Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs - Page 494 - AVS | Home Theater Discussions And Reviews
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post #14791 of 14798 Old Yesterday, 09:31 PM
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Originally Posted by markus767 View Post
I don't bother with the auto target because it doesn't match my speaker directivity nor my requirements for equal loudness compensation...
What's the general rule of thumb when it comes to setting a target curve around the directivity of the speakers?

Also curious what you think of my measurements in this post Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs if you have the time. Thanks.
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post #14792 of 14798 Old Today, 01:09 AM
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^
Don't know what I'm looking at. Looks like a comparison of different screen materials taken with a Radio Shack meter? I'd recommend getting a properly calibrated mic, e.g. UMIK-1.

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post #14793 of 14798 Old Today, 04:46 AM
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Originally Posted by markus767 View Post
^
Don't know what I'm looking at.
Sorry, that was the wrong link. Please get the MDAT here: https://drive.google.com/open?id=0Bz...eDg&authuser=0 .
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post #14794 of 14798 Old Today, 05:10 AM
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Originally Posted by markus767 View Post
Let me describe how I approach this with Dirac Live.

I'm trying to get a common crossover point for all speakers. This will lead to the most predictable results. So what I do first is to measure all speakers, check how low they can go and determine a common crossover point that is achievable with EQ. Ideally this would be 80Hz.
What criteria do you look for to determine "how low they can go"? Must not drop more than x dB by what point, what what threshold do you use for x?

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Then group all satellite speakers in DLCT, load your preferred target curve...
How do you get a feel for what a preferred target curve is? I know what my preferred target curve is for the low end. I assume that is what's referred to as a "house curve". I have that at +8 dB at 20 Hz rolling to +0 dB at 80 Hz. But I'm not sure what types of target curves can be good for the high end. I have a related question to this about adjusting for hearing loss that I'll post separately after this message to expand on this more.

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...into that set and set the lowest breakpoint one octave below your desired crossover frequency.
How do you determine what value is one octave below a given frequency?

Quote:
Move the "curtain" to the left (or edit your target curve file and set LOWLIMITHZ to 10), add another breakpoint below and drag it down. The resulting curve should look similar to the blue curve in the response graph above.
Do the same for your sub, i.e. set the highest breakpoint one octave above your desired crossover frequency. Move the curtain to the right (or edit HIGHLIMITHZ in your target curve file), add another breakpoint above and drag it down. The resulting curve should look similar to the red curve in the response graph above...
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post #14795 of 14798 Old Today, 05:40 AM
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Quote:
Originally Posted by lovingdvd View Post
Also curious what you think of my measurements in this post Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs if you have the time. Thanks.






Here are my quick impressions:

The frequency response seems to drop off the shelf above 8Khz. What is going on with your high frequencies? Are you applying EQ up there? The average level of the signal above 100Hz is 65-70dB. The curve rises to 90dB at 20Hz. I have heard of house curves, but this seems to be quite heavy in the bass. Surprisingly, the waterfall shows pretty good control of the bass resonance--what bass treatments are you using? With the aggressive bass boost, I expected more ringing, but the absence of ringing suggests that the bass probably sounds pretty tight.

On the ETC, place the cursor at the -20dB mark. Any ETC spikes that extend above the cursor represent a level of reflections that are likely affecting the quality of your audio in the specular region. The ETC shows some serious reflections going on in your listening room, and should be a primary focus of improvement activities. For comparison, here is an ETC showing better reflection control:

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post #14796 of 14798 Old Today, 05:46 AM
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Making a target curve to adjust for hearing loss

Is it possible (or worthwhile) to make a target curve that can help compensate for hearing loss at high frequencies? I did some Googling around and surprisingly I didn't come across much if anything about creating a target curve for older ears.

My hearing has never been that great to begin with. As I've gotten older its gotten considerably worse. I can certainly still appreciate music and know what sounds good to me and what doesn't. When I go into a HT room that has been over-deadened, I can immediately hear that (and others with good hearing will confirm its not just my imagination). That said I am sure there are many fine nuances in music that I am not hearing. For example kids will hear frequencies and noises that I can't hear no matter how hard I try and how isolated the sound is.

So with this in mind, I'm wondering - its it possible to set a target curve design specifically for "older ears" that I could use when I'm the only one in the theater (such as in an 88A preset)? I suppose this would involve boosting the upper frequencies. Starting around what point, and going up by how much? I wonder how much this could help and if this is even practical? I'm sure there are some high frequencies that I couldn't hear (that younger folks can) no matter how loud it was. But perhaps there is a range that could be boosted that would be useful?

I'm thinking maybe I could do some sort of "hearing test" in my theater. Like use REW to play back tones at a low level of increasing frequency, and find the point where it becomes noticeably lower. Then see how many dB I have to boost it to hear it at the same level. Then keep going higher and rinse repeat, until I got to a point where increasing the dB any reasonable amount (+5 dB, +10 dB?) at a certain frequency range made no difference and stop there knowing that no matter how reasonably I boosted that frequency it didn't help.

I just did a quick test online, playing tones at certain frequencies using my cheap speakers while sitting at my computer. At a moderate listening level I could hear 8 kHz just fine. I could also hear 10 kHz a bit quieter. For 12 kHz I had to turn the volume up some, up more to hear 14 kHz and up again to hear 15 kHz. At 16 kHz and above I couldn't hear even at max volume.

With this in mind, could it work to create a target curve that boosted these upper frequencies starting at say 11 kHz? I'd use it only when listening alone, since otherwise the boost would likely sound terrible to someone with good hearing.

I know you have to be careful not to apply too much boost (or any much beyond a small amount, really) to the low end / sub frequencies. But do you have to worry about clipping of speaker damage boosting frequencies in these upper levels?

Thanks!
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post #14797 of 14798 Old Today, 05:54 AM
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Quote:
Originally Posted by lovingdvd View Post
Is it possible (or worthwhile) to make a target curve that can help compensate for hearing loss at high frequencies? I did some Googling around and surprisingly I didn't come across much if anything about creating a target curve for older ears.

My hearing has never been that great to begin with. As I've gotten older its gotten considerably worse. I can certainly still appreciate music and know what sounds good to me and what doesn't. When I go into a HT room that has been over-deadened, I can immediately hear that (and others with good hearing will confirm its not just my imagination). That said I am sure there are many fine nuances in music that I am not hearing. For example kids will hear frequencies and noises that I can't hear no matter how hard I try and how isolated the sound is.

So with this in mind, I'm wondering - its it possible to set a target curve design specifically for "older ears" that I could use when I'm the only one in the theater (such as in an 88A preset)? I suppose this would involve boosting the upper frequencies. Starting around what point, and going up by how much? I wonder how much this could help and if this is even practical? I'm sure there are some high frequencies that I couldn't hear (that younger folks can) no matter how loud it was. But perhaps there is a range that could be boosted that would be useful?

I'm thinking maybe I could do some sort of "hearing test" in my theater. Like use REW to play back tones at a low level of increasing frequency, and find the point where it becomes noticeably lower. Then see how many dB I have to boost it to hear it at the same level. Then keep going higher and rinse repeat, until I got to a point where increasing the dB any reasonable amount (+5 dB, +10 dB?) at a certain frequency range made no difference and stop there knowing that no matter how reasonably I boosted that frequency it didn't help.

I just did a quick test online, playing tones at certain frequencies using my cheap speakers while sitting at my computer. At a moderate listening level I could hear 8 kHz just fine. I could also hear 10 kHz a bit quieter. For 12 kHz I had to turn the volume up some, up more to hear 14 kHz and up again to hear 15 kHz. At 16 kHz and above I couldn't hear even at max volume.

With this in mind, could it work to create a target curve that boosted these upper frequencies starting at say 11 kHz? I'd use it only when listening alone, since otherwise the boost would likely sound terrible to someone with good hearing.

I know you have to be careful not to apply too much boost (or any much beyond a small amount, really) to the low end / sub frequencies. But do you have to worry about clipping of speaker damage boosting frequencies in these upper levels?

Thanks!
As I mentioned in my earlier post, your high frequencies are significantly attenuated now, based on the REW measurement. How much of the missing high frequencies is a result of your hearing loss, and how much is due to what seems to be a severe roll-off in your tweeters?

If you had something like the 88A, you could certainly design a HF boost, and then test to see whether your ears can tell a difference. I have experimented with adjusting the HF curve, and have not been able to hear much of a difference, even though I can hear test tones up to 14Khz or slightly higher.
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post #14798 of 14798 Old Today, 07:00 AM
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I'd be worried about the distortion:


Did you really need to quote that entire post in your reply?
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