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| REW Forum First measurement: 2 big problems. Any solution?Discuss First measurement: 2 big problems. Any solution? in the Equalization | Calibration forum; First measurement: 2 big problems. Any solution? Hi all.
Ive installed my 4*AE 15 IB in my 15*12feet room. Im currently powering it with an old receiver ... |
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Views: 676 - Replies: 18
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| First measurement: 2 big problems. Any solution? Hi all. Ive installed my 4*AE 15 IB in my 15*12feet room. Im currently powering it with an old receiver so its probably getting around 150W or so. Im getting a Behringer ep 2500 as soon as i manage to sell it though. Anyways. Since I have a BFD I wanted to see what im hearing (which just sounds incredibly good btw) and what I see looks like, well, not something that i would expect to sound so nice! I ran my first set of sweeps. This isnt looking good. Well, from 8-45 or so it looks great, but then theres a huge dip between 45 and 65. Is it even possible to do anything about this? Second problem comes when looking at the LF Waterfall plot. What is going on at and around 50hz? Anyone know how to solve this or what the problem could be? Any help would be much appriciated! | ||||
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| Re: First measurement: 2 big problems. Any solution? First you need to make some changes in your graphs. Use a vertical axis of 45dB-105dB and a horizontal axis of 15Hz-200Hz. Note the icon that looks like a little floppy disk in the lower left corner of your graphs - click it and use it to save your graphs (at 800 wide) for posting, rather than showing the entire REW page. Waterfall plots use the same axis as response graphs and must be set to LOGarithmic rather than LINear. Use the Freq Axis button for that. Once you've done that, can you tell us if this is a sub only or a sub + mains measurement. The first plots you should do are sub only, with the crossover set in the receiver to the one you normally use, and the mains disconnected. That way, you can see what the sub is doing in the mix without influence. BTW, a 10dB house curve is a bit extreme. brucek | ||||
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| | #3 | ||||
| Re: First measurement: 2 big problems. Any solution? Hi there. Alrighty. Changes per request done to pictures and uploaded, see below. These measurements were done with both sub and mains, crossed over at 80hz in my receiver. IŽll redo measurements with sub only if that help. The 10db house curve was just a test to see if i used the correct syntax in the .txt file. The house curve is not implemented nor are any other changes. The included measurements are with no filters added to the BFD. So, any idea whats wrong? The 50hz ringing and wide gap in the frequency respons is somewhat troublesome for me. | ||||
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| | #4 | |||||
| Re: First measurement: 2 big problems. Any solution? Quote:
When that's complete, you add the mains and check the interaction at the crossover (where the biggest mix effect is taking place). Then usually, a small phase adjustment to the sub will clear the crossover problems. You also need to measure from 0-200Hz (don't stop at 80Hz). I can pretty well tell you that you won't require a BFD. Start off by removing that house curve and running a sub only test from 0-200Hz (with the 80Hz crossover) at 75dBSPL target. brucek | |||||
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| | #5 | ||||
| Re: First measurement: 2 big problems. Any solution? Bruce, He's got an IB. | ||||
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| Re: First measurement: 2 big problems. Any solution? Quote:
Quote:
Regards, Wayne | ||||||
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| | #8 | |||||
| Re: First measurement: 2 big problems. Any solution? Quote:
Everything is turned off. If i run a sweep without any signal to the subwoofer (only the Conrad mic connected to the computer) I get the below graph. Peaks at 50, 100 and 200Hz. With lots of ringing.. Anyways. I redid my graphs according the BrucekŽs info above and the result I got can be seen below. I also changed my soundcard setting to recognize the SPL meter as "line in". (Green graph below), Which is the correct setting? Comments? Last edited by steveo1234; 08-23-08 at 10:57 AM.. Reason: Added picture | |||||
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| | #10 | |||||||
| Re: First measurement: 2 big problems. Any solution? Quote:
* Use a vertical axis of 45dB-105dB and a horizontal axis of 15Hz-200Hz.* Quote:
You'll get a graph such as this: ![]() Quote:
brucek | |||||||
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| | #12 | ||||||
| Re: First measurement: 2 big problems. Any solution? Quote:
Your best bet is simply to boost the 40-65 Hz range as needed, provided your sub system has enough headroom (which of course any equalizing requires). Quote:
![]() Since it's not being generated by your system, then it is of no consequence with regards to equalizing your subwoofer. Regards, Wayne | ||||||
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| | #14 | |||||
| Re: First measurement: 2 big problems. Any solution? Quote:
Well, its not technically a peak I guess. But, it is very easy to hear that the IB is "bottom heavy" which is a bit distracting. I will try boosting to see what happens. Im currently having a lot of problems getting measurements. My mic either refuses to send a signal to my computer or REW is registering (an impossible) 240dB. I need to play around a bit more to find the source of the error... | |||||
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| | #15 | ||||
| Re: First measurement: 2 big problems. Any solution? Hi all. I decided to give REW a new try today. I spent some 2 hours trying to get resonable levels on the input and output as well as the SPL-meter and managed to get this respons: To me it looks kind of hopeless to fix with the BFD? ![]() | ||||
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| | #16 | ||||
| Re: First measurement: 2 big problems. Any solution? Well, it certainly is a challenge. Did you ever try boosting the depressed area with the BFD? Regards, Wayne | ||||
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| | #17 | ||||
| Re: First measurement: 2 big problems. Any solution? Not yet. Ive been playing around with the filters in REW trying to get a good curve and I ended up with this: ![]() http://img291.imageshack.us/img291/7...rrectedoh4.jpg That will take 6 and 7 db boost at 53 and 60hz. Not sure how it will work out but im going to feed the BFD with this and see what happens. I have a lot of headroom with subs and amps so itŽs possible it might work. | ||||
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| | #18 | ||||
| Re: First measurement: 2 big problems. Any solution? Ok. With 5 filters, most of them with a gain of -4 or -5 I got the following result: This looks pretty good to me. I decided not to touch the "bump" from 10-30hz as I enjoy the extra infra energy. On the downside: I had to add a 55hz filter with a wide gain of 10dB. This isnt something I expected and im not sure I should keep it, but, it DOES give a good curve. Any comments? (Added original measurement for reference) | ||||
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| | #19 | |||||
| Re: First measurement: 2 big problems. Any solution? Quote:
Regards, Wayne | |||||
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