tag:blogger.com,1999:blog-6890046273025265768.post7679027271779144571..comments2024-03-18T03:10:30.572-07:00Comments on NwAvGuy: RightMark Audio AnalyzerNwAvGuyhttp://www.blogger.com/profile/00309644608738074125noreply@blogger.comBlogger26125tag:blogger.com,1999:blog-6890046273025265768.post-491215053619556282012-08-26T22:45:55.463-07:002012-08-26T22:45:55.463-07:00Sorry disturbing your extremely interesting discus...Sorry disturbing your extremely interesting discussion. But I do not even get RMAA 6.x running on none of my PCs or Noteboosks (XP/Win7) after installation. It immediately crashes due to application errors,<br /><br />Reiner<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-21073125776135018432012-07-24T08:56:26.486-07:002012-07-24T08:56:26.486-07:00Of course, it is not a perfect solution, and proba...Of course, it is not a perfect solution, and probably not many people would build and use it, but it can make a useful improvement.<br />For example, I tested the noise level of a sound card, recording its output with another in the same PC (all the following dB values are A-weighted, referenced to a 2 Vrms full scale signal, and have a bandwidth of 22 kHz), and without the differential amplifierAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-19020653732127029042012-07-24T07:42:36.179-07:002012-07-24T07:42:36.179-07:00"and at low frequencies it does not agree bet...<i>"and at low frequencies it does not agree between the noise and dynamic range test"</i><br /><br />Well, this actually turned out to be not a filter problem; the dynamic range test has a "noise floor" itself that is higher than that of the noise test, but it is not high enough to be an issue when testing real analog hardware.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-79454815651805492722012-07-23T06:16:41.552-07:002012-07-23T06:16:41.552-07:00More on RMAA (v6.2.4):
- it is not entirely true t...More on RMAA (v6.2.4):<br />- it is not entirely true that "there’s no capability for other important twin tone tests such as the popular CCIF 19 Khz/20 Khz", since the "Intermodulation distortion + noise (swept freqs)" test actually includes that. This test generates two tones at equal amplitude (about -3 dBFS total), with a +/- 500 Hz offset relative to the frequency being Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-5211130330596108482012-07-18T14:37:05.664-07:002012-07-18T14:37:05.664-07:00That could be a partial workaround. The trick is h...That could be a partial workaround. The trick is having enough common mode rejection in a cheap DIY diff amp as the op amp will be operating with substantial common mode signals. Any common mode garbage has to be below the noise floor of whatever you're trying to measure and that's harder to pull off than just low noise and distortion with a single-ended input op amp. Most differential opNwAvGuyhttps://www.blogger.com/profile/00309644608738074125noreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-24577929588705331842012-07-16T00:46:17.732-07:002012-07-16T00:46:17.732-07:00One possible workaround to the grounding problems ...One possible workaround to the grounding problems that is not mentioned, although it might not be practical for the casual RMAA user, is to build a simple differential amplifier. This can also be implemented with different gains to extend the input voltage range. Of course, the amplifier itself also introduces some degradation to the signal, but this can easily be outweighed by the advantages of Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-17907530611025725602012-07-16T00:33:23.379-07:002012-07-16T00:33:23.379-07:00RMAA (at least versions 6.2.3 and 6.2.4 at 96 kHz/...RMAA (at least versions 6.2.3 and 6.2.4 at 96 kHz/24 bit, I did not test 6.2.5 yet) seems to report noise and dynamic range values that are about 2.5 dB better than they really should be, and the crosstalk is also "improved" by about 6 dB. These may be random bugs, or the result of "designing backwards".Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-8554675009671234852012-07-04T10:02:52.487-07:002012-07-04T10:02:52.487-07:00Thanks for your comments. I stated at the beginnin...Thanks for your comments. I stated at the beginning of the article I think RMAA can be useful and the price is right. Towards the end I talk about calibration and how to work around some of the limitations. And throughout I point out that many of the limitations are related to typical PC audio hardware and not the software.<br /><br />The main point I was trying to get across is when you see NwAvGuyhttps://www.blogger.com/profile/00309644608738074125noreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-58933398074709667332012-07-02T18:55:22.889-07:002012-07-02T18:55:22.889-07:00NwAvGuy, you are being a little hard on RMAA. The...NwAvGuy, you are being a little hard on RMAA. The issues you point out are not limited to RMAA and most will apply to any PC soundcard based system. My serious analogue testing goes back to Radford LDO & Distortion test set which dates me a bit.<br /><br />I went bush for more than a decade and was pleased to find, on emerging computer power so cheap & available, that many test methods Ricardonoreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-36870436377055862832012-06-05T05:59:15.496-07:002012-06-05T05:59:15.496-07:00That's true but bad results are bad results. A...That's true but bad results are bad results. And I've documented several other ways in which RMAA results can be, and often are, invalid for comparison purposes. The cell phone problem is but the tip of a much bigger iceberg of problems hidden under the water.NwAvGuyhttps://www.blogger.com/profile/00309644608738074125noreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-43604249191675002212012-06-04T17:26:42.276-07:002012-06-04T17:26:42.276-07:00'Because RMAA doesn't show you anything (b...'Because RMAA doesn't show you anything (besides the calibration level) in realtime you can't see intermittent problems--like those created by a mobile phone. You just get corrupted data when RMAA finishes. With a real audio analyzer you can get real time data and intermittent problems are usually obvious as you see the readings, spectrum, etc. fluctuate in real time.'<br /><br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-73026478891713479082012-05-28T11:08:38.444-07:002012-05-28T11:08:38.444-07:00Because RMAA doesn't show you anything (beside...Because RMAA doesn't show you anything (besides the calibration level) in realtime you can't see intermittent problems--like those created by a mobile phone. You just get corrupted data when RMAA finishes. With a real audio analyzer you can get real time data and intermittent problems are usually obvious as you see the readings, spectrum, etc. fluctuate in real time.<br /><br />You'reNwAvGuyhttps://www.blogger.com/profile/00309644608738074125noreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-1808722213578403422012-05-27T13:47:32.470-07:002012-05-27T13:47:32.470-07:00Isn't it the case that a mobile phone can caus...Isn't it the case that a mobile phone can cause erroneous measurements in many pieces of audio gear regardless of what equipment is being used to measure them?<br /><br />Why bring it up in the context of RMAA then?<br /><br />You're exaggerating the case against RMAA and other soundcard-based software measuring systems to make your own equipment and techniques look better by comparison. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-35189187074200145062012-04-15T19:01:21.111-07:002012-04-15T19:01:21.111-07:00Bumps are welcome.... That's a tough question....Bumps are welcome.... That's a tough question. If you just want to explore audio as a casual hobby, you can either stick with proven DIY designs, manufacturer reference designs, or try to get the most out of RMAA and a decent USB audio interface to measure your own designs. <br /><br />If you want to go further with audio design, especially to design something that outperforms a lot of NwAvGuyhttps://www.blogger.com/profile/00309644608738074125noreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-59626091336785387652012-04-15T18:38:09.602-07:002012-04-15T18:38:09.602-07:00Sorry to bump this article.
I was reading through...Sorry to bump this article. <br />I was reading through your Testing methods article, and was wondering. If someone is an electrical/computer engineer student (cough, me cough) and has an interest in DIY audio, for the testing equipment alone must we spend a large amount? So if we see this as a future hobby, and want to buy something as an AP ATS for 8.5k for example, would you recommend that forAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-53174847558885671732011-12-15T06:19:31.986-08:002011-12-15T06:19:31.986-08:00@Anon, sorry but I'm not aware of much besides...@Anon, sorry but I'm not aware of much besides some spectrum analyzer and acoustic software between RMAA and the professional products like Audio Precision, dScope, etc. That's especially true for non-realtime analysis as you describe (playing a file). <br /><br />The professional choices are mainly Audio Precision and the Prism Sound dScope that I use. But they start at around $5000 for NwAvGuyhttps://www.blogger.com/profile/00309644608738074125noreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-56542494857673041812011-12-15T01:02:32.561-08:002011-12-15T01:02:32.561-08:00I'm looking for software like Rightmark to tes...I'm looking for software like Rightmark to test a digital system by playing out a reference file and looping it back to record another file then analyse it. Rightmark does this, but seems a bit flakey. I don't mind paying for it - but I have not been able to find anything suitable. Any pointers?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-65619117647825553972011-11-24T06:22:46.380-08:002011-11-24T06:22:46.380-08:00There may be a lot of things why measurements are ...There may be a lot of things why measurements are wrong, even if you use Audio Precision $25k gear. So if it's FFT problem inside Audio Precision DSP of or just common problem of your hardware/software setup? We made direct comparison of results RMAA vs. APS2 with E-MU engineers. There was no significant difference. Numbers were the same, a little bit lower in loopback as it was expected. Maximhttp://audio.rightmark.org/noreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-38105334934724947872011-11-23T10:57:59.462-08:002011-11-23T10:57:59.462-08:00@Maxim, please provide documentation how the math ...@Maxim, please provide documentation how the math is done in RMAA? There is much that is not explained as there is very little good documentation for RMAA and how the software really works. There are many RMAA results that do not agree with professional instrumentation (even measurements within the capability of the PC sound hardware used).<br /><br />Many times, RMAA does not even agree with NwAvGuyhttps://www.blogger.com/profile/00309644608738074125noreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-4870375124285065502011-11-23T07:22:00.595-08:002011-11-23T07:22:00.595-08:00Most of issue do not connected with RMAA anyhow. I...Most of issue do not connected with RMAA anyhow. It's more likely common problem for ANY measurement on PC without Audio Precision gears.<br /><br />"Some of the FFT/math used to calculate the results is apparently wrong" - that's completely UNTRUE. RMAA made by Ph.D and uses Intel IPP library. There are no FTT/Math errors inside Intel IPP. We can trust it entirely.<br /><br />Maximhttp://audio.rightmark.orgnoreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-16768556135725513742011-07-15T18:18:26.743-07:002011-07-15T18:18:26.743-07:00Correct, i read your posts, very interesting indee...Correct, i read your posts, very interesting indeed. In fact, i am not an apple fan, but for weird circumstances i got an ipod 6th half price (in fact the design is very comfortable) an an ipad 2 with 200 dollars in accesories for free so i thought it was good deal and got one (i'm good bargaining, that is what i do for living).<br /><br />Anyways, although the stuff is fairly good, I was edohttps://www.blogger.com/profile/12335559753011532700noreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-20507744552399459492011-07-15T00:14:31.282-07:002011-07-15T00:14:31.282-07:00Hey Edo, thanks for the praise. It is an iPad 1G o...Hey Edo, thanks for the praise. It is an iPad 1G or 2G? I have the 1G and plan to test it. I don't have a 6G Nano, however. Considering how tiny the Nano is, I would expect the iPad to have the edge. The Nano, like several Apple products, is all about form over function. It's more like a piece of jewelry than serious audio gear.<br /><br />If you check out the Sansa Clip+ review on this NwAvGuyhttps://www.blogger.com/profile/00309644608738074125noreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-63290996786718801982011-07-14T22:51:21.511-07:002011-07-14T22:51:21.511-07:00I loved your blog, very professional in a sea of o...I loved your blog, very professional in a sea of opinions.<br /><br />I'd like to ask if you can give me some tips to test the audio quality of an Ipod 6th and an Ipad 2 (i have both). The thing is i tried some apple lossless and felt that the audio was better in the ipad (strange), so I'd like to test that.edohttps://www.blogger.com/profile/12335559753011532700noreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-28795027710675787832011-07-14T22:47:55.360-07:002011-07-14T22:47:55.360-07:00I actually loved your blog, it is very professiona...I actually loved your blog, it is very professional and I have not found any place with a professional point of view regarding sound quality.<br /><br />I have one question I'd like to make. The thing is I have an ipod nano 6th and and ipad 2, I ripped a couple of cds to apple lossless and synced them in the ipod and the ipad. To my surprise I felt the ipad had a better audio quality, the edohttps://www.blogger.com/profile/12335559753011532700noreply@blogger.comtag:blogger.com,1999:blog-6890046273025265768.post-42659742102238669252011-06-02T15:22:41.036-07:002011-06-02T15:22:41.036-07:00To Anonymous, this is a classic case of "you ...To Anonymous, this is a classic case of "you get what you pay for". For the price, RMAA, is a useful tool. But, beyond the suggestions in the article regarding how to get the most out of it, I'm not sure what to suggest that doesn't involve spending some serious money. <br /><br />Unfortunately, any PC audio device--soundcard, firewire, or USB--is going to have serious NwAvGuyhttps://www.blogger.com/profile/00309644608738074125noreply@blogger.com