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post #1 of 31 Old 03-17-2012, 04:11 PM - Thread Starter
 
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I'm sure that I'm going to get flamed on this but I have been eqing my subs and. Have got a curve within 7 db +-. But It just seems like now I'm missing something. I have watch and listened for a week now and I'm just not sure a flatter curve is for me. Does anybody else feel this way? I'm an old car audio guy so I know that doesn't help but is there some sort of happy medium? Thanks
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post #2 of 31 Old 03-17-2012, 04:41 PM
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Quote:
Originally Posted by qx56 View Post

I'm sure that I'm going to get flamed on this but I have been eqing my subs and. Have got a curve within 7 db +-. But It just seems like now I'm missing something. I have watch and listened for a week now and I'm just not sure a flatter curve is for me. Does anybody else feel this way? I'm an old car audio guy so I know that doesn't help but is there some sort of happy medium? Thanks

"Flat" from what freq to what freq? Measured where and how and with what?

What does 7dB +- mean? If you mean +-7dB, then that is a 14dB window-which most people would not consider "flat". But it depends on what your "reference" is.

Most people prefer the subs to be run a bit "hot". How much is very much up for debate.

A lot more information would really help.

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post #3 of 31 Old 03-17-2012, 05:01 PM - Thread Starter
 
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Sorry.I ran it from 18-100. And there was a 7 db total difference. Useing the radio shack meter. I know it has its flaws but whether I use the correction table or not I still haven't been pleased. With the results. Even tried it in 3 locations. Thanks agin for the help and your take on this.
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post #4 of 31 Old 03-17-2012, 05:55 PM
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Our human hearing is less sensitive in the low frequencies, so boosting the bass will sound perceptually flat to us (which most people prefer), even though it won't measure flat.

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post #5 of 31 Old 03-17-2012, 05:56 PM
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If you are in a 7 dB window (are you using any corrections for the RatShack meter's deviations from flat?) then you are plus or minus 3.5 dB, which is pretty good although many here appear to have even better results. (FWIW, I seem to be plus or minus 4.5ish post Audyssey).

Do you know what your response looked like before you EQed? A couple of things may be happening. First you may have become accustomed to a boosted response at some frequencies, which can sound exciting, although it also wil be "wrong" versus what the conent creators intended.

Second is if you had a rising response as you go lower, and you listen at quieter volumes, you had a sort-of loudness curve correction built into your response, which is not the end of the world, especially if you don't use something like Audyssey Dynamic EQ to account for how differently we hear bass and high treble at quieter volumes.

I quite like how things sound with Dynamic EQ boosting the lows at the quieter levels I tend to listen at.

On the other hand, quite a few members have "house curves" built into their frequency response, and that's okay, too.

But I think the advice I've seen here before makes sense. To the extent you can, leave things as flat as you can get them for a week or two. See if when you then switch back to the exaggerated response you had before it sounds "funny" or sounds disappear because they're masked by the louder-than-intended bass at certain frequencies.
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post #6 of 31 Old 03-17-2012, 06:05 PM
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Quote:
Originally Posted by qx56 View Post

I'm sure that I'm going to get flamed on this but I have been eqing my subs and. Have got a curve within 7 db +-. But It just seems like now I'm missing something. I have watch and listened for a week now and I'm just not sure a flatter curve is for me. Does anybody else feel this way? I'm an old car audio guy so I know that doesn't help but is there some sort of happy medium? Thanks

There is the notion of "perceived flat" and "measured flat" and they aren't the same thing.
Perceived flat = perceived equal loudness. Google 'Equal Loudness Curve' to see how the human ear is less efficient at low and high frequencies and most efficient between 1-5kHz or thereabouts. Most folks prefer a tilted up bass as frequency falls.

Measured flat = a very small variance across some frequency bandwidth according to an acoustical measurement tool. You seem to be listening to a 'measured flat' response. Try raising the SPL from 100hz down to 20Hz. I think my 20Hz is 15dB louder than 100Hz and it is this way on purpose to try and emulate the equal loudness curve. Multiple subs will help get you the bass frequency "shape" you desire.
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post #7 of 31 Old 03-17-2012, 08:52 PM
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For music with drums I adjust my subs so that a kick drum sounds and, more important to me, feels like a kick drum in my room and will error on the side of excess. This can be anywhere from -6 to +15dB depending on how long I've been listening, overall listening levels, which 7-channel dsp mode is being used, and how it was recorded. For movies I go about 6 dB hot or lower as I find canned LFE effects kind of annoying and distracting after awhile.

Unless I've done something drastically wrong with my setup I couldn't imagine one setting, flat or otherwise, being suitable for everything.
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post #8 of 31 Old 03-17-2012, 09:57 PM
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Quote:
Originally Posted by sdurani View Post

Our human hearing is less sensitive in the low frequencies, so boosting the bass will sound perceptually flat to us (which most people prefer), even though it won't measure flat.

I never can quite decide what to make of this. While I agree that for test tones adjusting to the FM equal loudness (or alternative) curves should sound perceptual flatter, isn't music mixed/mastered on systems that presumably measure relatively flat, and thus shouldn't any equal loudness adjustments already be applied at that stage?

I know that the above considers only a single volume level, and that the curves are a function of level as well (and that some dynamic volume algorithms attempt to adjust for that as well).

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post #9 of 31 Old 03-17-2012, 10:20 PM - Thread Starter
 
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I have ypao witch does nothing for a sub so I got the eq.2 and have been messing with that. When I started I had a variance of almost 20 db total with q dip at 30-40hz and a peek at around 60hz. These are some great comments thanks for the help guys.
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post #10 of 31 Old 03-17-2012, 10:41 PM
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Quote:
Originally Posted by Bigus View Post

I never can quite decide what to make of this. While I agree that for test tones adjusting to the FM equal loudness (or alternative) curves should sound perceptual flatter, isn't music mixed/mastered on systems that presumably measure relatively flat, and thus shouldn't any equal loudness adjustments already be applied at that stage?

I know that the above considers only a single volume level, and that the curves are a function of level as well (and that some dynamic volume algorithms attempt to adjust for that as well).

My understanding is that the material is mastered "flat" not "v-curve" and the playback is assumed to deal with whatever EQ to get "perceived flat" working. For example, Dolby/THX specify the LFE playback level to be some 20 dB (acoustic SPL) over the other channels, which would compensate for the Fletcher-Munson curve.
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post #11 of 31 Old 03-18-2012, 12:52 AM
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Quote:
Originally Posted by walbert View Post

My understanding is that the material is mastered "flat", not "v-curve" . . .

That is my understanding as well, and that it is flat for a practical reason: If the low-end or high-end were to be boosted above the rest of the music, that would leave less dynamic range for the bulk of the frequencies in between the low-end and high-end.
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post #12 of 31 Old 03-18-2012, 02:11 AM
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This is a very good discussion and topic. I hope some recording engineers stop in and let us know how recordings are typically mastered to account for this.
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post #13 of 31 Old 03-18-2012, 07:15 AM
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Quote:
Originally Posted by qx56 View Post

Sorry.I ran it from 18-100. And there was a 7 db total difference. Useing the radio shack meter. I know it has its flaws but whether I use the correction table or not I still haven't been pleased. With the results. Even tried it in 3 locations. Thanks aging for the help and you take on this.

OK a little bit more information on how you ran your "test". Exactly how did you do it? Did you run tones? and measure the SPL? IF so how far apart were the tones?

Or did you run a sweep and watch the meter move during the sweep? If so how fast was the sweep?

What were the settings on the meter? A or C, fast or slow etc.

Just because something is "measured" does not mean it was measured PROPERLY.

There are all sorts of computer programs for measuring freq response. We see all the time people posting what they "measured". Yes it shows up on the computer screen-but the data is invalid and wrong-because the measurement procedure was wrong. Jsut because a meter shows it or it is on a computer screen does NOT mean that it is correct. Sometimes you have to go a bit further. Getting good/accurate loudspeaker measurements is NOT as easy as many people think. Gettting "something" to show up on the screen is pretty easy-but is it accurate?

Just try this for a little bit of fun. Put in a 60hz tone (or something in that area).

Now read the level-anyplace in the room. Now walk around with the meter (with the same tone playing) and see if the level changes at different spots in the room.

Now change freq (say to 80Hz) and do the same thing.

You are not looking for a difference between 60 and 80Hz, but rather the difference of the same freq at different places in the room.

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post #14 of 31 Old 03-18-2012, 07:43 AM
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Yes movies are mixed on systems that are flat and it is assumed the playback system is as well. The mixer that adds bass or effects until it sounds like he wants it, so yes this takes into account equal loudness curves since it is what he is hearing. The part that is missing is matching the level the movie was mixed at. Our perception changes as loudness changes and that is what things like Audyssey Dynamic EQ address. If you listen at reference level it does nothing, but as you lower the volume it starts to increase bass and high freq. Since most people listen at -15 or more from reference it is very beneficial.
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post #15 of 31 Old 03-18-2012, 08:59 AM
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Quote:
Originally Posted by primetimeguy View Post

The mixer that adds bass or effects until it sounds like he wants it, so yes this takes into account equal loudness curves since it is what he is hearing.

This has been my understanding. I'd love to hear more thoughts on this topic as there seems to be perpetual confusion, much of it mine.

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post #16 of 31 Old 03-18-2012, 09:48 AM
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Probably the relative flatness of music mixing (and mastering) facilities is all over the map. In my experience, FWIW, the bass has to be pretty close to flat, or the engineer very familiar with the peculiarities of their own systems, to get a mix that translates well from system to system. If the bass is hot in the mixing room, the mixer may set bass buitar and kick drum lower than he would on a flat system, and may EQ out some lows so that the bass isn't out of control in the studio. Take that to a system that is flat (let alone bass-shy) and suddenly there is no bass.

I've never seen FM curve adjustments made in a studio, FWIW. In other words, the system is left at it's base EQ and one mixes the sound around that EQ. Levels and EQ are set instrument by instrument in multitrack recordings so it sounds good all together in the mix. Then they check the mix in the car, on a boom box, etc., to make sure it translates well.
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post #17 of 31 Old 03-18-2012, 10:22 AM
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Originally Posted by JHAz View Post

Probably the relative flatness of music mixing (and mastering) facilities is all over the map.

For music recordings, there's no probably about it.



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post #18 of 31 Old 03-18-2012, 10:51 AM
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And for music there is no reference level standard so the volume you listen at has a major impact. And with the level of dynamic range cmpression applied to most music these days it is tough to make any of it sound good.
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post #19 of 31 Old 03-18-2012, 12:24 PM
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Quote:
Originally Posted by RUR View Post

For music recordings, there's no probably about it.

Agreed, but the OP also stated "But It just seems like now I'm missing something."
If he's been listening to various recordings, then your graph proves (by law of averages) that sometimes he should have GAINED something.

I think the OP is experiencing what many others have noticed, and that is when subs are EQ'd for "flat" measured frequency response, the subjective effect is that "the bass sounds weak now".
Now I'm sure that equal loudness curves could have something to do with that, but most who read this forum not only like their bass, but they like to reproduce it loud when called upon. EL curves shouldn't really play a part of weak sounding bass when the levels are high, and yet some find the sound is still not balanced at those levels.
I've experienced the same effect but was astounded to read that there are others in this forum who state that they actually prefer a measured flat response, or even a reduction in bass output to make sounds seem natural!

I'm curious, is there anyone out there who had a system that measured flat and thought it sounded weak in the bass department, but has since upgraded to a receiver that has Audyssey Dynamic EQ function engaged and finds the bass to sound balanced now?
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post #20 of 31 Old 03-18-2012, 03:02 PM
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I'm curious, is there anyone out there who had a system that measured flat and thought it sounded weak in the bass department, but has since upgraded to a receiver that has Audyssey Dynamic EQ function engaged and finds the bass to sound balanced now?[/quote]
Yes, I was that way until got a receiver with dyn eq a couple years ago. I used a BFD to eq the sub flat, but then also had one program with a boost at the low end. Or I just left it flat and boosted the sub level by about 4-6db. I think you will find many people who don't have something like dyn eq tend to run their subs hot because flat sounds weak.
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post #21 of 31 Old 03-18-2012, 04:33 PM
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^^^

yup... same experience here...

there's a reason most of us "of a certain age" ran our equalizers with the "smiley face" curve...

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post #22 of 31 Old 03-18-2012, 04:39 PM
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Originally Posted by ccotenj View Post

there's a reason most of us "of a certain age" ran our equalizers with the "smiley face" curve...

Cuz it looked cool; duh!
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post #23 of 31 Old 03-18-2012, 04:51 PM
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^^^

lol...

it's funny the things you notice... swmbo and i are catching up on social trends by finally watching the sopranos (hey, we are only 10 years behind the times )... in one of the episodes, christopher and adriana are in his place, and the camera pans past his "stereo system", and sure enough, there was a smiley face curve...

noticing stuff like this makes me think i need a life...

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post #24 of 31 Old 03-18-2012, 06:02 PM
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Quote:
Originally Posted by primetimeguy View Post

Yes movies are mixed on systems that are flat and it is assumed the playback system is as well.

Not so - the movie industry standard for both soundstages (production mixing) and theaters (playback) is the X-curve. See History of the X-Curve on Dolby's site.

As RUR noted, there is no comparable standard for the music industry.


Quote:
Originally Posted by qx56 View Post

I'm sure that I'm going to get flamed on this but I have been eqing my subs and. Have got a curve within 7 db +-. But It just seems like now I'm missing something. I have watch and listened for a week now and I'm just not sure a flatter curve is for me.

You might be a candidate for a house curve. You can find an article on the subject in my signature.

Regards,
Wayne A. Pflughaupt



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post #25 of 31 Old 03-18-2012, 07:14 PM
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Well, yes the x-curve is used but that doesn't apply in the home. The x-curve essentially makes a theater sound like near field which is much closer to most home settings. So for the purpose of this thread it is flat I guess.
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post #26 of 31 Old 03-18-2012, 08:51 PM
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Once the sound leaves a speaker it s no longer flat when the soundwaves interact with the room and everything in it.

Mosst recordings arent done ruler flat and most speakers arent flat either.

One shall stand... One Shall Fall... - Optimus Prime
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post #27 of 31 Old 03-21-2012, 01:11 AM
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What equipment do I need to EQ the sub for a gradual boost the lower it gets? I don't mean a uniform boost below the XO.

Audiosceptics accept audio trials using 25 people. A recent Oxford study with over 353,000 patient records from 639 separate clinical trials shows for every 1,000 people taking diclofenac or ibuprofen there would be 3 additional heart attacks, 4 more cases of heart failure and 1 death every year.

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post #28 of 31 Old 03-21-2012, 05:24 AM
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A parametric equalizer will do the trick.

Regards,
Wayne A. Pflughaupt



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post #29 of 31 Old 03-21-2012, 07:47 AM
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Quote:
Originally Posted by ccotenj View Post

^^^

yup... same experience here...

there's a reason most of us "of a certain age" ran our equalizers with the "smiley face" curve...

The speakers of the day were often very rolled off, top and bottom.

Also, we weren't listening at a loud enough level in many cases. We were compensating for the Fletcher Munson effects.
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post #30 of 31 Old 03-21-2012, 07:48 AM
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Quote:
Originally Posted by Kilian.ca View Post

What equipment do I need to EQ the sub for a gradual boost the lower it gets? I don't mean a uniform boost below the XO.

A parametric equalizer is the tool of choice for this.

Graphic eqs have definite limits in this application, but in general they are like equalizers with training wheels.
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