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Kali Audio MV-BT Review (Balanced Bluetooth Receiver)

abdo123

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I don’t think they concluded to use SBC on Android, they concluded that it was better than AAC on Android, and also noted that SBC was capable of decent quality, but where quite limited on most (or all) implementations. In real world, with Android, AptX sounds, subjectively, but significantly better than SBC. Of course if it’s to be transmitted to cheap tiny BT battery powered speakers, the difference don’t matter. AAC indeed should only be used with Apple device. AAC is quite good there.

Edit: I see Amir concluded differently but something seems wrong with this product.


AptX has repeatedly measured worse than LDAC and AAC.
 

PeteL

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AptX has repeatedly measured worse than LDAC and AAC.
I don’t know LDAC, I didn’t say it measures or sound better than AAC. I talked about SBC, but as stated in different articles linked on this thread. The implementation on SBC varies, so it’s safe to assume the experience and measurment will vary depending on the source device. I assume all measurments on this site is from the source
 
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abdo123

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I don’t know LDAC, I didn’t say it measures or sound better than AAC. I talked about SBC, but as stated in different articles linked on this thread. The implementation on SBC varies, so it’s safe to assume the experience and measurment will vary depending on the source device. I assume all measurments on this site is from the source

Every once in a while Amir does one of those Bluetooth measurements. From what i’ve seen AptX is always performing poorly, on several devices.

I don’t know what you mean by implementations, the Bluetooth chips on these devices are almost always the same. If you mean the encoding device, then still a test tone should be very easy to encode.
 

edechamps

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It's up to the OS developer to define bitrate-limiting SBC parameters and virtually all the time, those are set very low.

Using Windows as a source device, I can easily achieve the highest possible SBC bitrate (bitpool 53) streaming to a Bose QC35 or an Anker SoundCore Liberty Air, and it sounds great. However, some Bluetooth sinks don't support high SBC bitrate - for example Samsung Galaxy Buds don't go higher than bitpool 37, which results in highly objectionable compression artefacts in most content.

Bluetooth audio is a complete mess. It's a jungle of codecs with various incompatibilities between source and sink devices, it's unreliable, and it's extremely hard to understand what's actually going on because most source and sink devices do not provide any way to diagnose the details of the audio stream (e.g. codec used, bitrate, packet loss events), making troubleshooting very painful. I would not use it for anything serious.
 

respice finem

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Possibly silly thought from a non-engineer, but I don't understand why the standard for wireless audio transmission is BT and not simply Wi-Fi, energy consumption?
 

PeteL

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Every once in a while Amir does one of those Bluetooth measurements. From what i’ve seen AptX is always performing poorly, on several devices.

I don’t know what you mean by implementations, the Bluetooth chips on these devices are almost always the same. If you mean the encoding device, then still a test tone should be very easy to encode.
I’m saying that bluetooth transmission takes 2 devices. the measurment amir does apply to both. Yes AptX may perform poorly, but At least in some cases SBC perform worst that’s all, and note that I edited my comment, I’ve measured and made extensive listening tests with aptX HD but not so much with AptX
 

Steve Dallas

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Music1969

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Sound effects were hilarious @amirm

The dancing noise with AAC comment too - I was expecting X-Factor spooky music.
 

YSC

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Hi Amirm, did you test it's channel balance throughout the volume pot if that's hardware volume?
 

HionHiFi

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Nice review. I’d buy v2 if this unit if they were to improve the performance. Functionality wise it’s on point. The execution however unfortunately doesn’t do it justice.
I recently picked up a $79 Bluetooth module to use with my electronic drum set. It’s an “audiophile” type of receiver/transmitter. You can find it on Amazon.

1Mii Bluetooth 5.0 Transmitter Receiver for Home Stereo TV, HiFi Wireless Audio Adapter with Audiophile ESS DAC & AptX HD/Low Latency, Long Range, Optical RCA AUX 3.5mm Outputs/Inputs
 

PeteL

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Nice review. I’d buy v2 if this unit if they were to improve the performance. Functionality wise it’s on point. The execution however unfortunately doesn’t do it justice.
I recently picked up a $79 Bluetooth module to use with my electronic drum set. It’s an “audiophile” type of receiver/transmitter. You can find it on Amazon.

1Mii Bluetooth 5.0 Transmitter Receiver for Home Stereo TV, HiFi Wireless Audio Adapter with Audiophile ESS DAC & AptX HD/Low Latency, Long Range, Optical RCA AUX 3.5mm Outputs/Inputs
In the end I find that looking at a few of them, they might be all the same, “audiophile” tagged or not. It’s the Qualcomm reference design, feeding trouh IIS a choice of mid tier DAC at the output. with or without an optical digital out. It’s basic stuff but we seem to be seeing here with the balanced one a problematic design. To me, assuming the analog output is to be used, that would be the differentiator. THey are all around 80$. I’d pay maybe 40 more for care given to get a real 2V, and noise optimized, a complete specification sheet that show it’s been measured, not just trow around of a bunch of google friendly keywords like “ess sabre dac”, then, maybe with this type of documentation available we maybe able to assess the performance a bit better. I’m not being snarky here and trying to tell you your product is a dud, It may be good it just seams that this class of product is marketed as a commodity, and we are not really expected to worry about specs. So the audiophile thing is marketing.
 

Propheticus

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Possibly silly thought from a non-engineer, but I don't understand why the standard for wireless audio transmission is BT and not simply Wi-Fi, energy consumption?

That is a large part of it. More processing power needed = size + power consumption. There's other low power wireless technologies, but bandwidth is very limited.
Another important aspect is (standardised) inter-device operability without the need for separate network infrastructure (access point/router). Devices like smartphones can act as an access point, but this means losing its own connection to the home's WiFi network and it consumes power.

There's low power WiFi (Wi-Fi HaLow/IEEE_802.11ah or the upcoming WiFi 6/IEEE_802.11ax) meant for connecting battery powered IoT devices, like sensors and doorbells. But that still relies on access points. Power saving in part happens due to Target Wake Timers, turning WiFi on and off periodically and polling/sending data in bursts. Continuous streaming of audio would defeat that or you'd need to use data buffering making it unfit for low-latency.
WISA could be a contender, power consumption is in the same ballpark as Bluetooth and is low latency. The WISA modules are still too big for portable applications though:

"Earbuds, headsets, and portable speakers aren’t in the mix yet, simply because the current shipping module that Summit Wireless Technologies, Inc. showed me isn’t small enough for those form factors, and its power consumption is still too high. The specified power requirements, however, are stated to be about the same as that of Bluetooth. So according to WiSA, those types of products remain a distinct possibility."
https://www.techhive.com/article/3378198/wisa-low-latency-wireless-multi-channel-audio-standard.html
 
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MediumRare

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@amirm, could you test one or a couple of our preferred Topping BT DACs and see what a (hopefully) good implementation is capable of?
 

GGroch

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.......it just seems that this class of product is marketed as a commodity, and we are not really expected to worry about specs. So the audiophile thing is marketing.

You might be right...but that is why more testing here would be so useful. I have owned a lot of Bluetooth transmitters/receivers and they have varied a lot in quality, that is, the quality varies even when they are using the same Bluetooth chipset and have the same codex. In addition to the chips, which are standardized, there are real differences in range, stability, ease of connection, and features that cannot be attributed to the chips alone.

I am most skeptical of Bluetooth devices by brands like Kali, who may offer one model to accompany their "real" products. There are companies like Avantree (U.S. based) and 1Mii that specialize in Bluetooth, and my guess is they would perform best. But, I'd like to see Amir test more of these because no one else really is.
 

infinitesymphony

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As a new company working to build their professional / prosumer audio brand reputation starting from an association with JBL, this is a disappointing and somewhat scary result for Kali. I guess it's sort of a niche product for people who want a one-and-done solution for phone > BT receiver w/digital volume control > balanced monitors, but the performance...
 

PeteL

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It's odd that it doesn't have a USB out, which would make it compatible with more of their DACs (e.g. D10s).
That would be really odd. and quite complex, and pricy. Do you know other products than cell phones or computers that have a USB output?
 
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