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Discussion Starter · #1 · (Edited)
Hi, just wanted some general response as to how this looks, I think it SOUNDS really good, and from what I've been reading and comparing it to other waterfalls the ringing / decay seems pretty decent. This is achieved with the natural furniture in the room as well as an Antimode 8033C for the subwoofer, and manually tweaking the standing wave control of my Pioneer receiver for the main/front speakers. The cutoff frequency for the subwoofer is 100hz (to help the main speakers avoid the room mode at around 45hz as much as possible).

The main room gain is at 45hz and was originally about 10dB.

This is my best effort so far, and I'm really happy with the sound :)

The speakers are the B&W 804s and a small XTZ 99W10.16 10" subwoofer is doing the low end.

Would you consider additional room treatment with this result, or should I be happy with this? :blink: :)





The low end still needs some work, I'm aiming to get a house curve that ends up at about 9dB at 30hz, but the main work has gone into smoothing out the curve and the decay so far. :) I haven't decided if I should punish the subwoofer to go that extra mile in the low end, or keep the headroom available instead. This is mainly aimed at music, where the sub 25hz information doesn't matter all that much (some of you will disagree I'm sure) :)

EDIT: Looking at the graphs now, maybe I should do something to increase the level between 80 and 100hz slightly.. ?
 

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Discussion Starter · #2 ·
An overlay of before and after scaled out to 600ms shows quite an improvement in ringing. Nothing has been done physically to the room before/after.


 

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A lot of what you call ringing in the before I don't think is ringing at all, but looks much more like extraneous noise in the setup... based on it reaching a point where it doesn't seem to be decaying at all... I'm looking at the big stuff just over 100Hz and just over 120Hz... that being said, it's more usual to see those effects at 60 and/or 120Hz (50/100 in EUR)... How tightly sealed is this room? Is there a chance there are other noise factors at work here, such as HVAC systems?
 

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A lot of what you call ringing in the before I don't think is ringing at all, but looks much more like extraneous noise in the setup... based on it reaching a point where it doesn't seem to be decaying at all... I'm looking at the big stuff just over 100Hz and just over 120Hz... that being said, it's more usual to see those effects at 60 and/or 120Hz (50/100 in EUR)... How tightly sealed is this room? Is there a chance there are other noise factors at work here, such as HVAC systems?
If there was a HVAC system at work, wouldnt it still be in the after waterfall?

Either way, the after response is looking good enough to me, as its all within the 300ms (target) window. I do think that if the response target house cure is aimed at music, then boosting the bottom end is probably not as big an issue as it might be for movies. Music uses the sub 30hz regions much less than movies might, and even then its usually a more gentle use of those frequencies albeit more sustained in some cases. It'll just be a case of being aware of how hard your pushing your kit.

All in all you have a decent smooth low end response I think I would be quite leased with.
 

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If there was a HVAC system at work, wouldnt it still be in the after waterfall?
Not necessarily... HVACs are expected to cycle on/off periodically...
Either way, the after response is looking good enough to me, as its all within the 300ms (target) window.
No agrument there.
If you're concerned about the small dip around 80-100Hz, since it's within range of the crossover, you might play with the phase control...
 

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Discussion Starter · #6 ·
Hm, I guess some of that from the before waterfall may have been external noise sources. Don't know what it could have been as it is gone now. The room is quite tightly sealed, but I guess it could have been a refrigerator temporarily turning on or something like that?

I'll do some more work on calibrating today to see if I can further improve the curves.
 

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Discussion Starter · #7 ·
Music uses the sub 30hz regions much less than movies might, and even then its usually a more gentle use of those frequencies albeit more sustained in some cases. It'll just be a case of being aware of how hard your pushing your kit.

All in all you have a decent smooth low end response I think I would be quite leased with.
Yep, I'm thinking the same thing, so I probably won't push the low end any further. I'm planning on focusing on 80-350hz today, and see where that brings me :)
 

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Its worth monitoring the waterfall then, if you cant reproduce the apparent noise in the ringing then I think you can safely right it off as an anomaly caused by 'something'. If it does reappear at some point, you could start looking for what might be causing it, just so you know :T

Its worth keeping in mind, that you can end up endlessly chasing another 1 percent and go a little insane doing so :D :gulp:, I did for a while :R. You have to try find the point at which your efforts arent really gaining you anything more, and try be happy with what you have got. Its just telling your brain its time to forget about it thats the hard thing.
 

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EQ'ing certainly helps you get the absolute best from your system, and really helps account for room effects :T
 

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Discussion Starter · #12 · (Edited)
I got quite a lot of background noise from the computer/soundcard while measuring, so I ended up doing the measurements at 75dB today anyhow.. (http://www.hometheatershack.com/for...ve-measure-75db.html#post219656#ixzz0b06QThRw)

Redid the calibration of both antimode and my Pioneer receiver, and this time I had the Full Band Phase Control activated on the Pioneer, as I've found the sound to better and more..rhythmic and tidy with this activated in the past. So I'm now running it with this option activated. Seems to work out well.

Ended up focusing on the 20-100hz area today as well, and managed to increase the overall response somewhat. It was a little bit on the lean side earlier. Got back a bit of the ringing at 45-60hz though, not sure how that happened, or wether it's background noise again (it seem to go on forever). Also measured up to 2khz and the overall decay was around 300ms all the way.:)

Here is a graph of the result from last session compared with the end result today (green is from today):

 

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Discussion Starter · #13 ·
I would never run my system without EQ, but I'm done doing ten setups a day just to get that last 1%, it's not worth it, and it's definetly not audible. :)
Hehe, I agree - I prefer listening to music over sweeps any day, and I guess that's what the antimode is about as well, set it and forget it. :) But it gets a bit addictive too.. But hopefully 2010 will be more about listening than measuring :)
 

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I certainly like the most recent FR better in the crossover region... if you like the "house curve" you've dialed into the sub 80Hz then you can leave that... if you want to flatten the crossover region some more, you'll want to start by taking independent scans of the sub, left main, and right main, to begin to see what's causing what. If you want to track down that ringing, you might try playing a single tone at the frequency you see the ringing at, and see if you walk around the room if you hear anything rattling or the like...

I seem to have the opposite problem everyone else does... I leave my setup the same thinking it's the best sounding setup in the world for years until I hear something better or someone points out a flaw I didn't notice, then I fix that and again stop, not realizing just how much further I could go, until someone else points out what they don't like...:coocoo::dumbcrazy::hissyfit:
 

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Discussion Starter · #15 · (Edited)
Glaufman - thanks for that advice, now I have to dedicate another day to this stuff. :sweat: :blink:

I just spent a few hours now, using my ears as much as my meter, and I'm pretty satisfied now. But you are probably right that running each speaker independently could help me sort out the crossover area even more. But now it sounds really tight and good. It was a bit bass heavy after yesterdays session, but now I think it sits just about right.

Red curve was yesterday, green curve is after today. I actually increased the 125hz and 250hz area somewhat on the 10 band EQ in my receiver, as the overall volume between 100-500hz was a bit low. Not sure if that is the actual frequency response of my speakers. Anyhow, that made the peaks a bit bigger between 100 and 200hz, with my current setup I don't have enough EQ power / bands to do anything about that. Perhaps I should reduce 125hz by 1dB or something again. Anyway, it sounds good. :foottap:


Here is 15hz-1500hz smoothed 1/3.


And here is waterfall of both 20-200hz and 20-1500hz:





Lots of work but I guess it's worth it. I sure learn a lot about parametric EQs, only wish I had more bands to play with. (but then again - then I'd probably be tweaking for weeks, not days) :R
 

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Discussion Starter · #17 · (Edited)
Just remember that very often you can achieve very much with only a few filters used. Don't go out of your way to EQ every little wiggle on the curve. Move your head 10cm and all that goes out the window.
Yep, I discovered that when I took a break of about two hours, and then remeasured without actually touching any EQ settings, and got a relatively different result. I don't know if the temperature/humidity in the room changed or whatever. Probably moved the mic a little bit as well. But the result is surprisingly uniform in the bass area even though I move the mic stand around a bit in the couch.

But yes - getting the overall sound better, and not just measuring to make the curve look its best appears to be a good approach :) I paused the EQ process to listen to the result with ears and music a lot today - and the bass response feels much more right than it did yesterday. :)

But remember I've only got the antimode (which does its magic without my intervention) and then the three band parametric EQ for the sub channel and three band parametric eq for the mains (the pioneer standing wave control) - so a total of 6 bands for the bass area. So it wasn't about adding 20 different filters, just spending a lot of time trying to get the most out of the few I had (I was surprised how smooth I could get the curve by correctly combining them).

It was also interesting to see how much effect it had to insert filters for the main channels well below the cutoff frequency. Cutoff frequency is a bit misleading - as it is probably a 12dB filter it's a lot of output from the speakers down in the bass area even though the cutoff frequency is set to 100 hz. :)
 

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I always save a baseline measurement before I start tinkering, so I can compare to where I am today. The measurements usually vary a bit, but with the baseline I can see if I'm in the ballpark of if something is messed up. Saves me alot of trouble, usually. I once measured and tweaked a whole night ithout realizing all my measurements were worthless due to a fridge.
 

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Discussion Starter · #19 ·
I always save a baseline measurement before I start tinkering, so I can compare to where I am today. The measurements usually vary a bit, but with the baseline I can see if I'm in the ballpark of if something is messed up. Saves me alot of trouble, usually. I once measured and tweaked a whole night ithout realizing all my measurements were worthless due to a fridge.
Yep, I store the final result from the last session and use as a baseline the next time I measure.

By the way, I'm getting a bit annoyed with the fact that REW can only hold 9 measurements at the same time. Seems like an artifical restriction to me. Or have I missed some setting where this can be increased? If not I'd really like that to be increased in the next version :)
 

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By the way, I'm getting a bit annoyed with the fact that REW can only hold 9 measurements at the same time. Seems like an artifical restriction to me. Or have I missed some setting where this can be increased? If not I'd really like that to be increased in the next version :)
I'll bring it up for you :smashin:. I believe their will be a version 5 at some point.
 
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