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I plotted three graphs using three different calibration files in the rangen 20–800 Hz(ignoring the first sample).
The graphs looked like random noise. I don't think scaling could fix the 20–800 region.
I don't think it would be scaling of the data that is already there in the .txt file, but rather the data that the .txt file was generated from, that has been incorrectly processed in some way. At least that's what Tony @ minidsp seems to be implying.

It'll be interesting to see once new calibration files come through whether it's just the 20-800hz range that gets changed or if its the 800+ , or both.

Despite the dodgy calibration file I've managed to use REW + Umik1 + minidsp to turn my horrible boomy, muddy, bloated Audioengine 5+ speakers into delightfully clean sounding "monitors". They had real issues with 100hz-300hz range booming away at +12dB which was easily sorted with REW's automatic EQ correction biquads which I then imported into minidsp:


http://i.imgur.com/JZKGH8C.jpg


Apparently the UMIK-1 is pretty accurate in that range anyway even without the cal file, which is probably why I'm hearing such a dramatic improvement in the bass :sn:

One question though, where should the Umik's volume be set in Windows 7 properties? The default is "10" on my laptop. Should I leave it at 10 or should it be at max? Does it make any difference to REW? I feel that my Umik is reporting levels in REW lower than they actually are. For example when the mic says 80dB SPL, it sounds very loud to me. I actually got sore ears from playing that sine sweep at 80dB, and REW kept telling me to increase it to 90dB!
 

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It is a relief to be getting a detailed response from MiniDSP, and a relief that fresh calibration files can hopefully be generated without having to return microphones for recalibration. No doubt they are aware that the solution will be scrutinized by the user community. I too am very curious to see what happens below 20 Hz, at those discontinuity points, and to see by looking both at individual curves and at an updated group plot of all the new curves together (we are all hoping that someone will be generous enough with their time to generate and post one) that all portions of the curves look like truly valid individually-measured calibration curves.:bigsmile:
 

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Will have to wait till Monday or Tuesday next week for new files to be generated. Fingers crossed.
 

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where can I find a pdf document that clearly explained the complete REW set up with umik-1. I found it yesterday but did not save it. I have spent over 30 mts to find it today to no use.

can some one point me in the right direction please.
 

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I plotted three graphs using three different calibration files in the rangen 20–800 Hz(ignoring the first sample).
The graphs looked like random noise. I don't think scaling could fix the 20–800 region.
I hear what you are saying and it would really be most unfortunate for everyone involved if that turns out to be the case... right now I'm hoping they can 'fix' the files by rescaling... but until they can actually talk to their supplier and get a look at those original calibration data, everything said so far about just using a simple script to re-scale the original data will fix the issue is conjecture on their part at this point, however it is the hope I am going to cling to until I can view those re-scaled files for myself next week.
 

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I missed delivery of mine today. Have to drive to post office tomorrow to take delivery.
 

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where can I find a pdf document that clearly explained the complete REW set up with umik-1. I found it yesterday but did not save it. I have spent over 30 mts to find it today to no use.

can some one point me in the right direction please.
In the upper right corner of your browser (hope you're using Internet Explorer), click on the star, then click on History. You should be able to find it there.
 

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...I too am very curious to see what happens below 20 Hz, at those discontinuity points...
Its interesting to note that in that first batch, all the mic response curves seem to do a dip at what appears to be around 20-22Hz... do you suppose that could be yet another measurement technique switch-over frequency? If so, then maybe when all the files were compiled someone just forgot to include the "below 20Hz" calibration measurement file data? (A probability I think not inconceivable given all the other compilation mess-ups... ouch! all this does not bode well for some one's start to the New Year when they get back to work on Monday.)
 

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Have you looked at the vertical scale on the graphs? The "dip" is about 0.15 dB...
Yes but size of the dip is not really relevent to the phenomenon... Every single line that I can clearly decipher has the exact same slope dip in the exact same place by the same amount... more than mere coincidence don't you think? Nowhere else on those graphed lines do I detect this type of universal behavior in unison. How would you explain this universal behavior amoung so many mics with differing response curves?
 

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Hi all,

Just wondering if anyone has ordered the mic from the UK and if so how long customs took to clear the package? Mines been there a week now and the tracking from SpeedPost still states pending customs inspection. Not sure who deals with the transit of the mic from customs to my delivery address, guessing it would be a national courier such as ParcelForce. Also did anyone get charged customs duty? If so how much was it? Don't want to have to pay much more..wishing I had bid on an ebay item now!

Cheers
 

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A representative of miniDSP has responded over on the manufacturer's website forum with an explanation of the error and assures it is just a simple script fix away... however it won't be available until next week sometime when their supplier gets back from a week long holiday (for Chinese New Year). There is some skepticism that the 'fix' may take more than a simple script to correct but no one (including the miniDSP tech) really knows anything for sure at this point in time... in fact, we won't really know anything until the updated corrected files are online to be viewed and downloaded. I'd suggest waiting 'til next week (probably by mid-week) and see what the scuttle-butt is by then.
 

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Monomer, thanks for your reply mate. I really appreciate you explain that well.
Have another quick question...

I have a Tuba HT (THT subwoofer), and looking forward to calibrate it. The speakers are Def Tech Mythos ST lineups.
And i am beginning to understand the eq process using rew.
However can someone guide me to a fantastic simple beginners guide to eq'ing using UM1K-1 and miniDSP.
What minidsp is ideal for me.
 

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Yes but size of the dip is not really relevent to the phenomenon... Every single line that I can clearly decipher has the exact same slope dip in the exact same place by the same amount... more than mere coincidence don't you think? Nowhere else on those graphed lines do I detect this type of universal behavior in unison. How would you explain this universal behavior amoung so many mics with differing response curves?
Agreed, it does seem indicative of there being some stitching together of portions of the curve at that point. It makes you wonder, if the offset is the same for all samples, why is there any offset it all? Unless there is a known sensitivity difference between test beds being accounted for. Not a big concern, but a curiosity, and something to keep an eye on.
 

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Agreed, it does seem indicative of there being some stitching together of portions of the curve at that point. It makes you wonder, if the offset is the same for all samples, why is there any offset it all? Unless there is a known sensitivity difference between test beds being accounted for. Not a big concern, but a curiosity, and something to keep an eye on.
Though small, its mere existence does give me hope that there actually exists a calibration file for the below 20Hz response that somehow missed being incorporated into the "botched" calibration files for the seond batch of UMIKs we now have... meaning that the whole freq range (this time starting from at least 15Hz) can be properly recreated from the original measurement data. I really wish I understood the mic calibration process better.
 

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...And i am beginning to understand the eq process using rew.
However can someone guide me to a fantastic simple beginners guide to eq'ing using UM1K-1 and miniDSP...
Though I have been using REW for quite a few years now, I'm just a novice when it comes to miniDSP... in fact, mine should be delivered today, (said with fingers-crossed). I read all the info I could find on the manufacturer's website and carefully read the datasheets they made available and viewed the YouTube videos (there are only two put out by miniDSP). Soon after purchase of the plug-in (4-way advanced) I downloaded it and played with it... I think this is going to be easy to manipulate but because of its amazing flexibility, I predict it will be quite time-consuming and complex to get my system to optimum in-room response over large area because of my particular situation (MY SITUATION: 4 subs total, two mid-bass units and two-ULF units needing first to deal with cross-over points between subs and then to get the best compromise of in-room response over 8 seated locations consisting of adjustments to gain, phasing/delay, parametric EQing, and judicious sub placements... with each change confounding the others). However I believe for most situations, especially with a single sub, it will be a snap...
...What minidsp is ideal for me.
Here is a posting I wrote on another forum trying to help someone else with a similar question understand how to chose a miniDSP and a plug-in...

Using my meager knowledge of these devices/systems I will try to simplify the process of selection for you:

1)What do you want to accomplish? First you must have a clear idea of what exactly it is you're intending to do and be able to visualize the steps you are going to take to do it (paying attention to the order in which you are planning to do them)

2)Select the Hardware. Decide on how many inputs and how many outputs this is going to require. Now you should be able to select the appropriate basic miniDSP module... also if you have Pro equipment then select a 'balance' module otherwise 'unbalanced' should do. Select it as a "kit" if you are going to physically house this device (usually within a larger enclosure... maybe inside a speaker cabinet? etc) otherwise you'll want to choose it as an "in a box" model. Don't worry about Rev A or B as these can be changed by an internal jumper later if necessary... this just switches the maximum input level (sensitivity) from .9Vrms to 2.0Vrms.

3)Finally select a plug-in. This is the programming that allows you to access the power of the circuitry of the DSP. If you selected a 2X4 miniDSP module (which I think will suffice for most situations involving multiple subwoofers... 4 or less that is) then either the 2.1-way or the 3/4-way plug-in should be your only choices for sub(s) control. The 2.1 plug-in should work in most instances where you'll need to use two separate inputs (like involving a left and a right channel) in conjunction with your sub(s)... having 2 outputs dedicated to each (left and right channels) while the other 2 outputs feed a sub or two. The 3/4-way is more applicable when you need lots of individual control for each output and not so much on the input side (like feeding it the LFE from a receiver say). Select the "Advance" version if you intend to use REW to configure the biquad values of the parameteric EQ for you.

Bottom line here: I can see where in the vast majority of situations a 2X4 miniDSP with a 4-way advanced plug-in would be just the ticket.

Hope this helps.
 

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I also hope they can recreate the original file measurement. I suspect we will hear some feedback by mid next week although their website is saying Monday. Fingers crossed.
 
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