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Post by cdy2179 on Feb 23, 2009 7:40:50 GMT -7
I just installed two 18" Fi's between my two mains, at first it sounded horrible (painfully pressurized the room on Nemo's glass tap) , so ordered a BFD and while it was on its way i ran REW and found a huge peak from 20 hz all the way to 60 hz, And this is with corner traps. After the eq it sounds much, much better.
Here's my question
I entered the radio shack calibration file i found on Home Theater Shack, and brought my measurements down to that calibrated level, just wanted to make sure that that's correct. a lot of the graph JPEGs on this forum don't seem to follow a meter calibrated line, I'm guessing most on here may have better meters that don't need a calibration file.
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Post by ThomasW on Feb 23, 2009 8:20:04 GMT -7
I'm not sure what a calibrated level means..... nor do I believe there are 'set' reference levels everyone needs to use.
Cal files are an educated guess regarding correction, and are based on a sampling of a few devices. They tell you nothing specific about your meter. That said most people I know use a cal file...
IMO the output from the sub should be set considering the output of the mains and no I'm not talking about a multi-channel calibration.
The output level of the sub should be set so the midrange from the mains doesn't sound 'wooly' or 'chesty'. What's that mean? Listen to a solo female voice. Does it have the proper sonic characteristics (meaning does it have the characteristics of the live female voice? no? Well if it's too 'thin', raise the sub output level. If she sounds to 'chesty' (you know like someone recovering from a chest cold) the sub output level is to high.
The above analogy is true for any voice or instrument, if there's too little or too much output from the sub, it will change the characteristics of the midrange frequencies.
If the room has too much or too many acoustic traps that will effect the mid/hi frequencies and make things sound bass heavy
BTW do you have any pictures of your installation? If so we love to see them...
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Post by cdy2179 on Feb 23, 2009 11:13:22 GMT -7
I'll try and get some pics later tonight. I think i may have confused you with my question. this is with only the sub playing 5-80hz. When i loaded the RS cal. file it gives me a black line on my graph that gradually slopes away from my target line as the hertz drop.. The Radio shack meter is like 20 something db's off around 20hz so the slope is pretty drastic at that point. i added filters using the BFD until it was brought down to the mic cal. line. When i used REW auto set filters feature it cut everything to the target line, i cut it down even more to get to the black mic cal. line, i figure because the RS meter is incorrect i need to filter my sub using the mic cal. line and not the target line. Is this correct??
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Post by ThomasW on Feb 23, 2009 11:30:14 GMT -7
No confusion here.
I don't use Room EQ Wiz, so I'm not a tech support source for it.
That said there are numerous people here that do use it. If you post screen shots of what you're talking about I'm sure people here can help...
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Post by weverb on Feb 23, 2009 18:42:57 GMT -7
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Post by chrisbee on Feb 24, 2009 2:04:57 GMT -7
The black line which the cal file produces on the REW graph simply indicates the correction applied to the SPL meter by the REW software.
You aren't supposed to adjust your subwoofer response with the BFD to follow the line downhill or you will lose all your deep bass.
Your subwoofer response may well rise in level as it falls in frequency. Particularly if you have free room gain at the bottom end of your sub's frequency response.
Thomas' advice is valid and an excellent test for balance between the sub and mains. It sounds as if your sub output level may be set too high compared with your mains.
Relative levels are very much a matter of taste. Some like their bass hot. Others like it more natural and some even like their bass understated. It may even be a matter of the programme material. Action films suit louder bass. Some classical music can sound very silly with heavy bass.
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Post by cdy2179 on Feb 24, 2009 7:08:41 GMT -7
![]() [/img]Thanks, after doing my nearfield measurement again last night i realized that i need to follow the target line, my nearfeild is perfectly straight and then plummets at 16 hz, my plate amp may have a rumble filter on it or something, which vacuums! I have a 28db peak from 20 -60hz. I knocked it all down but it's not pretty, bu it sounds good. Will knocking it down this much affect the clarity or anything? can't figure out how to load the JPEG of my graph.... This is my first IB but my 5th DIY sub, I definitely know how i want it to sound, although I've never used an EQ with it until now, great piece of equipment. The almost 30 db peak is what was killing me. It was painful, at all four of my seating locations!  |
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Post by ThomasW on Feb 24, 2009 8:00:07 GMT -7
This forum's software doesn't support the uploading of attachments. To put an image in a post you need to upload the image to a hosting service (flickr, photobucket, image shack, etc.,) then paste the URL of the image into your post.
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Post by weverb on Feb 24, 2009 12:29:19 GMT -7
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Post by cdy2179 on Feb 24, 2009 14:08:33 GMT -7
Great, more reading  .... this stuff is addictive. I just glanced at the home theater shack link.... i have 12 filters set ... guess i should keep reading it, Thanks! |
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Post by cdy2179 on Feb 25, 2009 12:15:28 GMT -7
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Post by cdy2179 on Feb 25, 2009 13:23:02 GMT -7
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Post by weverb on Feb 25, 2009 13:23:50 GMT -7
Need a bigger picture. Saved it too small. |
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Post by weverb on Feb 25, 2009 13:24:55 GMT -7
Second one is a little better.
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Post by ThomasW on Feb 25, 2009 14:10:57 GMT -7
Nothing I do allows me to see the 1st picture.
The second one looks ok if the goal is absolutely flat response. Most people use a some boost to create a house curve.
I continue to suspect the plate amp is the problem
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Post by mtbdudex on Feb 2, 2011 3:45:40 GMT -7
Just FYI, REW v5 has been released www.hometheatershack.com/roomeq/We are excited to announce the full release version 5.0 of Room EQ Wizard is now available for download.
Best Regards,
John Mulcahy
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Post by FOH on Feb 2, 2011 13:18:55 GMT -7
I'm not sure what a calibrated level means..... nor do I believe there are 'set' reference levels everyone needs to use. Cal files are an educated guess regarding correction, and are based on a sampling of a few devices. They tell you nothing specific about your meter. That said most people I know use a cal file... IMO the output from the sub should be set considering the output of the mains and no I'm not talking about a multi-channel calibration. The output level of the sub should be set so the midrange from the mains doesn't sound 'wooly' or 'chesty'. What's that mean? Listen to a solo female voice. Does it have the proper sonic characteristics (meaning does it have the characteristics of the live female voice? no? Well if it's too 'thin', raise the sub output level. If she sounds to 'chesty' (you know like someone recovering from a chest cold) the sub output level is to high. The above analogy is true for any voice or instrument, if there's too little or too much output from the sub, it will change the characteristics of the midrange frequencies. If the room has too much or too many acoustic traps that will effect the mid/hi frequencies and make things sound bass heavy BTW do you have any pictures of your installation? If so we love to see them... Obviously this is an old post, but Thomas I've read you allude to this before, but with out further explanation. Here, I finally read your entire thought process. I'm a relative greenhorn in these parts, but I couldn't agree more. This calibration stuff I've ran into here and at AVS, had me perplexed at first. I too have always used female voice, (and other things including male voice) of recordings I'm intimately familiar with to adjust relative levels of octave to octave balance. I've tuned systems of all sizes by ear, and I've tuned systems by RTA. Anyone that has had this opportunity knows exactly where I'm going here. There are endless aspects affecting the end result tonal balance at the LP, either it's anemic, too chesty, or correct. I'm very glad I balanced systems by ear before I ever began to see what was going on,...as I may have been led in a different direction. I've got a real problem with excessive mid bass chestiness in the vocal channel at live events as well. Once again, anemic, excessive or just about right. Regardless, very few forum posters seem to share this opinion of adjustment by taste. I couldn't agree more. Of course one strives for smooth response throughout the audible range, but a tilt in the right direction can sure make things a lot more listen-able. Thanks |
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