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I have tried enough conference call speakerphones that claimed to be full duplex to know that it's a safe assumption that the claim is 100% false. I haven't tr

by gomox 6y ago

I have tried enough conference call speakerphones that claimed to be full duplex to know that it's a safe assumption that the claim is 100% false. I haven't tried this specific one but from my point of view the odds of a microphone picking up your voice clearly from 2ft away, while happily filtering out a very loud sound being emitted 1cm away at the same time, are quite low. Much lower than the odds of a marketing drone getting away with lying on a product brochure. I'm not an audio expert, but I doubt the SNR is there for the noise cancelling to be effective when you have to substract a 10db echo to recover a 1db voice. On the other hand, Katie from the Amazon review seems knowledgeable and she has past reviews of other speakerphones so it might be worth a shot :) Still, I'll believe it when I hear it!

zamfi 6y ago
> you have to substract a 10db echo to recover a 1db voice You would think so, but subtracting the (speaker-generated, i.e., known-signal!) sound from 1cm away is trivial. The hard part is subtracting the echoes off your walls, laptop, desk decorations, etc. etc. etc. That's not 10db, but it's still on par with your voice! You are not wrong at a high level -- speakerphones are terrible -- but it's not because the speaker is right next to the mic!
tjansen 6y ago
So you made me curious and I did the following test: - I configured the 7200 as main speaker and played a youtube video in which someone was contineously talking. - I measured the distance to the 7200, which is next to my keyboard, and it was almost 2ft away from my mouth (standing desk). - Then I opened Quicktime to make an audio recording using the 7200 as input device, talking while the youtube video was running. The result: I could only hear myself on the recording. Even while I was talking, or making other sounds, I didn't hear the video at all. So yes, I think it's full duplex. And no echos.
- gomox 6y ago
  Interesting. I have one of the "known bad" speakerphones at home, I will test it out later and post my results. It could be that the echo cancellation software has been the culprit this whole time.

by gomox 6y ago

zamfi 6y ago

> you have to substract a 10db echo to recover a 1db voice You would think so, but subtracting the (speaker-generated, i.e., known-signal!) sound from 1cm away is trivial. The hard part is subtracting the echoes off your walls, laptop, desk decorations, etc. etc. etc. That's not 10db, but it's still on par with your voice! You are not wrong at a high level -- speakerphones are terrible -- but it's not because the speaker is right next to the mic!

tjansen 6y ago

So you made me curious and I did the following test: - I configured the 7200 as main speaker and played a youtube video in which someone was contineously talking. - I measured the distance to the 7200, which is next to my keyboard, and it was almost 2ft away from my mouth (standing desk). - Then I opened Quicktime to make an audio recording using the 7200 as input device, talking while the youtube video was running. The result: I could only hear myself on the recording. Even while I was talking, or making other sounds, I didn't hear the video at all. So yes, I think it's full duplex. And no echos.

gomox 6y ago
Interesting. I have one of the "known bad" speakerphones at home, I will test it out later and post my results. It could be that the echo cancellation software has been the culprit this whole time.