Author Topic: what's the best approach to have a +20dB rising house curve on subs?  (Read 2451 times)

Online sevenz

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Need some help....

Currently I'm trying to use REW to generate a +20dB rising house curve (straight line slope) from 95hz to 25hz on the subs. Then port the file/ parameters to my DSP.

Assumptions:
- room EQ will be Audyssey.
- DSP is antimode DC.

Mains vol target (baseline) to integrate with subs >> Use 75dB here for discussion. ie. at 96hz onwards, it will start from 75dB.

Currently i know of the below approaches. Can help advise/ comment which is better? And if there are any other suggestions to do this best? =)

Method 1 (see screenshot below):
- Raising overall subs SPL such that at 25hz, the SPL is 20dB higher than mains. ie. 75dB(mains target)+20dB=95dB.
- then perform 'surgery' using REW house curve tool to cut the unwanted parts away.
- my experience is this takes away a lot of bass energy even though the FR looks swee


2) Method 2 (see screenshot below):
- keep subs SPL at 75dB same as mains, then apply PEQ to boost 25hz to +20db more than 95hz.
- FR line not straight never mind


3) Method 3 (hybrid method, see screenshot below):
- raise subs SPL by 10db only; and lower all speaker channels volume by 10db >> so that total still get 20db rise
- Raise subs' SPL such that at 25hz, the SPL is 10dB higher than mains. ie. 75dB(mains target)+10dB=85dB.
- then, reduce all the other channel levels by 10dB, such that overall, my SPL at 25hz is still 20dB higher than 95hz when playing.
- so mean when i watch movies, i now have to play at main volume that is 10dB higher than usual.


4) Method 4:
- Use Audyssey app to have an initial rising house curve first
- If not enough, then use Antimode to apply LIFT to reach a +20dB rising curve
« Last Edit: February 11, 2020, 16:41 by sevenz »

Offline desray

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Why did you want to do that?

Offline Boxerfan88

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what's the best approach to have a +20dB rising house curve on subs?
« Reply #2 on: February 08, 2020, 12:47 »

3) Method 3 (hybrid method, see screenshot below):
- raise subs SPL by 10db only; and lower all speaker channels volume by 10db >> so that total still get 20db rise
- Raise subs' SPL such that at 20hz, the SPL is 10dB higher than mains. ie. 75dB(mains target)+10dB=85dB.
- then, reduce all the other channel levels by 10dB, such that overall, my SPL at 20hz is still 20dB higher than 100hz when playing.
- so mean when i watch movies, i now have to play at main volume that is 10dB higher than usual.


method 3

A conservative method to achieve your goal.
Reduce risk of clipping along the signal chain, with volume as the master control.

Sent from my iPhone using Tapatalk
« Last Edit: February 09, 2020, 16:43 by Boxerfan88 »
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Online petetherock

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Have you booked a date with ENT ;)
Please post instead of sending a pm, so more can learn.

My gear:
https://peteswrite.blogspot.com/2020/02/my-setup-22020.html

Offline desray

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Have you booked a date with ENT ;)

LoL...

Offline ronildoq

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Option 3 is a viable one

But you should first visit the purpose of boosting it +20db, can the dual 12” JL handle such a boost down Low?

Say u put in a high pass filter to protect the subs, things will be slightly more complicated , unless u have another big 18”  / 21” Monster subs for Low freq, they are best left untouched to roll off naturally. What follows is harmonic distortion when boosting past 20db

You may wanna try to limit the LFE instead, go to LPF for LFE and set this to 80hz, it will roll off earlier 80hz, doesn’t mean u will lose content. Then try not to boost too much

That way, your mains stereo bass will be much more balanced, but u still get your LFE feeling

Definitely revisit the purpose of boosting 20db

Last option, add more subs

Offline winwinc81

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All is applicable with 3rd with slight advantage, but very impt point, is that cutting is more important than boosting, this is to prevent clipping. If either power amp or driver can't take boosting. Either one will fry.

Offline desray

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Option 3 is a viable one

But you should first visit the purpose of boosting it +20db, can the dual 12” JL handle such a boost down Low?

Say u put in a high pass filter to protect the subs, things will be slightly more complicated , unless u have another big 18”  / 21” Monster subs for Low freq, they are best left untouched to roll off naturally. What follows is harmonic distortion when boosting past 20db

You may wanna try to limit the LFE instead, go to LPF for LFE and set this to 80hz, it will roll off earlier 80hz, doesn’t mean u will lose content. Then try not to boost too much

That way, your mains stereo bass will be much more balanced, but u still get your LFE feeling

Definitely revisit the purpose of boosting 20db

Last option, add more subs

Precisely!

Offline desray

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All is applicable with 3rd with slight advantage, but very impt point, is that cutting is more important than boosting, this is to prevent clipping. If either power amp or driver can't take boosting. Either one will fry.

Precisely!

Online sevenz

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method 3

A conservative method to achieve your goal.
Reduce risk of clipping along the signal chain, with volume as the master control.

Sent from my iPhone using Tapatalk

All is applicable with 3rd with slight advantage, but very impt point, is that cutting is more important than boosting, this is to prevent clipping. If either power amp or driver can't take boosting. Either one will fry.

Option 3 is a viable one

Thanks bros.

Yea wary about boosting. Will try to use cutting as much as possible.

One thing that bothers me about full cutting method is it takes away bass energy and energetic tactile feel. Winwinc - remember the difference u felt at my house when use the cutting method although FR looks perfect?

Trying to strike a balance kekeke
« Last Edit: February 10, 2020, 08:53 by sevenz »

Online sevenz

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Purpose is to replicate something I recently heard that I loved and brought a smile to me :)

Online sevenz

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Jag suggested another option.

First, use audy app to do whatever max rise the app allows on the sub channel. Then use antimode LIFT to settle the remaining rise needed. This way, the HC is first done within the room EQ filter itself. And minimise boosting.

Hope to have some good results on this.
« Last Edit: February 10, 2020, 10:11 by sevenz »

Offline ronildoq

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A few other things u really got to zoom in other than the frequency response

Look at harmonic distortion as well. How much more distortion when +20db boost is applied, apart from compression test

Secondly, look at the timing response, how these filter Low pass high pass are affecting the frequencies

Finally look at the channel balance, stereo bass vs LFE bass, how is the transition with mains

These measurements will reveal lotsa information, the frequency response chart is just to let u know the tonal balance.

Harmonic Distortion and timing is far more critical that is highly audible

Offline ronildoq

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Purpose is to replicate something I recently heard that I loved and brought a smile to me :)

This other sub u heard, was it also a JL 12” subs ? I would be surprised if it doesn’t go into distortion territory boosting +20db...

Unless played back at very Low volume levels , still 20db boost post eq is a lot, especially down lower frequency, quite massive

Online sevenz

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Dual e112 subs.

Measured the thd. Depending on method, the highest thd ranges between 3-6% (20hz @ 95db) at ard 20hz area . Boost method gave it a slightly higher thd.

3-6% ok?

 

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