something?
For all the years of audio mania, it seems to me that the component that consumes most of those precious watts are some overbuilt or heavily built crossovers, as well as the type of drivers used for the design of the speakers. Some rather large or what might seem to be very power hungry speakers, with large numbers of drivers can sometimes be more efficient than a pair of two way monitors (IE: array speakers)

Another consideration, especially with monitors, especially two ways, is that when their midwoofers are smaller, the more inefficient they are. Nevertheless, just because they are small and very inefficient (ie: 81 db per 1 watt at 1 meter) they are not necessarily hard to drive. An example of this are speakers that often accompany very cheap, low market mini system speakers that have this sort of spec, and yet, are rather loud with whatever low current watts that their companion amplifiers come with.

Efficiency is a matter of brands. Some brands seem to be notoriously difficult to drive, some that I associate directly with ineffiency are:


and other ones that I cannot readily remember.
Bemopti: Right on. The more complex the crossover, the more "power hungry" the speakers will be. Not only are such designs "sucking up power", they are "eating signal" at the expense of losing micro-dynamics and detail. After all, there wouldn't be any power there if the signal didn't call for it. Losing that power means losing signal. Thermal inefficiency / power loss due to heavy parts count in the crossover is directly related to "lifelessness" in presentation with a lack of liquidity. These are speakers that measure great, but sound boring.

In my experience, many companies that make their own drivers and farm them out to other companies should stay away from designing / building / marketing complete assemblies. Dynaudio, Morel, Focal aka "JMLabs", etc... are prime examples. These companies all make good to excellent drivers, but lose sight of what music is and try to make a product that is technically excellent. In the process, their efforts to design something that is "worthy of their technical excellence" and "design prowess" ends up stripping the music of its' "soul".

The above "thermal inefficiency" comment should NOT confuse speakers that are simply less efficient with designs that have too many passive parts between the amp / drivers. Sean
Both of you (Sean and Bemopti) mentioned the use of complex crossovers that are consuming the Watts. As far as I'm informed, the crossover in the Sonus Faber Extrema is very simple. It is in fact a design without capacitors in the signalpath. How do you explain the fact that these speakers (the Extrema's) in particular are very power hungry?
I'm not familiar with Sonus designs at all. The only thing that i can think of is tonal balance. A speaker with a very laid back or semi-sunken response will never sound as "loud" as a speaker with a more forward ( or even "flatter" ) response. From what i've read, the Sonus speakers have a rather laid back / soft presentation. Sean
I believe the motor magnet affects efficiency.
The stronger the magnet, the louder the speaker will play with x amount of power.
The size of the drivers is also a factor. Tiny drivers cannot move enough air (to go loud) with average power.
Dazzdax, maybe I have an explanation about the crossover of the Sonus being simple, and yet, why of their consuming such a large amounts of current? Last year, I was experimenting with an old Pioneer receiver from the 70s I have picked up from the garbage as well as a small midi JVC system (2002 model) that I had imported from Asia. I was trying to make them run with a pair of EPOS ES11, 87 db efficiency, no crossover, just one cap between the wires and the doomed metal tweeter. This load was supposed to be very benign...and yet, the sound was very distant, muddied, with both...I was running them with a pair of old radioshack wires I had both for non essensial duties...had chopped some and had decided to "solder" them together again.

Later, I ran the same set of wires to my powered sub and guess what, the same muted sound. I swapped cables and there the sub was, reproducing loud, clear volumes and programs.

The point is this, even with copper wire and simple solder, there can be a major hampering in the power and delivery of the signal to some drivers. Eventhough Sonus might have what it seem to the naked eyes as a "few" components, they still might be robbing the drivers of the "original" watts that were intended for them.

Do not get me wrong, people swear by Sonus Faber and other of these rather power hungry speaker manufacturers, but maybe it was the intention of the company to make somehow demanding speakers in order to get clientele who are moneyed, AKA: can afford to have monster amps, rather than some tube loving, hi efficiency owners of SET amps.

To make my speculation into conclusion, you will simply need to have the same pair of speakers, Sonus with one tweeter and one 6-7 inch midwoofer and another of the same type of set up, one tweeter and midwoofer, play the same source or selections for about 2 hours at medium volume. Then, touch the crossovers of the X brand of speaker and the Sonus. If the Sonus crossover components are warmer than the other speakers, then you will be able to determine that the Sonus Fabers soak up the watts and current converting them into heat rather than sound waves. Inefficient, even with a group of smaller crossover components!
JM Labs originated as a speaker manufacturer (JM= Jacques Mahul, the designer of said speakers). Allegedly, Focal acquired the speaker manufacturer who now operates as the finished (consumer) products division of Focal. So it wasn't quite a matter of fitting the drivers into a speaker enclosure -- at least, not in the beginning...
As a general rule, efficiency in drive units is a function of moving parts mass vs. magnet strength. High strength magnets are expensive.
Efficiency in the speaker system, as has been noted, is also a matter of how much energy is used by the filters (x-over, notches, zobels, etc, you name it).
Hence, average magnets with heavy filters, do not a dynamic speaker make! Ultimately, small level info is lost to our perception as Sean notes -- and the result can be pleasant, flat across the critical range, etc, and "laid back".

Re, Sonus Faber & others: don't forget that, while the x-overs may be capacitor-less, it doesn't mean they are simple (1st order, etc) all over (I don't know if they are...). Also, the drivers used, like the expensive Scanspeak woofs on some models, are not that sensitive to begin with... some are ref'd at 86-87db...
First let me state that I have seen improvements in the sound of many speakers through use of more powerful amplifiers. In particular, my MG 1.6 now enjoy 600 watts.
However, it is very obvious (a simple voltage measurement will do) that the power actually drawn by the speakers is nowhere near the amplifier's capability. There are other amplifier characteristric that come with high power capability that do the magic.

Crossover networks may have a lot to do with speaker performance, but they don't "eat up" power. If they did they would get very hot, which they don't, and could not be mounted inside a wool (or fiberglass) insulated box.

The first thing you learn in EE101 is that the power dissipated in a capacitor is zero.

The woofer inductor will generate a little heat because the woofer amps flow through the inductor. However, crossover inductors generally have low resistance compared with the driver, so most of the heat will end up in the driver voice coil.

A crossover without any capacitors means that the tweeter must have an inductor in parallel with it. To avoid a near dead short on the amplifier at low frequency a resistor must be put in series. This resistor, and the inductor will draw power, and will get hot. This "capacitorless" crossover is essentially a series crossover, with the woofer and its parallel capacitor replaced by a resistor.
Eldartford, thanks for the clarification.
I am running b+w 801s which are said to be power hungry.I can tell you that I tried a 170 watt bryston amplifier and it drove the speakers to earth shattering levels.You must remember that 99% of the time your speakers are only using a few watts(usually less then 20 to be sure).I think this "POWER" thing has been very much over stated.99.9% of the time a 25 watt amp would do the job.However it is when the large dynamic swings take place that one could use more power...the differnce between a 300 watt amp and a 600 watt amp is only 3 db (for every 3 db increase then double the power is required)...so the difference between a 150 watt amp and a 300 watt amp is miniscule...
Capacitors have varying levels of dielectric absorption and thermal losses as frequency is varied. Their transfer characteristics ( linearity ) can be measured and compared over a given frequency range. None of this is new technology and studying these factors along with many others is what have led to the breakthroughs in higher resolution / lower loss circuitry. This is part of why newer gear has the potential to sound better than older gear i.e. improvements in passive parts. Some capacitors that were believed to be "excellent" in the past are actually quite horrid in performance. Most electrolytics are amongst that group along with several others.

In order to get around this problem, some have experimented with using two different types of capacitors wired in parallel i.e. "bypasses". The non-linearities of one cap offset those of the other, summing together to improve the transfer characterstics of the circuit on the whole. This can be a VERY tricky business though as you can end up with two ( or more ) non-complimentary distortions, resulting in even poorer performance. This is why some folks say that "bypasses work well" and "bypasses create other problems". Sean
Start looking at bass transients into low sensitivity and / or low impedance and / or highly reactive loads and you need hundreds upon hundreds of watts. Combining all of the above will mean that you need a MONSTER sized amp to do the job right. This is part of the reason why high powered "digital" or high effiency amplifier designs have been finding their way into more and more systems. They can work quite effectively as sub amplifiers. There are some simple tricks that can be done to these amps that make them even better for this purpose. Sean
Sean...Even as I typed it I knew that you would take issue with my comment about capacitors dissipating no power! OK. An ideal capacitor dissipates no power. Real capacitors are not ideal. But, with regard to power dissipation, they are darned close.

Have you ever experimented with a capacitorless crossover? What do you think? With your multiKilowatt amplification system a little power loss could be tolerated.

Sean125...As you say, "Earth shattering" or "ear splitting" volume does not require many watts. Doing it so that your ears are not split is the purpose of high powered amps. By the way, we tend to judge loudness by the presence of distortion. If it is distorted it sounds loud, even if an accurate SPL meter proves otherwise.
I am well aware of what distortion represents.I can assure you that I heard very loud spl at low distortion lvls..I am not saying that a bigger amp isn't more desireable.But to get sound pressure lvls it is simple to figure out and NO...A few watts won't give it to you very very high spls as you have suggested..that is unless you speakers are extrememly efficient..ie.a speaker with 88bd efficiency goes as follows
1 watt= 87 db
2 watts=90 db
4 watts=93 db
8 watts=96 db
16 watts=99 db
32 watts=102 db
64 watts=105 db
128 watts=108 db
256 watts=111 db
512 watts=114 db
1024 watts=117 db
So ,I think the person who started this thread can see from the above what power is required to do what.Bottom line is this..Unless you have extremely inefficient speakers or you listen at very high levels then a 600 watt amp is not a must have.I am not saying it isn't better to have the power but if money is an issue etc then don't get too hung up on the wattage ...
El: My main system is actively crossed. No capacitors between amp and speakers other than the speaker cables themselves.

My Brother's system was previously quad-amped using passive networks a while back. He is now actively crossed and the passive networks came out of the system. The difference between active and passive was staggering to say the least. Bare in mind that the passive networks were VERY simple first order designs.

Sean125: The chart that you provided doesn't take into account the speaker going into compression and is also based on 1 meter spl's. Taking measurements at the seated listening position would alter those readings DRASTICALLY.

What others may find interesting and i find to be "coincidental" is that the mains in my HT system are rated at 87 dB's @ 1 w @ 1 meter. I was running these with two amps and passively biamping. I had 400+ wpc up top and 500+ wpc on the bottom end. When running these in two channel mode, even with this much power, i could drive the amps into saturation. Moving to a single amp that is rated at 1200 wpc and clips at slightly over 1450 wpc gave me the headroom that i needed. Not only does the system play louder, it does so in a cleaner fashion.

With that in mind, those interested in being able to sustain high spl's and / or obtain very dynamic peaks might want to print out and save the chart that you provided. They should also consider that they will be running two speakers when in stereo mode, so you effectively double the spl level for the same rated power output. As such, things are looking better in terms of trying to obtain clean dynamic output with lower power. Only problem is that most speakers WILL go into noticeable compression when you start throttling them.

The mains in my HT system are 4 ways with 5 drivers, limiting the power and bandwidth that any given driver has to deal with. If you want to "crank" the system and maintain linearity, you either have to use this type of approach ( multi-way with large surface area ) OR you can go with fewer crossover points, but use more total drivers i.e. two way line arrays, etc... Line arrays tend to maintain spl's better into the distance, so they are well suited to situations where you have a longer rooms and / or further listening positions.

Lots of variables in selecting speakers and there are quite a few different ways that "linearity" comes into play. Sean
Well room etc ...all play a roll...I do not disagree with what you are saying but I think you know what I am getting at
Sean..So you have your capacitors in line level circuits instead of in the speaker circuit. Can you describe why these capacitors are OK, while others are fraught with problems?

I gather that you drive your tweeters directly from full range power amps (trusting the input signal to limit LF output). Isn't this a bit risky? It seems to me that the inductor based high pass filter would be ideal for tweeter protection.

In the past I have had many biamp (and multiamp) systems. When stereo was introduced I "canibalized" a biamp system to get the necessary two channels. I do believe that modern amplifiers have very much reduced the advantages of biamping, except for extreme situations like pro sound systems, and that biamping between a subwoofer and mains (which I still do) is where it is still worth the trouble.
When I say "in the past" I am talking of 10 watt amplifiers with 1 percent IM distortion. That's when biamping really helped!
Dazzdax, to get back to your question....Driver manufacturers have to balance efficiency, durability, linearity, smoothness, and frequency response, at least, to provide an excellent driver. Limiting factors is smaller two-ways are almost always the bass roll-off of the smallish woofer in its chosen bass alignment in a given volume (with or without vent, etc.). Usually the result is a rising frequency response unless crossover components are used to roll the mid/woofer off. Almost always tweeter sensitivity is higher than the mid/woofers used, so the tweeter must be "padded", usually with a resistor, to bring the response down to the desired spectral tilt. Lots of tweeters are left pretty "hot", resulting in that "tipped up" or "bright" response of some manufacturers' designs. This can also make it a bit easier to slightly inflate an efficiency spec, or at least provide a louder response with a given input signal. Other designers, seeking a warmer response, will pad the tweeters more, resulting in a fatter perceived bass, but resulting in lower overall efficiency, and the requirement of turningthe gain up to achieve a desired loudness.
Balancing bass response and extension with a chosen upper octave spectral tilt is the meat and potatoes of this, not power absorbed by simple crossovers, nor tweeter resistors, as they're operative above crossover frequency.
Indeed, adding MORE drivers, all other things equal, will increase efficiency nicely, just like using a bigger amp. ence the use of 3-way designs or multiple woofers. So in a simple way, you can see that a formula is to use as many woofers as necessary to match the sensitivity of the tweeter, for max efficiency using these drivers. Since lots of OE tweeters have sensitivities in the 89-93dB/w range (I'm guessing), it's pretty easy to design speakers with highish efficiencies if you use enough woofers and/or box volume to get equivalent efficiency in the bottom octaves. Dorealize that voice coils get REALLY hot...with consequent non-linear response, changes in resistance, blah blah. If a driver manufacturer uses too small a voice coil gap to increase motor efficiency they risk insufficient heat-sinking so the driver blows up...or even scrapes as it hangs off-center! Huge ss amps have allowed woofer manufacturers to design relatively inefficient drivers that are durable. Problem is you need to push 'em to get a lot of bass response, or again use a big box, or multiple drivers, pushing up costs dramatically.
I look to the Spendor SC3 center channel speaker I use, as a simple example. It uses two 5" mid/woofs and a 3/4" tweeter, and sports 88dB efficiency, exactly matching the 6.5" two-way S3/1P's that comprise my HT front trio. I could have bought the SINGLE-woofer S3 (old LS3/5) versions, but these have damped tweeters squashed down to match the much lower sensitivity of using only one woofer, and thus spec at 84dB or so (there are vent and box volume diffs too, the efficiency difference isn't exactly algebraic). You might have asked why the same-tweetered speakers have such a different rated efficiency (sensitivity). Now you know. Hope this helps.
El: active crossovers betweem preamp and amps, not passive. Sean
Sean...Actually, low level crossovers can be passive, (I think that Marchand sells one) although that is usually not the case. Anyway, active crossovers are implemented with capacitors.
I could go on a tirade here about how passive crossovers "suck" ( both power and sonically ), but i've already pissed off enough people lately. It's bad enough that those with vented speakers don't like me, i don't need to add those with sealed, TL's, etc... that are passively crossed-over to that list. The amount of people running sealed & stuffed / actively crossed speakers is a pretty slim percentage of all audiophiles out there, so i'll stop while there are at least two or three people that don't want to tar and feather me : ) Sean
Ah Sean, I still love ya!
Actually, Sean, passive x-overs CAN be great:) Passive LINE-level x-overs yield excellent!
Goodbuy opamps (good thing, IMO), hello caps (not so good). Or, one could use coils (less losses than caps -- BUT who's got the patience & the workmanship to make them, to required specs...)

But that's still PRECEDING the amps; amps still driving voice-coils directly (an excellent thing IMO).

Overall, the story of our lives seems to be that good/v. good/ excellent amps drive less than stellar quality x-overs, rather than the speakers' drivers... Oh well
Op-amps can sound quite good when properly selected and implimented. Obviously, there are vast differences amongst Op-amps. Stereophile ran a very interesting article on the subject a few years back. Sean
Sean, I'm not a techy. I just want to understand where your inverse equation (more efficient = less distortion) figures fit into my least efficient speaker's spectacular performance.

There must be some serious variables skewing the distortion versus efficiency equation. Take, for instance, the tweeter/mid ribbon array in my speakers. My speaker's 50' of naked aluminum ribbons, governing all signal above 700 hz, cost my speakers dearly in efficiency.

I have heard hundreds of vaunted systems at homes, and shows. I wouldn't trade my amp burners for any one of the speakers in those systems.

I honestly have never heard more true to life speakers.
Some distortions are not "additive" in nature i.e. they aren't creating / adding additional output on top of what the original signal had. This means that losing some ( any portion ) of the signal also equals to distortion. Since more power = more heat and more heat = thermal loss, you end up with more distortion from the speaker.

On top of that, lower sensitivity designs have to move more air to produce the same amount of air that a higher sensitivity design does. In order to do that, the driver has to make longer excursions. The longer the excursion that a driver takes, the more distortion that it will generate. Another side effect / drawback is that a longer excursion will also generate more reflected EMF ( electrical "back-pressure" ), making it harder for the amp to control & load into the speaker.

Besides those primary factors, the electrical characteristics of a speaker change as the power levels are raised. Depending on what power level / spl range a speaker was tuned or "voiced" at, one can end up running the speaker in a range where it is less accurate / running out of the linear pass-band of operation. Then again, the reverse is also true of a speaker that was tuned to operate at higher spl's being run at / not working as well at lower spl's.

As a side note, vented systems will suffer from what becomes a "roving resonance" depending on the transfer efficiency of the port itself. While ALL speakers end up raising their frequency of resonance as you drive them harder, "straight" ports or ports that are only flared on the exit side are much more sensitive to this phenomena than a double-flared port or passive radiator design. Passive radiators have their own problems though as they have the moving mass of the drone cone itself to overcome. This problem becomes more apparent / harder to deal with as spl's are raised. Since greater mass is harder to accelerate and / or stop rapidly, trying to do so with the longer excursions / more inertial momentum compounds the problem. This situation also occurs with sealed designs, but not as severely. That's because the pressure or "air spring" inside of a sealed box remains consistent regardless of the drive levels applied.

Other than that, most all of my speakers are sealed and of lower efficiency. This means that i need pretty sizable amounts of power to obtain good performance. On top of that, most are also low impedance designs, meaning that i need even more power to get them moving / keep them under control. Even with all of the above in mind and much like Muralman, the aforementioned trade-offs still aren't enough to make me want to get rid of them and move over to more efficient, but typically sloppier designs. The high efficiency designs that i do have ( 96 dB's and 104 dB's ) are both sealed. Since you can't get something for nothing and maintain linearity, the efficiency of the 104 dB design is achieved via horn loading. Due to the length and size of the horn used, low frequency extension is reduced. In order to obtain ultra high efficiency and maintain good extension, you have to go to a BIG horn like the ones that Mike aka Magnetar builds and uses. You can see what i'm talking about here on his "horny" website. The three subwoofer horns are the huge cabinets behind the mains ( they take up the WHOLE front wall ) and look like wood trim surrounding black centers. Yes, Mike is a "little" crazy, but he's a real nice guy. You just wouldn't want to live next door to him : )

The little 96 dB units that i have are horn loaded for the mids and tweeters, but not the woofers. As mentioned above though, you can't get something for nothing, so these too are also limited in terms of low frequency bandwidth.

By the way, the rear wave of a driver can be sealed or vented when using some type of front loaded horn. My larger horns are sealed and as far as i know, i think that Mike's MEGA horn's are too. Sean
Everything you had to say, Sean, left the science behind my speakers (.8ohm/76db) unscathed. The prodigious energy required of my amps (class D) goes into creating the huge force fields needed to move large surface area ribbon drivers. The ribbons don't move to the naked eye. Even the great bass panels merely shimmer under loud 30hz passages. All the negatives you list don't apply.

Your discussion about speakers being driven harder than they were designed for hit home. For my speakers, there have been few amps in the past that could take them past 70db.

I have briefly driven my speakers to a median 95db, leaving plenty of room for huge transients. Never have they lost their composure. When these speakers were built, such levels weren't possible.

It is the nature of large surfaces utilized to produce sound levels that enable the speakers to go far beyond their designer's target. it also allows this speaker to side step drawbacks that other drivers encounter.
I assume that you're talking about Apogee's based on your impedances and mention of ribbons. Having said that, you state that the speakers are 76 dB's yet only a few amps could drive them beyond 70 dB's. How is that possible? It would require less than 1 watt to do this based on your own figures. Was it due to "protection" circuitry kicking in? If so, you need an amp without protection circuitry.

Other than that, i agree that a low bias output stage / high efficiency amp works very well with loads like this. Due to the lack of duty cycle that the amp reproduces / reduced current & heat involved, some of these newer designs truly are an "answer to audio prayers".

As far as 95 dB's go, i consider that to be a "moderate" listening level. While some recordings ( acoustic based music, etc.. ) sounds very good ( even "loud" ) at that level, it just wouldn't cut it for large scale Classical or hard Rock music. Bare in mind i'm talking about spl's as measured at the seated listening position, not one meter from the speaker.
Sean, I generally listen to my Scintillas at levels around 75db. Maybe I'm paranoid, but I believe my hearing will be better preserved. I've attended scores of live events, from intimate acoustic to stadium extravaganzas. I'm comfortable with my listening levels. I reserve 90 db and above for the likes of Led Zeplin once in a very great while. My seating a orchestral events is generally a third back, or balcony. 80 to 90db approximates the gestalt to my memory.

As for my speaker's ratings, you say, "1 watt should do." Am I listing it's specs wrong? Or are you being fecicious? ;) I am aware of successful powering of the Scinny with an 85 watt home made expressly for the Scinny. I had dissapointing results trying respectable amps of five times more power rating. Amp design is very important when pushing difficult loads.

Brand new class D amps are unfazed by the load. I'm thrilled by the results. The speaker playing field has been greatly leveled. I like to describe the sound as tubes on steroids.

Getting back to the question of efficiency, do you not agree large driver surfaces, resulting in minute travel, is a valid solution to speaker distortion? I can put my ear right to the ribbons, and hear the music as clear as fifteen feet away. There isn't any of that low level high frequency fuzz I've heard on domes and cones.
You mentioned an spl rating of 76 dB's. At 70 dB's, this would allow you 6 dB's of headroom before you reached 1 watt of input. As mentioned though, i didn't know if you were measuring at 1 meter ( which is useless except for sake of comparisons to reviews ) or at the seated listening position. Given that most rock music only offers appr 5 - 6 dB's of dynamic range, you would be using 1 watt of power to produce the full dynamic range of such a recording based on the above information. This isn't to say that i was recommending such an installation or that it would work as well as theory dictates, i was just spouting off figures based on the math that "acoustic theoriticians" would tell us was sufficient. We all know better than that.

I was also wondering by what you meant by the statement that very few amps would drive them beyond 70 dB's??? Obviously, most any amp could generate 1 watt of electrical output relatively easily, so what's the fuss? As mentioned, the only thing i can see coming into play here is the low impedance / protection circuitry kicking in.

As to why the Class D amps work better, that has to do with the reduced duty cycle that the amp sees, the lack of sag in the power supply and lower levels of reflected EMF generated by the speaker. As you reduce the duty cycle of the amplifier, you also reduce the amount of drive applied to the speaker. Less drive equates to lower levels of reactance, which gives us less reflected power to deal with. This in turn allows the amp to load up more efficiently, which is just more icing on the cake. If the switching frequency is high enough, the power is delivered in very short and fast pulses, giving the power supply ample time to recover from the small amount of power drawn from during those bursts. If the switching frequency is too low, you can hear the "pulsing" of signal and it sounds fuzzy, choppy and lacks cohesiveness. A higher switching frequency limits the duration between pulses and the energy in the gaps is somewhat "filled in" by what is called "the flywheel effect". In English, the overshoot of energy initially applied keeps the forward or reverse momentum going until the next pulse is delivered. The potential for distortion with such a design is quite high, but with newer technology and MUCH higher switching rates, they are finding ways to get around this. Sean
Thank you, Sean. Perhaps the 76db rating of the Scintilla is not the limiting factor in it's compatability with amps. I should add that the Scintilla is rated .8 ohm, or neary a dead short, which is what nearly all amps choke on.

Yes, class D modules engineers are having success getting around the switching speed devil. I use amps utilizing B&O's ICE module. I can't say I understand the white papers, but I can attest to it's amazing delivery.

Sean...I find that "large scale classical" pieces often run about 76 dB most of the time, with occasional louder passages. The way I determine this is by playing a concerto (for example: violin) or a vocal piece. I ask myself "is the violin louder than a real violin can play?" or a similar question for the vocalist. I often find that it is easy to crank the volume up higher than this criteria would allow. Perhaps this is because we are used to listening to "live" performances that are "reinforced". Amplification of an instrument above its true volume is like putting your girlfriend's complexion under a microscope. You will not like the result.

Down in New Orleans last week (I have almost sobered up) I spoke with some musicians who suggested a reason for the exaggerated bass that seems to be so prevalent. They suggested that the guys who do the audio mixing have been overexposed to loud music, and have lost LF hearing. (I thought it was HF that goes first, but they said No, LF). To these guys the exaggerated bass sounds right.
Somebody started a good thread recently exposing the purposefully cranked up bass response of recent ultra expensive speakers, the explanation being, "That's what the buyer wants."

Those of us looking for the Holy Grail of true fidelity are in a decided minority.
Eldatford -- few recordings are actually made at 0db, containing "optimum" dynamic range of the (digital) medium. Mostly thiongs are compressed and, as you note, processed. So, the actual sound level can go up & down -- accordingly, don't we often play with the volume control during the same symphony?
OTOH, I read s/where that classical can have a dynamic range of ~110db (at a large auditorium). That's staggering for our rooms & equipment, let alone actually recording such ranges. BUT, a Mahler cd I have goes from ~65db (spl) to ~85 at listening position (so count in room reflections as well) in the same movement!
Muralman: Is the "Current Trends in Multi Thousand Dollar Speakers" thread the one that you were talking about?

As to Greg's comments, most recordings take advantage of sizable amounts of compression, particularly rock / pop recordings. This is less true in Classical recordings and you can always tell this when trying to listen to something in your car. Some passages are SO much quieter than others that it becomes difficult to hear them when you have the volume adjusted for "reasonable" listening during the crescendo's. It would be nice if the car audio industry introduced some type of switchable "compander" ( DBX type circuitry ) into their head units. I think that the reduction in sound quality would be more than made up for by the increases obtained by being able to hear the entire presentation without having to strain. Sean
Yes, Sean, what is your take on it?
I started and finished that thread. Need i say more ??? : ) Sean
The ones I know Dyn Audios.