Pro vs hifi drivers - pros and cons?

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If you take a 85db speaker move back 12 ft you would be lucky to get 105db from the pair with 100 watts where you listen. That sounds like a rather high SPL level but it's not with a well recorded music where the dynamics are properly recorded. A snare drum rim shot could get you there in a heart beat, even playing at a more modest 85db average.
Rob🙂

I agree but there are also hi-fi drivers with efficiency of 90dB and more. Apart from that, most high SPL's in music are of an impulse nature so the average power on the voice-coil isn't nearly as high as suggested.
 
I think Earls right we need a Dynamic Linearity test to really see what's happening.

Rob🙂

I think that the test protocal is not too hard to develop, I've done that, and I've taken some data. I just need to get the time to analyze it.

Like here Subwoofer testit - DVD Plaza Forums

Do pro drivers tend to have much lower hysteresis than hifi company (eg Seas, Peerless) drivers? I assume they do, but just thought I'd ask. Thanks

I don't think subs are part of the "dynamics" issue.

What do you mean bu "hysteresis"? in a loudspeaker?
 
Makes me wonder how paper voice coils have lasted through half a century, and are also said to result in very good sound, especially with silver wire

I've had more than a few, none with silver wire, and these particular ones did sound quite good. Most have been rather efficient types with relatively low rated continuous power - within reason I have not noticed thermal compression to be a major issue with them either - but it is easily measurable if you push one of these drivers close to its rated power. I've also burned up a few as well quite unfortunately.. (The saddest of which were some very nice Coral full range drivers that I bought new in my teens - they did not long survive my first 30W per channel stereo receiver purchased a couple of years later.) :hot:
 
I posted the link to subs only as an example, because they measure power compression

I'll quote something that explains hysteresis distortion:
Hysteresis distortion implies that the system transfer characteristic is not always singlevalued for a given instantaneous input and will vary with both the change of direction and the level of the input and that it will therefore produce distortion that has a different phase to that produced by harmonic distortion.

Hifi drivers tend to use very lossy surrounds compared to most pro drivers, which I assume introduces hysteresis distortion.
 
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but it is easily measurable if you push one of these drivers close to its rated power. I've also burned up a few as well quite unfortunately

Ofcourse they have the low power limits
High sensitivity is essential
Sure, low sensitivity combined with low power handling might be a real problem
Even so, some of those seem to make many people happy nonetheless
Expectations to SPL would be a major player

btw, In my youth I accidentally put full supply power into my Lowther fullranges, due to some amp malfunction
ALL of the voice coil wire was literally thrown out of the gap, in a messed up bundle hanging in front of the drivers
Funny "picture", but it wasnt much fun when it happened
I cant bare the thought of owning the exstremely expencive Feastrex drivers, and always have to fear the moments(rare) with alcohol on the table
 
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In my youth I accidentally put full supply power into my Lowther fullranges, due to some amp malfunction ALL of the voice coil wire was literally thrown out of the gap, in a messed up bundle hanging in front of the drivers
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What kind of amp, and what kind of malfuction?

I've experienced blown tweeter by old leaky filter caps in ancient tube amp. I was in another room and heard suspicious noises, like some muffled fireworks. It was odd that the noise was not loud, and there're output transformer and series cap before the tweeter. One of the tweeter was still blown.
 
I posted the link to subs only as an example, because they measure power compression

I'll quote something that explains hysteresis distortion:
Hysteresis distortion implies that the system transfer characteristic is not always singlevalued for a given instantaneous input and will vary with both the change of direction and the level of the input and that it will therefore produce distortion that has a different phase to that produced by harmonic distortion.

Hifi drivers tend to use very lossy surrounds compared to most pro drivers, which I assume introduces hysteresis distortion.

I knew what hysteresis was, I was questioning why you thought such a thing existed. To the best of my knowledge this is not a significant factor in any loudspeaker that I have ever seen.

I am not even sure that I could design one that had significant amounts of hysteresis let alone it happening naturally.
 
Thanks, I knew it was a physical occurence but didn't know it wasn't audible. You learn something new every day =)

I only asked because some people say they prefer high Qms drivers because they sound more open at low volumes, so I had assumed it was audible
 
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Do you have data to support that?


If you listen in a small room and you sit 3 feet away by yourself .....this discussion isnt for you!

For the general situation, here are some simple numbers that you might want to consider before you think lower sensitivity speakers are not clipping.

12 or more feet distance does have a drop off of 10dB or more.
Content (Movies and Music has 20 to 30dB peaks).
Average person has less then 100Watts per channel.


If your speakers are 90dB or less you will have distortion (speaker compression or amp clipping). If you even want average listening levels of 80dB at the listening position.

As I said before if manufacturers you label has hifi made 95dB sensitivty drivers then I would be happy to choose them (Woofers only though since dome tweeters need not apply at all because they suck IMO).

Its a new world and power handling actually matters 😉
 
Thanks, I knew it was a physical occurence but didn't know it wasn't audible. You learn something new every day =)

I only asked because some people say they prefer high Qms drivers because they sound more open at low volumes, so I had assumed it was audible

Audibility is not what I was refering to, I was refering to the physical occurance. I've never seen it to be significant. Audibility is another issue altogether, but you can't hear what doesn't exist.
 
here are some simple numbers that you might want to consider before you think lower sensitivity speakers are not clipping.

Hi Doug

I quite agree. Many people just don;t get how much effect a lower sensitivity has on the power requirements and then how this much higher power effects the sound quality. People always say "I don't listen that loud", but its "normal" listening levels that we are talking about, not extremes. At extremes (above 100 dB at-seat listening levels, which aren't really that extreme for a HT) the power handling of a pro unit is a no-brainer, virtually a flat out minimum requirement.
 
I've just found a quote that confirms what Dr Geddes previously said:

"Hysteresis distortion, as much as it exists in loudspeaker suspension systems and heavily damped soft diaphragm assemblies, does not manifest itself as an intrusive distortion. It is certainly not particularly evident in other measurements, for example, transient response, magnitude response or in harmonic distortion measurements. In fact, if care is taken over the choice of both diaphragm and suspension materials then they will largely have the characteristics of a simple damped spring and exhibit negligible hysteresis"
 
I've just found a quote that confirms what Dr Geddes previously said:

"Hysteresis distortion, as much as it exists in loudspeaker suspension systems and heavily damped soft diaphragm assemblies, does not manifest itself as an intrusive distortion. It is certainly not particularly evident in other measurements, for example, transient response, magnitude response or in harmonic distortion measurements. In fact, if care is taken over the choice of both diaphragm and suspension materials then they will largely have the characteristics of a simple damped spring and exhibit negligible hysteresis"

Hi Matt

Yes, I completely agree with that quote. One can find hysteresis in some components, most notably the magnet, but I have not seen it as a significant attribute of a completed loudspeaker.
 
Remember about 50 pages ago we discussing what there is above 10Khz and if it's important?

Well tonight I was listening to some jazz and just happened to have the mic and RTA running. Saw lots of stuff up there, mostly cymbal splashes. And since I'm running a digital x-over....

So I low passed the system at 10KHz - 4th order butterworth. The difference is easy to hear, at least when the drummer is on the cymbals. In other music not so much. Guitar is slightly duller when low passed, but it's subtle. But I sure can hear it on cymbals.

FYI, my system goes up to about 22K, but it's down a few dB by that point. Certainly down at the listening position. The next test might be to try a low pass at 11K, 12K, 13K, etc. At what point do I not notice it?
 
So I low passed the system at 10KHz - 4th order butterworth. The difference is easy to hear,

Yes I quite agree. Very easy to hear with the right source material. I would think 15-16K would be more appropriate. I have a couple of systems that have response that rolls off above 15K and sound OK to me. I also have a couple others that go out past 20K and they seem to have more detail and clarity than the rolled off systems. Could be that they are doing a better job in the more audible 8-10K region or it's the added extension. Not sure why they seem to sound better in the 10-20K octave.

Rob🙂
 
I continue to be amazed at how my comments were misinterpreted. I never said that above 10 kHz was inaudible under any circumstance, I said that that above 10 kHz is a marginal aspect of sound quality. All of the comments above confirm that. Its "just audible" on "some" material.

The point that I keep trying to make is not to get obsesseed with the minor things, like > 10 kHz, but to concetrate on what really matters - directivity from 1 kHz - 10 kHz. Audiophiles are forever getting all tied up in the minor aspects - like cables and axial FR - and ignoring the major ones like rooms and directivity. You simply have to put things in perspective - rank order the effects and prioritize your designs arround those things that are most important, not those things that are on the fringes. Audio is all tied up in paying far too much attention to those things that are easily measured and ignoring those things that aren't so easy to measure. Unfortunately our ears don't see (hear) things that way.
 
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