Sensitivity ?
- Thread starter opus007
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Haoleb
Super Member
Higher is better because it means that a speaker will be able to play louder (and more efficiently) with less power. meaning you can choose from a wide variety of amps etc. Generally though you will find that speakers with very high sensitivity like 99db are not made for quality as much as they are made for volume levels
All else being equal (although this is rarely the case), I prefer high-sensitivity loudspeakers over moderate- to low-sensitivity ones. Why? Two reasons:
1) High-sensitivity speakers typically sound more lifelike due to their superior dynamic range and speed.
2) High-sensitivity speakers typically sound more tonally correct at low listening levels.
Of course, loudspeakers rated at 99dB+ are quite ruthless in terms of exposing any background noise (hum, hiss, etc.) that your amplifier might produce. And there are LOTS of amplifiers out there - both tube and solid-state - that sound perfectly quiet with moderate-sensitivity loudspeakers, but irritatingly noisy with high-sensitivity ones. Unless you're using an ultra-low-power SET amp that virtually DEMANDS high-sensitivity speakers, you'll probably have to do some careful auditioning in order to determine if this is the right path for you...
1) High-sensitivity speakers typically sound more lifelike due to their superior dynamic range and speed.
2) High-sensitivity speakers typically sound more tonally correct at low listening levels.
Of course, loudspeakers rated at 99dB+ are quite ruthless in terms of exposing any background noise (hum, hiss, etc.) that your amplifier might produce. And there are LOTS of amplifiers out there - both tube and solid-state - that sound perfectly quiet with moderate-sensitivity loudspeakers, but irritatingly noisy with high-sensitivity ones. Unless you're using an ultra-low-power SET amp that virtually DEMANDS high-sensitivity speakers, you'll probably have to do some careful auditioning in order to determine if this is the right path for you...
Markw
Super Member
I wouldn't get too hung up on this.
...unless you are into running flea powered amps. Then it's a major issue and you NEED ultra high efficiency speakers, which will limit you greatly.
Good sounding and performing speakers come with all sorts of efficiency ratings. USe sound to make your selections.
A 3 decible INCREASE in sensitivity means you will get the same "loudness" level with HALF the power. Conversly, a 3 decible DECREASE in sensitivity means you will need TWICE the power for the same "loudness".
Unless you base your selection on sensitivity only, you will probably choose a speaker that sounds "good" to you and purchase an amp accordingly. That's the way I would recommend.
Also remember that those published figures are only valid one meter from the front of the speaker. After that, room acoustics take over and further decrease toe sound reaching your ears in a most non-linear fashion.
USe these figures like you use CAFE standards on gas mileage on new cars. A rough guideline only.
Remember, watts are cheap compared to speaker efficiency.
...unless you are into running flea powered amps. Then it's a major issue and you NEED ultra high efficiency speakers, which will limit you greatly.
Good sounding and performing speakers come with all sorts of efficiency ratings. USe sound to make your selections.
A 3 decible INCREASE in sensitivity means you will get the same "loudness" level with HALF the power. Conversly, a 3 decible DECREASE in sensitivity means you will need TWICE the power for the same "loudness".
Unless you base your selection on sensitivity only, you will probably choose a speaker that sounds "good" to you and purchase an amp accordingly. That's the way I would recommend.
Also remember that those published figures are only valid one meter from the front of the speaker. After that, room acoustics take over and further decrease toe sound reaching your ears in a most non-linear fashion.
USe these figures like you use CAFE standards on gas mileage on new cars. A rough guideline only.
Remember, watts are cheap compared to speaker efficiency.
Don McR
Well-Known Member
This is a common misconception that the only consequence of lower sensitivity is the amount of power required. There are physical reasons why low sensitivity speakers can sound different than high sensitivity speakers. The following is a generalization (there are many exceptions), but it should give an indication of the factors involved.
All speakers demonstrate a spectral shift in their frequency response as power levels and output increase - they only differ by degree. Certain frequencies become attenuated relative to others with increased power causing the overall frequency response to change. The culprit is dynamic compression and it tends to plague low sensitivity speakers much more than their high sensitivity counterparts.
In a moving coil loudspeaker, dynamic compression results from a number of factors - the most significant of which is heat. Since the moving coil is a resistive electrical element, it gives off heat. Put more power to it, and you generate more heat. This heat will cause a reduction in strength of the permanent magnetic field and changes in coil impedance that all act to reduce output. This has a two-fold effect. Dynamic range (the difference between the loudest and softest sounds) becomes restricted as output increases. In a multi-way speaker, each driver has differing levels of dynamic compression causing the previously mentioned spectral shift.
Distortion levels can also become a factor related to sensitivity. The interaction of the current in a moving coil loudspeaker and the permanent magnetic field of the motor results in flux modulation or constant variation in the strength of the permanent field. This translates into 2nd order harmonic distortion. The greater the current, the greater the flux modulation, and hence, the greater the distortion
All things being equal (and they never are) the high sensitivity speaker will exhibit lower levels of dynamic compression and lower levels of distortion than a low sensitivity counterpart. With the high sensitivity speaker, the drivers are operating at lower current levels, generating less heat and flux modulation. This makes it easier to engineer dynamic compression and distortion to very low levels. The sonic result is that high sensitivity speakers are generally asserted to have a more effortless sound and freedom from strain. Adjectives such as “lively”, “visceral” and “rhythmic” are often used to describe such speakers.
To put all of this in perspective, there are valid engineering reasons for designing high efficiency speakers beyond reducing power requirements. However, they are not absolute. It is possible to engineer a low efficiency speaker to have very low dynamic compression and minimal flux modulation. It is very expensive and few manufacturers are willing to bear these costs. That is why my preference leans towards high efficiency speakers. However, it is also true that it is very easy to engineer a high efficiency speaker that sounds bad so that sensitivity should never be the sole arbiter of what sounds best. That’s the job for your ears.
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gonefishin
Super Member
You've got some good explanations above.
I'll only add my personal experiences. The others are right...that you have to go listen for yourself and decide what your ears like. I've heard good and bad designs of both speakers...but the best speakers I've heard (to date) have all been higher efficiency.
limited dynamic compression, low distortion and great tonal qualities are the reasons I enjoy the well made high efficiency designs. These qualities don't matter at what volume they're played at either. super low or nearing live levels...the music remains dynamic, clean, detailed and gooood
If you take high efficiency pro drivers and mate them within the applications they were meant for...and use a suitable enclosure...you can end up with some glorious sound.
But no...just because something is low efficiency...doesn't mean it will sound bad (or good)...and just because a speaker is high efficiency doesn't mean IT will sound good (or bad).
take care>>>>>>>>>
opus007
Active Member
Thanks for all the response.Only reason I asked was my Acoustic Research AR9's say 1 watt will produce 87db SPL on axis at 1 meter.Effective System Q: 0.5 at resonance .i have no idea what that means either.Was just wondering if that was good or bad.Seems good as they sound good.
Thatch_Ear
Addicted Member
One thing that needs to be considered is that WATTS are now a selling tool. Voice coils made from inferior metal and extrmly stiff spiders (the round part below the cone and above the magnet) are often used to get a speaker to handle the extremely high wattage amp, especially in car audio.
Another reason for lower efficiency is that the tower style speakers with small footprints often use multiple small drivers and have complicated crossovers to get proper performance out of the speakers. Small drivers made to do the job of one many times its size many years ago usually is not going to be very efficiant. The crossovers suck power as well.
Good sounding high efficiency speakers tend to sound good with any quality amplifier, while inefficient speakers need a higher power quality amplifier to overcome the design defficencies.
Of course there are no absolutes.
Another reason for lower efficiency is that the tower style speakers with small footprints often use multiple small drivers and have complicated crossovers to get proper performance out of the speakers. Small drivers made to do the job of one many times its size many years ago usually is not going to be very efficiant. The crossovers suck power as well.
Good sounding high efficiency speakers tend to sound good with any quality amplifier, while inefficient speakers need a higher power quality amplifier to overcome the design defficencies.
Of course there are no absolutes.
WhiskeyRebel
Registered thread killer
I had wondered whether the design aspects that contribute to accuracy reduce sensitivity. Musical instrument speakers (like those in guitar amps) tend to be extremely efficient but they have a ton of coloration. This may have been inadvertent back in the old days but it's so much a part of the characteristic sound of electric guitar that it's very deliberate now. Perusing the specs listed in the Parts Express catalogs and the like tends to show much lower sensitivity for the home-stereo type drivers that are advertised as especially accurate.
Now somebody is going to snob out and sniff that no reputable speaker mfg would sell through that catalog I suppose.
Do some speaker makers also use unnecessarily heavy cones and limp suspensions as a way to lower resonant frequency on woofers? Or are those normal design methods to achieve a low Fs?
Now somebody is going to snob out and sniff that no reputable speaker mfg would sell through that catalog I suppose.
Do some speaker makers also use unnecessarily heavy cones and limp suspensions as a way to lower resonant frequency on woofers? Or are those normal design methods to achieve a low Fs?
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