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Quote:
Originally Posted by Rich-n-Texas
This is a before graph. I'll start setting up filters next, but I just wanted to get some comments...
Rich, does this include the correction values for the Rat-shack meter?
Ha ha ha....look at that..bet you didn't think you were missing half an octave of bass did ya?
This is where the fun begins. And this is where all bets are off too on what the "right thing to do is". For my setup, it was a few days of trial and error. I can't just look at a graph and say this frequency, that Q, that many dB's, presto.
Maybe Sir T or Wooch can chime in but, I would probably start with a guess that you'll want a cut for starters around 38Hz or so to lower all that stuff a bit...maybe at 1/6 octave bandwidth? You might even want to cut all that stuff below 40 Hz down to minimize the effect of that big dip, but I'm guessing that's 2 filters. You might get lucky though and get away with one filter, leaving you a nice "house curve" below 35 Hz that gradually rises. Then on the other side of your sick suckout at 45 Hz I'd probably want to think about cutting the peaks at 56, and 80Hz.
After each filter is set, go back and measure again...the curve might look different outside the range of frequencies of the filter. Always start from lowest to highest.
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Quote:
Originally Posted by kexodusc
Rich, does this include the correction values for the Rat-shack meter?
What gets plotted is the compensated SPL with the correction added in using a formula for each cell.
Quote:
Originally Posted by kex
Ha ha ha....look at that..bet you didn't think you were missing half an octave of bass did ya?
I don't know. Did I set something up wrong? I used the test tones that started @ 16Hz - 160Hz, so for the graph I deleted the rows in the table that contained tones below 16Hz and above 160Hz.
Quote:
Originally Posted by kex
This is where the fun begins. And this is where all bets are off too on what the "right thing to do is". For my setup, it was a few days of trial and error. I can't just look at a graph and say this frequency, that Q, that many dB's, presto.
Understood. I haven't read the explanation on Q and House Curves yet, but one good thing about trial & error is that I'll be able to setup filters and such in my sleep after all's said and done.
Quote:
Originally Posted by kex
Maybe Sir T or Wooch can chime in but, I would probably start with a guess that you'll want a cut for starters around 38Hz or so to lower all that stuff a bit...maybe at 1/6 octave bandwidth? You might even want to cut all that stuff below 40 Hz down to minimize the effect of that big dip, but I'm guessing that's 2 filters. You might get lucky though and get away with one filter, leaving you a nice "house curve" below 35 Hz that gradually rises. Then on the other side of your sick suckout at 45 Hz I'd probably want to think about cutting the peaks at 56, and 80Hz.
Don't know. I haven't read that part yet. :confused: Thanks for the ideas though.
Quote:
Originally Posted by kex
After each filter is set, go back and measure again...the curve might look different outside the range of frequencies of the filter. Always start from lowest to highest.
Maybe I'm interpreting my graph wrong, but when I compare it to the sample graph included in the Shack's guide, it seems flatter overall.
I'll tell ya one thing, I spent a LOT of time silencing all the rattles in the room that the test tones caused. The TV rattled, the fireplace rattled, stuff in the front hall closet rattled... and on and on and on. I've got shims all over the place! :crazy:
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Great post Kex. I tried to dish out some green but I need to recharge.
Rich, you got a freakin crater going on over there :frown2:
Kex is right. You gotta get yourself a couple of free hours and have a crack at it. This is when those ear plugs are gonna come in handy :biggrin5: Make sure you record everything you do.
I'm interested in what the rest of the guys have to say. Come to think of it, does Sir T drop in anymore?
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Quote:
Originally Posted by L.J.
...Rich, you got a freakin crater going on over there :frown2:
:lol: I agree. BUT, IMO it legitamizes my graph when compared to the sample graph on the Shack's guide where there's a huge dip at close to the same frequency.
Quote:
Originally Posted by L.J.
Kex is right. You gotta get yourself a couple of free hours and have a crack at it. This is when those ear plugs are gonna come in handy :biggrin5: Make sure you record everything you do.
Will do. I've used Excel quite a bit in my working life, so I know my way around it pretty well. I've got a couple sets of earplugs too...
Quote:
Originally Posted by L.J.
I'm interested in what the rest of the guys have to say. Come to think of it, does Sir T drop in anymore?
I haven't seen The T in quite a while. If it's because he's sick of pix, and it comes to a vote of who to ban, dumbass gets my vote hands down. :mad5:
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Quote:
Originally Posted by Rich-n-Texas
Will do. I've used Excel quite a bit in my working life, so I know my way around it pretty well. I've got a couple sets of earplugs too...
Yeah if you tweak something and get bad results, you can always go back and start from a decent spot. I had to do that A LOT of times. Yeah, your about to have some serious fun :lol:
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Quote:
Originally Posted by L.J.
Yeah if you tweak something and get bad results, you can always go back and start from a decent spot. I had to do that A LOT of times. Yeah, your about to have some serious fun :lol:
Heck, I can still send it back and just be happy with the results of the sub's new placement. :p
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Quote:
Originally Posted by Rich-n-Texas
Heck, I can still send it back and just be happy with the results of the sub's new placement. :p
you'll do a good job. it's not the easiest thing to worth with but it gets the job done and the results are worth it.
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BTW, before I forget, I watched U-571 in glorious DTSHD-ma last night on "loud". Some of the explosions hit 92 dB in the room ( :yikes: ), but at no time did they clip at the BFD, so all things being equal to the bullet test scene in Dark Knight, the bullet test scene wins the peak dB matchup on my equipment. :yesnod:
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A few inaccuracies in my post #82, especially about my graph looking flatter than The Shack's example. It looks to me like my first filter should start just after the first test tone: ~17Hz. don't ya think?
Quote:
Originally Posted by kex
Always start from lowest to highest.
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Congrats Rich. I am glad to see that you are enjoying your new toy.
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Quote:
Originally Posted by Rich-n-Texas
A few inaccuracies in my post #82, especially about my graph looking flatter than The Shack's example. It looks to me like my first filter should start just after the first test tone: ~17Hz. don't ya think?
Well, that's up to you....you might want to leave the frequencies below 30 Hz a few dB higher - the BFD pages call this a "house curve". You might not.
Either way. At 17 Hz, you are near the extreme of your subs bass ouput.
Now, remember how a filter works. It is "centered" at a certain frequency, but the curve is as wide or narrow as the Q setting you plug in. Remember the filter is basically going to apply a cut in a sort of "U" shape depending on how much cut you apply and how wide the Q.
So say you cut -10 dB centered at 30 Hz, if your bandwidth is wide enough, you'd expect 30 Hz to be down by -10 dB, and the frequencies lower and higher to be cut by less. So 25 and 35 Hz might only be cut by 4 dB, and 20 and 30Hz only cut by 2dB for example (those are made up numbers).
So your bandwidth will need to be wide to reach 17Hz, and it would be cut weaker than the center frequency is cut.
And cutting at 17 Hz will cut frequencies on either side...you probably want to focus on "center frequencies" when cutting.
Not sure that made any sense?
Oh, you generally only want a few filters on this thing (3 or 4 I see most often), so use them wisely.
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Quote:
Originally Posted by kexodusc
Not sure that made any sense?
Sounds good to me :yesnod:
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Quote:
Originally Posted by GMichael
Congrats Rich. I am glad to see that you are enjoying your new toy.
Thanks GM. Maybe after this project I'll stop tweaking for a while... Maybe...
How's your piggy-bank looking?
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Quote:
Originally Posted by kexodusc
Oh, you generally only want a few filters on this thing (3 or 4 I see most often), so use them wisely.
The rest I get, but why is it that fewer filters is better? Wouldn't it be more precise to have more filters with smaller Q's? Do you end up with a smoother curve with fewer filters? Does the overlap become too complicated?
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Quote:
Originally Posted by Rich-n-Texas
Thanks GM. Maybe after this project I'll stop tweaking for a while... Maybe...
I gotta couple of things on my to do list but that's just me taking it to the extreme. I think that once you get your bass squared away the rest of your system should be sounding good.
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Quote:
Originally Posted by Rich-n-Texas
Thanks GM. Maybe after this project I'll stop tweaking for a while... Maybe...
How's your piggy-bank looking?
At least until someone pricks your interest in something new.:ciappa:
Piggy is looking OK. That other problem is finally coming to an end. Should be done in a couple weeks. But now we have GM 2.0 on the way. Most of my wanted upgrades will still be on hold. The BFD should be within budget though. We'll see.:idea:
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Quote:
Originally Posted by GMichael
At least until someone pricks your interest in something new.:ciappa:
I'm more comfortable with the word "piques" as opposed to the word "pricks". :sosp:
Quote:
Originally Posted by Dad-to-be
Piggy is looking OK. That other problem is finally coming to an end. Should be done in a couple weeks. But now we have GM 2.0 on the way. Most of my wanted upgrades will still be on hold. The BFD should be within budget though. We'll see.:idea:
And everything is well with Mom-to-be I trust?
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Quote:
Originally Posted by Rich-n-Texas
I'm more comfortable with the word "piques" as opposed to the word "pricks". :sosp:
You say tomato.........
Quote:
Originally Posted by Rich-n-Texas
And everything is well with Mom-to-be I trust?
Everything? If by everything, you mean that the morning sickness (that's really 24/7) is part of being well. Or that the moodyness is well. Or that she won't let me "play through" is well. Then yeah, everything is great.
We go for more sono-pics this Wednesday. We should be able to tell if it's going to be Sarah or Michael.:3:
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Quote:
Originally Posted by GMichael
The rest I get, but why is it that fewer filters is better? Wouldn't it be more precise to have more filters with smaller Q's? Do you end up with a smoother curve with fewer filters? Does the overlap become too complicated?
No. Well, I shouldn't say that. If you are a master EQ-er and know what you're doing, then yeah, go ahead and perform surgery cutting up those frequencies.
However, I've always been told over and over at the HTshack and by the sages here, that the BFD is a great tool, but has it's limits like any eq. The more filters you apply, the more unwanted impact you're going to have on frequencies on either side of the filter. You could be distorting the signal unintentionally. You might also have an effect on mulitples of the frequencies you target. I don't profess to be the BFD guru here though, so I'm hoping Wooch or someone will chime in and help you out.
In general, we aim to flatten the big peaks, those are the audible ones. Our ears are less sensitive to smaller deviations. And a few well placed broad filters can smooth everything out rather nicely. If nothing else, killing the big peaks accomplishes most of the benefit you're aiming for.
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I think I get it now. Less is more. More or less.
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Well...........................
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Well, you know how lazy I am. I have to make sure I've heard a variety of sources and formats before I take the next step, so I can be SURE it's making a difference, right? :biggrin5:
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"The First Cut is the Deepest"
Edit: I went ahead and increased the BW to 15Hz.
Here's my first attempt to level the response out. At this time I've only set 1 filter just to see if I'm following the steps correctly and if what I think should happen actually does. This graph is what I expected to see.
BFD parameters:
- Freq = 20Hz
- Setting + Fine = 20 + 0
- BW = 15Hz
- Gain = -10dB
http://i115.photobucket.com/albums/n...0ASW2ndcut.jpg
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Looks like you got something going on around 45 htz.
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You ain't kidding buster! :eek6:
I had a different graph up there with an explanation relevant to that one, but I went ahead and replaced it with one where I set the filter to have a wider bandwidth. I didn't do a very good job of editing the text after I replaced the graph, so the post probably didn't make much sense.
Anyway, as kex suggested, I'm trying to flatten out the response starting from the lower frequencies and then working my way up. If I can get everything up to 40Hz toned down closer to the 62 dB level where my lowest frequency measurement starts, then that huge dip won't look so dramatic. I'll worry about the "House Curve" setup later on.
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Damn, I need to get myself a nice HT system and tweak away too!!! This is the kind of stuff I'd love to do..
Good luck with it Rich, you're getting all the advice you could possibly need! :3:
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I have to tell ya the truth. I'm starting to lean towards the REW method. The only other piece of hardware I need is the USB "soundcard" which has Line-out L/R & Line-in L/R. I can get exactly what the crew at HTS talks about direct from Behringer for under $50, and since I already have a laptop and necessary cabling, there'd be no other expense. The materials I need to finish my panels have already been paid for as well.
I get it that the manual mode, while tedious is probably going to give me better results, as has been pointed out, but OTOH the REW would quicken the process and satisfy the computer geek in me. We'll see, but in the meantime I'm plodding along in manual mode. :rolleyes5:
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Quote:
Originally Posted by Rich-n-Texas
I have to tell ya the truth. I'm starting to lean towards the REW method. The only other piece of hardware I need is the USB "soundcard" which has Line-out L/R & Line-in L/R. I can get exactly what the crew at HTS talks about direct from Behringer for under $50, and since I already have a laptop and necessary cabling, there'd be no other expense. The materials I need to finish my panels have already been paid for as well.
I get it that the manual mode, while tedious is probably going to give me better results, as has been pointed out, but OTOH the REW would quicken the process and satisfy the computer geek in me. We'll see, but in the meantime I'm plodding along in manual mode. :rolleyes5:
Hey rich - get crackin'.
I wouldn't bother with the frequencies below 20 Hz much. Go after the audible stuff in 20's and higher first. Try some cuts, tell us what you did and post your results. Shouldn't take too long. I made a cheat sheet on a note pad to get the steps in the right order - made it quicker for me.
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I didn't see it listed in the thread, but there's a correction list for the Radio Shack SPL meter Rich is using with substantial correction for the low frequencies. I found this one on the Audiogon Forum site. It's listed all over the web.
10Hz +20.5
12.5Hz +16.5
16Hz +11.5
20Hz +7.5
25Hz +5
31.5Hz +3
40Hz +2.5
50Hz +1.5
63Hz +1.5
80Hz +1.5
100Hz +2
125Hz +0.5
160Hz -0.5
200Hz -0.5
250Hz +0.5
315Hz -0.5
400Hz 0
500Hz -0.5
630Hz 0
800Hz 0
1KHz 0
1.25Khz 0
1.6KHz -0.5
2Khz -1.5
2.5Khz -1.5
3.15Khz -1.5
4KHz -2
5KHz -2
6.3KHz -2
8KHz -2
10Khz -1
12.5KHz +0.5
16KHz 0
20KHz +1
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Quote:
Originally Posted by Rich-n-Texas
I'm starting to lean towards the REW method. The only other piece of hardware I need is the USB "soundcard" which has Line-out L/R & Line-in L/R.
Rich, I have a USB SC I'm not using anymore if your interested. Let me know.
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What a place we have here!
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Quote:
Originally Posted by Luvin Da Blues
Rich, I have a USB SC I'm not using anymore if your interested. Let me know.
Thanks LDB. It has to have Line-in & Line-out as opposed to Mic & headphone. I'd suggest that shipping it would cost more than just buying one since it would be an overseas shipment correct?
bfalls, the Excel table that I plug the readings from the RS meter into automatically convert the raw SPL numbers to "compensated" numbers (based on the model # of the meter) using a formula in each cell. Thanks for posting that in any event.
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Quote:
Originally Posted by Rich-n-Texas
Thanks LDB. It has to have Line-in & Line-out as opposed to Mic & headphone. I'd suggest that shipping it would cost more than just buying one since it would be an overseas shipment correct?.
Well Rich, it does have line in and 5.1 line outs, unfortunately they're 1/8" mini jacks. Yer probs right bout the shippin' tho.
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I'll be in the US in a month and was hoping to buy an SPL meter while I'm at it. Can I simply go to any Radio Shack store and buy one? If so, how much is it and would a be a good choice?
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The model number of the Radio Shack SPL meter I got is 33-4050. This is the analog readout style, and you can use the correction table from the Home Theater Shack site to compensate for this el-cheapo meter when you're taking the measurements.
I ordered mine online, FYI.
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Here are the results of my first attempt. I'm including the settings for the five filters because I really don't understand why I got the results I did, so maybe by including them, someone can explain this graph to me.
Filter #1: Freq = 20Hz - Setting + Fine = 20+0 - BW = 55/60 - Gain = -15
Filter #2: Freq = 38,3Hz - Setting + Fine = 40-4 - BW = 30/60 - Gain = -15
Filter #3: Freq = 50Hz - Setting + Fine = 50+0 - BW = 20/60 - Gain = -8
Filter #4: Freq = 80Hz - Setting + Fine = 80+0 - BW = 20/60 - Gain = -15
Filter #5: Freq = 110Hz - Setting + Fine = 100+8 - BW = 10/60 - Gain = -5
It's still not quite clicking in my head how the bandwidth settings are made and how they effect the response curve, even though kex has explained it to me every which way but Sunday. :mad2:
http://i115.photobucket.com/albums/n...DSetupRev1.jpg
Your help in this matter is highly anticipated and appreciated. :cornut:
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I watched a movie last night with a DTS-HD sound track, and as expected (I assume), the sub output was down. I experimented by switching the BFD into bypass, and while the lows picked up a bit, it still didn't seem to have the same impact as previously when I used Dark Night as a reference, so I'm blaming it on the rental (Saw IV). I still have to readjust the volume on the sub's amp to get it level-matched with the other speakers, so last night's tryout was just preliminary.
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It looks like a good start to me Rich. It was expected that your overall output would be down. You had to lower the output of all the frequencies around your dip at 45 to get a flatter response. You can turn up the master volume on your sub to bring it back up to where you like. Now you should be able to hear more of the 45 htz than before, while the rest are under control.
I would guess that there is still more you could tweek though.
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Thanks GM and I agree. That 45 Hz dip, while not as dramatic anymore could use some boost. When I tried to boost that range previously, the actual gain seemed to occur at about 54Hz and took that 56Hz peak through the stratosphere so I quickly removed it.
I was calibrating with the sub's volume at about 1/3 so yeah, I have plenty of wiggle room.
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Quote:
Originally Posted by Rich-n-Texas
Thanks GM and I agree. That 45 Hz dip, while not as dramatic anymore could use some boost. When I tried to boost that range previously, the actual gain seemed to occur at about 54Hz and took that 56Hz peak through the stratosphere so I quickly removed it.
I was calibrating with the sub's volume at about 1/3 so yeah, I have plenty of wiggle room.
You could have some room canceling going on. (That whole node, mode or whatever thingy) If so, then I think that all your boosting at 45 will do no good other than to boost everything around it. Did you put those panels up yet?
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