[murphy11]

Hey all,

I'd appreciate any advice you can offer on what I'd need to measure my room. Looking for an affordable way to objectively set the crossover, phase and level of the amp and woofer on my Onix mini strata speakers.

I was going to treat the cabinets with norez in the thread here  http://www.audiocircle.com/index.php?topic=121600.msg1280833#new but the cost has made me take a step back for now and consider whether I can get a better or free 'tweak' by first optimizing the speaker settings, placement, and room.

I have a laptop, tripod and Ratshack analog sound meter. What else would I need to measure the system to see what is going on so I can objectively change speaker settings?

[murphy11]

The Radio shack meter I have s the http://diyaudioprojects.com/Testeq/RadioShack_33-2050/33-2050.htm and I have a microphone from my Integra 5.9 receiver but I'm guessing that won't work.

[murphy11]

Read a few threads via google and just ordered https://www.parts-express.com/dayton-audio-umm-6-usb-measurement-microphone--390-808 and downloaded REW. Mic will be here Monday - hope that is all I need to buy.

[SteveRB]

Keep going!

I'm interested to see what the experienced members of this forum have to say as far as room testing procedure and software/hardware calibration.

[jk@home]

A lot of folks use the REW program:

http://www.hometheatershack.com/roomeq/

Although you will have to spend the dough on the equipment to use it, definitely worth it. I use a Behringer  mike, mike stand, a m-audio mobilepre usb, and an old laptop.

[Ethan Winer]

I'd appreciate any advice you can offer on what I'd need to measure my room.

I too use and recommend REW, and this tutorial shows how it works and what it all means:

Room Measuring Primer

--Ethan

[murphy11]

I got the umm-6 USB today and can't figure out how to get REW and the card and levels and mike to all play nice together. Using the latest REW 5.0 I think. Headed to bed and will try tomorrow with a fresh brain.

[murphy11]

I will try to get a usable measurement later this morning or afternoon and could use some help before I measure. 

My setup when used for listening is a Lenovo Thinkpad running Win 7 -> Dragon USB DAC -> ONIX A60 integrated -> ONIX min strata. The microphone is a Dayton UMM-6 USB and I have REW v 5.0 installed.

When I have the EMM-6 connected to a USB port and the dragonfly -> A-60 -> mini setup as normal I see in REW the following options for output and input:
output - default device, primary sound driver, speakers (dragonfly) speakers (realtek)
input - default device, primary sound driver, microphone (umm-6), microphone (realtek)

What specifcally should I set for input and output on the soundcard? If it makes a difference I can take the dragonfly DAC out and connect amp straight to microhone or headphone jack.

[murphy11]

This is the left speaker. mini amp settings are crossover 30, phase 0 and level at 9AM...   thoughts?

[Vedder323]

I owned the stratas in the past...  first of all... 

is that measurement with the subs on? You need to take your first measurement with the subs off. Also, do one speaker at a time and we need to see both speakers measurements.

[Ethan Winer]

What specifcally should I set for input and output on the soundcard?

You should set the input to the USB microphone, and the output to whatever sound card drives your loudspeakers.

--Ethan

[murphy11]

I owned the stratas in the past...  first of all... 

is that measurement with the subs on? You need to take your first measurement with the subs off. Also, do one speaker at a time and we need to see both speakers measurements.

Thanks. The posted plot was the left speaker only with amp turned on. I will turn it off and take another measurement. I think when the amp is turned off on the mini the phase, level and crossover don't matter but I will go ahead and leave phase as 0, level at 9AM, and crossover at 30 for comparison sake.

[Vedder323]

Thanks. The posted plot was the left speaker only with amp turned on. I will turn it off and take another measurement. I think when the amp is turned off on the mini the phase, level and crossover don't matter but I will go ahead and leave phase as 0, level at 9AM, and crossover at 30 for comparison sake.

Yeah its process of elimination. We first need to identify what the room looks like without the subs turned on. Then we can help you smooth out whats missing.

[murphy11]

This is the right speaker toed in approx 20 degrees, amp is approx 19" from back wall, tweeter 34" from back wall, 12" away from right bookcase. Amp is off.




This is the left speaker toed in approx 20 degrees, amp is approx 19" from back wall, tweeter 34" from back wall, 12" away from left wall. Amp is off.

[murphy11]

For the heck of it I hooked up both speakers without changing anything and got measurement below.

[Vedder323]

interesting...  ok, so based on what you can see here, what do you think?

If those were my measurements, id be starting with the sub as low (30-40hz) as it can go on the crossover and try another reading with the volume just barely kicking on...

Take another measurement and see what happens.

[murphy11]

interesting...  ok, so based on what you can see here, what do you think?

If those were my measurements, id be starting with the sub as low (30-40hz) as it can go on the crossover and try another reading with the volume just barely kicking on...

Take another measurement and see what happens.

This is been an interesting and frustrating process. Not ready to give up yet but maybe it's like enjoying sausage and then seeing how they are made; better off leaving well enough alone and not knowing.

I was relatively happy with spikes on the back of my minis and speakers tipped forward, amp on and set to 12AM. Sound width was wide and bass sounded right to me. In the process of moving speakers and measuring, the spike and thread broke so minis are not spiked. After measuring with less toe-in amps off, they measured pretty flat.

Turning amps on and volume very low produced the best measurements. Phase and crossover had little effect on meaurements but turning amp level higher produced a fairly big dip from 60-90 so I turned the level back down.

Below is both speakers with the flattest measurement I could get. Now the sound width seems very narrow and bass seems lacking. Maybe this is similar to calibrating a TV and thinking a tuned picture seems 'soft'. Not sure if I like this; I plan to keep everything as is for a few days and see if the sound grows on me.

[bladesmith]

Did you calibrate your mic yet. ?

https://www.youtube.com/watch?v=21wUsNfF2Lw&feature=youtube_gdata_player

[murphy11]

Did you calibrate your mic yet. ?

https://www.youtube.com/watch?v=21wUsNfF2Lw&feature=youtube_gdata_player

No I didn't do that; I loaded the cal file downloaded from the dayton site on the mic tab. I will review that video and others on that page and try again. Thanks for the feedback!

[EuroDriver]

One test procedure I found very helpful to understand what is going on in your room is to read off the peak frequency (with the sub off) which looking at your graph seems to around 85 Hz

Use this frequency with REW's tone generator and let it play constantly.

You can then walk and crawl around your listening room and listen and feel the areas where there are peaks, and perhaps in some of those locations you can put in bass trapping.

You can also move your speakers around and see how the nodes and anti-nodes change position and volume.  You can also experiment to see which listening position is a good compromise

A anti-node location could be a good place to put your sub-woofer.  You definitely do not want to place your subwoofer where there is a strong node unless you can run the sub phase inverted, and then it might work with some good effect to tame the room modes