Articles, Reviews and Measurements of Audio Products

This is a review, detailed measurements and listening tests of Sonic Lamb wired/wireless noise cancelling (?) headphone with built-in "subwoofer." It is a kick-starter type of product which a member kindly drop shipped to me after waiting a year. It is currently on sale for $US 239.

As you see, the style is "applesque" white with very supple but somewhat small ear pads. I got a kick out of the box packaging:

It felt like you were opening a bird's nest!

So while first impressions were positive, it kind of went downhill from there. No manual was included and I could not find one online. An app is available but when I installed it on my Samsung S23 Ultra, its mandatory registration was buggy. I got past that only to be greeted with a gray, blank screen. I believe it allows custom EQ developing using it and if so, that could be great.

There is no charge indication on the unit. I plugged in a USB-C cable and...

This is a review, detailed measurements, listening tests and equalization of Sennheiser HD 490 Pro open back headphone. It was kindly drop shipped to me and costs US $399.

The headphone is ultra light courtesy of plastic composite that manage to also feel extremely solid. The included cord feels like premium silicone material. It even has a little coil next to the connection to the headphone as to offer some slack in case of hard pull. Overall there the look and feel matches the "Pro" designation at its price point.

A set of velour pads came installed on the headphone. Another set of thinner, gray tweed pad is also included. The box nicely shows the frequency response of each but sadly, misses to label them anywhere. I had to measure them to figure out that the velour pad is the "producer" one with more bass and the tweed, "Mixing."

If you are not familiar with my headphone...

This is a review and detailed measurements of the Mofi Studiophono MM/MC phono preamplifier. It is on kind loan from a member and costs US $349.

The packaging has a retro feel to it and I don't mean that as a positive. When a device has the word "studio" in it, I expect solid metal enclosure, not plastic. There is selectable subsonic filtering but oddly, you have to press the button in to defeat it! There is also a mono switch which I understand to be very useful for playing vintage mono LPs.

The thing I really dislike about the StudioPhono is the seemingly endless number of DIP switches underneath:

Not only the plurality is a problem, but so is the stiff switches. I was worried I was going to break the tiny tabs in trying to move them. Worse yet, you can't...

As most of you probably know, I reviewed the Tekton M-Lore speaker back in October of last year. Company recently complained that my measurements were in error due to woofer being listening axis and not the tweeter (speaker manual disputes this). And that without the feet, the holes that house them go all the way through causing additional leakage. Owner/designer @Eric Alexander has implied that these make a big difference. So much so that he was planning to litigate against me back in March of this year:

Company has failed to this date to provide any measurements of its own, backing that I have "damaged this loudspeakers reputation." Instead, it has repeatedly demanded that I either delete the review or lately, to remeasure it.

I had responded to him that changing the...

This is a review and detailed measurements of the Topping D50 III balanced stereo DAC with support for parametric equalization. It was sent to me by the company and costs US $229.

Sorry for the quality of the picture/display. It is quite dim compared to my photography light and when I tried to brighten it, it brought out the chromatic aberrations in my lens. While tiny, it is very sharp and clear white color. Back panel shows the innovation of using 1/4 jacks to bring balanced output in such a small enclosure:

The remote is bluetooth so you don't have issues with how you point it. If you are using it as a USB DAC, you can plug that cable to the one labeled USB-C and be good to go. That is how I tested it using the hub in my monitor as I do with all DAC tests. There is auxiliary power input as well if you are not using USB but the S/PDIF options. I *think* you can also use that for higher quality power if your...

Here is a review and measurements of the recent
Topping D50 III DAC



The D50 III is a small DAC.
From above, it looks like a square of approx 13x13cm .
I purchased it new from Audiophonics for around 230€ (pre-release discount included).
This is one of the cheapest DACs with balanced and unbalanced outputs, LDAC Bluetooth, SPDIF inputs, level control and remote.

It comes with usual connectors: USB, Optical and coaxial (RCA) SPDIF inputs, and of course a pair of unbalanced analog RCA outputs.
On top of that, it adds a pair of TRS balanced outputs.


In the box, there is also a (bluetooth + IR) BC-15A remote, but NO power supply.
This for sure helped to lower the price.
The DAC may be powered from any USB source, so just a USB power cable is provided.
It worked for me from any USB power source I had at hand, including a...

As many of you I am sure have followed, both Erin and I were hit with legal threats from a company post our reviews. Given the unfairness of the situation, many of you came to our defenses and provided incredible level of support both financially and in many other ways such as legal and business advice. While I have always had this risk in mind and had prepared for it in some ways, it was still major source of pain for me and especially for Erin. While this crisis is not fully over, I think we need to look to the future to see how we could be better prepared for it.

I propose that a new lightweight organization be created that I call Right to Fair Review (RFA) Association (RFAA). The things we need to cover in there are:

1. Education. What are the legal issues involved in writing independent reviews of products? What is the law exactly? What are the best practices for writing/creating video reviews as to lower chances of litigation? What to do when threat of litigation or...

The Pacific Northwest Section of the Audio Engineering Society has presented meetings with jj that I and many of us really like and appreciate. The Chair of that group, Dan Mortensen, is trying to be nominated to be President of the parent AES organization, and needs 100 nominations from full voting Members, or from Associate members who want to upgrade their memberships in an easy procedure, in order to reach the ballot.

I have nominated him already, and encourage any of you who are willing to do so to read the document at this link:


I really like the work Dan has done to enable remote attendance using Zoom and such...

This is a review, listening tests, EQ, and detailed measurements of the Revel F206 Floor-standing speaker. It is on kind loan from a member (new) and costs US $1347.50 each.

Please excuse the mobile phone picture quality and plastics that are still on the speaker. I try to keep products as fresh as possible. The port is in front and not much in the back other than binding posts.

NOTE: Our company, Madrona Digital which is in the business of custom system integration is not in retail business but we are a dealer for Harman products including Revel. If I am not mistaken, the owner actually purchased this speaker from us. My measurements are standardized and no changes where made for testing of this speaker but feel free to read whatever level of bias you like in my subjective comments.

If you are not familiar with my speaker tests, please watch this video first...

I don't know how many of you have been reading the Tekton review thread. But it seems that the company designer/owner has threatened Erin, forcing him to take down his video and written review of one of his speakers. As we all know, Erin's core contributions are measurements of the speaker and what he speaks of, is his subjective opinion. Neither of these is cause for threats of lawsuit and intimidation to take down a review with nary an attempt by the company to show what is in error. The right of a product owner to send what he has bought for testing and publication of the same is one of the most cherished things in my view. I hate to see Erin cave in just because he doesn't have the money to defend his work and injure consumer's rights in the process.

So what you all think about creating a fund to help him?

If you are in favor, someone needs to help setup the fund and let Erin know.

Edit: this is what we are dealing with...