Good pointers but for right now I'm not moving anything. Sorry, this is a working living room and re-arranging speakers isn't something I'm willing to do this year.
I will however retest the tweeter without the crossover and at 18" soon with a 102.5db signal.
Best,
Erik
He meant just for the measurements, not to keep them there. That would be very low WAF
I do all my acoustic measurement in my living room. The wife is patient with me; knowing I will put things back in order once done.
I hope that 102.5 dB signal to the tweeter is filtered heavily!
And what is the purpose of measuring distortion at 85-90dB?
At that level, the ambient noise and/or room reverb is greater than distortion of any tweeter, and it masks them successfully, so it is pretty much irrelevant.
At least, this level has some true meaning when we talk distortion, as transients, crescendos, louder passages, will be played at that level in critical listening sessions and the distortion products will begin to have some meaning between what is measure and what is heard.
IMHO, this level weeds out the good from the bad, showing what you could really expect in "audibility of measurements" terms.
Significant correlation of measurement results and listening tests can't be reached with measurements at 1W and debate about measurements vs. audible quality will continue forever if we keep measuring the stuff at unrealistic, but convenient levels.
In any case, Karl had already performed the measurement of his speaker at realistic level, which if correct, show that this particular tweeter, when crossed properly, is the least troublesome part of that speaker, reflecting his listening impressions and good opinions of Mundorf AMT.
This particular measurement that I asked him to perform, with midrange and crossover taken out of the picture, is just out of my personal interest in drawing correlations of how crossover region influences the distortion and to see differences between tweeters, as I happen to have a measurements done at that level.
I may see it, or I may not, no big deal. I can get all that from Mundorf or Kaiser Acoustics, anyway, but I couldn't publish them here, so I can't satisfy any general interest in that as Karl can. That is, if there is any general interest in that.
At that level, the ambient noise and/or room reverb is greater than distortion of any tweeter, and it masks them successfully, so it is pretty much irrelevant.
At least, this level has some true meaning when we talk distortion, as transients, crescendos, louder passages, will be played at that level in critical listening sessions and the distortion products will begin to have some meaning between what is measure and what is heard.
IMHO, this level weeds out the good from the bad, showing what you could really expect in "audibility of measurements" terms.
Significant correlation of measurement results and listening tests can't be reached with measurements at 1W and debate about measurements vs. audible quality will continue forever if we keep measuring the stuff at unrealistic, but convenient levels.
In any case, Karl had already performed the measurement of his speaker at realistic level, which if correct, show that this particular tweeter, when crossed properly, is the least troublesome part of that speaker, reflecting his listening impressions and good opinions of Mundorf AMT.
This particular measurement that I asked him to perform, with midrange and crossover taken out of the picture, is just out of my personal interest in drawing correlations of how crossover region influences the distortion and to see differences between tweeters, as I happen to have a measurements done at that level.
I may see it, or I may not, no big deal. I can get all that from Mundorf or Kaiser Acoustics, anyway, but I couldn't publish them here, so I can't satisfy any general interest in that as Karl can. That is, if there is any general interest in that.
He meant just for the measurements, not to keep them there. That would be very low WAF
No.
I'm not moving a thing.
The world will have to wait longer for me to take better woofer measurements. Besides, the important thing for us is the tweeter, right? That's not what needs the speakers to move.
Best,
Erik
The Mundorf's have a reputation for rugedness, but I can use the test signals with the bass removed for this exercise, so no worries there.
But FYI, I asked about this before. The 135 W power handling is not a misprint. Even if I ran full range signals, I doubt 10W worth would matter.
Still, it is bad luck to start the year with a blown tweeter in the relationship Feng Shui corner of the house. I'll be careful.
Best,
Erik
Compression testing @ NRC - deviation from linearity
Below is a link to soundstage.com site. They sponsor a lot of speaker tests which are done at Canada's National Research Council's anechoic lab. The link is to a specific test done on a Golden Ear Triton One speaker which Soundstage gave a glowing review*.
SoundStageNetwork.com | SoundStage.com | NRC Measurements: GoldenEar Technology Triton One Loudspeakers
Scroll down to the 'deviation from linearity' test. It is done at two SPL levels, 70 and 90 dB. I believe the chart is a representation of the difference between the two FR's. In theory, if the speaker can faithfully reproduce the same FR at both levels, then the deviation line would be flat all the way across. I have tried a few times to contact the NRC to get more info on exactly how they conduct the test, which is quite unique. There's been no response back. If any readers of this post who may know someone involved with speaker testing at NRC, I sure would appreciate it you could get some info on their test methodology. They do describe how some of it is done, but not all of it.
The NRC's distortion tests (2) showed some distortion artifacts in the 2-3 kHz range. Similar in shape but located higher in freq. than Eric's distortion tests.
Note though, the Goldenear's speaker has an AMT tweeter that's private labeled for their brand and thus it's source is unknown. A poster over at PETT (PALLAS) seemed to make a blanket negative appraisal of AMT tweeters based on the NRC compression test that showed some significant compression effects at higher freq.
*SoundStage! Hi-Fi | SoundStageHiFi.com - GoldenEar Technology Triton One Loudspeakers
Below is a link to soundstage.com site. They sponsor a lot of speaker tests which are done at Canada's National Research Council's anechoic lab. The link is to a specific test done on a Golden Ear Triton One speaker which Soundstage gave a glowing review*.
SoundStageNetwork.com | SoundStage.com | NRC Measurements: GoldenEar Technology Triton One Loudspeakers
Scroll down to the 'deviation from linearity' test. It is done at two SPL levels, 70 and 90 dB. I believe the chart is a representation of the difference between the two FR's. In theory, if the speaker can faithfully reproduce the same FR at both levels, then the deviation line would be flat all the way across. I have tried a few times to contact the NRC to get more info on exactly how they conduct the test, which is quite unique. There's been no response back. If any readers of this post who may know someone involved with speaker testing at NRC, I sure would appreciate it you could get some info on their test methodology. They do describe how some of it is done, but not all of it.
The NRC's distortion tests (2) showed some distortion artifacts in the 2-3 kHz range. Similar in shape but located higher in freq. than Eric's distortion tests.
Note though, the Goldenear's speaker has an AMT tweeter that's private labeled for their brand and thus it's source is unknown. A poster over at PETT (PALLAS) seemed to make a blanket negative appraisal of AMT tweeters based on the NRC compression test that showed some significant compression effects at higher freq.
*SoundStage! Hi-Fi | SoundStageHiFi.com - GoldenEar Technology Triton One Loudspeakers
Why is it that when you are named Erik, Eric, or Erick people feel permission to reinvent the spelling of your name? << sigh >>
Back to the topic. The November 2015 Stereophile is one long amorous sonnet to GoldenEar. I think they named it budget speaker of the millenium or something like that. Having heard these speakers in person, I am surprised the NRC's results are as good as they are. The treble was so hard and painful to listen to that evaluating the rest of the speaker by ear was impossible. That there was so much compression below the treble is funny.
Fear not though, for there is hope! If you spend 3 times as much and can give up on the idea of a smooth frequency response from end to end you can get the Focal Sopra, which is at least 2x better in terms of linearity.
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That is is very nice data representation!
I would expect that compression will be dominant, but especially interesting are the regions that go into peaks and dips in linearity difference. Those are probably level dependent resonant frequencies and breakups that start raising their ugly head...
This is a very bad result on tweeter compression. I wonder if that's some PTC doing the protection...
Here is a link to the impressive library of NRC loudspeaker measurements. It's a good reference if nothing else.
http://www.soundstagehifi.com/index...-goldenear-technology-triton-one-loudspeakers
If you go back to the Soundstage.com home page, you can find that they not only measure speakers, but other audio gear as well.
http://www.soundstagehifi.com/index...-goldenear-technology-triton-one-loudspeakers
If you go back to the Soundstage.com home page, you can find that they not only measure speakers, but other audio gear as well.
Sorry for the delays everyone. End of year plus being sick made it difficult to do more. Also got new internal wiring and added some foam liners to the speaker cabinets which have messed with the speaker tuning. I tried to do too much at once I'm afraid.
I plan to do several tests this weekend, and I'll follow up with the tweeter measurements then.
Hey RAAL, when you get a chance, would you post a larger pic of your 102.5db distortion graphs? I can't read your graphs, they're just too small for my old eyes.
Best,
Erik
End of year plus being sick made it difficult to do more. Also got new internal wiring and added some foam liners to the speaker cabinets which have messed with the speaker tuning. I tried to do too much at once I'm afraid. I plan to do several tests this weekend, and I'll follow up with the tweeter measurements then.
Hey RAAL, when you get a chance, would you post a larger pic of your 102.5db distortion graphs? I can't read your graphs, they're just too small for my old eyes.
Best,
Erik
Must be nice to be in Europe, going from one audio show to another.
Now I can read it!
Thanks!
Erik
I know all of DIY was waiting breathlessly for these charts, so let's get started!
As you may remember, I use OmniMic V2. For all these tests I used 20uF capacitance in series with the tweeter to prevent damage. This did lower the 2kHz response by about 1.3-1.5 db in simulations, but flat soon after that.
Measurements were taken 2' away, centered on the tweeter axis.
For the FR charts, I used the Short Sine Sweep with Bass Removed tracks. This starts around 150 Hz. For the distortion charts I had no such choice, so the 'Long Sine Sweep' signals were used.
I used a Parasound P7 preamp feeding A23 amplifiers. Sadly, I could only get within 1 db of desired resolution, so please keep this in mind when evaluating the data. I also was lazy and relied on the volume control after the first settings. It is not 100% accurate, but close enough to let me get this work done over the weekend.
First chart is the compression tests. I collected data at 70, 90, 100 and 102.5 db, however the compression is so low that it makes no sense to show you anything but the 70 and the 102.5 data. I have offset the 102.5 data to overlay it on top of the 70 db data. As you can see there is hardly any compression at all.
Next, the distortion tests. Again, running tests at 70,90, 100 and 102.5 db. I'm too tired to interpret or re-format the data with % figures, so I'll leave that up to the experts. To summarize the data properly I am showing only the sum of the 2nd through 5th harmonic at each volume level.
Enjoy!
Erik
As you may remember, I use OmniMic V2. For all these tests I used 20uF capacitance in series with the tweeter to prevent damage. This did lower the 2kHz response by about 1.3-1.5 db in simulations, but flat soon after that.
Measurements were taken 2' away, centered on the tweeter axis.
For the FR charts, I used the Short Sine Sweep with Bass Removed tracks. This starts around 150 Hz. For the distortion charts I had no such choice, so the 'Long Sine Sweep' signals were used.
I used a Parasound P7 preamp feeding A23 amplifiers. Sadly, I could only get within 1 db of desired resolution, so please keep this in mind when evaluating the data. I also was lazy and relied on the volume control after the first settings. It is not 100% accurate, but close enough to let me get this work done over the weekend.
First chart is the compression tests. I collected data at 70, 90, 100 and 102.5 db, however the compression is so low that it makes no sense to show you anything but the 70 and the 102.5 data. I have offset the 102.5 data to overlay it on top of the 70 db data. As you can see there is hardly any compression at all.
Next, the distortion tests. Again, running tests at 70,90, 100 and 102.5 db. I'm too tired to interpret or re-format the data with % figures, so I'll leave that up to the experts. To summarize the data properly I am showing only the sum of the 2nd through 5th harmonic at each volume level.
Enjoy!
Erik
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So if I read this right, and using the handy dandy online calculator, the worst distortion is about 55.8 db. 102.5 - 55.8 = 46.7 db.
Converting this to %THD = 0.46% THD around 2kHz. Not bad.
Of course, I'm probably doing something wrong.
Best,
Erik
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