A few months ago and not fully dialed in. You can see the cyan (after) and yellow (before of just moving the speakers 1.4 of an inch.
No dsp and no subs
No dsp and no subs
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Post Your Frequency Response Curve!
- Thread starter Ron Resnick
- Start date
Below you find my Frequency Response Curve and the RT60. The high and down 41 hz on the Frequency is room mood
I bought an Omni mic and downloaded REW….. After a few hours I realised that I lacked the skill. Couldn’t even calibrated the microphone.
My listening room is our living room, dining room and kitchen. A big room around 80 m2. 6 * 13 meter. Thé setup is on the left side. Firing across. I had problems with low frequencies and the balance of the sound. Whatever I do for acoustics must fit in as my wife says.
So looked for help. I found a company not too far from us. A German company HOFA specialised in acoustics. Thr came over twice. First to measure existing acoustics. Second time to measure the result. I bought the room treatments from them so got a discount on their visits. I am very pleased with the result.
I bought an Omni mic and downloaded REW….. After a few hours I realised that I lacked the skill. Couldn’t even calibrated the microphone.
My listening room is our living room, dining room and kitchen. A big room around 80 m2. 6 * 13 meter. Thé setup is on the left side. Firing across. I had problems with low frequencies and the balance of the sound. Whatever I do for acoustics must fit in as my wife says.
So looked for help. I found a company not too far from us. A German company HOFA specialised in acoustics. Thr came over twice. First to measure existing acoustics. Second time to measure the result. I bought the room treatments from them so got a discount on their visits. I am very pleased with the result.
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Subs would really fill in that bottom octave nicely. I can see a pair of JLAs or Rels in your room.
Subs would really fill in that bottom octave nicely. I can see a pair of JLAs or Rels in your room.
Have tried a few and at some point I may add one permanently, but getting one that is fast enough to keep up with the basshorns and not color the midrange. I need more time in the selection process
I was recently given a link to this article, which shows how the moving microphone method can allow a meaningful and repeatable room correction curve to be applied. The problem with taking a room measurement is that you can sometimes get a drastically different result just by moving the microphone a little, which makes it difficult to know what's a valid problem, and what's just a very localized Freq. Response anomaly that should be left alone.
I tried it, and the results were very consistent with repeated measurements, and showed I needed to take down a peak at 400Hz, and turn my tweeter down slightly. I've been impressed enough with the resulting sound to keep it. The tweeter issue is a result of my unorthodox DIY speakers. Most of you have thoroughly engineered and tested speakers that don't need any direct correction. It's only room effects that are consistent around the listening position that should be corrected.
I tried it, and the results were very consistent with repeated measurements, and showed I needed to take down a peak at 400Hz, and turn my tweeter down slightly. I've been impressed enough with the resulting sound to keep it. The tweeter issue is a result of my unorthodox DIY speakers. Most of you have thoroughly engineered and tested speakers that don't need any direct correction. It's only room effects that are consistent around the listening position that should be corrected.
In the mids and highs, maybe, depending how stable your mic stand is, but for low frequencies no as a little movement won't affect massive wave lengths. And again, you're looking for general guidance, a slope that suits your taste and any big anomalies - wide dips and peaks to rectify.
I'm not sure what you're getting at concerning the stability of the mic. stand. I don't use a mic. stand when doing a moving microphone measurement. Agreed, you shouldn't see any big change in the low bass. Between 100 and 600 Hz if the moving mic. method shows a consistent peak or dip, it makes a lot of sense to try correcting it and then deciding by ear if it's an improvement or not. I wouldn't be so confident to try to correct anything in that range from a single position measurement, as it's not as likely to be perceptually relevant, and you'll get something different if you try a slightly different mic. position.
It is interesting that you can try it several times, holding the mic. different ways, moving the mic. different ways, and get very close to the exact same result each time, and if you see a peak or dip from that, you're probably hearing it.
You stated, "The problem with taking a room measurement is that you can sometimes get a drastically different result just by moving the microphone a little,". It's common to use a mic stand to get the mic at ear level, hence my response based on common user setups, so I'm not sure what you're not getting.
Also, you greatly generalized when you stated "Between 100 and 600 Hz." and mic movement. A 100hz wavelength is about 10 feet, moving the mic a little will have minimal effect in the FR, however a 600Hz is a different story at just under 2 feet and moving the mic will have some, but not much of an effect on the FR.
It is true that the significant amplitude and width of peaks/ dips matters most.
You are right, the moving mic method is going to show less change at 100hz than 600. 1/4 wavelength things can start happening, and the moving mic. will move it around the ear area by a few feet. I used this method many years ago with an EQ/RTA system I had, and thought I had invented the method myself. Back then I made the mistake of using it to correct the entire frequency band, but when kept to below about 600 Hz I'm finding it more effective at getting a good sounding result in that troublesome transition zone than other methods I've tried, which mostly involve playing sweeps with a fixed microphone position. Honestly though, the only real change is the 4 dB cut at 400Hz I have now. I thought I was hearing too much energy somewhere in there but it wasn't clearly showing on the fixed mic. measurement. I also ended up turning the tweeters down slightly, and I like that better. Weird that the fixed mic. with sweep didn't show them as being a little too loud overall, while the moving mic. method did. My setup is weird, with the tweeters closer and in tighter than the mids and woofers, so it's difficult to figure out where to set the volume on the tweeters. There's also 3 tweeters, and only two of everything else. What measures perfect with a fixed mic. sweep at the sweet spot seems a little too bright, and so I thought it was interesting that the moving mic. showed it that way. My tweeters are crossed over at 900 Hz.
You raise a good point in that what we hear does not always exactly correlate with what we measure and see on a graph. Also, we each have our own sonic preferences and our ears change (degrade unfortunately) over time. I've heard some systems' of older folks (not that I'm 40 or younger) that had a strong HF roll off yet they had no idea, then I've heard others whereby it was overly bright yet they couldn't detect that either and enjoyed both aforementioned systems. It's something no one seems to talk about much on forums but is reality as we all age. apologies for the tangent
1/24 octave smoothing. No room correction. Was lucky here with the lowest frequencies apart from the 43 Hz null.
Your range is too broad to discern anything, can you please change to 40-90DB and repost?
I did some removal of room damping material which makes my average RT60 time around 450mSec in my 30'x20' room (300Hz-10kHz). This also smoothed out the listening position response a bit (the graph below is listening position of the right channel with 1/6th octave smoothing). The subwoofers in this graph are intentionally a bit high in level.
Just a quick tip - when you display your FR, use a scale that's represents the response visually, for example 40 - 90DB. Using 0 - 100DB zooms out too far for any meaningful comments and appreciation of your hard work.
A bit harsh
I quite like the fact that it shows the overall slope quite clearly but has 1db increments to zoom into the detail
I am interested in software, window and gating used
I agree. 5dB per major division is a good compromise and avoids 'too much data' which would obscure the response trend and generally make the graph harder to read. Graphs like I posted can always be clicked upon to see a full size version.A bit harsh
I quite like the fact that it shows the overall slope quite clearly but has 1db increments to zoom into the detail
I am interested in software, window and gating used
Another suggestion if we're really getting down into the weeds here - and one I'd like to see - is the posting of the original .mdat files from REW which preserves ALL the data, the good the bad and the ugly for those who want to get into the specifics of RT60, distortion, step response, waterfall plots etc. It's all right there in the .mdat file. It's easy enough to do by sharing the file on your Google drive or whatever you may have.
To show how foolish I am, I'll go first. Mine can be downloaded HERE. Note that my subwoofers are set really high in these plots - normally they're much more moderate in level.
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You guys must be kidding me, I said, a quick tip, grow up.
Zooming out too far yields no way to assess and help should it be deemed warranted. Next time I'll put 7 smilees and 6 hearts.. ;-)
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