Log in
Register
Home
Forums
New posts
Search forums
What's new
New posts
New profile posts
Latest activity
News
Members
Current visitors
New profile posts
Search profile posts
Features
Log in
Register
Search
Search titles only
By:
Search titles only
By:
New posts
Search forums
Menu
Install the app
Install
Reply to thread
Home
Forums
Pro Audio
Product Reviews
Loudspeaker Sensitivity
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
<blockquote data-quote="Ivan Beaver" data-source="post: 82576" data-attributes="member: 30"><p>Re: Loudspeaker Sensitivity</p><p></p><p></p><p>I am not the one to argue with standards-but the nice thing about standards is that there are so many to choose from.</p><p></p><p>However-regarding using noise-have you ever tried to use noise and set it to 2.83V? With it jumping all over the place-the best you could do would be some sort of visual average-on both the output level and the measuring device.</p><p></p><p>In my opinion-this could lead to all sorts of "errors" and we know which way this can go.</p><p></p><p>And how would you relate freq response (-3dB. -10 points) to band limited noise-unless you use a WHOLE LOT of bands? To me (I have not read the "standard") that would mean a different test-which means they (sensitivity and freq response) are no longer tied together-and just opens up another can or worms for incorrect specs.</p><p></p><p>Regarding impedance-to ME (not necessarily the opinions of others) the impedance rating should be used to give an idea of the load that "overall" is presented to an amp.</p><p></p><p>So what if it dips down a little bit at one freq? What if the rest of the curve is well above the rated impedance. I feel it should be more of an "average" across the intended freq range of usage-unless it get really low for a wide are of response. No I do not want to begin to put any "numbers" to that statement.</p><p></p><p>Let's look at example you give. Let's say a loudspeaker is called 8 ohms and there is a little dip 1/3 oct wide (how much resolution is used in the measurement will affect what the graphs looks like also) that is 6 ohms (less than 80% of the rated impedance) but the average impedance is more like 9 ohms.</p><p></p><p>Are they saying it should be rated at 4 ohms? That number would not be anywhere near close to the average load presented to the amp or give the user an idea of how many speakers they could run off of an amp channel.</p><p></p><p>It is MY opinion (again not that of others) that specs should not be a "contest" but rather give the user a REAL WORLD idea of what to expect from the particular product.</p><p></p><p>And this goes beyond speakers-look at some amplifiers (particularly in powered speakers). Some rate the power as a 50ms test burst. That is ONE CYCLE at 20Hz or TWO cycles at 40Hz!!!!!</p><p></p><p>Is that real? When was the last time you had any type of material that had 1 or 2 cycles in it?</p><p></p><p>NO-REAL music is longer-sometimes VERY much longer in duration. So that particular amp cannot produce its rated output and the level drops down quite a bit-as much as 6dB or more. So the use of the very short tone bursts is nothing but a "game" that some manufacturers use to get higher numbers-that the end user expects to be able to get-yet cannot. So what that means is that the maximum output of the loudsepaker woudl have to be 6dB lower-now who would buy that?</p><p></p><p>But it the loudspeaker can produce a 1 or 2 cycle tone at a particular SPL, then that is "considered" to be the "peak" output. YEAH-that is real USABLE-NOT! Just try putting a normal SPL meter up to it and drive it as hard as you want-and see if you can measure anywhere near the ratings. To me-you should be able to do that-but I am just weird in that way.</p><p></p><p>Yes I do agree that modern amps are not the continuous output types I grew up with-that is fine-but the short term peaks have to be long enough to reproduce a "normal" (that needs to be defined and everybody has different opinions on that) audio signal.</p><p></p><p>There is at least one loudspeaker manufacturer who has a stupid high number that is basically a "Maximum physical output" and as far as I can tell they give an SPL number that the loudspeaker will produce one a one cycle tone right at the limit of destruction.</p><p></p><p>Is that real? NO-but are they lying-I would assume not-but they are HIGHLY misleading the user as to how loud of a SPL they can get out of the loudspeaker in a real world situation.</p><p></p><p>I try to stay in the real world and not live in fantasy land-but that is probably because I am to honest and was a user for decades before I got into install and manufacturring.</p><p></p><p>So I want to know the REAL WORLD results I can expect out of a particular product-NOT some special test procedure that gives some special number-What about ME! and MY gigs-can I get the type of numbers the manufacturers provide-THAT is what is important to me.</p><p></p><p>And that is the type of numbers I try to present on the spec sheets I write.</p><p></p><p>And I will stand behind any of the numbers I put on a spec sheet-even though they are as "good" as some other products-at least you (the average Joe) can reproduce them in your own back yard. And that is what is important to me.</p><p></p><p>Getting off soap box now.</p></blockquote><p></p>
[QUOTE="Ivan Beaver, post: 82576, member: 30"] Re: Loudspeaker Sensitivity I am not the one to argue with standards-but the nice thing about standards is that there are so many to choose from. However-regarding using noise-have you ever tried to use noise and set it to 2.83V? With it jumping all over the place-the best you could do would be some sort of visual average-on both the output level and the measuring device. In my opinion-this could lead to all sorts of "errors" and we know which way this can go. And how would you relate freq response (-3dB. -10 points) to band limited noise-unless you use a WHOLE LOT of bands? To me (I have not read the "standard") that would mean a different test-which means they (sensitivity and freq response) are no longer tied together-and just opens up another can or worms for incorrect specs. Regarding impedance-to ME (not necessarily the opinions of others) the impedance rating should be used to give an idea of the load that "overall" is presented to an amp. So what if it dips down a little bit at one freq? What if the rest of the curve is well above the rated impedance. I feel it should be more of an "average" across the intended freq range of usage-unless it get really low for a wide are of response. No I do not want to begin to put any "numbers" to that statement. Let's look at example you give. Let's say a loudspeaker is called 8 ohms and there is a little dip 1/3 oct wide (how much resolution is used in the measurement will affect what the graphs looks like also) that is 6 ohms (less than 80% of the rated impedance) but the average impedance is more like 9 ohms. Are they saying it should be rated at 4 ohms? That number would not be anywhere near close to the average load presented to the amp or give the user an idea of how many speakers they could run off of an amp channel. It is MY opinion (again not that of others) that specs should not be a "contest" but rather give the user a REAL WORLD idea of what to expect from the particular product. And this goes beyond speakers-look at some amplifiers (particularly in powered speakers). Some rate the power as a 50ms test burst. That is ONE CYCLE at 20Hz or TWO cycles at 40Hz!!!!! Is that real? When was the last time you had any type of material that had 1 or 2 cycles in it? NO-REAL music is longer-sometimes VERY much longer in duration. So that particular amp cannot produce its rated output and the level drops down quite a bit-as much as 6dB or more. So the use of the very short tone bursts is nothing but a "game" that some manufacturers use to get higher numbers-that the end user expects to be able to get-yet cannot. So what that means is that the maximum output of the loudsepaker woudl have to be 6dB lower-now who would buy that? But it the loudspeaker can produce a 1 or 2 cycle tone at a particular SPL, then that is "considered" to be the "peak" output. YEAH-that is real USABLE-NOT! Just try putting a normal SPL meter up to it and drive it as hard as you want-and see if you can measure anywhere near the ratings. To me-you should be able to do that-but I am just weird in that way. Yes I do agree that modern amps are not the continuous output types I grew up with-that is fine-but the short term peaks have to be long enough to reproduce a "normal" (that needs to be defined and everybody has different opinions on that) audio signal. There is at least one loudspeaker manufacturer who has a stupid high number that is basically a "Maximum physical output" and as far as I can tell they give an SPL number that the loudspeaker will produce one a one cycle tone right at the limit of destruction. Is that real? NO-but are they lying-I would assume not-but they are HIGHLY misleading the user as to how loud of a SPL they can get out of the loudspeaker in a real world situation. I try to stay in the real world and not live in fantasy land-but that is probably because I am to honest and was a user for decades before I got into install and manufacturring. So I want to know the REAL WORLD results I can expect out of a particular product-NOT some special test procedure that gives some special number-What about ME! and MY gigs-can I get the type of numbers the manufacturers provide-THAT is what is important to me. And that is the type of numbers I try to present on the spec sheets I write. And I will stand behind any of the numbers I put on a spec sheet-even though they are as "good" as some other products-at least you (the average Joe) can reproduce them in your own back yard. And that is what is important to me. Getting off soap box now. [/QUOTE]
Insert quotes…
Verification
Post reply
Home
Forums
Pro Audio
Product Reviews
Loudspeaker Sensitivity
Top
Bottom
Sign-up
or
log in
to join the discussion today!