Augerpro did a lot of testing and included the TD12M and is waiting on a TD15M. Our frame supplier sent the wrong frames after I paid $1400 to air ship them in from China. I've been waiting months for replacements that should finally get here next week and then I can get a TD15M together.
Here are TD12M results:
http://sites.google.com/site/drivervault/driver-measurements/tang-band-75-1558se/ae-speakers-td12m
TD15X results are here:
http://sites.google.com/site/drivervault/driver-measurements/15/ae-speakers-td15x
"So I have had some time to look at things and I think the 12" roundup is starting to shake out. The TD12M is clearly the best in every facet except sensitivity."
http://www.avsforum.com/avs-vb/showpost.php?p=16715538&postcount=73
John
Here are TD12M results:
http://sites.google.com/site/drivervault/driver-measurements/tang-band-75-1558se/ae-speakers-td12m
TD15X results are here:
http://sites.google.com/site/drivervault/driver-measurements/15/ae-speakers-td15x
"So I have had some time to look at things and I think the 12" roundup is starting to shake out. The TD12M is clearly the best in every facet except sensitivity."
http://www.avsforum.com/avs-vb/showpost.php?p=16715538&postcount=73
John
In Brett's testing, what are the mounting conditions? It's not clear from his write-up. What size is the baffle and is it open or closed? Does he adjust the responses for the baffle diffraction?
Also, why can't we get impulse responses as data files? The photos are not very useful. The reason that I ask this is that the writeup claims a 7 ms reflection free window, but the data shows it to be only about 3 ms. The 90 dB range of the FR plots is also not very useful as this is not nearly enough resolution.
Finally, I do not get the same results on drivers that I have tested as Brett is showing and having his impulse response data files would go a long way towards coaberation of the results. These files are far small than photos so bandwidth can't be an issue.
Also, why can't we get impulse responses as data files? The photos are not very useful. The reason that I ask this is that the writeup claims a 7 ms reflection free window, but the data shows it to be only about 3 ms. The 90 dB range of the FR plots is also not very useful as this is not nearly enough resolution.
Finally, I do not get the same results on drivers that I have tested as Brett is showing and having his impulse response data files would go a long way towards coaberation of the results. These files are far small than photos so bandwidth can't be an issue.
I did do power compression testing, but haven't posted the results yet. I plan to do a second round with slightly different conditions, and I'll post those probably. I haven't published the first round because the difference among drivers was very small, like 0.1 to 0.3 ohm difference. Considering the meter is only accurate to 0.1 ohm and you can see much error would be involved in comparing driver A with 0.1 ohm and driver B with 0.2 ohm. If you had higher resolution you would see that both may very well be identical, instead of driver B being twice as bad as driver A. I will do a longer test to get a better idea of how these drivers dissipate heat, but really, when the worst one was 0.3 ohm I just don't see power compression being a factor with any of these pro drivers in a home environment. 105dB of pink noise is incredibly loud, and ten minutes of it would never happen with any material. But we'll see if round two changes my mind.
One question for the experts, would the absolute value of resistance or the % change be the better indication? I was assuming % change, but now that I think about more I think the actual resistance change is a better indicator.
One question for the experts, would the absolute value of resistance or the % change be the better indication? I was assuming % change, but now that I think about more I think the actual resistance change is a better indicator.
Brandon...not Brett or Brendan. You must be getting old Earl 
I've been meaning to post the dimensions of the baffle, I'll do that today. It's pretty big as you can see from the diffraction sims I posted on the main measurement page. The goal was to get as smooth a response as possible down to the cutoff frequency due to the gate length.
I've been meaning to post the dimensions of the baffle, I'll do that today. It's pretty big as you can see from the diffraction sims I posted on the main measurement page. The goal was to get as smooth a response as possible down to the cutoff frequency due to the gate length.
It's % change that matters. I think that there are better ways to do the thermal test than measuing DCR however. For example; if you recorded the current and voltage at the end of the test, a spectral calculation could determine an Re change very accurately with no issues with meter resolution. I would expect .01 to .001 ohm accuracy with the right signal processing.
augerpro said:Brandon...not Brett or Brendan. You must be getting old Earl
I've been meaning to post the dimensions of the baffle, I'll do that today. It's pretty big as you can see from the diffraction sims I posted on the main measurement page. The goal was to get as smooth a response as possible down to the cutoff frequency due to the gate length.
Sorry about that - I'm not "getting old", I am old.
And what about the impulse response data files so that we can coaborate your data? (I edited my post to add some more questions)
I'm not posting the IR because the text files were 7mb in size. Don't ask me how a text file gets that big, but that is what they are. Now I *may* send them to others if I have good reason to do so. But because someone's own measurements do not agree with mine is not a good enough reason to go through the hassle of burning a cd and mailing it to them.
What exactly is different? How about you send me YOUR IR and I'll check it out?
The gate is accurate, and so is the scale on the plot, it just isn't easy to read as it doesn't give you 1ms graduations. You can see where the IR starts and the gate ends where I cut off the screenshot on the right side.
IF there is good reason I can reproduce some plots to post here. What drivers and what sort of scale do you want to see?
What exactly is different? How about you send me YOUR IR and I'll check it out?
The gate is accurate, and so is the scale on the plot, it just isn't easy to read as it doesn't give you 1ms graduations. You can see where the IR starts and the gate ends where I cut off the screenshot on the right side.
IF there is good reason I can reproduce some plots to post here. What drivers and what sort of scale do you want to see?
I have a pair of Apollo 15M's that have for a project.
My project has been delayed so they have not been used to this day.
I have however obtained LEAP 5 + LMS and when I have a handle on the software I plan to model the drivers (LTD) and do some measurements per the manuals.
It would be useful if John advised the 15M mmd.
Ian
My project has been delayed so they have not been used to this day.
I have however obtained LEAP 5 + LMS and when I have a handle on the software I plan to model the drivers (LTD) and do some measurements per the manuals.
It would be useful if John advised the 15M mmd.
Ian
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