[Brooko]

  I've been struggling with lighting here in the cold and dark Dutch winter. I'm gonna see if I can make one of those light boxes if I can get around to it sometime
 
May I ask how you built that?

 
Sure
 
For starters I was going to build the frame myself, but I looked around our office supplies stores, and found some light collapsible storage containers.  The main prerequisite needed to be that I could remove the sides.  The side of these were made of woven mesh - so they were ideal.
 
Next step was taking the two sides out and also reinforcing the sides slightly with heavy cardboard to that it was a little more rigid.
 
With the sides removed, I went to a tailors warehouse and purchased some white very fine gauzy material (it is actually like a thin satin - and used in bridal-wear creations).  When doing this, my tip is to take a small flashlight with you.  What you're looking for is something that will diffuse the light, but not show any patterns on your interior (the mesh / weave must be very fine).
 
Affix the weave to the sides.
 
Final step is to have a heavy sheet of white paper.  It's then hung in a continuous drop from the rear top to the front bottom (so it basically creates a reversed logarithmic curve shape).  The reason you do this is you want no corners showing when you photograph.
 
Then all you need is two spotlights (I prefer a colder light than warmer), and you are away laughing.
 
My next one will be larger (wider and taller), and I'll probably include 3 light sources - sides and top.
 
If you google "building a light box", there are a heap of tutorials.

 

[flinkenick]

Thanks man appreciate it! I am not a very handy guy, so I'm going to give this some thought. Knowing myself, it might get stuck on a to do list for the beginning of eternity - but on the other hand I really need one. 
 
-edit-
Just realized there are a ton for sale on amazon and ebay. Anyways, thanks for pointing me in the right direction.

 

[Brooko]

   I'm having second thought about the shure attenuator thing you're using to match the levels for 2 IEMs(not that this is exact science anyway). isn't it simply adding resistance to the circuit? if so it would change the signature of many IEMs.
if you don't have yet a multimeter, you can test it with the veritas, changing the volume setting on the shure attenuator and seeing if some IEMs with wild and low impedance(most multi BA drivers) have a change in overall frequency response due to that added resistance from the attenuator.

 
I checked with the mulitmeter.
 
1 ohm of resistance (actually 0.99) with volume on low. Exactly same reading with volume on max.  This is with no current flowing.  Next time I measure a multi-ba though, I'll check the curves.  So far though - looks like I'm good.

 

[Brooko]

 
<detailed instructions - see post>

 
Built my resistor - works great. No problems with volume matching.  The impedance in a low voltage source looks like its going to be a bit harder.  My multi-meter isn't accurate enough - so I'll grab a new one in a couple of weeks.  Thanks so much for your help though - learnt a lot, and when I get set up properly, it should make my reviewing output more accurate
 

 

[castleofargh]

  I checked with the mulitmeter.
 
1 ohm of resistance (actually 0.99) with volume on low. Exactly same reading with volume on max.  This is with no current flowing.  Next time I measure a multi-ba though, I'll check the curves.  So far though - looks like I'm good.

pretty cool. I'll wait for a curve "just in case", and maybe I'll get myself a shure remote like that. I have 2 old craps that are just basic rheostats and add mad impedance as I lower the volume, so I could never really use them for anything serious outside of testing for the impact of impedance.

 

[h1f1add1cted]

   
Built my resistor - works great. No problems with volume matching.  The impedance in a low voltage source looks like its going to be a bit harder.  My multi-meter isn't accurate enough - so I'll grab a new one in a couple of weeks.  Thanks so much for your help though - learnt a lot, and when I get set up properly, it should make my reviewing output more accurate
 

 
I'm glad to hear, sadly the most reviewers never "care" about such important thinks like volume matching, or try to make blind tests as best as possible and finally we have massive overwhelming pure "fan boy" reviews with a ton of superiors descriptions how much better the new gear is compared to others. I ignore and skip such "reviews" pretty quick, because I know from which users I have a trustful and interessting review from the first lines one.

 

[MMansell]

great review ... ehem .. I mean thread, Brooko! when I read this, I updated my Beyerdynamic mmx 102 ie's review and added a hyperlink to your post:
"
even if I had a perfect ear, because I didn't use proper devices, comparing two headphones without them is always prone to being wrong and so always take them with a grain of salt
"
also  -with my entry level engineering knowledge- I can say that both formula's given by castleofargh and h1f1add1cted are correct. 

 

[Podster]

   
Built my resistor - works great. No problems with volume matching.  The impedance in a low voltage source looks like its going to be a bit harder.  My multi-meter isn't accurate enough - so I'll grab a new one in a couple of weeks.  Thanks so much for your help though - learnt a lot, and when I get set up properly, it should make my reviewing output more accurate
 

We never stop learning unless it's by choice Paul, excellent blog and why I trust what you hear and write

 

[serman005]

Thanks for an excellent discussion. It is too bad we don't have more and better instruments to measure our ears and the hearing apparatus. If you think  about it, we're really only able to evaluate half the process (auditory input). The listening part is pretty much a black box.  I long for the day when we can measure hair cell function or details of the vestibulocochlear nerve's auditory meanderings. That's some measuring gear I could really get behind.

 

[Brooko]

  Thanks for an excellent discussion. It is too bad we don't have more and better instruments to measure our ears and the hearing apparatus. If you think  about it, we're really only able to evaluate half the process (auditory input). The listening part is pretty much a black box.  I long for the day when we can measure hair cell function or details of the vestibulocochlear nerve's auditory meanderings. That's some measuring gear I could really get behind.

 
Good point - but I'm afraid that might be the end of my reviewing hobby 

 (when people find out my hearing doesn't really extend past 15 kHz).  Seriously though - I often think the best reviewers aren't the ones who can hear the most, but who are able to articulate what they hear.  I have to be very careful nowadays with my research - and often have to "borrow" my wife's or daughter's ears to help identify noise or hiss.  Sadly my ears just don't hear it any more.  It's actually a blessing in disguise sometimes 

 

[originalsnuffy]

I can't hear the 19 khz noise from old tube TVs anymore.  Wait.....there aren't any more Tube TVs anymore.
 
Oh, nevermind.

 

[Hisoundfi]

I can't hear the 19 khz noise from old tube TVs anymore.  Wait.....there aren't any more Tube TVs anymore.

Oh, nevermind.

I still have two in the workout room of my basement.

Boom

 

[ngoshawk]

Good point - but I'm afraid that might be the end of my reviewing hobby   (when people find out my hearing doesn't really extend past 15 kHz).  Seriously though - I often think the best reviewers aren't the ones who can hear the most, but who are able to articulate what they hear.  I have to be very careful nowadays with my research - and often have to "borrow" my wife's or daughter's ears to help identify noise or hiss.  Sadly my ears just don't hear it any more.  It's actually a blessing in disguise sometimes 

Excellent points, all. Brooko, I really appreciate the tutorial of how to get started on a budget. This makes me want to invest the minimal sums outlined here to help verify my reviews (not many, but more coming).

Thank you again for the wonderful blogs, they are quite useful to someone getting back into this hobby who would also like to repay the hobby back with unbiased reviews. Thanks again, cheers!

 

[carmatic]

 
Other issues include consistency – basically to get the coupler to have consistent fit all the time I need to use foam tips – and sometimes I have to switch the settings around to get a decent reading.  I’ve also often measured and measured for hours sometimes to make sure the read get is consistent.  For me it is not usable unless I can get practically the same result again the very next day.
 

is it possible to get a sort of 'average' graph, whereby you insert the IEM, take a reading, remove it, re-insert it, and take another reading .... doing this with a technique which as consistent as externally possible, and for as many times as necessary to get a 'stable' running average, it should yield an acceptable result 

 

[Brooko]

  is it possible to get a sort of 'average' graph, whereby you insert the IEM, take a reading, remove it, re-insert it, and take another reading .... doing this with a technique which as consistent as externally possible, and for as many times as necessary to get a 'stable' running average, it should yield an acceptable result 

 
Yes - I normally take 5 readings and average them - but it's from the same seating of the IEM in the coupler.  I could re-seat it each time and average, it would just take a lot more time - and unfortunately that its a commodity I can't really afford to spare at the moment.