Recent content by Sliderule

I agree about the loopback response being flat. Motu specs it as +0dB, -.01dB 20Hz to 20KHz. The phase response is what is causing the high frequency rolloff in my speaker measurements. FWIW I tested everything including multiple computers, Motu's, cables, ASIO vrs Java, - you name it and I...

Yes, I am using the Behringer ECM800 which calibrated by Cross-Spectrum and loaded into REW. I have been using REW for over 12 years and made many hundreds of measurement and never had an issue until I got the Motu M2.

Thanx for your response. I have spent the last 8 months trying to find out why my very expensive speakers had a huge roll-off above 10KHz. I have tested everything with multiples - computers, audio cards, cables, you name it. The frequency response dies after 10KHz. No matter what test...

I have been having some high frequency measurement issues (excessive rolloff). I have been using a Motu 2 for audio interface. I have attached a couple off screenshots. Screenshot 71 is my old mobile Pre audio card. The phase is linear to nearly 22KHz. Screenshot 69 is my Motu 2. The...

I would like to use REW to measure the linearity of the micrphone input of my Motu M2 USB audio interface. I did a bench setup using a HP 34401A multimeter to measure frequency and amplitude. Tek 465B scope and HP 3312A function generator. I am using an xlr to bnc adaptor to input. I...

I just ran some tests with the Motu 2 1. swapping calibrated mic's. 2. Swapping XLR cables 3. Swapping speakers. The problem is basically in the Motu M2 mic input. Not very happy camper.

wow, the RTA-2 was introduced in 1978. I downloaded the manual and found there was no way to calibrate the RTA-2. What I did suggest to the user was to connect the pink nosie output to the mic input and monitor the response. it is an easy tool for production people to monitor quality(?).

I have conlicting results with two measurement systems. I have multiiple measurements of a panel speaker made with REW and Moto M2 audio interface with an ECM8000 calibrated mic. The speakers measured show a rapid drop-off above 12KHz. The attached screen shot (63) shows the drop-off...

I don't think REW supports simultaneous multichannel measurements.

Thx for your input. As it rules out amplifier/signal chain variation it leaves the size of the speaker/transducer size as the main variable. The new speaker has at least 16 times the radiating area of the of the RTR tweeters that measured flat. The speaker has 7 vertical columns segmented in...

Hi John, Thx for the quick response. I have an amplifier with none/minimal group delay that measures high frequency speaker signals with no problems. Measuring the the new speaker with a sound level meter using the signal generator shows the speaker is not drastically rolling off the high...

I recently bought some new speakers and decided to run frequency response plots on them. The plots were showing an 18-22dB level drop off from 11KHz to 20KHz. (See screenshot) I had run plots full range with my previous 4-way speakers over the past 12 years with with no high frequency rolloff...

White making frequency response measurements of my speakers I noticed that the high frequency rolloff was excessive. It was 16-25dB down from 1oKHz to 20KHz. The calibration frd was working fine with my ancient Mobile Pre audio interface (which finally died) and REW which I confirmed by...

I had imaging issues with poor left speaker imaging. While going thru my REW files I noted that the right speaker was 4dB higher than the left speaker. Although I had set both amplifier gains to full apparently the left channel had been moved. After resetting it I them measured near field...

I am having problems with ASC support responding. Vince can you send me a text and I will respond within 30 minutes (doing yard work) -david