kr1s1
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Posts: 33
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Post by kr1s1 on Oct 22, 2022 7:00:44 GMT
I would like to measure the frequency characteristics of my turntable. Actually the cartridge frequency response. I have a LP test disc and a computer. Maybe some advice, please?
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Post by Hexspa on Oct 22, 2022 13:25:53 GMT
I don't know if the free melda equalizers include response averaging but for sure MAutoDynamicEQ does. Also, I believe plugin doctor can analyze hardware inputs. RME Digicheck has a 30 band spectrum analyzer. There are probably several tools but those are the ones I'm familiar with.
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kr1s1
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Posts: 33
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Post by kr1s1 on Oct 22, 2022 16:22:53 GMT
Thank you Hexspa.
I have recorded sweep tone from a test disc. So I'm talking about a simple program application to draw some graph. The idea is to analyze the recording file. As simple and free as possible.
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Post by rock on Oct 25, 2022 23:28:50 GMT
One App we use for acoustic measurements is REW but it supplies it's own sweep which is applied to the speaker system and picked up by a mic which feeds the app the raw data and REW spits out all kinds of graphs. I don't know if REW can accept an audio sweep from from an external file like you have but if if did, that would be the answer. So we need to find you (and everyone else who would like one) an app that will take our sweep file and spit out a response graph. Here's someone who did that but it's almost from the last century  pensa.fr/freqresplot/indexe.htm Who knows it might work for you! If it does, please let know how it works and share your results! If that doesn't work, I think if you search the internet for "Frequency sweep to graph converter" app or something like that you might find something. Again, please let us know, it's would be a handy tool. Another type of app I have seen are spectrum analyzers. They might possibly have a frequency graphing function too. Good Luck! |
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kr1s1
New Member
Posts: 33
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Post by kr1s1 on Oct 26, 2022 17:40:31 GMT
Thank you rock.
Unfortunately Frequency Response Plotter is not installable (windows 10). There are some messages, but in French. I searched earlier myself, but found nothing. I was hoping that someone here would know. I wrote Ortofon an email a few days ago to ask, but so far I have no answer. I have REW and a microphone, so room measurement is not a problem. Frequency response of a turntable is a problem;)
P.S. REW has an RTA tool. I tried it, something can be obtained similar to the frequency response. Maybe Ortofon will write back? Just kidding.
PS.2. However, I found something. On another Forum someone gave settings for REW to get a frequency response graph. And these settings work. To draw the graph, ARTA is good, but it is shareware and in the demo version it works, but does not open files. REW is the solution to the problem.
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Post by rock on Oct 28, 2022 13:07:58 GMT
Thanks for getting back to us. Yes, it does look like the RTA tool in REW is the way to go. I'll have to try it. Thanks again!
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Post by Hexspa on Nov 6, 2022 9:33:17 GMT
You can upload it here. That host is giving me trouble.
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kr1s1
New Member
Posts: 33
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Post by kr1s1 on Nov 20, 2022 7:08:40 GMT
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kr1s1
New Member
Posts: 33
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Post by kr1s1 on Nov 23, 2022 15:19:42 GMT
You can use REW and RMAA for this. The problem is that these programs draw a flat characteristic if you open a sweep of constant amplitude. Such a sweep corresponds to white noise, as it were. But the audio signal corresponds more to pink noise. If I open a file with a turntable recording, the programs give a 30 dB REW or 25 dB RMAA drop. I'm not an engineer and that's why I don't know something. My guess is that I need to somehow change the settings of the programs to make them draw as I expect. |
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Post by rock on Nov 24, 2022 14:59:11 GMT
Hi kr1s1,
Thanks for reporting with your attempts but it looks like a head scratcher:( I'm sorry but I have not tried to do any sweeps like you're doing.
In the past, when I wanted to check a frequency response of analog electronics, I have simply hooked up my audio frequency sine wave oscillator on the input and O-scope and dB meter on the output and manually swept the oscillator and noted any level changes on the scope and the meter. This is admittedly primitive, but you can get a pretty good idea.
BTW, you really don't need both a scope AND a meter but the scope gives you an instant response and meter better accuracy. Some scopes have built-in metering but cost $$$. I got a good deal on a dual trace Craigslist some years ago, before that I had a single trace (that I never use anymore:(
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kr1s1
New Member
Posts: 33
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Post by kr1s1 on Nov 29, 2022 18:55:50 GMT
Problem solved. The sweep on the test disc is without RIAA equalization. If you add it, you have what you need.
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