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List of Reference Level, High Sensitivity & SPL Speakers - Page 17

post #481 of 820
Thread Starter 
Quote:
Originally Posted by psgcdn View Post


Reference level means that the low sensitivity speaker won't be well beneath it operating limits. You'd need 670Watts to get 105 dB from a 88 sensitivity speaker 12 feet away.
A 105 dB sensitivity speaker will require 13 watts to get 105 dB 12 feet away, 50 times less. It will be well beneath it operating limits. Unless you can give me an example of a HE 20Watt speaker from the list? wink.gif
 

 

Quote:

Originally Posted by Eyleron View Post

I think JerryLove will take issue with saying "a higher sensitivity speaker will have less distortion than a low sensitivity speaker."

For instance, if both speakers are well well beneath their operating limits, why will the lower sensitivity speaker distort more? 

 

Quote:

Originally Posted by psgcdn View Post


Exactly. 105 dB vs 88 dB sensitivity makes a pretty generalized comparison; there's no point in comparing 94 dB vs 96 dB.

 

 
Quote:
Originally Posted by Eyleron View Post

Granted that example theoretical case of 2 speakers with 10db different sensitivity and 10x power handling is pretty extreme.
Humor me with a 3db difference and 2x power handling, then. A 90db 400w versus a 93db 200w.

 

Quote:
Originally Posted by Eyleron View Post

Right. Regardless of threshold of what, today, we call high or low sensitivity...
Will one see the same amount of distortion between the 2 speakers if they are both driven to the same percentage of their limits?

 

Quote:
Originally Posted by MKtheater View Post

I don't consider either a high sensitivity speaker.

 

We got here because some of us are trying to see where there are rules of physics, general rules of thumb in speaker design, rules of thumb in analyzing/comparing speakers. I'm trying to learn if there's anything to know/extrapolate between "the manufacturers' marketing" and "Buy $10k+ worth of speakers and build a test rig and measure them and keep what you want." 
I was trying to find out if they're anything to the concept of two speakers playing at equivalent percentages of their operating limits yielding similar amounts of distortion. JerryLove initially used an extreme example of a 10dB difference in sensitivity with the lower sensitivity speaker having 10x the power handling. If this theoretical example is too silly to regard, then I tried to throw out something more realistic. When talking theory, I am more interested in "higher sensitivity" that is more generally applicable.
 
When we're talking about speaker theory, I don't think the physics care about what we happen to label as "high sensitivity". Heck, with the last page of posts, there's no agreement on whether that's 90dB, 95dB, 100dB, or 105dB! I figured if there's anything to learn, what's  applicable to 87 vs 90dB should also be applicable to 90dB and 96dB or 85dB versus 100dB. (like calculating the physics of a car accident is applicable for motorcycles and semi-trucks). But maybe I'm wrong. Maybe the "rules" are different below some threshold?
 
Anyway, from what MKTheater and Bill are saying, it sounds like one can't used the published power handling numbers to divine where the limits of clean output are. However, it sounds like if we had "RMS watts at 10% THD (over a frequency range)" and "Peak watts 1 second at 10% THD (over a frequency range) we could more accurately compare two speakers. 
And my takeaway from Bill's statement about easily finding speakers with wildly varying %THD at different percentages of their power handling advertising: is that there is no relationship between the two? That some drivers will develop higher distortion well before they reach the XLim banging against the poles to destruction, and others remain more linear closer to the advertised spec? And are we talking about peaks or RMS? I believe a few people have said that generally speakers start to compress at about 1/8 power and I believe that was RMS?
post #482 of 820
Thread Starter 
Quote:
Originally Posted by Bill Fitzmaurice View Post

So just as manufacturer sensitivity ratings without SPL charts to back them up are worthless...

I know what you're saying, but I think the marketed sensitivity has some utility.

A car's "City miles per gallon" rating is considered highly inaccurate and unattainable in any realistic driving, But I consider it at least a benchmark for the best the car could achieve (if they advertise 20 MPG City, I can bet that I will get worse than that, but most likely not 25 MPG).

 

Likewise, if I think an application needs a minimum of 95dB sensitivity, I feel like I can drop the speakers with < 95dB from the running. Like, I wouldn't worry about investigating the 87dB speakers. 

post #483 of 820
There are a few speaker builders who would rate to a % of distortion.

If you ever get a chance to read through Roger Russell's site, it discusses analysis of distortion from source, from amp, from wire, from speaker, and from hearing loss over age. It's something they spent a great deal of time studying and experimenting with.

Indeed, if you look at Toole, Russell, Olive, or Wilkins; you'll see a significant focus on the control of various forms of distortion. Bill's comment to the contrary: it's not something that he discovered that a century of PhD's were unaware of.

I agree with Bill that I'd like to see distortion measurements; though it would remain an approximation. There are so many types of distortion, and so many manifestations, and they occur so unevenly across frequencies and power-levels that it's not entirely do-able; but something along some standard would be better than nothing.
post #484 of 820
Thread Starter 

What's "High Sensitivity"?

Quote:
Originally Posted by MKtheater View Post

I don't consider either a high sensitivity speaker.

 

Quote:
Originally Posted by Bill Fitzmaurice View Post

+1. There's no set definition but most agree that 95dB the lowest that should be considered high sensitivity. Still, many horn purists call that medium sensitivity, with 100dB or more being high sensitivity.

 

Quote:
Originally Posted by psgcdn View Post

+1
Thus my example of 105 dB.

This is a tough one. I mean, there's not even a generally accepted usage of the term "high efficiency car". Is that 20mpg, 30mpg, 80mpg?

 

I think there are at least two threads of thinking about this.

  1. One is "what is our semantic definition for the purposes of discussion of 'high sensitivity' amongst a crowd of people interested in such speakers?" 95dB sure sounds reasonable.
  2. The other might be in the context of how the average home theater fan might be using a speaker that exhibits too much THD for his application. 
    The speakers commonly known by him, suggested to him, and available to him, may exhibit too much THD. 

 

We hear of so many people complaining that higher SPL = bad because they turn it up and it sounds bad. We suspect that their less sensitive speakers, mated to a 100w amp, is driving the amp into clipping. Or if listening to compressed music (without much dynamic range), they're heating up the voice coil and achieving even greater compression in the speaker. Or in watching a film, their speaker is handling the average levels with aplomb, but on the brief peaks they're experiencing compression at best where they simply don't get the SPL dynamics they should be getting, and more likely they are experiencing unpleasant distortion. 

 

They may need a 91-94dB sensitive speaker that maintains the midbass output at 110dB from the speaker so they can use their probable 110w amp. 

Based on the scarcity of such speakers, for many people, I think High Sensitivity is going to be anything over 90dB? Or maybe we should say "high output speaker with less distortion"?

 

I would not include the speakers with a 6.5" woofer that has an F3 of < 60Hz, because it sounds like those are speakers that gave up max SPL in favor of extension (to look good in the marketing). 

post #485 of 820
Quote:
Originally Posted by psgcdn View Post

my room response is pretty bad (and placement options limited by the sheer size of the THT) and so I aggressively EQ to get the best response and have up to 13 dB of gain at a certain frequency (!!).
You need a second sub to overcome that much of a cancellation mode. Time to buy a bigger house. biggrin.gif
Quote:
I know what you're saying, but I think the marketed sensitivity has some utility.

A car's "City miles per gallon" rating is considered highly inaccurate and unattainable in any realistic driving, But I consider it at least a benchmark for the best the car could achieve (if they advertise 20 MPG City, I can bet that I will get worse than that, but most likely not 25 MPG).
With no SPL chart it's the equivalent of a car manufacturer saying that the mileage is 'really good'. Without a measured power input for 10% THD it's like saying the trunk capacity is 'really big'.
Edited by Bill Fitzmaurice - 12/9/12 at 1:07pm
post #486 of 820
Thread Starter 
Quote:
Originally Posted by JerryLove View Post

There are a few speaker builders who would rate to a % of distortion.
...
I agree with Bill that I'd like to see distortion measurements; though it would remain an approximation. There are so many types of distortion, and so many manifestations, and they occur so unevenly across frequencies and power-levels that it's not entirely do-able; but something along some standard would be better than nothing.

 

You're right: most manufacturers won't post distortion data. I was gratified to see PowerSoundAudio (new company by some of the SVS founders) posting compression data. However, the graph stopped short of showing the level where compression was obvious. The Audioholics review showed two additional 5dB levels. 

 

I'll point again to the data-bass.com project and Audioholics' subwoofer reviews using Ricci's testing. Long term compression by frequency at different drive levels. Short term peak handling under a threshold of THD by frequency. Isn't this the stuff we're asking for?

Who can talk to Audioholics or some other reviewer about incorporating such testing into speaker reviews?

post #487 of 820
This is a great thread.

I'd like to go from reading to taking measurements of my set up ( subwoofer excluded) to see (graphically) how they are performing @ ref volume (0db on master volume on my Denon 4520 CI) 400hz-20khz, safely above the translation freq..

I've got REW with calibrated EMC8000, if there is a existing thread point me there.
Else, guide me and I'll post my results here.
Room size, speakers, etc below.
HT%252520Plan%2525202x4%252520Seats-Riser-acoustics.JPG


Sent from my 32GB iPhone4 using Tapatalk
post #488 of 820
Quote:
Originally Posted by Eyleron View Post

Who can talk to Audioholics or some other reviewer about incorporating such testing into speaker reviews?

Gene would be my first thought.
post #489 of 820
Thread Starter 
Quote:
Originally Posted by Bill Fitzmaurice View Post

With no SPL chart it's the equivalent of a car manufacturer saying that the mileage is 'really good'. Without a measured power input for 10% THD it's like saying the trunk capacity is 'really big'.

I guess I think less of the current published City MPG numbers. :) They're already pretty bad. Very optimal controlled conditions. "Like, if you drive this slow, never brake and accelerate, on level roads, with no traffic."

post #490 of 820
Thread Starter 
Quote:
Originally Posted by mtbdudex View Post
I've got REW with calibrated EMC8000, if there is a existing thread point me there.
Else, guide me and I'll post my results here.

I haven't found much yet on REW or HolmImpulse on measuring distortion on impulse peaks. But I haven't tried the latest version of REW that supposedly does more with THD or downloaded H.I., so I hope to know more in a week!

 

The limitation I had with REW last year was while there are sine wave and pink noise test signals, there are no brief bursts that simulate program peaks. Maybe that's what's changed? 

So while I could feed sine waves and see what sort of max output with what distortion components showed up on long-term signals, I didn't see how to do peaks. The best I did was use some gun blasts in Die Hard 4 apartment scene and use REW's realtime SPL graph capability to see max peaks as I turned up the drive level. This was useful to see where output gave out, but I didn't know if I was amp-limited at that point, or the speaker, and what sort of THD I was getting (hard to judge quality on quick explosions! ;) ).

 

Ideally, this thread should be about the list of speakers, the utility of such, what should or shouldn't be on it, and some judgement of said speakers. If we could get any better qualitative numbers added to the chart I'd be all over it!

 

I'm interested in your testing, so I'll for sure subscribe and follow along!
 

And if Bill or one of the other speaker builders could post some examples and graphs of commonly-used drivers, it'd be pretty illustrative for people to see "what's going on with a speaker like this." It'd be pretty eye-opening for people to see a driver or speaker that they would have reasonable assumed should be able to handle anything they throw at it, instead exhibit high distortion in reasonable use (like trying to get movie theater like sound in their room).

post #491 of 820
Thread Starter 
Quote:
Originally Posted by MKtheater View Post
 He then said this is the best it has ever sound and don't you change a thing! He said I am not kidding, it is not even close, the energy, clarity, dynamics, are all much better than ever. The detail is much better as well. This happens to be the most sensitive system I have put together as well.

I'd be interested to see the numbers showing why y'all regard it as so much better. Like, is it because you're trying to get 110dB peaks at LP, and your previous setup was pooping out in mid-bass or something?
Or has your testing showed that while earlier improvements got you the SPL you wanted, you see that you're getting 30% THD in some frequency band and so it sounds bad, and now you've fixed that? Do you have graphs of this?

 

It's not quite as applicable to the masses, since your system is extreme and many people would discount it as such. But the principles should be universally applicable, and since you've been testing for distortion, I think there's a lot to learn from that!

post #492 of 820
Quote:
Originally Posted by Eyleron View Post


We hear of so many people complaining that higher SPL = bad because they turn it up and it sounds bad. We suspect that their less sensitive speakers, mated to a 100w amp, is driving the amp into clipping.

I'd also add room as a factor why ref. level playback may sound bad even when good HS speakers are used. Dedicated HT rooms with extensive accoustic treatments seems to be the requirement.
post #493 of 820
Quote:
Originally Posted by Eyleron View Post

So while I could feed sine waves and see what sort of max output with what distortion components showed up on long-term signals, I didn't see how to do peaks.
You don't do peaks. With HolmImpulse the THD is shown on the FR graph as a second chart. You calculate the THD% based on how far down the THD measurement is compared to the FR measurement::

-60dB = 0.1%
-55dB = 0.2%
-50dB = 0.3%
-45dB = 0.5%
-40dB = 1%
-35dB = 2%
-30dB = 3%
-25dB = 5%
-20dB = 10%
-15dB = 15%
-10dB = 30%

To see how THD is related to power measure at various power levels. As power goes up so does THD.
post #494 of 820
Quote:
Originally Posted by Bill Fitzmaurice View Post

You need a second sub to overcome that much of a cancellation mode. Time to buy a bigger house. biggrin.gif
House is big enough, but, yeah, a second sub may be required. Either a thin THT on the opposite side, or a 30-inch THT in the back adjoining room with just the opening into the room on the back wall.
post #495 of 820
Quote:
Originally Posted by psgcdn View Post

a 30-inch THT in the back adjoining room with just the opening into the room on the back wall.
+1, gets the job done without taking up any floor space. Try it first in the room aiming at the wall to find the sweet spot, then cut the hole in the wall and put it on the other side.
post #496 of 820
http://www.bksv.com/doc/BO0385.pdf

BTW: I ran as loud as I could take it (covered ears), and cannot account right this moment for what the stock amp in the laptop may be doing, but I measured 1% through almost all of the frequency range except for a double-spike to 5% around 200hz. (single mic, mic calibration not applied, 1m, untreated room, MTM MWTL speaker. no db meter to determine absolute volume (but very loud))
Edited by JerryLove - 12/9/12 at 6:27pm
post #497 of 820
Thread Starter 
Quote:
Originally Posted by Bill Fitzmaurice View Post

You don't do peaks. With HolmImpulse the THD is shown on the FR graph as a second chart. You calculate the THD% based on how far down the THD measurement is compared to the FR measurement::
...
To see how THD is related to power measure at various power levels. As power goes up so does THD.

Oh, shoot. Measuring distortion on peaks seems to be the missing component in measuring. 

A 90dB sensitive speaker will achieve the average 85dB levels in-room with 2-3 watts. While some speakers may exhibit a lot of distortion at 2% of their power handling, I suspect most do okay?

 

It's how that same speaker will handle 500ms of 200w to get the 105dB reference level peak, with what levels of distortion, that I'm interested in. What's the easiest way to measure that?

post #498 of 820
Thread Starter 
Quote:
Originally Posted by zheka View Post

I'd also add room as a factor why ref. level playback may sound bad even when good HS speakers are used. Dedicated HT rooms with extensive accoustic treatments seems to be the requirement.

Yeah, and I think even Toole would agree that if the room is going to give bad reflections, you might be best served with controlled directivity. Especially in a multichannel setup with ambiance and spaciousness provided by other speakers.
post #499 of 820
Non treated rooms are much louder than mine or require much less on the MV control. If using the level on the MV or reference untreated rooms use less power. Of course I like the way a treated room sounds with no echoes of any kind and even at 126 dBs of LFE no rattles or room sounds, just waves of bass. The bad is I literally knocked out one of my recessed lights! I will try to measure my speakers tomorrow. Measuring at 1 meter and not knowing the spl won't tell you anything about THD. Yeah 1% but how loud and who listens to their speakers that close? One time I read a person liked a speaker better than another because it sound clearer or smoother when his ear was at the speaker. I would never do that.
post #500 of 820
Quote:
Originally Posted by JerryLove View Post

I think your response has lost context. I responded to a claim about sensitivity disadvantage with one about power disadvantage.
Let's go back to that post you are referencing:
"I don't care about the power-handling, nor the efficiency of a speaker until and unless it becomes a problem. Then I do." - Jerry Love #438
So do you think I brought this up because I care about power-handling?
"I suspect that, when discussing SPL, it's a disadvantage which is negated by higher sensitivity. You'd need less than 3db after-all" - Jerry Love #438
So do you think you are telling me something new when you claim that the power disadvantage is off-set by the sensitive advantage when SPL is the goal?
It just feels like you are responding to a caricature of my position rather than what I actually said. Do you see what I mean with the above posts? The response really feels like a religious one rather than a rational one. frown.gif
My speakers do what I want them to do and they do it as well or better than any speaker I had listened to. When I find something better still, and if I can afford it, it will be the next thing on the list. I don't care what the sensitivity or power handling is. I care only about how I like the sound in my real use. Is there something wrong with that?



Than why are you posting n this thread if you don't care about high sensitivity speakers? That's whats in the title if you haven't looked.

Edited by Reddig - 12/10/12 at 12:40am
post #501 of 820
Quote:
Originally Posted by Eyleron View Post

Oh, shoot. Measuring distortion on peaks seems to be the missing component in measuring. 
Measure at low power, measure at full power, and at a few spots in between. What you're really interested in is how much power the system will take before reaching 10% THD. That's your peak. And don't assume if THD is 10% or even higher that it won't sound good. Many's the audiophile willing to lay out big bucks for tube amps for their 'warmth'. Warmth is coloration, coloration is distortion.
post #502 of 820
I also know that when my friend loved the feeling of his paradigms which gave him goosebumps it was all distortion doing it.
post #503 of 820
Quote:
Originally Posted by MKtheater View Post

I also know that when my friend loved the feeling of his paradigms which gave him goosebumps it was all distortion doing it.
If it sounds good it is good. But we don't all agree on what 'good' is. I guess that's what keeps Budweiser and Pizza Hut in business. rolleyes.gif
post #504 of 820
Quote:
Originally Posted by psgcdn View Post

House is big enough, but, yeah, a second sub may be required. Either a thin THT on the opposite side, or a 30-inch THT in the back adjoining room with just the opening into the room on the back wall.

I bet you could take care of the nulls with one or two small sealed or bandpass boxes using geddes approach. Of course if you are looking to boost SPL, then it is a different story.
post #505 of 820
Quote:
Originally Posted by Eyleron View Post

Yeah, and I think even Toole would agree that if the room is going to give bad reflections, you might be best served with controlled directivity. Especially in a multichannel setup with ambiance and spaciousness provided by other speakers.
if my experience is any indicator, even CD loudspeakers sound harsh at ref. levels in an untreated room. I have light to moderate amount of a. t. in my theater room and I almost always at -3dB to -10dB below ref.
I am curious if there are anybody who actually finds ref. level comfortable in a living room set up.
post #506 of 820
Quote:
Originally Posted by MKtheater View Post

Non treated rooms are much louder than mine or require much less on the MV control. If using the level on the MV or reference untreated rooms use less power. Of course I like the way a treated room sounds with no echoes of any kind and even at 126 dBs of LFE no rattles or room sounds, just waves of bass. The bad is I literally knocked out one of my recessed lights! I will try to measure my speakers tomorrow. Measuring at 1 meter and not knowing the spl won't tell you anything about THD. Yeah 1% but how loud and who listens to their speakers that close? One time I read a person liked a speaker better than another because it sound clearer or smoother when his ear was at the speaker. I would never do that.

what MV in "the MV control" stands for?
post #507 of 820
Quote:
Originally Posted by Bill Fitzmaurice View Post

If it sounds good it is good. But we don't all agree on what 'good' is. I guess that's what keeps Budweiser and Pizza Hut in business. rolleyes.gif

Yes, except he wanted them even louder and blew up his tweeters.

BTW, The only lower sensitivity speaker that could do reference and maintain all the dynamics in my room were the M&K S-5000's. M&K rated them at 92 dBs and 400 watt power handling. Don Keele tested them and input over 4000 watts to them with no problems. This is why they could play at reference because they are underrated but most overrate their speakers.
post #508 of 820
Quote:
Originally Posted by zheka View Post

what MV in "the MV control" stands for?

Master volume
post #509 of 820
Quote:
Originally Posted by Bill Fitzmaurice View Post

+1, gets the job done without taking up any floor space. Try it first in the room aiming at the wall to find the sweet spot, then cut the hole in the wall and put it on the other side.

Thanks Bill!
post #510 of 820
Quote:
Originally Posted by zheka View Post

I bet you could take care of the nulls with one or two small sealed or bandpass boxes using geddes approach. Of course if you are looking to boost SPL, then it is a different story.

Don't know Geddes' approach. Link?
I doubt I want to integrate a sealed sub with a horn-loaded sub, but...
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