TOPIC:

Hello,

I got a few questions regarding the UMIK-1.

Long story:
Currently I have the Z-2300 loudspeakers from Logitech which has a big separate bass. I like the speakers, but I upgraded a few days ago my sound-card to the ASUS Xonar DX and realized it might be time to also upgrade my speakers To get that true sound quality and also because I currently don't like the big bass blasting everywhere. I have been searching and found the KRK Rokit 5 might fit my needs. These monitors are according to people online good and can go very low (45Hz) and have low tones towards the listener, so no separate bass needed. But, I thought, investing so much money in good monitors is great, but if my room is not good, it is not much use. So I started searching on the web for stuff about this and eventually found info about room acoustics and the UMIK-1.

Questions:
So here is the big question, is it possible to use the UMIK-1 to improve the sound quality in my room physically (I can't move walls for example) and digitally? And will it be noticeable? I have attached to this post a 3D image of my room for the physically part. And how to do this digitally? I read about REW and how it can generate improvements, but how would I apply this to my sound card? Adjusting the EQ doesn't look like the most precise way to do this... I listen a lot of music from Spotify. As far as I know it does not have a plug-in option to adjust the sound, so it should be done by the sound-card driver or windows?

I would also like to improve the sound of my TV (and perhaps parents TV). Is it possible to use the UMIK-1 on a laptop/PC and send a test signal over hdmi? But what if I don't watch over hdmi, how do I apply a digitally 'correction'? Or should I manually try to get a nice flat response by adjusting the EQ on the TV? (Samsung LE32D550). I'm a bit confused how this would work for TV's with built-in speakers and how much improvement I should expect.

In answer to your question, the UMIK-1 will only provide measurements of the room. It won't do any processing so you'll need to find a place in your audio signal chain to do it (e.g. on HDMI) or inside the PC (i.e. another algorithm like JRIVER or Dirac Live PC - you can google to find more about these options).
The nanoAVR is another way to do it I guess. HDMI processing on the audio path between your PC and your TV.

Thank you for the reply.

Can I, based on the UMIK-1 measurements in combination with REW, determine how to improve my room acoustics physically and digitally? Let's say I got a dip of 10dB at 70Hz. Is there information (on this site or the web) to flatten this dip (even with my strange room layout? see attachments first post)? Now, let's say I can't or don't want to change the room any more, can I flatten the other hills/dips with only the equalizer (EQ) within the TV and the sound card? On the TV I only got; 100,300,1K,3K and 10K Hz. Which is not much to adjust, but the TV sound is less important than that from the PC. The PC sound card has: 30,60,120,250,500,1K,2K,4K,8K,16K. Could that be enough? Or are the EQ adjustments too rough to fix sharp hills/dips?

Hi there, your intuition is correct, basically, the EQ adjustments you have (one octave on the PC, even worse on the TV) are too coarse to do more than act as overall spectrum shaping/tone controls. It would be best to figure out how you can get a miniDSP device into the audio chain. There are a lot of app notes on this site that may help with understanding all of this: www.minidsp.com/applications

Note that you can still use the UMIK-1 to do your measurements, but adjusting EQ accurately won't be possible with what you've indicated you have.

Thank you for your reply, John.

I'm not (yet) comfortable in spending a lot of money on sound quality, so I want to spend it wisely and I don't know if a miniDSP is needed (haven't done any measurements...), if it can fix all my possible problems and if these possible problems are worth fixing (perhaps I won't even hear the difference). I think that perhaps a good DIY bass-trap might be a better investment. Do you think that spending 90 euro on an UMIK-1 is a good investment if I can only use the tools given in my previous post (so one octave EQ and DIY sound/bass traps)? Or can I better spend it on something else? Like a (DIY) bass trap which is just only based on the room-size and no precise measurements (like from an UMIK-1).

I'm currently investigating how I'm gonna make sure that the acoustical axis point is correctly aimed at my ears. I read that this is very important for near-field speakers and it looks like a cheap and easy way to improve sound quality.

Anybody else perhaps got an opinion about what is the best investment?

@ Byteside,

In the scale of things (i.e. compared to the cost of typical equipment), a UMIK-1 to get an idea of what your system sounds like is the bare minimum we'd say. How are you going to "treat" a room (DSP or acoustically with some panels) with no ideas as to what/where is the issue in your spectrum? I'm a bit confused on how you plan to do so unless you have golden ears (very rare...

A UMIK-1 will help you understand your room when combined with REW. Once you know you can start to play with panels, moving speakers around. If your source is all driven from your PC, you can always use a PC software to provide the EQ you need.

DevTeam

I was thinking about making bass traps based on the room size. I have seen calculations on the web that show at what frequency your room will resonate. However I also just read on the web that these bass traps can also 'trap' high frequencies which is not desirable. So yes, I need something to measure the room acoustics and see if my adjustments really improve the sound quality. I ordered the UMIK-1 and hope to see it soon. Once it gets here, I will post a plot of the room acoustics (freq. vs dB, what are these plots called?) with my current set-up, a Logitech Z2300 2.1 set. I think the plot will show a very wiggly line.

This line I found on the web also convinced me to get a measurement microphone:
"Putten van - 20 dB is bij wijze van spreken alsof je een toets blokkeert in een piano. (Eric Desart) " from www.homerecording.be/gids/akoestische-behandeling

Which roughly translates to:
"Dips of -20 dB are, so to speak, like blocking a key on the piano"

We don't want that!

I was kinda shocked when the UMIK-1 arrived, I got charged 34 euro's. I should have know there are import duties, but it makes it an unpleasent experience. I think you guys should really make this more clear on the website! Even better would be the option to pay import duty in advance, so that the package gets here faster and I don't have to pay a ridiculous 18 euro for so called handling cost.

I attached to this post a SPL plot with my current Z2300 Logitech (2.1) speakers. I think I understand some parts of it, but perhaps someone can enlighten me.

The dip at 60Hz looks like a room resonance frequency. Is that correct? So to fix this, I would need to add a bass traps? The dip around (or before) 200Hz might be the crossover frequency? Not sure, I did move the bass a little and that did have some effect on this dip. The rest of the fluctuations are reflectance? Can I or should I test this with a near field measurement?

//edit: I uploaded a large image, but it got resized. Also, the bbcode editor doesn't work, it keeps saying "Loading BBCode editor..."...

I used EqualizerAPO and got some nice results, I think, although it does sound a little strange to me. Might need some getting used to and fine-tuning.

I only looked at the SPL vs frequency, I used all speakers during testing (2.1) and did not look at other stuff like waterfall, reverberation etc. Also, when doing the sweep I use 256k (5,5s) instead of 128K. Does this all have much effect?

During the sweep I could here some stuff rattling.... this is not good. This is because I have the speakers for the test at 75dB (set up with pink noise), which is quite loud.

//edit: What should I do next? Go for room treatment? How do I decide how to do this? Any information online?

//edit: I got EQ's with -15 dB and +15 dB, is this not too much? What is the max dB for EQ I should use?