Improving room acoustics

mjp200581 · Feb 17, 2015

Thanks for catching that in time for me!

I've changed my order to the Behringer.

Tenson · Feb 17, 2015

Once you have the outputs of the audio interface hooked up to your hi-fi for testing the room acoustics you can have a quick play with using that as your source. You will probably be surprised how close it comes to a good quality hi-fi source

You could also try processing a few tracks with corrective EQ and then comparing to uncorrected and test out the results of room EQ. Any audio editor with a parametric EQ would let you do that. There are also ways to make anything you play from the PC have EQ applied.

mjp200581 · Feb 26, 2015

Time for an update...

I've now got my microphone, an XLR microphone cable, the Behringer interface and a pair of 1/4" jack to RCA adaptors. Hopefully that's everything I need for my purposes of measuring the room response.

I've been messing with it for hours today and I can't seem to get it working.

So here's the situation:

Connected to my laptop via the USB cable the unit has power (power on light lit up). If I use the headphone output on the front panel of interface and connect that to my HiFi amplifier with the 'direct monitor' switch depressed I can hear that the mic is working (mic output from HiFi speakers). However I can't get anything from the regular output sockets mounted on the rear panel of the interface.

I was surprised that the unit didn't come with any software and the instructions are supplied are only very basic and not helpful. I've done a google search and it seems that there are quite a few people who have experienced driver software problems with the Behringer. Furthermore I read one review which stated that Behringer have not published a driver for Windows 7 64 bit which I think is what I have on my laptop.

So at the moment I'm completely stumped and not sure what to do.

mjp200581 · Feb 26, 2015

I've done some more faffing about and I reckon it's a driver issue.

Tenson · Feb 27, 2015

The latest driver on the website says it supports up to win 8.1, but you are saying it is only the 32-bit versions? That is stupid of them!

While WDM drivers may not work, I wonder if ASIO might. Run the installer for the interface, then go to ARTA and go to 'Setup - Audio Devices' and see if you can select the interface in ASIO mode.

If it doesn't work I'm sorry I recommended it to you!

If all else fails, you could of course run a dual boot with Win7 32-bit just for acoustic measurements. Rob does that with his Mac and a dual boot of Windows.

mjp200581 · Feb 27, 2015

No need to apologise Simon, it's not something you could have foreseen.

I downloaded the generic ASIO4ALL driver which is supposedly pretty universal but still no joy.

Today I signed up as a member on the Behringer forum and asked for advice there.

I've also fired off an email to Behringer customer support asking for guidance.

I'll let you know how it goes.

mjp200581 · Feb 28, 2015

Wahoo! I've got it working!

I had a response on the Behringer forum directing me to the correct driver.

Do I need to buy an SPL meter so that I can calibrate the system or is it not important for my purposes of measuring the room response?

mjp200581 · Feb 28, 2015

Right then, here is my first effort at taking some measurements.

This is a sweep test done using little Wharfedale bookshelf speakers and a cheap 'n' nasty Ariston amp. I'm only going test my main system when I'm sure I know what I'm doing!

The curve has been smoothed.

Tenson · Feb 28, 2015

Is this Arta?

I'd use the impulse measurement option with a feedback channel (dual channel measurement mode). Then use periodic pink noise.

I'll make a small video.

mjp200581 · Feb 28, 2015

Is this Arta?
Click to expand...

No, it's REW

I'd use the impulse measurement option with a feedback channel (dual channel measurement mode). Then use periodic pink noise.
Click to expand...

I hope that's less complicated than it sounds!

Tenson · Feb 28, 2015

I've made a video showing how I do room measurements with ARTA.

I've got the mic plugged into channel 1. Then also a feedback channel from output 1 to channel 2. I used the headphone output which is a duplicate of output channels 1&2 to feed my system.

The feedback channel allows the software to subtract any anomalies that are part of the soundcard such as noise and frequency response.

To be honest though you don't need to use the feedback channel just for room measurements. Single channel mode would work the same just with 'dual channel mode' unticked.

Do not be surprised by some HF roll-off for listening position measurements, it is down to the directionality of the tweeters and microphone and room absorption.

Here is my video:

.

mjp200581 · Mar 1, 2015

Thanks, that's extremely helpful!

I tried to replicate the measurements as shown on the video and this is what I got.

Dual (stereo):

And Single:

Apologies for the lousy photos, I couldn't figure out how to take a screenshot with ARTA.

When doing the dual measurements I get quite a different looking plot to the one shown in your video. Your plot starts abruptly with a big spike at c10ms and you selected a gate from just before this. When I do it I get a plot which seems to start immediately and looks like this: