Articles, Reviews and Measurements of Audio Products
Hifiman Ananda Nano Headphone Review
This is a review, listening tests, equalization and detailed measurements of the Hifiman Ananda Nano headphone. It was kindly purchased by a member for testing and costs US $499.
The Nano looks attractive although the feel is not that of luxury. It is a bit light. The forward part of the pad is quite a bit thinner and I had a bit of difficulty mounting it on my GRAS 45CA test fixture. The suspension headband is not adjustable but was comfortable enough for me. But again, causes some difficulty in measuring as it would not let the cups go lower.
Hifiman Ananda Nano Headphone Measurements
Let's start with our usual headphone frequency response tests and comparison with our desired target:
As noted, we have good compliance over an important range of frequencies. Above and below we have some deficiencies. There is quite a bit of wiggliness in the response. Relative response shows variations that...
The Nano looks attractive although the feel is not that of luxury. It is a bit light. The forward part of the pad is quite a bit thinner and I had a bit of difficulty mounting it on my GRAS 45CA test fixture. The suspension headband is not adjustable but was comfortable enough for me. But again, causes some difficulty in measuring as it would not let the cups go lower.
Hifiman Ananda Nano Headphone Measurements
Let's start with our usual headphone frequency response tests and comparison with our desired target:
As noted, we have good compliance over an important range of frequencies. Above and below we have some deficiencies. There is quite a bit of wiggliness in the response. Relative response shows variations that...
Fosi Audio V3 Mono Amplifier Review
This is a review and detailed measurements of the Fosi Audio V3 Mono class D amplifier. It was sent to me by the company. The price with the power supply I tested is US $139.99.
I must say the concept of a "monoblock" amplifier in such a small size runs foul of any expectation a longtime audiophile would have! But monblock it is even though it is a very small block. Controls are on/off/trigger audio and selection of XLR vs RCA inputs -- just like the big boys!
I am not showing the sides of the amp but there are very large holes with attractive orange color grid showing through. Nice. Back panel is again a bit of a shock to the system seeing XLR input:
The power supply as noted, is quite beefy with 48 volts at 5 amps on tap (240 watts). The amplifier is stated to...
I must say the concept of a "monoblock" amplifier in such a small size runs foul of any expectation a longtime audiophile would have! But monblock it is even though it is a very small block. Controls are on/off/trigger audio and selection of XLR vs RCA inputs -- just like the big boys!
I am not showing the sides of the amp but there are very large holes with attractive orange color grid showing through. Nice. Back panel is again a bit of a shock to the system seeing XLR input:The power supply as noted, is quite beefy with 48 volts at 5 amps on tap (240 watts). The amplifier is stated to...
Measuring Some Vintage Speakers
I thought this group would be interested in how some vintage speakers compare to each other under the same measuring conditions. I have a collection of vintage speakers and simple measuring setup. No Klippel machine for me! I measured the frequency response of each speaker with:
Here's the setup.
Here's the collection.
Here's all the graphs together. I'll post each frequency response curve separately.
- Laptop PC with Creative soundcard
- REW software
- Dayton UMM-6 microphone, with calibration loaded in REW
- Random Denon amplifier
- 1 meter distance, on the tweeter axis
- 20x24 garage with hard floor and 9.5' ceiling
- Small amount of damping on the floor
Here's the setup.
Here's the collection.
Here's all the graphs together. I'll post each frequency response curve separately.
Ascend Sierra-1 V2 Speaker Review
This is a review, listening tests, EQ and detailed measurements of the Ascend Acoustics Sierra-1 V2 bookshelf speaker. It is on kind loan from a member and costs US $998 for a pair ($948 on sale).
The finish is nice enough. The cabinet feels quite heavy for its size and especially in the front indicating beefy low frequency woofer. I do wish the grill was magnetic though rather than plastic tabs that are more delicate. I did my testing without it and would have been nice to not see those holes.
Back panel put a big smile on my face:
See the "NFS Optimized" tag! A couple of years ago I tested an Ascend speaker and found the performance wanting. Needless to say, the company owner/designer, Dave, was not happy. But...
The finish is nice enough. The cabinet feels quite heavy for its size and especially in the front indicating beefy low frequency woofer. I do wish the grill was magnetic though rather than plastic tabs that are more delicate. I did my testing without it and would have been nice to not see those holes.
Back panel put a big smile on my face:
See the "NFS Optimized" tag! A couple of years ago I tested an Ascend speaker and found the performance wanting. Needless to say, the company owner/designer, Dave, was not happy. But...
KEF R11 Meta Tower Speaker Review
This is a review, listening tests, EQ and detailed measurements of the KEF R11 Meta floorstanding speaker. It was sent to me by the company and costs US $3250 each.
The R11 Meta is gorgeous looking with high gloss finish and cabinet that has been shrunk as much as possible to basically hug the drivers. The coax center driver is the star of the show carrying most of the audible band from 200 Hz up (see measurement below). I was impressed with the engineering that went into binding terminal of all things:
With a turn of a knob, you connect the bass to the coaxial and vice versa! No jumpers here. Even the cardboard that the speaker came in has clever features like plastic that you pinch and it releases the sides of the box so you can get it out easier. First class...
The R11 Meta is gorgeous looking with high gloss finish and cabinet that has been shrunk as much as possible to basically hug the drivers. The coax center driver is the star of the show carrying most of the audible band from 200 Hz up (see measurement below). I was impressed with the engineering that went into binding terminal of all things:
With a turn of a knob, you connect the bass to the coaxial and vice versa! No jumpers here. Even the cardboard that the speaker came in has clever features like plastic that you pinch and it releases the sides of the box so you can get it out easier. First class...
Chapeau ou non? (PCM5102MK non-HAT DAC review)
Hi, Guys!
Use of French in the title is not arbitrary.
Chapeau ou non? literally translates to: “Hat or not?”. However, chapeau is also frequently used as expression of admiration, approval, respect and is short for chapeau bas (literally “hat down”) in a same sense as in English “I take my hat off”, “well done” or just doing the hat tip gesture. (https://www.oed.com/dictionary/chapeau_n?tl=true)
If Chapeau ou non? in common language translates to: “Well done or not?”, why bother with French?
In this review I will take a closer look to a small DAC board that has printed PCM5102MK on it and I will refer to it as that (+ v2.0). As name suggests, it uses TI PCM5102A DAC chip. Usually, it can be found in entry-level Raspberry Pi’s (RPIs) Hardware-Attached-on-Top (or HAT for short) DAC designs.
However, PCM5102MK reviewed here is not a HAT.
I hope by now you start to appreciate...
Down4Sound JP95 Car Amplifier Review
This is a review and detailed measurements of the Down4Sound JP95 4/1 channel car audio amplifier. It is on kind loan from a member and is on sale for $250.
This is a massive amplifier with incredibly beefy terminals and many features. I am shocked that it sells for just $250.
I configured the amplifier for 4 channel use and defeated all the filters I could. Alas, it seems the main channels always have a high pass with a minimum of 20 Hz (see measurements). Testing is focused on Channels 1 and 2.
Power was provided by a custom Lithium back with capacity of 300 amp hour and peak current above that. Lab supply was used to augment the battery bank as needed (I checked and it had little impact on measurements).
Down4Sound JP95 Amplifier Measurements
As usual, we start with our 5 watts test into 4 ohm load:
Distortion is actually kind of reasonable at -92 dB. It is the noise that is the problem...
This is a massive amplifier with incredibly beefy terminals and many features. I am shocked that it sells for just $250.
I configured the amplifier for 4 channel use and defeated all the filters I could. Alas, it seems the main channels always have a high pass with a minimum of 20 Hz (see measurements). Testing is focused on Channels 1 and 2.
Power was provided by a custom Lithium back with capacity of 300 amp hour and peak current above that. Lab supply was used to augment the battery bank as needed (I checked and it had little impact on measurements).
Down4Sound JP95 Amplifier Measurements
As usual, we start with our 5 watts test into 4 ohm load:
Distortion is actually kind of reasonable at -92 dB. It is the noise that is the problem...
Akitika GT-108 Stereo Amplifier Kit Review
This is a review and detailed measurements of the Akitika stereo amplifier kit. It was purchased preassembled by a member and kindly sent to me.
As you see, the case is rather simple but for a kit, it is not bad. That large power switch is reassuring, giving you the feeling that it could switch a lot of "gigawatts."
We can excuse the lack of serial number.
The unit is rather heavy which I imagine is due to power transformer. Company notes says the kit originally was based on a TI IC but that was hard to get so they switched to a discrete design. Manual is very comprehensive. There are a ton of parts in there so you better have lots of patience to assemble it!
Akitika GT-108 Amplifier Measurements
As usual we start with our dashboard:
[ATTACH type="full" alt="Akitika GT-108...
As you see, the case is rather simple but for a kit, it is not bad. That large power switch is reassuring, giving you the feeling that it could switch a lot of "gigawatts."
We can excuse the lack of serial number.
The unit is rather heavy which I imagine is due to power transformer. Company notes says the kit originally was based on a TI IC but that was hard to get so they switched to a discrete design. Manual is very comprehensive. There are a ton of parts in there so you better have lots of patience to assemble it!
Akitika GT-108 Amplifier Measurements
As usual we start with our dashboard:
[ATTACH type="full" alt="Akitika GT-108...
How good is bad? (Raspberry Pi 4B headphone output DAC review)
Hi, Guys!
A short intro:
I have been following ASR for last 4 years, since friend of mine showed this forum and somewhat initiated my journey in all-things-related-to-audio. 1 month ago, I decided to buy TOPPING E2X2 audio interface due to its quite good ADC (up to 110 SINAD) to make some basic, practical measurements. (More info on E2X2: https://www.audiosciencereview.com/...ds/topping-e2x2-audio-interface-review.49127/)
First “gadget” I decided to test is built-in 3.5 mm (headphone) output of Raspberry Pi (RPI) 4B when used as a DAC.
If you are rolling your eyes already, hear me out.
My motivation is simple – I couldn’t find detailed measurements of it. Since RPI streamers + DACs are still quite popular, in any audio forum a natural suggestion to newcomers planning such system will be to use dedicated I2S (usually hat) DAC or USB DAC, because audio from RPI headphone output is bad...
JBL Conceal C83 Invisible Speaker Review
This is a review and detailed measurements of the JBL Conceal C83 "invisible" speaker. It is on kind loan from a member and costs US $1,100.
As the name indicates, this is basically a flat surface that you cut out in the wall and "tape and mud" the edges. Once painted, it can be made to look just like the rest of the wall and hence "disappear." In the inset, I am showing the stock photo from JBL showing a center woofer and dual higher frequency transducers. All work to excite the front panel.
These type of speakers are high desirable in higher-end stereo, ambient and home theater applications where you want a completely hidden audio system. They require careful project management with the builder/trades to make sure accommodations are made for them during the construction phase of the house. It is highly advised to use appropriate limiter/protections in the amplifier driving...
As the name indicates, this is basically a flat surface that you cut out in the wall and "tape and mud" the edges. Once painted, it can be made to look just like the rest of the wall and hence "disappear." In the inset, I am showing the stock photo from JBL showing a center woofer and dual higher frequency transducers. All work to excite the front panel.
These type of speakers are high desirable in higher-end stereo, ambient and home theater applications where you want a completely hidden audio system. They require careful project management with the builder/trades to make sure accommodations are made for them during the construction phase of the house. It is highly advised to use appropriate limiter/protections in the amplifier driving...