Thank you. Great info. Really cool how some of the designers during that period at N.R.C. actually made your own chambers. Such an important time for most of the speaker designers World wide. Continuing with such details/studies to this day. A completely necessary tool especially for design/study purposes.
Absolutely right, although our chamber and the one at the NRC were both built by a company in Morrisburg, Ontario. Always appreciate your comments, thanks for watching.👍
I've learned a lot from you guys and your videos. You definitely care! Super interesting to see that super tall tower for anechoic bass measurement calibration. I'm guessing its pretty windy up there. How do you monitor the condutions up there? And do you have a tolerance for how much wind there can be before your results are invalidated? And I'm one of those soon to be backyard speaker testers. I have a stepper controlled 8ft tower turntable that i plan to use to get some Sound Power / Spinorama data on my DIY speakers and the commercial speakers i have / buy. I knew the measurements wouldn't be accurate (especially at lower frequencies) but your video has me thinking: if I could get measurements on a speaker I know was tested in a known chamber and measure that with my homemade setup, I wonder how close I could calibrate my system to the known good measurements.
I have not seen their near-field measurement technique in person, or see any direct comparisons of a speaker measured with their system and a calibrated chamber. At the end of the day we KNOW what we are getting from a calibrated chamber is correct. I would like to see the Klippel system in action some day, and I will say they their driver measurement system is the best in the world.
The on axis measurement is of the entire speaker in front of the cabinet. The microphone is aimed at the design axis for that particular product. It might be directly at the tweeter, or at a point between a tweeter and woofer in a 2-way system or between a tweeter and midrange in a 3-way system. The measurement is normally taken with the microphone 2 metres from the front of the loudspeaker and then the SPL output level is corrected to 1 metre.
Fantastic video. Great job explaining the challenges when measuring loudspeakers. I believe that bad measurements are the cause for this widespread non-sense: "Measurements don't matter". Measurements are important and very useful when performed properly.
@@Cakebattered I think that the early days of the high-end press were a breath of fresh air at a time when some magazines were only measuring and then having a quick listen and declaring the product great if the measurements looked nice. Unfortunately that was taken too far to the subjective side. Thankfully there are some publications that can balance both.
RIR is indeed linear time-invariant, but the corrections required go far deeper than gain differences at the various harmonics. I suggest checking out some of Wolfgang Klippel’s papers on the subject.
@@AxiomHomeTheaters I am a mathematician myself, while Dr. Klippel is not. Non-linear systems can not be characterized/treated in the way "audioscience" does it. IMHO, THD is utterly meaningless because the Fourier basis is nowhere close to KL, etc, etc
Here eye go again, in my long rambling story telling manner, for posterity of course, i.e, if the melting ice doesn't get us first! hahaha I have just now come onto this quite excellent presentation, after hearing that my ole buddy, JT, no no, not *that* JT, is now CEO of Bryston. hahaha Personally, I wouldn't want an E-zine reviewer to interpret well-done measurements. What could be done, especially after 25 years of experience in measuring transducers, is to *correlate* what is measured, to what could be experienced by a seated listener, in a typical listening room at home. This could've been done decades ago, especially since the NRC protocol developed, not just by Floyd Toole, but, all of those manufacturers who drove to Oh-tah-wah,ON-Terrible [expats only :-)] lugging their gear and test mules with them. The design protocol was referred to as "preference testing". Lo and behold, the snapshot was flat frequency, broad dispersion, lowm bass, inaudible THD at normal listening dB levels, with a smooth declining sound power at higher frequencies. Audio motherhood! hahaha Stateside reviewers like REG loathed this with a passion! Too bad, so sad. What the industry, and make no mistake, it IS as such, hated, was a design protocol that displaced personal listening by magazine reviewers with blind listening tests, that so easily correlate what is heard with what is measured. Doug, that's what I meant by implication more than 20 years ago, when I so carefully stated, [as is my wont...hahaha] that 'you, Doug would be outta a job'. Through all of this, I am reminded of what the very late Mike Kakadelis aka Mike Kay of Lyric Hi-Fi, NYC said to me personally in 1987: "John, the best loudspeaker in the world is a sold loudspeaker." And one more for the road, Dave Johann partner of Tanner at Whitby Audio in 1986 stated to me: "John, I like you and I like your speakers, but, it's not important that I sell them. It's only important that I sell someone's [speakers].
Hey Jordan, we’re always trying to get our products in for review, but in many cases it either takes a long, long time or they never appear in print. There is some good information on the LFR1100 actives here: www.hometheaterforum.com/community/threads/magnepan-lrs-and-other-american-made-hi-fi-bargains.367055/#post-4873217
Thank you.
Great info. Really cool how some of the designers during that period at N.R.C. actually made your own chambers. Such an important time for most of the speaker designers World wide. Continuing with such details/studies to this day. A completely necessary tool especially for design/study purposes.
Absolutely right, although our chamber and the one at the NRC were both built by a company in Morrisburg, Ontario. Always appreciate your comments, thanks for watching.👍
I've learned a lot from you guys and your videos. You definitely care!
Super interesting to see that super tall tower for anechoic bass measurement calibration. I'm guessing its pretty windy up there. How do you monitor the condutions up there? And do you have a tolerance for how much wind there can be before your results are invalidated?
And I'm one of those soon to be backyard speaker testers. I have a stepper controlled 8ft tower turntable that i plan to use to get some Sound Power / Spinorama data on my DIY speakers and the commercial speakers i have / buy. I knew the measurements wouldn't be accurate (especially at lower frequencies) but your video has me thinking: if I could get measurements on a speaker I know was tested in a known chamber and measure that with my homemade setup, I wonder how close I could calibrate my system to the known good measurements.
Are the Klippel analyzers beyond reproach compared to an anechoic chamber?
I have not seen their near-field measurement technique in person, or see any direct comparisons of a speaker measured with their system and a calibrated chamber. At the end of the day we KNOW what we are getting from a calibrated chamber is correct. I would like to see the Klippel system in action some day, and I will say they their driver measurement system is the best in the world.
I need to know more about measuring speakers
You might find some good points in this video where Ian & Andrew discuss the family of curves ua-cam.com/video/sL-W3qn4-WU/v-deo.html
Love these videos great explanation 👍
So glad you are enjoying the videos, and thanks for watching! Don't hesitate to ask about topics you'd like to see covered. 👍
Is an on-axis measurement right in front of the tweeter or in front of the cabinet as a whole?
The on axis measurement is of the entire speaker in front of the cabinet. The microphone is aimed at the design axis for that particular product. It might be directly at the tweeter, or at a point between a tweeter and woofer in a 2-way system or between a tweeter and midrange in a 3-way system. The measurement is normally taken with the microphone 2 metres from the front of the loudspeaker and then the SPL output level is corrected to 1 metre.
@@AxiomHomeTheaters appreciate the response!
@@Mike_v_E you're welcome 👍
Fantastic video. Great job explaining the challenges when measuring loudspeakers. I believe that bad measurements are the cause for this widespread non-sense: "Measurements don't matter". Measurements are important and very useful when performed properly.
Thank you, Boyd! Measurements are all part of the equation and are an integral part of audio design.
The "Measurements don't matter" mantra came from the Harry Pearson school of Audio Sommeliers.
@@Cakebattered thanks for this info!, he was a major influence indeed.
@@Cakebattered I think that the early days of the high-end press were a breath of fresh air at a time when some magazines were only measuring and then having a quick listen and declaring the product great if the measurements looked nice. Unfortunately that was taken too far to the subjective side. Thankfully there are some publications that can balance both.
No, you don't need an anechoic chamber to measure THD. RIR is LTI, but you have to account for gain differences at f, 2f, 3f, etc
RIR is indeed linear time-invariant, but the corrections required go far deeper than gain differences at the various harmonics. I suggest checking out some of Wolfgang Klippel’s papers on the subject.
@@AxiomHomeTheaters I am a mathematician myself, while Dr. Klippel is not. Non-linear systems can not be characterized/treated in the way "audioscience" does it. IMHO, THD is utterly meaningless because the Fourier basis is nowhere close to KL, etc, etc
Doug needs to get on camera more often!
Couldn't agree more, he's got a great way of conversing and explaining things. Thanks for watching!
Here eye go again, in my long rambling story telling manner, for posterity of course, i.e, if the melting ice doesn't get us first! hahaha
I have just now come onto this quite excellent presentation, after hearing that my ole buddy, JT, no no, not *that* JT, is now CEO of Bryston. hahaha Personally, I wouldn't want an E-zine reviewer to interpret well-done measurements. What could be done, especially after 25 years of experience in measuring transducers, is to *correlate* what is measured, to what could be experienced by a seated listener, in a typical listening room at home.
This could've been done decades ago, especially since the NRC protocol developed, not just by Floyd Toole, but, all of those manufacturers who drove to Oh-tah-wah,ON-Terrible [expats only :-)] lugging their gear and test mules with them. The design protocol was referred to as "preference testing". Lo and behold, the snapshot was flat frequency, broad dispersion, lowm bass, inaudible THD at normal listening dB levels, with a smooth declining sound power at higher frequencies. Audio motherhood! hahaha Stateside reviewers like REG loathed this with a passion! Too bad, so sad.
What the industry, and make no mistake, it IS as such, hated, was a design protocol that displaced personal listening by magazine reviewers with blind listening tests, that so easily correlate what is heard with what is measured. Doug, that's what I meant by implication more than 20 years ago, when I so carefully stated, [as is my wont...hahaha] that 'you, Doug would be outta a job'.
Through all of this, I am reminded of what the very late Mike Kakadelis aka Mike Kay of Lyric Hi-Fi, NYC said to me personally in 1987: "John, the best loudspeaker in the world is a sold loudspeaker." And one more for the road, Dave Johann partner of Tanner at Whitby Audio in 1986 stated to me: "John, I like you and I like your speakers, but, it's not important that I sell them. It's only important that I sell someone's [speakers].
Case in point your last review that was over a year ago had 1.1k views. That's all. Must be the best kept secret speakers around.
Hey Jordan, we’re always trying to get our products in for review, but in many cases it either takes a long, long time or they never appear in print. There is some good information on the LFR1100 actives here: www.hometheaterforum.com/community/threads/magnepan-lrs-and-other-american-made-hi-fi-bargains.367055/#post-4873217
Seth Rogen looks like you