# After REW + EQ, bass seemed to be ringing/boomy



## wackii (Jul 13, 2006)

Hi guys,

I finally found sometime to put up my system at my new house. After running REW and BFD, it seemed like the bass sounds ringing or boomy. How should I eq this? See REW graph below:

My sub at new location before and after EQ (I didn't have much time to play with eq)









This is the waterfall of the after EQ graph.









I've read something about setting the delay or distant of sub on the receiver will help this scenerio. Am I right? What are my options?

Thanks.

Al,


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## lsiberian (Mar 24, 2009)

It's tough to tell with the two lines on one graph. could you post them separately by any chance.


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## Wayne A. Pflughaupt (Apr 13, 2006)

You definitely need to work on the EQ. I can’t tell which trace is which. I’d also suggest exploring other placement options, if that’s possible.




> I've read something about setting the delay or distant of sub on the receiver will help this scenerio. Am I right? What are my options?


Delay or phase adjustments do not affect ringing. They smooth response through the crossover region. You’d have to take a reading with both the mains and subs to see how it well it worked.

Regards,
Wayne


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## fitzwaddle (Aug 25, 2010)

(caveat: I'm a REW noob)

I would increase the time range on the waterfall to say 700 ms so you can get a feel for what your room is doing (RT) - as it stands, almost the whole range is "clipped" in the graph.

Based on "boomy", I would suspect you need some room treatments (bass trapping), but the revised waterfall would help to see if that's the case.


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## wackii (Jul 13, 2006)

lsiberian said:


> It's tough to tell with the two lines on one graph. could you post them separately by any chance.


Here you go. Thanks for helping.

No EQ









With EQ (I tried to cut the peaks but it looks like I'm just shifting it a bit, however I managed to remove the peak at around 30hz)









Al,


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## wackii (Jul 13, 2006)

Wayne A. Pflughaupt said:


> You definitely need to work on the EQ. I can’t tell which trace is which. I’d also suggest exploring other placement options, if that’s possible.
> 
> 
> Delay or phase adjustments do not affect ringing. They smooth response through the crossover region. You’d have to take a reading with both the mains and subs to see how it well it worked.
> ...


Wayne,

Placement is an issue for me since this is a pretty big sonotube (300L). I can't move it much. I will mess around with the mains and sub this weekend. Thanks.

Al,


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## wackii (Jul 13, 2006)

fitzwaddle said:


> (caveat: I'm a REW noob)
> 
> I would increase the time range on the waterfall to say 700 ms so you can get a feel for what your room is doing (RT) - as it stands, almost the whole range is "clipped" in the graph.
> 
> Based on "boomy", I would suspect you need some room treatments (bass trapping), but the revised waterfall would help to see if that's the case.



Here you go. Thanks.

It looks like the 40hz and 50hz regions need some EQ work.









Al,


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## wackii (Jul 13, 2006)

I've just purchased the Shure DFR11EQ to EQ my sub. I installed the software but I'm kinda confused on how to use this thing. Anyone here has experience with this unit and its software? Please help. I need to HP filter at around 15hz, how can I do that? It appears that I can only set parametric EQ starting from 25hz on? I looked at the software and the lowest freq for parametric EQ is 25hz. Is that right or I am doing something wrong?

Thanks.

Al,


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## Wayne A. Pflughaupt (Apr 13, 2006)

I don’t know of anyone who’s used that one, but from what I can see in this user guide it looks pretty straight forward. There are menus for parametric filters, and shelving/roll-off filters. There are fields where you click a button to change the setting – Hz, gain, etc. - and the numeric values for the settings are shown in the field. If the filter settings don’t extend as low as you want, that’s just the way it is. There’s nothing you can do about it, unless there is firmware upgrade available.

Regards,
Wayne


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## wackii (Jul 13, 2006)

Thank you, Wayne. That link helps me out. I think I got it working now. My sub doesn't need much work on the below 25hz so I am all good. I just wanted to set the HP filter at 15hz to protect my driver. Anyway, I guess I need to mess around with it some more... I will post some graphs later.

Oh btw, I switched the FBD 1124P for the mains just to test it out. It does have some noise if you put your ear close to the speaker. Other than that, it works pretty good for the mains. 

Thanks,

Al,


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## Wayne A. Pflughaupt (Apr 13, 2006)

If you have to switch the BFD to +4 because you’re running it into clipping, it’ll really get noisy then. If you want to EQ your mains, get a Yamaha YDP2006 digital parametric. It’s as good as it gets. These days they go begging on eBay for ~$100. You can find links to more information on the YDP2006 here.

Regards,
Wayne


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## wackii (Jul 13, 2006)

Thanks, Wayne.

I got the BFD on -10 but it still has some noise. I just looked into ebay on the Yamaha unit. It's $339, a little too pricey for my taste. Thanks though. I will keep an eye on it.

Al,


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## Wayne A. Pflughaupt (Apr 13, 2006)

Yeah, that guy’s had that one up for nearly a year. He’s not going to move it, not when other sellers can’t get $110 for theirs. I picked up my most recent one for a mere $50 earlier this year. Quite a price drop from the $200 I paid for my first one three years ago. 

Just do a “saved search” and be patient. Shoot me a PM when you find a prospect and I’ll let you know some “gotcha’s” to look out for. :T

Regards,
Wayne


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## wackii (Jul 13, 2006)

Thanks, Wayne. I will definitely PM you if I see something is up 

Al,


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## wackii (Jul 13, 2006)

*Update*

I've been busy lately and did not have time to play with this. Yesterday, I got to the house to myself for 4hrs so I did some REW and eq. 

FYI for whoever consider the Shure dfr11eq for main speakers, dont do it cuz' this unit has noise on full range but perfect for sub. Shure unit has much more noise than the BFD 1124 on full range, you can hear it pretty loud even on the -10dbs mode. 

The BFD has noise but you can't hear it at all from listening position (any volume). You can only hear the noise if you put your ear next to the speakers otherwise you can't hear it... So for now, I am using BFD 1124 for the mains and the shure dfr11eq for the sub until I'm able to get the Yamaha YDP2006 (per Wayne's recommendation) for cheap or decent price. 

Anyway, below are some for my measurements and EQ done on my system. All graphs below are the average of 4 positions. I must have done more than 40 measurements yesterday.

Sub average positions No EQ (forgot to turn off my main speakers). 








Sub average positions With EQ








Sub average positions before and after (I still need to do a lil more EQ on this. Only use 5 filters). Green = before, red = after









Left Main average positions No EQ








Left Main average positions With EQ. I did a fairly good job on this but I lower down the volume during measurements and forgot to turn it back on to the same level as before EQ measurements.








Left Main average positions before and after









Right Main average positions No EQ








Right Main average positions With EQ








Right Main average positions before and after









I'm very happy with my EQ. Most important, it does sound much better now. I can hear a fairly noticable improvement :T

That's all for now. Thanks Wayne for the advices... Hopefully I can get the Yamaha unit soon 

Al,


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## Wayne A. Pflughaupt (Apr 13, 2006)

Graphs look good. :T Did it make an audible improvement for the mains? That’s the goal after all. 

Don’t know if you picked this up elsewhere on this Forum, but when EQing the mains it’s probably best to use matching filters for the left and right channels above about 300 Hz. I’ve found that separate L/R filtering of the upper frequencies does weird things to the stereo imaging. That’s what I found with less-precise 1/3-octave equalizing at least – haven’t checked into that with more precise parametric filtering. Below 300 Hz it’s okay to use separate filters. 

Check this thread for more info and tips on full-range equalizing.

Regards,
Wayne


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## wackii (Jul 13, 2006)

Wayne A. Pflughaupt said:


> Graphs look good. :T Did it make an audible improvement for the mains? That’s the goal after all.
> 
> Don’t know if you picked this up elsewhere on this Forum, but when EQing the mains it’s probably best to use matching filters for the left and right channels above about 300 Hz. I’ve found that separate L/R filtering of the upper frequencies does weird things to the stereo imaging. That’s what I found with less-precise 1/3-octave equalizing at least – haven’t checked into that with more precise parametric filtering. Below 300 Hz it’s okay to use separate filters.
> 
> ...


Thanks for the tips. I didn't know that I'm supposed to use matching filters on the mains. I'll re-do the measurements tomorrow and get ready for the Thanksgiving weekend.

Al,


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