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Discussion Starter #1
I like the line from Armageddon…


Now, “is this good or bad” I busted my for the past few hours having to write down the numbers and walk up to the BFQ2496 and input the data I tested original laserdisc to DVD-RW Star Trek the motion picture Dolby stereo 4:2:4 with sub bass diverted to the main sub JBL 4645.

I noticed during the wormhole sequence as Enterprise hurtles out of control while picking up tremendous speed!!! I noticed some parts of the sub bass was vibrating right under my feet and in the sofa at different times, or more or less a several milliseconds apart.

With the BFQ2496 in bypass it was more of an uncontrolled sub bass, not that it was broken it lacked in few places due to being non-equalized.

Graph below shows the frequency sweep that I conducted with correction


Numbers that I entered into the BFQ2496

 

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You have many, many more filters than are required to correct your measured response. Try using a lot fewer, as a starting point try just one at 36Hz or so. For info, here is what your individual filters look like:
 

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Yeah, what John said. The way to approach it to identify the center of a peak - REW can tell you the exact frequency if you click on it - then adust the bandwidth and gain until the filter is wide enough to fill the full width of the peak. It doesn't require a multitude of narrow filters to fill a broad peak like the one you have at ~33 Hz. It can be addressed with only a filter or two.

Even better, if you're unsure what to do, REW can tell you what filters to use. Did you try running the auto EQ function?

Regards,
Wayne
 

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Discussion Starter #4
Morning

Yeah cheers John.

(Auto) Wayne, where’s the ON and OFF switch for that function to run, I thought this was manual hands on unit? I still don’t have the lead to patch into the BFQ2496 so this is all done with measuring and then looking at the good and the bad side of it then, you get the idea.

So the (automatic button) please if you’d be so kind to point me in the right direction so I can enable REW to do its magic.

Thanks.
 

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Another thing that I noticed with the (BFQ2496) was the smoother frequency response during the wormhole sequence with it in bypass there was less (floor vibration) less vibes travelling up my legs and partly some frequencies vibrating the sofa in different areas that I noticed on my body, felt good.

When I bypassed it and set the sub bass level down from +10db to 0db there was less involvement sure it can still play very LOUD and deep, it was just too much in the lower register, (boomy) the floor wasn’t as alive as it was with BFQ2496 ON and +10db rise because I noticed the (db drop) when I was doing the EQ.

So if you feel I should take another crack at it, I’m not going anywhere, its cold outside…!



What we need is computer that can listen! (Computer. EQ sub bass).:rofl:
 

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So the (automatic button) please
The auto-EQ Wayne was referring to was the auto-EQ that every receiver now has. It's usually a good idea to run that first before adding filters to a sub equalizer.

There is a method in REW that will recommend your filters. It is located in the left pane under filter tasks. Click on Find Peaks and then Assign Filters and then Optimize PK Gain & Q. This will offer filters to enter into the 2496.

Hopefully, you have read and are completely familiar with the REW HELP files.


REW TIPS:
For subwoofers, always use the standard Vertical graph axis of (45dB - 105dB) and the Horizontal graph axis of (15Hz - 200Hz) using the Graph Limits button in the top right corner of REW.
Also note the small floppy icon in the bottom left corner of your jpg. It saves a jpg of the graph only for posting of the correct 800 bits wide.

brucek
 

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Discussion Starter #8
Okay cheers for that fellas I’ll explore it and hmmm, and perform another frequency sweep and adjust accordingly.


Thanks.
 

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Discussion Starter #9
Okay task complete wow that was fast. I’ll post the selected filters and the new frequency grapth up in sort while I have to write down the new data and input it and test it out with my Dolby stereo demo Star Trek the Motion Picture “wormhole”.

I’ll test the film with the settings I made last night again, while making physical notes as to how the sub bass extension is behaving with the floor and sofa also other issues like (boom) lets see if this works now shall we.

Thanks guys, I’ll be back.
 

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Discussion Starter #10
I have to stress the :duh: (error page script) that I keep constantly getting on this site. [Sigh] no matter the show must go on.:bigsmile:

I tested the EQ that I did least night with the settings made with tonight’s settings.



 

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Did you read this?

REW TIPS:
For subwoofers, always use the standard Vertical graph axis of (45dB - 105dB) and the Horizontal graph axis of (15Hz - 200Hz) using the Graph Limits button in the top right corner of REW.



brucek
 

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Discussion Starter #12
No I haven’t read it as of yet is it easy to use easy to understand?
 

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Discussion Starter #13
I was going to post the frequency response of the second sub bass that is only used for Dolby digital / dts discrete only, that was before the sodden internet provider service went down and I lost my rag big time!

I’ll post to tomorrow I need to get a early nights sleep later on.
 

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Discussion Starter #14
Okay I see it so are you saying I’ve got to do this again LOL not now tomorrow I’m too tired at the moment to run another frequency sweep and I’m starting to get sloppy in my typing. I’m getting some sleep now, closing the shop down, I’ll read this thread in the morning, good night.

Thanks.
 

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Did REW's auto EQ function recommend all those filters? Strange...

A single filter centered at ~35 Hz w/ something like a 1/4 or 1/3-octave bandwidth should do the trick. It's going to take a pretty severe cut, though...

Also, the little floppy icon at the bottom left corner of the graph will save the graph for you - no need to do screen shots...

Regards,
Wayne
 

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Cut your graph Fr to 15-200hz and with a db range of 45-105db. Check your FR with a 0-200hz sweep with the mic at the listening position approximate to where your head would be. This is the standard graph used here and makes it easier for people to read waht you have going on.:T There are times when you would use different settings of course, but when you are looking at general FR or EQ setting suggestions here this is the best one to use.
 

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Discussion Starter #17
Afternoon guys.

Its getting bit chilly over here but hopefully this new graph taken only 30 minutes is a bit more satisfactory I like it, feels and sound’s good enough for the room.

The only issue I’m stuck with at the moment is a few rattles over the TV, its not an issue to sort out rattles at different frequencies and sound pressure levels.

I made some changes like setting the frequency sweep at 15Hz to 200Hz but this has to pass though the internal AVR crossover when doing the test with Dolby stereo at 0db switched the BFQ2496 to bypass and commenced the sweep test.

Each time I ask it to do auto it would only do the 100Hz range as this is set in default mode along with 0.143 Q.

I just entered these frequencies and switched to (auto) and this is what I got.

This site is giving me issues and I can’t deal with this! So does anyone know how to deal with it?

Its taken me nearly 25 minutes to do a simple post this is pathetic.:explode:

Anyway hare is the graph and numbers I’m switch off because I have very short fuse and this page error script is making me mad.:explode:

I can’t get the file to save as jpeg and I’m patients are now running thin. So this will hath to suffice.

Thanks.



 

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Discussion Starter #18
Note: the script page error occurs when refreshing the sites page to view any new posts, also when clicking a new thread. Also when starting a new post and finalizing the post.

I don’t get issues with (fast post) now a few simple answers to solve this would be helpful.

Thanks.
 

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Andy,

The "Auto" indication on the filters panel is only to tell REW whether or not it is allowed to adjust that filter. To use REW's auto features use the controls in the Filter Tasks panel, i.e. "Find Peaks" then "Assign Filters" then "Optimise PK Gain & Q". For more detailed info read the help files, either in REW or online
 
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