UMIK / REW, small space, ADSL810, HPM60

[HowlerMonkey]

These are my first measurements using the UMIK and REW in the mancave.
(~10' wide x 18' long, w/vaulted ceiling. Speakers are 32" from the side wall, 45" from the back wall, stands are (2) trash cans 11" tall each, mic is placed ~7ft away from the horizontal line between the speakers front baffles and 3ft above ground)

The purpose of these measurements:
1. Learn how to use the UMIK and REW
2. Take baseline measurements of ADS and HPMs to find best speaker location, stands height,
3. Evaluate problematic Fs, mainly bass treatments, acoustic treatment.
4. Eventually find ideal place for furniture, seating position etc.

First Impressions
* easy to use both Umik and REW
* higher noise floor level compared to SPL app. (Umik Noise Floor ~50db, phone app 30db.)
* provided calibration file seems acceptable for measurement comparison but might need a tweek for accurate SPL
* good repetitive results
* Loss of bass in the 200Hz range with both speakers ---> room problem

Plots are z weight, full range 20-20K sweep, loudness on phone app was ~70db

 

[HowlerMonkey]

setup when I recorded HPM60


setup when I recorded ADSL810


ADSL810 sound test

 

[canuckaudiog]

When you measured both sets, did you put them in the exact same location? Or did you measure them as they are sitting in your room now? It looks like you did not put them in the same place based on your measurements.

 

[HowlerMonkey]

When you measured both sets, did you put them in the exact same location? Or did you measure them as they are sitting in your room now? It looks like you did not put them in the same place based on your measurements.

yes the speakers where in the same pedestal position when I took the acoustic measurement. (plots)...I had the HPM on the pedestals first and recorded one plot...then I swapped the speakers, put the ADS on the pedestal and the HPM on the floor, and I recorded the other plot. (see pics on 2nd post for visual)

The video with the test song was just for fun and was recorded using a different microphone. (zoom H2n)

I think what you see on the acoustic plots are the different characteristics of each speaker, I am not expecting the speakers to perform the same way acoustically.

 

[canuckaudiog]

yes the speakers where in the same pedestal position when I took the acoustic measurement. (plots)...I had the HPM on the pedestals first and recorded one plot...then I swapped the speakers, put the ADS on the pedestal and the HPM on the floor, and I recorded the other plot. (see pics on 2nd post for visual)

The video with the test song was just for fun and was recorded using a different microphone. (zoom H2n)

I think what you see on the acoustic plots are the different characteristics of each speaker, I am not expecting the speakers to perform the same way acoustically.

More what I was getting at was the bass response being so wildly different. It could be the speaker, but I wonder if there's a phase change going on or something.

 

[HowlerMonkey]

More what I was getting at was the bass response being so wildly different. It could be the speaker, but I wonder if there's a phase change going on or something.

The green plot is from the ADSL810s (stock) which are known for having a bass bump...they use (2x) 8" woofers per speaker on separate chambers.

The red plot is from the modified HPMs and a crappy 10" woofer that will be on the chopping block soon.....the HPMs are using an active crossover with a 4th order linkwitz riley alignment to avoid phase shift and minimize lobing error.
The HPM sound nice and probably image better than the ADSL810 but the mids and bass of the ADS are more enjoyable...Still some work to do on both speakers.....and bass traps....etc...

 

[roger2]

Interesting and informative posts!

I have recently become interested in the UMIK/REW combination. From your posts, I am not clear on how you injected signal into the speakers. Did you use a test signal from a phone app into a DAC?

Was the test signal pink noise? In your first post you said "full range 20-20K sweep", which implies the test signal was not pink noise. Is REW able to process a signal of varying frequency? Or put another way, can REW process either pink noise or a signal sweep?

Have you done further testing?


@HowlerMonkey

 

[HowlerMonkey]

Interesting and informative posts!

I have recently become interested in the UMIK/REW combination. From your posts, I am not clear on how you injected signal into the speakers. Did you use a test signal from a phone app into a DAC?

Was the test signal pink noise? In your first post you said "full range 20-20K sweep", which implies the test signal was not pink noise. Is REW able to process a signal of varying frequency? Or put another way, can REW process either pink noise or a signal sweep?

Have you done further testing?


@HowlerMonkey

Hi
1. The signal is generated by the REW software. And I used my computer & DAC to send the signal to the preamp.
I was using the Phone app to measure SPL and compare it to the SPL reading of the UMIK...this was just for curiosity and comparison.

2. REW comes with a signal generator. I used the linear Sweep but Pink and white Noise and other options are also available. I was trying to compare 2 speakers systems with the same signal source.
https://www.roomeqwizard.com/help/help_en-GB/html/siggen.html

3. I am planning to do more testing soon because I changed some equipment and room furniture. And I want to measure the HPMs again before I let them go. I hope I can make it happen in the next couple of weeks.

Regards

 

[roger2]

Ahhh OK, thank you. I didn't know that REW has signal generators. It is amazing what can be done with a @ $100 mic and free software.


Another cool program that I found recently is Jeff Bagby's Baffle Diffraction and Boundary Simulator. It has been around for quite a while and plots from it show up in lots of forum threads (outside of AK especially). If you are not already aware of it you may want to check it out.
http://audio.claub.net/software/jbabgy/BDBS.html

 

[JoeESP9]

A Umik 1 mic is $75 direct from Mini DSP.