How can the bass from 50 hz correct ?

user44455555

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I have small speakers that need boost the low bass end. I have individual max boost set to 9 but it do not boost. I try srt the target level to low values. with 60 db rew add only 1 filter and do not correct the rest. i use 1/1 octave smoothing. with other smoothing work, but i notice best sounding results from mid to high i get when i use 1/1 smoothing and flatness target 1 db and i need not much values add to DSP. so how i can correct the bass range from 50 hz ?. in the example screenshot i set target level very low to reduce mids and high so bass is more. but at 60 db it fail to correct more. please see screenshots.
target level 64 db.jpg
target level 61.jpg
target level 60.jpg
 

John Mulcahy

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See the help, relevant section copied below. Variable smoothing is probably best for EQ, though applying EQ above a few hundred Hz is best avoided unless addressing some characteristic of the speaker's anechoic response.

Note that by default REW will not apply filters below the frequency at which the measurement first exceeds the target or above the frequency at which the measurement last drops below the target to prevent trying to boost a response beyond its natural roll-offs, if you wish to lift the low or high end response this can be done with manually applied filters but beware of exceeding the excursion limits or headroom of the woofer or power handling limits of the tweeter.
 

skid00

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My AV System  
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2 x Adcom GFA 555
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Carver Amazing Platinum Mark IV
John Mulcahy wrote: "Note that by default REW will not apply filters below the frequency ..."

I have worked around that limitation by dropping the target response about 10 dB lower than the measurement dB at 1000 Hz. I *do* have the amp power and the speaker travel ( I listen at lower volumes ) to get away with this.
 

user44455555

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John Mulcahy wrote: "Note that by default REW will not apply filters below the frequency ..."

I have worked around that limitation by dropping the target response about 10 dB lower than the measurement dB at 1000 Hz. I *do* have the amp power and the speaker travel ( I listen at lower volumes ) to get away with this.
the workaround for the limit work with 1/2 octave smoothing or less but not with 1/1 smoothing. I can set Target Level to 55 db and it use 10 EQ. now when switch to 1/1 it use only 1 EQ and many is not correctet and stay at old level. My t.racks mini dsp have 7 EQ. so i thought its a small problem that can fix. The range i measure is from 30 hz - 20 khz. I also try out set match range from 80 to 10.000 .do not help
octave filter.jpg
half octave .jpg
 
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skid00

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You are over-smoothing the bass. Just use Variable smoothing in the Graph menu pull-down, and do not further smooth it with the IR Window Add frequency dependent window function. Then run the EQ function.
 

user44455555

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See the help, relevant section copied below. Variable smoothing is probably best for EQ, though applying EQ above a few hundred Hz is best avoided unless addressing some characteristic of the speaker's anechoic response.

Note that by default REW will not apply filters below the frequency at which the measurement first exceeds the target or above the frequency at which the measurement last drops below the target to prevent trying to boost a response beyond its natural roll-offs, if you wish to lift the low or high end response this can be done with manually applied filters but beware of exceeding the excursion limits or headroom of the woofer or power handling limits of the tweeter.
The Individual max boost option and overall max boost maybe do not work. I try many measured results and target levels that should boost few db. I never get a + db setting when i look at the EQ values when pressed EQ Filter knob. how can get + db values ?
 

skid00

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Please post your .MDAT, so we can show you screenshot of what to do.
 

user44455555

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I do save mdat and with this target level it create no filters. I notice when not do 1/1 smoothing it work. but 1/1 smoothing sound best. Here can hear in a video with diffrent smoothings and EQ. this EQ is phase linear btw. much smoothing sound best also in high freq
 

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skid00

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OK, I captured the steps I use to get flatter, deeper bass.

Please note that your speakers cannot reproduce frequencies below about 50 Hz. There's nothing you can change to fix that, outside of buying subwoofers.

Go to this series of images: imgur DOT com/a/4uVi3uX

1. Variable smoothing is close to how we hear sound. Set the filtering of your measurement to that.
2. Click the IR Windows button. You *might* want to also add this, especially to help reduce the effect of room reflections at higher frequencies. You can reduce the Left Window and Right Window values (I use 22 and 250, YMMV). *Additionally* you can add Freq Dependent Window. This also helps to reduce the effect of room reflections.
3. Click the EQ button.
4. These are the settings I would use to generate EQ for your speakers. Note that you can change the 'Rise' and 'Fall' slopes to create filters that give you the Harman curve. You'll need to generate multiple filter sets, and listen to them, to decide what you like. (If you use eqAPO to implement your filters - say by using a laptop to play your tunes - you can quickly switch between filters).
5. Click on the phrase 'Match response to target' to generate your filters.
6. Click on the gray EQ Filters button at the top of the window to see (and change!) your filters.
7. The EQ Filters window can be altered, and you will instantly see the results of changing Frequency, Gain, and Q. You can use this to alter deep bass, or other trouble spots. You can 'reserve' one/more of the 20 filter positions by changing Control to Manual. It will not be used during auto filter generation.
8. Click the phrase 'Export filter settings as text' and you will get to...
9. ...the list of filters. These can be used by eqAPO. If/when you decide to use eqAPO, let us know, and I'll document how I do that. But not today! :)
 

user44455555

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maybe people hear diffrent. If variable smooth is really close how ears can hear can easy verify. measure left and right speakers and correct them with variable smoothing or ERB smoothing. Now play sine tone and slowly increase frequency. if you hear on the measure position the middle of the sine tone is more out of middle as without correct then its not as ears hear and var smoothing do too much change. I hear when i use var smoothing lots out of middle in compare to not correct. also other hear this. I notice when i have between left and right channel more than 2 db diffrence between channels i hear it when i play bass or other solo instruments (when record a song). then some notes come from middle some a little from side. and with 1/1 smoothing i hear this problems not. my ears are ok i can also hear interaural time diffrence of 0.05 ms that position change.

I see with your filter screenshot that rew with variable smoothing boost db too, but with smoothing 1/1 it boost nothing. wy does boost of filters not work with smoothing 1/1 ?
 

John Mulcahy

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EQ is not a level control. If virtually your whole response sits far above the target you should raise the target.
 

user44455555

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EQ is not a level control. If virtually your whole response sits far above the target you should raise the target.
in the example mdat i upload sit the target control good. with smoothing 1/2 octave or other it boost EQ levels. with smoothing 1/1 it do no correction. wy does it not work on 1/1. with 1/1 it need not boost so much. I have set flatness target to 1 db and at 150 hz and 750 hz it should boost 2.5 db. individuel max boost is set to 6 db and overall max boost 6 db. but also set higher level does not help. i think it can boost 150 hz and 750 hz and boost 50 hz +6 db automatic with that setting
no filters set.jpg
 
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