I use Arta as well. On it's own it is quite time consuming to take several measurements, save impulse response, adjust window/gating, save frd exports and save to overlay. I modified to loop measurements script available in Arta website to support gated frd plots, automated/manual sequencing, working directory support and offsetting frd plots magnitude and possibility to add language support (needed for open/save as dialogs). I also made a another script to gate and plot existing impulse response files.
I would like to hear more about this because directivity plots are indeed a chore to produce. I did not know that Arta had a scripting interface. Now we are going to have to start a thread on a system with a positioning turntable!
Check out the video on this page:
Brushless DC Servo Motors with Integrated Drive & Controller by Teknic
These are currently available only to OEMs, but I know where I can get a few
.Can you send me any more info about your script? A link to the script page on Arta's site? Thanks in advance,
Z
Arta does not have scripting interface. The script is done with AutoIt scripting language, pretty straight forward automation tool for Windows. Script can be compiled into executable (.exe). The original script is available in arta website, support section. I modified it to suit my purposes better, above mentioned features. If you want to test drive, provide my with e-mail address (via private message) and I can send the executable for you. Or if you wish to compile it yourself or make changes, I can provide the source code as well.
Gusto Full range and Woofer... GuFaW!
Yes, heretical is the fact that one can build speakers out of flimsy foam core or cardboard using bottom of the barrel woofers and cheap fullrange drivers that sound good.. The only reason I posted here in Fullrange forum was that I am using the top as "fullrange" from 200 Hz to 20kHz. I agree it is kind of complicated now with DSP and bi-amp compared to a straight wire from the amp to the driver. However, I think that the DSP and bi-amping made this *Infinitely* more reachable and executable with decent results for a novice to cross overs like myself compared to doing it all at speaker level passives like the die hards on the Multiway forum. The cross pollination was very good I think.
I wonder if it should be moved to Multiway? Stuff can get lost in the noise over there because the forum is so active with new posts.
Yes, heretical is the fact that one can build speakers out of flimsy foam core or cardboard using bottom of the barrel woofers and cheap fullrange drivers that sound good.
. The only reason I posted here in Fullrange forum was that I am using the top as "fullrange" from 200 Hz to 20kHz. I agree it is kind of complicated now with DSP and bi-amp compared to a straight wire from the amp to the driver. However, I think that the DSP and bi-amping made this *Infinitely* more reachable and executable with decent results for a novice to cross overs like myself compared to doing it all at speaker level passives like the die hards on the Multiway forum. The cross pollination was very good I think. I wonder if it should be moved to Multiway? Stuff can get lost in the noise over there because the forum is so active with new posts.
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I have heard that a low cost and easy to interface turntable can be made from consumer telescope USB driven equatorial mounts.
I like using REW so much and maybe the creator of REW will add an automated extract to polar plot once you have collected a string of FR plots? Basically highlight all the plots of interest and click make polar plot. Within the polar plot diagram there is a pull down that lets you select freq to plot as a polar trace(a). Seems simple enough. Right now I find it quite effective to just plot multiple FR plots (kind of like a waterfall) that shows dependence on angle. It conveys all the info whereas a polar plot is specific to a single freq.
^problem for me in REW is that I haven't been able find out how you can extract "absolute phase" i.e same procedure that you adjust in Arta with cursor, marker and predelay. in REW, phase seems to be nailed to microphone and any attempt to extract distance corrected phase i.e driver's phase has failed. And that is an issue when simulating passive XOs. If anyone knows how to do that, please educate me
And the exported frd files have fixed frequency step, when other software uses logarithmic steps. good thing about REW is that you can have several measurements open at the same time.
REW is made for room measurements and I do not know if it can be used to measure drivers in multidriver passive speakers.
And the exported frd files have fixed frequency step, when other software uses logarithmic steps. good thing about REW is that you can have several measurements open at the same time.
REW is made for room measurements and I do not know if it can be used to measure drivers in multidriver passive speakers.
How do you measure drivers in multi driver passive speakers? The software simply collects the time-resolved sound file at measurement time. All plots are generated from the actual mic data that is stored (correct me if I am wrong). But that is why the data files are huge - they are essentially uncompressed wave files. I have never tried extracting the phase - you mean the phase displayed under the freq response plot?
I agree that the best feature of REW is the interface which lets you see multiple traces and the graphing is very nice and clean without too much manual intervention.
I agree that the best feature of REW is the interface which lets you see multiple traces and the graphing is very nice and clean without too much manual intervention.
driver by driver
I meant the raw driver measurements that are used for simulating XOs in for example LspCAD.Phase is automaticaly exported when you export the measurement to frd-file. the issue for me is that the phase REW exports, is nailed to the mic location. And phase in mic location vs. pahse in driver location is not the same. That's why I would like to get the "distance corrected" phase, which is nailed to driver location. that is easily done in Arta by adjusting the gates and predelay, but I have no idea how to do that in REW.
There is an impulse response gate pre-delay and delay adjustment dialog that then changes the freq response plot (and I assume the phase plot too). Have you tried that? It is the "IR" button at the top on the left side of the main buttons.
Measuring driver by driver is actually very easy and nice with REW as there can be multiple driver measurement windows open. You can even have multiple instances of REW open in separate Windows.
Measuring driver by driver is actually very easy and nice with REW as there can be multiple driver measurement windows open. You can even have multiple instances of REW open in separate Windows.
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I have. It changes the plot. But the changes are not exported for some reason. As gating does not affect the exported data as well. It might be just me, I haven't tested REW that much after I started using Arta. At a first glance Arta is old fashioned and cryptic, but when you get used to it, it offers very robust measurement package and with additional automation, it meets my needs.
It is much easier with Arta + automation script + turntable
Just define seconds between measurements (time you need to turn the table 5-10 degrees) and remember to turn the table when driver goes silent and make sure to keep clear of the cables lying around gating, plotting, saving files etc is handled by the script.But that si sort of irrelevant. I might dig into REW a bit more, unfortunately it does not offer me anything I miss at the moment. It would be strange if it did not offer the same possibilities to adjust/manipulate the impulse though.
Hey, want to make sure you know I meant no offense. Just thought it comical that this thread is in a forum where many of the posts are by folks are driving their single driver transmission lines using SET amps.
Once or twice, for some time ago. Never really dived deeper though. I'm quite satisfied with my current setup. I think this thread got a bit distracted because of my comments about REW, sorry for that x
No worries - I enjoyed the discussion and learned something new - that ARTA is scriptable.
I used to use Holmimpulse but find REW makes much nicer plots and lets me look at a dozen traces at once rather than just 3 - a severe limitation. REW lets you change gating after the measurment - just not sure if the changes to the phase are exportable as jlaakso points out. I will have to look into it but REW is currently my favorite and does what I need for now. Plus it also does impedance measurement and calculates T/S params! That feature works very well and is super handy.
I used to use Holmimpulse but find REW makes much nicer plots and lets me look at a dozen traces at once rather than just 3 - a severe limitation. REW lets you change gating after the measurment - just not sure if the changes to the phase are exportable as jlaakso points out. I will have to look into it but REW is currently my favorite and does what I need for now. Plus it also does impedance measurement and calculates T/S params! That feature works very well and is super handy.