Originally Posted by AustinJerry
Originally Posted by kbarnes701
Well, always wanting to run before I can walk, or REW before I can walk in this case, I have been looking at this:
Now this looks fascinating. I have had a play around with it and have got the general idea, but that is all. What interests me is that I have recently been moving towards the idea of using Parametric EQ to attempt to solve some niggles that Audyssey Pro can't overcome on its own. What is sensationally interesting in the EQ section of REW is the way you can use it to create filters to combat problems and then to upload those filters automatically to something like the Behringer FBQ2496. All more or less automatically.
Problem is, I have reached the limit of my current understanding, despite having read the relevant section of the REW Help a couple of times. The Help is very good at explaining the 'how' but not so good at explaining the 'why'. I shall persevere.
Keith, have you posted your latest graphs? I would be interested in seeing what you consider as "niggles". And are you sure that PEQ will resolve them?
Can we see a L+R+Subs, and a Waterfall?
I haven't posted any graphs for a week or so Jerry and I will tell you why. I had a helluva week last week and came close to throwing in the towel. It started with the new treatments which arrived on Tuesday and were duly installed where my magic string dictated they would do best. After installation, just for the hell of it, I ran the usual set of REW measurements and they were noticeably worse than before. I put this down to not having yet run Audyssey, so I did, and guess what - they were worse still!
Here, for example, is my worst channel of the lot - the centre channel, before adding the new treatments (the RF and LF + subs are measuring much better):
And here it is after adding the new treatments and after running Audyssey (overlaid on the above):
WTF?? What has happened around the XO region? I have no explanation for this at all. The graph is actually better with the treatments added and without re-running Audyssey! But it is still worse than the first one above.
So I have spent an entire week troubleshooting, First thing I did was remove all the new treatments and then load the Audyssey cal that I have been using happily since last November. That took me back to square one. I then added the new treatments one at a time, measuring each time as I went. Not a deal of difference between them (the latest treatments are 'icing the cake' and I wasn't expecting dramatic differences from them - the big differences had already been earned with the original treatments some time back).
Next I made a new Audyssey Pro calibration, without the new treatments and it was not as good as the original above. But I then referred again to my November notes and saw that I had used a different mic pattern in November - 7 positions clustered around the MLP and two around the other seat. I didn’t have the strength to do yet another Pro calibration (you know how long it takes!) so I reinstalled the treatments and measured again, with the Audyssey cal just made (with all 9 mic positions around the MLP).
The next day I redid the Pro cal yet again, using the mic pattern from November, and, surprisingly, the result was better - not as good as the original but a lot better than the disaster above. By now I was half crazy.
I then spent one or two days tweaking things like the sub distance, experimenting with Pgm1 and Pgm 2 of my Submersives, different crossovers and so on. Finally, I managed to get an improvement, although still not as good as the original at the top of the this post.
Here is the best I could get, overlaid on the original:
It's not bad - and much better than the disastrous one - but still not as good as the original. And what explains that boost to the bass? I have NFI! I have triple checked everything - DEQ is off, the subs are in the same Pgm mode etc. (Please note that that dip centred on about 450 Hz is a 'feature' of my room and cannot be removed with anything, other than repositioning subs/speakers/MLP. which is impossible (believe me, I have tried).
Yesterday some semblance of sanity returned as I realised that the system sounds amazingly good. Imaging is palpable. Dialogue is so good the actors could be in my room with me - I can hear them breathing and sometimes moving their tongue inside their mouth. Bass is extended and powerful but without being overbearing. Ringing is minimal and the best I can do with my room and placement limitations. It sounds fabulous. So I am wondering how OCD I have become. I am looking at things on graphs that apparently cannot be heard in real life. Remember Bill Fitzmaurices 'Graphitis Nervosa' and his remark about barely being able to hear the initial impulse at 20Hz, let alone the reverberations of it? Look at the difference between the two plots above - the blue plot has kept a smile on my face since last November. The purple plot is a few dB different at 1/6th smoothing, which I am told more or less represents the way we hear things. Can I hear any difference? No. Can I see a difference? Yes.
Having said all that, I am not the kind of person who gives up easily. Which is why I have been reading up on Parametric EQ and checking out the amazing EQ tab of REW - just go and have a play with it and see it flatten the plots in real time as it creates correction filters. Use the Behringer which permits for 20 filter adjustments - it is nothing short of amazing. I am even starting to wonder if, assuming I can master it, Parametric EQ might give me a better result even than (hushed tones) Audyssey? We have our rooms treated, so a lot of Audyssey's magic work in the time domain is not really needed for us...
With a Behringer FBQ2496 I could create, with REW's magic, 20 different filters, adjusting them for response, loudness and Q. Even my ignorant playing with the EQ tab reveals the potential here.
So, I am still not satisfied that I cannot do better. I still have unanswered questions (like why is there a bass boost in the latest graphs, why did Audyssey apparently make things worse not better?). I will continue over the next few days to ponder it and to see if I can improve it, or at least get it back to November's status quo. But meanwhile I am trying to remember what my hobby is - it is movies - and reflecting on the amazing aural experience <oo-her> that I can get in this small, awkward little room of mine.
Any ideas are, of course, more than welcome!