Articles, Reviews and Measurements of Audio Products

This is a review and detailed measurements of the Paradigm Monitor SE Atom bookshelf speaker. It was kindly sent to me by a member for testing. It costs US $239 from Amazon including shipping for a pair.

I have to say, the Atom looks better than its price indicates:



Look at the nice grill over the tweeter and curvy smooth waveguide. Even the woofer seems like a step up from bargain basement with inverted dust cap and such.

The back naturally looks plain:



In case you are not familiar with Paradigm, they are a Canadian speaker company and a spin off of the research at NRC where Dr. Toole and Sean Olive worked. So similar pedigree. How well they follow that science is what we are going to examine here.

Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement...

This is a review of the Purifi SPK5 reference speaker design for their PTT6.5W04-01A 6.5 Inch Woofer. It was built and sent to me by the company, Celuaris (member @sgoldwin). The unit was shipped from UK and did not travel well. Just about everything that could come loose, did come loose. I had to take the back apart and reconnect everything and solder a few components in the Purifi crossover board. Final product from the company will not have these issues. Still, I think we can get a lot of valuable data from the design as is.

Celuaris has built the speaker to Purifi spec and visually it looks to be so:



The backside is butchered up by me opening it back together (screws were very stiff resulting in me stripping a bunch ).



The port is "S" shaped inside. There was barely enough room for it inside and since it was not glued together, it may not be in the optimal position as designed.

The...

This is a review and detailed measurements of the CEntrance Hifi-M8 V2 portable headphone amplifier and USB DAC plus Bluetooth. It was kindly sent to me a member who waited over a year for it to ship! The Hifi-M8 V2 costs US $750. Yes, popcorn blew out of my nose too when I saw that price.

The unit strives for a pro/field recorder look:


I was quite surprised that the slide switches for gain and such are completely recessed and cannot be changed without a tool. I used a screwdriver but some paper clip looking thing comes with the unit for that purpose. Why, oh why? I get that you don't want that switch to change while in your pocket but there are plenty of switches that are flush mounted yet you don't need a tool to change them. And why protect the gain switch when the volume control can change easily with a brush of hand?

The side that you see is the low power output which I did not test. The other side is the high power one...

This is a review and detailed measurements of the Neumann KH 310A active monitor (speaker). It was kindly sent to me by the company for testing. I see it discounted to US $2,200 (each) as of this writing.

This is one dense and heavy 3-way speaker:



I was relieved to find "rack mount" ears to grab onto for lifting it:



Nice to see big heatsinks in the back indicating good amount of power on tap. Testing was performed with all the switches as you see.

What you don't see is a port.

Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field")...

This is a review and detailed audio measurements of the 9th generation Amazon Fire 7 headphone capability. It was kindly purchased new and dropped ship to me months and months ago! I see it going for US $50 right now but the owner paid just $30 for it! That is a remarkable price for a full function tablet. If it has good audio performance, it will be a great alternative to digital audio players (DAPs).

This is relative small tablet at 7 inch but then again, much larger than any DAP:



Aspect of price subsidy is abundant in constant nagging it does to sign up for various Amazon services. Even though we use Amazon shopping everyday and I don't have an ill opinion of the company, even I was annoyed with so much pushing. They slow down a machine that is already rather slow to operate.

My favorite media player -- Roon -- complained that resolution was too low and wanted to run full screen which I let it. There were a few second pauses at times trying...

This is a review and detailed measurements of the Universal Audio Apollo X16 Interface (ADC, DAC and DSP). It was kindly sent to me by the company for testing and costs US $3,499. The X16 is the longest requested interface for us to measure going back to when I had barely started measuring audio electronics. Interest was driven by seemingly impossible distortion and noise specifications. So it is very fortuitous that we finally get to test it.

The X16 is designed for rack mounting:



The only computer interface is Thunderbolt ()TB). It was hell getting TB capability on my PC motherboard. Once there, I had to buy a cable which at $40 (from Apple) for a 2.5 foot version, was outrageous. Then again the interface is running at ultra high-speed with very low latency so the passive cables are short by definition. This made it hard for me to see the display on the unit so I have no feedback on it. However, I did use the extensive software...

This is a review and detailed measurements of the Boston Acoustics A 25 bookshelf speaker. I purchased these a while back at a discount. Seems that they were originally released back in 2011 for US $300 a pair. At the time I purchased them the price had dropped to US $180 a pair. There were taxes and shipping costs added to the price. After discount, my net cost was $155.

The fit and finish of the speaker belies its very low price:



As you see there is some kind of faux leather surrounding the front baffle. Same is used underneath which is useful in keeping the speaker planted. Sides are gloss which gives the speaker fair bit of class. The cabinet feels dense, solid and heavy for its size.

Back panel shows nice provisions for hanging the unit and same leatherette finish:



Hard to imagine this speaker is being sold for so little. Externally anyways....

Measurements that you are about to see were performed using...

This is a review and detailed measurements of the multifunction Minidsp SHD Power amplifier with Dirac Room EQ and general signal processing. It was kindly sent to me by a member and costs US $1499 including a measurement microphone.

The SHD Power has a muscular look and feel to it:



I like the large display and size of the big knob. Then again, for a right handed person I like to see the knob on the right, not left! Sensitivity of the rotary encoder is good for volume changes but not for selection of inputs. It is not predictable how much you need to turn it to change inputs. It also has many functions overloaded into its single click making it hard to use. I understand a remote comes with but I did not have it so don't know to what extent it remedies these issues.

The back panel shows unique set of inputs and outputs;


As you see from the dual XLR outputs, the SHD Power supports four (4) channels of processing and...

This is a review and detailed measurements of the Dynaudio Excite X14 bookshelf speaker. It was kindly sent in by a member for review. It came out in 2014 and has been discontinued. It cost US $1,500 then. I see used ones at almost that price.

While somewhat plain due to black finish, there is still some style in this Danish speaker:



The cabinet feels dense and there is good bit of weight to the X14. Here is the back panel:



Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise...

This is a review and detailed measurements of the multifunction Loxjie A30 power (speaker and headphone) amplifier with integrated USB DAC and Bluetooth input. It was kindly sent to me by a member and costs US $159 plus $7 shipping on Amazon.

The A30 sports a high resolution and high contrast LCD display which I liked:



I wish that they would highlight the volume in big letters though rather than the input:


A customized remote control comes with as well as a rather massive "laptop" power supply:



The A30 was nice to use and look at.

The A30 is based on Infineon MERUS™ MA12070P Digital filter-less Class-D Audio Amplifier which is a departure from many other desktop amplifiers we have tested. So it will be interesting to see how it performs.

Loxjie A30 Measurements: Amplifier
Because we have both analog inputs and digital, we need to look at the performance of both. Here is analog...

This is a review and detailed measurements of the SMSL SH-9 THX headphone amplifier. Product was just released and will be available shortly. The sample I have was kindly sent to me by SHENZHENAUDIO and costs US $290.

The market for high performance headphone amplifiers has become quite crowded but SH-9 sets itself apart with a gorgeous digital display and volume control:



A 256-step attenuator using resistor ladder implements volume control which should result in perfect channel matching (see measurement later). Typical of these systems, the volume control changes a bit slow compared to analog counterparts. The chatter of relays controlling which resistors are being used is rather quiet which is a relief.

The back side shows that there is only input and no pass through/pre-amp mode...

This is a review and detailed measurements of the Carmody S2000 DIY speaker as built by our own member, @Rick Sykora. He has nicely documented his build of S2000 speaker from the kit. According to him the cost for a pair of these with everything included, sans labor to assemble is about US $244.

I like that the kit comes with Baltic Birch plywood which gives it a nice half-way finished look:



You could literally use it like this or finish it with a stain and top coat. I would personally use it as is.

And yes, these are very small speakers.

The back is not exciting other than showing the port:



The binding terminals Rick used are easy to turn since they are not inset in a cup like commercial speakers are.

Measurements that you are about to see were performed using the...

This is a review and detailed measurements of the Revel F328Be floor standing speaker. I purchased a single unit through our company (Madrona) with kind discount from Harman Sales (I asked for a review sample from the PR group but was told "don't call us, we will call you."). The retail cost of F328Be is US $8000 each or $16,000 for a pair. This makes it the most expensive speaker we have tested to date.

I chose the color black and I must say, this is one gorgeous speaker:



It comes in an exquisite finish with sparkles in it in the top panel:


Even the Beryllium tweeter exudes beautify (in the eye of an audiophile of course):



Here is a closer shot of the speaker itself:


As you see, there are three 8 inch woofers backed by two large ports in the back. There is then a mid-range and tweeter.

Measurements that you are about to see were performed using the...

This is a review and detailed measurements of the just announced Gustard X16 Balanced USB DAC with hardware decoding. It was kindly sent to me for testing by SHENZHENAUDIO. The X16 costs US $499.

The X16 is based on the new ESS ES9068AS DAC which has built-in hardware decoding of MQA bitstream. Until now, this was performed upstream of the DAC but now the functionality is core to the DAC chip itself.

The X16 has a solid feel to it but doesn't distinguish itself from other desktop DACs:



While a remote control is provided, navigation is easy enough using the rotary control and center button. I like the informative display but as with other Gustard products, I question showing the volume level in such tiny letters. It needs to be center and large with the sample rate shown small.

Back panel shows the usual connection including Bluetooth...

This is a review and detailed measurements of the Qudelix-5K USB DAC and balanced headphone amplifier with Bluetooth receiver. I purchased this myself but a member kindly donated one third of the cost. The Qudelix 5K costs US $110 on Amazon including shipping.

The Qudelix comes in a nice looking package with a belt clip:



Note that it has a rechargeable battery built-in so does a lot more than a standard headphone dongle. To wit, you can use it that way to listen using Bluetooth with wide range of codecs supported including LDAC (which I tested below).

"Balanced" output is provided for more power in addition to standard output via 3.5 mm jack:



On the side are easy to press buttons for volume control, Bluetooth and "VCR" controls (play, stop, etc.). Note that you have dual volume controls: the ones in the host and on the device. The latter have 0.5 dB increments which is very nice. The host volume control is way...

This is a review and detailed measurements of the Sabaj A1 desktop (small) amplifier. It was kindly sent to me by a member. Not sure if it is still in production but you can still find it for $60 or so. Main interest in testing this unit is the use of the TPA3118 class D amplifier which is used in all kinds of other devices including Genelec 8030c powered monitor!

For the price the enclosure is not half bad:



A little LED display shows the active input (there are two) and current volume level. As is typical, a laptop sized power supply provides the juice:



The unit runs cool. If you overtax it, it will reset and power back on at low output level.

Sabaj A1 Measurements
As usual we start with our 5 watt dashboard:



As you see I set the gain to 29 dB...

This is a review and detailed measurements of the Chord Huei phono stage/pre-amplifier. It was kindly sent to me by a member. The Huei costs US $1,495.

The Huei is one of the most exquisite and nicest implementation of the Chord design language:



The unit weighs a ton and feels like excellently machined and finished piece of desktop audio. The back is even prettier than the front:



The shiny RCA jacks look and feel like jewelry. And I love the inclusion of the balanced XLR output to help reduce impact of noise and hum that RCA connections bring.

Despite all of the above, the functional design of the Huei is a total fail! If you are familiar with Chord products you know that they use colored LEDs to communicate the status of some setting. That makes the device difficult to operate due to the need to then remember the color of the button meaning different things. Here, that design has been taken to level of...

This is a review and detailed measurements of the JBL 308P MKII 8-inch Monitor (powered speaker). I purchased this from a member a few months ago. New, they cost US $249.

The 3 series look the same for good or bad:



The large plastic waveguide is really in your face. Wish JBL would provide a matt version of it.

Back panel has the usual controls:



Drivers are powered using dual 56 watt class D amps. Crossover is stated at 1.8 kHz.

Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise...

This is a review and detailed measurements of the NAD M33 Streaming Player with Purifi Eigentakt Amplification. It is kindly sent for testing from a member and has a retail cost of US $4,999.

The NAD is part of their "Masters" series and has one of the best industrial designs of any audio gear I have seen:



It is both modern and luxurious. The touchscreen is not as fast and accurate as your phone or tablet but ages ahead of many other displays on audio gear. On the other hand, as I have noted before, I hate the touch power button on top which seemingly requires multiple touches to actually turn the unit off.

Notice the cool instrumentation panel telling you the internal temperatures. Then again the unit runs so cool that such monitor is not needed in practice.

The back panel shows decent connectivity although I was very disappointed to not see balanced XLR pre-out:



There is balanced input but why not output?

Dirac...

This is a review and detailed measurements of the Rega Fono MM MK3 phono stage. It was kindly sent to me by a member and costs US $395. Despite its relatively high price, it only supports Moving Magnet cartridges.

I was disappointed in the plastic case and overall look:
EDIT: case is actually aluminum.



Not much to see on the back either:


As you see, it uses an AC transformer which allows it to generate both positive and negative DC voltages it needs internally with ease. Because of this the power supply is not universal so if you are importing it, better make sure it is rated for your voltage or pick up your own 24 volt supply.

Rega Fono MM MK3 Measurements
As usual we start with our dashboard using 5 millivolt to simulate a moving magnet cartridge output:



SNIAD which is typically the relative sum of both distortion and noise tends to be noise limited in phono preamplifiers...