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Guys Iam willing to try a few things but, I don't want to waste a bunch of time if I can help it. There seems to be a bit of confusing advice here, can we get it sorted out before I go down the wrong road???
As AJ rightly indicated, there is no consensus on how to EQ, and indeed you might not be happy with the results you get following either of our suggestions! So, experiment. Ultimately, the results should net you an audible improvement in sound quality. If not, then try a different approach. There’s always a chance that you’ll think any equalization doesn’t sound as good as unequalized.

Regards,
Wayne
 

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Discussion Starter #42
Hi Wayne,
Well all of this started because I was not happy with the boomy bass I had in my system. So i decided to get the gear to measure the room and acoustic treatment to go with it. All this was a learning expirence for me.
Once i got rid of the boomy bass I wanted to take it to the next level, now before i saw any of the measurements I loved the way the system sounded other than boomy bass. Now it more of a quest to get a good looking curve and have it sound god too!!! So that's where I am just trying get the ost out of the system...
 

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Ok guys I finally got off work before 9:00 pm so maybe these curves will help. I took these the same day as the one posted in my other thread, these are from the LP of each speaker and then both together flat no eq or subs. The red is left speaker, the green is right speaker, the purple is both together.
Regarding the red and green graphs, I think a filter at ~4000 Hz, with a bandwidth of ~1-octave or a bit less, and cut ~6 dB would make a significant improvement in SQ.

As for as the purple graph, notice the overall loss of signal below 1000 Hz. That tells me your speakers are out of phase – check your speaker wiring to make sure the polarity isn’t reversed on one of them!

Regards,
Wayne
 

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Discussion Starter #44 (Edited)
Regarding the red and green graphs, I think a filter at ~4000 Hz, with a bandwidth of ~1-octave or a bit less, and cut ~6 dB would make a significant improvement in SQ.

As for as the purple graph, notice the overall loss of signal below 1000 Hz. That tells me your speakers are out of phase – check your speaker wiring to make sure the polarity isn’t reversed on one of them!

Regards,
Wayne
OK Wayne,
I am confused by this, at 4000hz that looks to be a valley not a peak. Why would I want to cut that??? Also i check all the connections they are all correct!!!
 

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Hi, you must be looking at the narrow notch, Wayne is referring to the overall broad peak ("bandwidth of ~1-octave or a bit less").
 

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jcmusic,
You may find it helpful to EQ to one of the "House Curves" that are commonly used. The B&K curve is often mentioned a good starting point for music listening. There are others that can be found as well. Your current curve is a very large departure from any of these common recommendations and, since you asked, we are all suggesting you try something more conventional to see if you like it. There is no guarantee that you will chose one of the common recommendations as your favorite as very situation is different.

You can set a target house curve into REW and have REW automatically calculate the needed filters or you can manually adjust the filters within the REW's "EQ Filters" popup. REW will predict the new response overlaid with the target and the current response so that you can easily see the expected change. When the filter are implemented in your hardware the actual measurements will closely agree with the REW prediction. This makes any adjustments relatively quick and easy. The bigger problem will be deciding on which target you prefer. :)

Good luck!
 

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I understand what you’re recommending - I just don’t see equalizing based on nearfield measurements as a “best practices” method.
How do you think DSP studio monitors end up with such smooth native response? What method do you think is used?

A speaker isn’t going to sound - or measure - the same at 3 ft. as it will at the typical 10-12+ ft. listening position – not even in an anechoic environment.

Regards,
Wayne
Unless it's a low diffraction point source in mono (anechoic). But yes, that's true 99% of the time...and in complete agreement with what I'm saying.
So what specific target (measured) curve does he EQ (measured) to at the LP Wayne?
If it's just twist knobs to his ears (audible) "preference", exactly what do we need measurements for?

cheers
 

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I am still not getting it!!!
The range from 2.5-5khz is high in relation to everything else. So a broad drop in that range would probably be preferrable.

Do we know that your mic and measurement system are accurate? I would think that response curve would be very bright and almost painful to listen to. Voices would be very harsh.
 

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Discussion Starter #50
Well the mic has a calibrated file and everything else seems to be correct. Now you say broad explain how this is to be done?
 

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As for as the purple graph, notice the overall loss of signal below 1000 Hz. That tells me your speakers are out of phase – check your speaker wiring to make sure the polarity isn’t reversed on one of them!
Also i check all the connections they are all correct!!!
Well that’s curious. Try playing a song with some heavy bass, and disconnect one of the speakers. The bass level should drop. If it gets louder, then you definitely have something wired wrong.

Hi, you must be looking at the narrow notch, Wayne is referring to the overall broad peak ("bandwidth of ~1-octave or a bit less").
I am still not getting it!!!
As they say, a picture is worth a thousand words. As I think I mentioned somewhere in this thread (if I didn’t I should have), with the main channels we’re interested not with all the little ripples in response, but bigger issues that are significant enough to make a negative impact. You have a big, broad hump there in the 3-4 kHz range that could easily be tamed with a single broad filter. Get the idea? :D


flat right only.jpg


Regards,
Wayne

 

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Discussion Starter #52
Hey Wayne,
Thanks replying i will try playing a bass heavy song and see what happens. Also i understand about the broadness correction just not sure how to do it.
 

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Also i understand about the broadness correction just not sure how to do it.
I gave the basic filter parameters in Post #43:


Regarding the red and green graphs, I think a filter at ~4000 Hz, with a bandwidth of ~1-octave or a bit less, and cut ~6 dB would make a significant improvement in SQ.
I actually based that filter recommendation on what I see in your combined (purple) graph because (as mentioned previously, I think) you want matching filters for both channels up in that frequency range. Your Yamaha YDP2006 equalizer doesn’t give filter bandwidth in octaves, but Q; a setting of 1.4 Q would be the equivalent of a one-octave filter.

It’s really tough to do this with sweeps; I’d recommend using REW’s RTA feature. It’ll play a continuous pink noise signal while you equalize. Start with filter at 0 dB, and apply negative gain and you should see that hump flatten out. You might have to shift the filter frequency back and forth a bit, and/or the bandwidth as well, to accurately accomplish the objective. You want to stop cutting at the point where the hump is roughly in line with the rest of response.

If you see the areas beyond the hump (i.e. in front of and behind it, such as at 600 Hz and 10 kHz) start dropping, then you've cut too far. As noted above, it probably won't take more than about a 6 dB cut, but that's just my best guess: If it takes more or less, no problem, that's perfectly fine.

If the areas beyond the hump start dropping before you get the hump flattened, then the filter is too wide.

If only one side or the other of the areas beyond the hump start dropping before you get the hump flattened, (like if it starts dropping at around 600 Hz, but not up at 10 kHz), then the center frequency is off and needs to be adjusted.

Keep in mind this will sound drastically different from what you’re used to hearing; it would be a good idea to live with it for a while to get acclimated to the sound. After several days, you might try switching that filter off, and see what it sounds like to you then. At that time you should be able to decide if you think the filter made an improvement in SQ or not.

Regards,
Wayne

 

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How do you think DSP studio monitors end up with such smooth native response? What method do you think is used?


Unless it's a low diffraction point source in mono (anechoic). But yes, that's true 99% of the time...and in complete agreement with what I'm saying.
So what specific target (measured) curve does he EQ (measured) to at the LP Wayne?
If it's just twist knobs to his ears (audible) "preference", exactly what do we need measurements for?
Wow, where to begin? Why don’t we just agree to disagree and part as friends. :D

Regards,
Wayne

 

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Wayne, I didn't see you and AJ as being that much in disagreement. It's common practice to perform measurements for loudspeaker design at 1m and AJ would I have no doubt be the first to acknowledge that depending on the speaker design a greater distance may be appropriate in some cases. But there is the fact that anechoic and in-room measurements are substantially different... right?
 

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Wayne, I didn't see you and AJ as being that much in disagreement.
We aren't. We're both telling jc he needs some form of EQ.:)
It's the why and how....

It's common practice to perform measurements for loudspeaker design at 1m and AJ would I have no doubt be the first to acknowledge that depending on the speaker design a greater distance may be appropriate in some cases.
Indeed, as I stated in post #24. Nearfield/gated/anechoic will show the issues being created at the source(s). LP is the whole mess. So now what is the target? A measured curve? Fiddle about until it sounds "good"?

But there is the fact that anechoic and in-room measurements are substantially different... right?
Yes. I see potential problems beyond the 4k peaking. There also appears to be a depression centered around the 400-500hz region. Care to guess the Klipschorn XO frequencies?: http://www.klipsch.com/klipschorn-floorstanding-speaker/details
yep, 450hz and 4500k. I suspect the "modded" speaker might have some phase alignment issues...and that is not correctable via amplitude at the LP. Cutting the 4k range will help. But nearfield/gated/anechoic (the last rather doubtful) would tell far more of what's going on, than pressure at a single mic at the LP.
YMMV.

cheers
 

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Dr_Suess said:
In reviewing many different graphs I have not yet seen what ideal graphs should look like. Can someone please post sample graphs for SPL, IR, and Waterfall.
What do Ideal Graphs Look Like ?



audiolin said:
Hello All,

Getting used to looking at REW curves of my room ( SPL and Waterfall) and realizing that I need a point of reference. It would be really useful to have an example of something that would be considered a very good curve. Can this be found somewhere on the forum? If no example exists perhaps someone could post one up.

Thanks,
gg
What does a good curve look like ?




Read all posts from Mitchco .

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