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What would you do from here? (REW Graph)

jester7677

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Below is a REW Graph from my main listening position, L+R. I took it with a new UMIK-1 and REW 5.20.13 with the SPL app showing 75db.

Environment: The HT/Listening are is 1/3 of a finished basement. | Workout Area | Work Area | Home Theater | Outside... There is the outside wall with windows that have full length curtains on them, and to the left of the left main speaker, there as a small wall that extends 4 feet past the speaker then stops and it's open after that.

Equipment: Marantz (that has EQ) -> XLR connection to 7 channel amp -> 12ga bi-amped connection to Klipsch RF7-IIIs and an XLR connection to a 15" powered sub. Mains are set to Large. Subwoofer is a bit of a challenge to control, it effectively has a phase and a volume (which is twitchy and I either need to clean it with contact cleaner or toss it, and I don't want to toss it).

Looking at the graph below, what would you do from here? I have ideas but don't want to influence the discussion.

IMG_5729 (1).jpeg
 

Purité Audio

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Bass might be nice.
Keith
 

PatentLawyer

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Yeah, something is wrong. It would be phase / room issue like I've never seen to cause *perfect* and total bass cancellation like that. Can you test the sub alone and see if it is really working? What output from the preamp is going to the sub?

The Klipsch speakers...well, above the bass, they have the response of Klipsch speakers. You might like that sound. But there's an objective issue in the bass that needs to be fixed.
 

sonitus mirus

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Yeah, something is wrong. It would be phase / room issue like I've never seen to cause *perfect* and total bass cancellation like that. Can you test the sub alone and see if it is really working? What output from the preamp is going to the sub?

The Klipsch speakers...well, above the bass, they have the response of Klipsch speakers. You might like that sound. But there's an objective issue in the bass that needs to be fixed.
Yes, agree with this as a 15" sub would typically show a frequency response measurement with something between 20Hz-50Hz, where the measurements are now absent, for all practical purposes.

Since the RF7 speakers I have seen measured, along with similar RP-280F models, seem to abruptly drop between 40-50Hz, while the OP's measurements are showing a significant drop around 75Hz. This leads me to believe the issue resides at the Marantz.
 

Rednaxela

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Please physically disconnect your fronts and perform and share a new measurement.
 

HarmonicTHD

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No but The fronts are set to large.
For the Marantz (Denon), basically Audyssey, to correctly integrate the Sub, the main speakers need to be set to Small even if they are not small physically and are capable reproducing low frequencies. It‘s just how Audyssey works.
 

AdamG

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Messed with Base management and the level of the subwoofer ... below is the updated graph. Red is before messing with the speaker size (which was stopping bass from being played from the subwoofer), green is with the sub.

View attachment 256456
Looks like your problem is solved! Excellent work with minimal interaction. ;) See links for further reading on Sub optimization.
 
OP
J

jester7677

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Could you make the y-axis span 50dB?

Green is the new measurement. My EQ only allows 63 - 125 - 250 - 500 - 1k - 2k - 4k - 8k - 16k

I could see a bump up at 125, 250, 4k... after that, it's sub placement and room treatments, right? Phase for the sub... always scares me to think about how to figure that switch out on the sub. It's at the standard 0, always wonder if I should ever switch it to 180.

Rew 01112023.PNG
 

kemmler3D

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Using EQ to cure dips in the bass doesn't really work because the sound is cancelling itself out (-2 + 2 = 0, -4 + 4 is also zero) so I would try it anyway, but plan to do a sub crawl right afterward, to see if you can fix that dip at 100hz by moving the sub. For the rest I would do an averaged or moving mic method check to see what can be done above 400 or so, if anything.
 
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jester7677

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Using EQ to cure dips in the bass doesn't really work because the sound is cancelling itself out (-2 + 2 = 0, -4 + 4 is also zero) so I would try it anyway, but plan to do a sub crawl right afterward, to see if you can fix that dip at 100hz by moving the sub. For the rest I would do an averaged or moving mic method check to see what can be done above 400 or so, if anything.
Will do all the suggestions above. I'm starting with LFE+Main, with the front speakers set to Large (so the Main Bass will get played by the Sub) and the crossover for the passing of that bass set to 200hz, and lets see if that fills in the big dip between 70 and 200. I'll do more testing on the weekend and report back.
 

Gringoaudio1

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I decided that the Marantz EQ and whatever Audessy was doing wasn’t sufficient. I have a SR-7005 receiver. So since I mainly stream from the PC and am in the process of putting all my CDs in JRiver why not use PC-based EQ. I am using Equalizer APO to apply filters generated by REW. I ended up adding 18 more parametric filters and a graphic equalizer in REW to better flatten the FR curve. All of the REW generated filters had to be tweaked. Slightly annoying to figure out all the software but rewarding in the end.
 
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