Plug & Play: Introducing the BTD 700

[zilax002]

Can anyone here speak to the performance of the BTD 600, specifically with regard to latency or PS5 compatibility (audio only).

Would love the 700 but I see the 600 are being offered as a promo for orders of Sennheiser's new open earbuds, which would be a great gift for my partner who doesn't like the occlusion of IEMs and has comfort issues with many earbuds.

 

[streetbeat]

The new app is available! Updated firmware from 3.0.5 to 3.0.11.
Here's a screenshot with Px7 S3 connected and playing media.

Also I can confirm we have proper LED colors now: pink-purple-ish for aptX Adaptive and proper purple for aptX Lossless. If you're unsure about which one you see, most likely it's the former

P.S. Poor latency in normal mode is still an issue, just in case.
P.P.S. Tried new app to check for updates for BTD 600 - waiting spinner appears and then app crashes after a few moments.

Can anyone here speak to the performance of the BTD 600, specifically with regard to latency or PS5 compatibility (audio only).

Would love the 700 but I see the 600 are being offered as a promo for orders of Sennheiser's new open earbuds, which would be a great gift for my partner who doesn't like the occlusion of IEMs and has comfort issues with many earbuds.

The latency in gaming mode is pretty much comparable to other dongles like Creative BT-W5 or FlooGoo FMA120 and virtually any headphones with aptX Adaptive on board. To my eyes it's something about 100ms, but for properly measured numbers (exluding other factors) you may refer to Rtings (for example, they measure Momentum 4 to have 65ms latency, which imo pretty much aligns with my observations). I can check PS5 compatibility a bit later.
Apologies, what written above is about BTD 700 actually...
BTD 600 provides only auto-optimized latency -- around 200ms, which is fine for less demanding content (at least for me), but substantially worse than dedicated game mode BTD 700 has.

 

[tonyt76]

The new app is available! Updated firmware from 3.0.5 to 3.0.11.
Here's a screenshot with Px7 S3 connected and playing media.



Also I can confirm we have proper LED colors now: pink-purple-ish for aptX Adaptive and proper purple for aptX Lossless. If you're unsure about which one you see, most likely it's the former

P.S. Poor latency in normal mode is still an issue, just in case.
P.P.S. Tried new app to check for updates for BTD 600 - waiting spinner appears and then app crashes after a few moments.


The latency in gaming mode is pretty much comparable to other dongles like Creative BT-W5 or FlooGoo FMA120 and virtually any headphones with aptX Adaptive on board. To my eyes it's something about 100ms. I can check PS5 compatibility a bit later.

Where can I download this?

Never mind, I had to refresh the webpage

 

[streetbeat]

Can anyone here speak to the performance of the BTD 600, specifically with regard to latency or PS5 compatibility (audio only).

Would love the 700 but I see the 600 are being offered as a promo for orders of Sennheiser's new open earbuds, which would be a great gift for my partner who doesn't like the occlusion of IEMs and has comfort issues with many earbuds.

And regarding PS5 compatibility... unfortunately, even if it's just a singleplayer game, BTD 600 + headphones work using HFP profile (call mode), which means bad sound quality. Not recommended at all. Works great with Steam Deck though

Edit: @zilax002 sorry, I just noticed a mistake in previous post, and updated it to answer actual question. All info combined, I guess BTD 600 isn't right option for your needs.

 

[zilax002]

And regarding PS5 compatibility... unfortunately, even if it's just a singleplayer game, BTD 600 + headphones work using HFP profile (call mode), which means bad sound quality. Not recommended at all. Works great with Steam Deck though

Edit: @zilax002 sorry, I just noticed a mistake in previous post, and updated it to answer actual question. All info combined, I guess BTD 600 isn't right option for your needs.

Thanks for the update! I'm looking at the Creative BT-W6 dongle now.

That seems to be a good option for $10 less and more mature firmware than the new BTD 700 ...

 

[aier8Robert]

Sennheiser’s BTD 700 is a tiny USB-C Bluetooth dongle that upgrades your audio with aptX Lossless, low latency, and multi-listener streaming.

 

[streetbeat]

Thanks for the update! I'm looking at the Creative BT-W6 dongle now.

That seems to be a good option for $10 less and more mature firmware than the new BTD 700 ...

BT-W6 would certainly be a great option in this case, especially if discounted like you said.

 

[rlw6534]

MTW4 uses some parts of LE Audio for Auracast functionality, but full implementation of LC3 is not quite finished yet.

Any timeline for LC3 support for MTW4? It's been a while waiting for it.

 

[ericpalonen]

Some rapid fire updates

So lots of promises. Console support, desktop app etc. Why you release a product that isn’t ready or at least give us a timeline

New firmware and desktop app are available now. The firmware update includes a PS5 mode (4x push to go back to A2DP over SBC; aka stereo audio without wires). If Sony were to unlock the USB ports and have the PS5 work as a class compliant device, the BTD 700 is ready.

I wonder if LE Audio/LC3 will work with the MTW4? I have yet to get to work with other dongles.

It will once MTW4 gets the full LE Audio upgrade. Something we're working on but I do not have a timetable yet.

I received mine today. AptX Lossless seems to work on my MTW4 (according to Smart Control Plus) using my Macbook. Note that the LED never turns purple, though. Maybe purple and pink are too close together for me to see, but I don't think so.

Please download the new firmware. The OP has a link to the desktop app for firmware (your OS version is at the bottom of that page)

@Sennheiser the BTD 700 aptx lossless mode does not work. Several users are also having this issue on Reddit. I am not sure how this was not tested before selling these to the public. Also, your firmware page for the BTD 700 is down.

If you are on the fence about buying this, I would wait until Sennhesier fixes it.

Page updated! aptX Lossless has a few conditional requirements regardless of device, one of them being a stable enough RF environment. If it is not stable enough (there is a threshold though I do not know what that is precisely) the connection falls back to the wider funnel of aptX Adaptive.

@ericpalonen @Sennheiser as reported above, can't seem to download the latest firmware from the website. Is this being looked into?

The website also mentions downloading the 'Dongle Control App' to 'update firmware with ease'. Is this still being worked on as I can't see it on the Google app store?

All set now!

Related question - do the MTW4 support LE Audio/LC3?

Edit: Of course I mean with the BTD 700.

MTW4 is slated to get LE Audio, and as-is works with BTD 700 in BT Classic using aptX Adaptive. For Auracast (which is under LE Audio), MTW4 [on its latest firmware] works great. BTD 700 can be a tiny Auracast station. Auracast is part of LE Audio however we do not have the full suite available yet. I don't think you'll get better latency or sound quality over LE Audio when compared to aptX Adaptive, though it should be competitive or slightly better for battery life vs aptX.

Just received my BTD 700. Few observations below.

1. I get same purple-ish color (sorry, bad at colors) for both M4 and Px7 S3. Seems aptX Losless negotiation doesn't work for the latter. Likely similar experience as reported by @tonyt76
2. User Manual says (see excerpt below) the dongle auto-optimize for low latency when devices support aptX Adaptive LL. I get terrible 350ms latency for M4... Have no such an issue with BTD 600 -- get about 200ms latency with very same M4 pair, i.e. its auto optimization actually works. So, the only way to have lip-sync experience with BTD 700 is manually enable Game Mode. I expected to have Game Mode for best latency (but manual control required), while auto optimization complements as some middle ground for less demanding use cases, e.g. YouTube et cetera.



Hopefully, that's something Sennheiser could address quickly...

Try the new firmware which has the LED update and improved mode switching. That said, the headphones/earbuds have to be optimized for low-latency AND be aptX Adaptive capable in order to establish low latency performance better than what aptX Adaptive negotiates. Not many aptX Adaptive earbuds/headphones are prioritizing low-latency that measures better than aptX Adaptive, as it requires custom firmware.

And regarding PS5 compatibility... unfortunately, even if it's just a singleplayer game, BTD 600 + headphones work using HFP profile (call mode), which means bad sound quality. Not recommended at all. Works great with Steam Deck though

Edit: @zilax002 sorry, I just noticed a mistake in previous post, and updated it to answer actual question. All info combined, I guess BTD 600 isn't right option for your needs.

BTD 600 would need to be updated to work with PS5 outside of HFP mode. BTD 700 just received this in the firmware update. I'll check on BTD 600 getting this update as well (4x push to enter BT Classic A2DP profile, essentially); I would not expect latency performance to be good in A2DP, so for competitive games where sound sync is critical, that combination isn't the ideal fit.

Any timeline for LC3 support for MTW4? It's been a while waiting for it.

Cannot commit to a timeline yet, but full LC3 support is in development. A portion of LC3 (Auracast, which required LE Audio's multicast tool kit) is enabled now on the latest MTW4 firmware.

 

[KB8P]

I'm digging into this right now and will report back
edit: The version of aptX Adaptive we use is indeed the version that folds in aptX Lossless for auto-negotiation, or selection of Lossless through our forthcoming companion app. I'll try to get the specific rev #.

I'm talking about the newer aptX Lossless 24/48 using bt LE audio, not the aptX lossless 16/44.1 based on bt classic.

 

[ericpalonen]

I was talking about the latest spec of aptX Lossless 24/48 that uses bt LE, not aptX lossless 16/44.1 based on bt classic.

As I understand it, Bluetooth LE Audio is a stack that aptX is not programmed for; the aptX suite works on BT classic only. aptX Lossless is a subset of aptX Adaptive, operating at 16-bit and 44.1 kHz ~1.1 Mbps bandwidth and nothing else when those conditions are negotiated between two compatible devices. Any deviation from this is no longer aptX Lossless and falls back to Adaptive.

LC3 should be able to encode/decode up to 24-bit / 48 kHz with lossy compression, so that is neither aptX nor lossless. Can you point me to your source? Thx!

 

[streetbeat]

Try the new firmware which has the LED update and improved mode switching.

Yes, a good improvement confirmed!

A few issues if you can pass on to the team:
1. Every time I open the app, I have to read and agree terms of use. Too much clickery to my taste... would prefer to do that just once at first run.
2. BTD 600 is recognized, but checking for updates crashes the app after a second or two. PC with Windows 10 Home.

I need to test it more, but seems LED light doesn't change dynamically, e.g. once I go farther from the dongle I'd expect light go from purple (Lossless) to pink (Adaptive). Idk, maybe my place is too wireless friendly Meanwhile, do you mind to confirm what's expected behavior in that case, please.

That said, the headphones/earbuds have to be optimized for low-latency AND be aptX Adaptive capable in order to establish low latency performance better than what aptX Adaptive negotiates. Not many aptX Adaptive earbuds/headphones are prioritizing low-latency that measures better than aptX Adaptive, as it requires custom firmware.

Here we're talking about Momentum 4 headphones. Hopefully you're quite confident these are capable ones Which is actually confirmed by combo with BTD 600. If we're still talking about normal (auto-optimization) mode of course...

 

[KB8P]

As I understand it, Bluetooth LE Audio is a stack that aptX is not programmed for; the aptX suite works on BT classic only. aptX Lossless is a subset of aptX Adaptive, operating at 16-bit and 44.1 kHz ~1.1 Mbps bandwidth and nothing else when those conditions are negotiated between two compatible devices. Any deviation from this is no longer aptX Lossless and falls back to Adaptive.

LC3 should be able to encode/decode up to 24-bit / 48 kHz with lossy compression, so that is neither aptX nor lossless. Can you point me to your source? Thx!

Xiaomi Buds 5(cn) and Buds 5 Pro support this specification, I was able to pair Buds 5 with Xiaomi 15 Ultra and use it, FlooGoo FMA120 dongle also supports this specification with the latest firmware update so I was able to use it.

https://m.mi.com/commodity/detail/20159
https://www.mi.com/global/product/xiaomi-buds-5-pro/https://www.flairmesh.com/Dongle/FMA120.html

 

[Nick24JJ]

@KB8P

Can you please comment on the below:

LC3 should be able to encode/decode up to 24-bit / 48 kHz with lossy compression, so that is neither aptX nor lossless.

Do you agree?

Please, provide a clear and concise reply.

Thank you

Spoiler: Copilot's response

That statement is true.

LC3 (Low Complexity Communication Codec), the default codec for Bluetooth LE Audio, is designed to support up to 24-bit / 48 kHz audio with lossy compression. It prioritizes efficiency, scalability, and robustness over wireless connections, especially in low-power scenarios like hearing aids and TWS earbuds.

Because LC3 is a separate codec from Qualcomm’s aptX family, and it uses lossy compression, it is neither aptX nor lossless. In contrast, aptX Lossless (a subset of aptX Adaptive) operates over Bluetooth Classic and is limited to 16-bit / 44.1 kHz in its lossless mode.

So yes - LC3 is a distinct codec with different goals and technical characteristics. Aptly put in the thread: LC3 ≠ aptX, and LC3 ≠ lossless. It’s its own thing.

 

[KB8P]

@KB8P

Can you please comment on the below:

LC3 should be able to encode/decode up to 24-bit / 48 kHz with lossy compression, so that is neither aptX nor lossless.

Do you agree?

Please, provide a clear and concise reply.

Thank you

Spoiler: Copilot's response

That statement is true.

LC3 (Low Complexity Communication Codec), the default codec for Bluetooth LE Audio, is designed to support up to 24-bit / 48 kHz audio with lossy compression. It prioritizes efficiency, scalability, and robustness over wireless connections, especially in low-power scenarios like hearing aids and TWS earbuds.

Because LC3 is a separate codec from Qualcomm’s aptX family, and it uses lossy compression, it is neither aptX nor lossless. In contrast, aptX Lossless (a subset of aptX Adaptive) operates over Bluetooth Classic and is limited to 16-bit / 44.1 kHz in its lossless mode.

So yes - LC3 is a distinct codec with different goals and technical characteristics. Aptly put in the thread: LC3 ≠ aptX, and LC3 ≠ lossless. It’s its own thing.

I'm talking about LEA aptX Adaptive codec, not LEA LC3. They are two different LE Audio codecs.