Audio Amp

[kinarfi]

I have 2 pair of Sena SPH10 blue tooth intercom head sets, https://www.sena.com/product/sph10/, and after wearing them for several hours, they become uncomfortable, so to take advantage of their capabilities, I want to build a circuit that will make them work with with a regular speaker by tapping into the signal to the ear phone or by using a microphone to listen to the ear piece and amplifying that to drive a car type speaker. Then all that would be needed is an extension lead for the microphone of the head set.
Does anyone have any suggestions as to what would be a good amplifier for this purpose?
Thanks,
Jeff

 

[ronv]

I have 2 pair of Sena SPH10 blue tooth intercom head sets, https://www.sena.com/product/sph10/, and after wearing them for several hours, they become uncomfortable, so to take advantage of their capabilities, I want to build a circuit that will make them work with with a regular speaker by tapping into the signal to the ear phone or by using a microphone to listen to the ear piece and amplifying that to drive a car type speaker. Then all that would be needed is an extension lead for the microphone of the head set.
Does anyone have any suggestions as to what would be a good amplifier for this purpose?
Thanks,
Jeff

Have a look at the TDA seriesa nd pick the power you want.

 

[spec]

I have 2 pair of Sena SPH10 blue tooth intercom head sets, https://www.sena.com/product/sph10/, and after wearing them for several hours, they become uncomfortable, so to take advantage of their capabilities, I want to build a circuit that will make them work with with a regular speaker by tapping into the signal to the ear phone or by using a microphone to listen to the ear piece and amplifying that to drive a car type speaker. Then all that would be needed is an extension lead for the microphone of the head set.
Does anyone have any suggestions as to what would be a good amplifier for this purpose?
Thanks,
Jeff

Hy Jeff,

I hope I have got this right, but surely all you need is a bluetooth amplifier or blue tooth speakers. You can then leave the bluetooth phones at home.

Chuck

Some links
https://www.ebay.com/sch/i.html?_fr...y+module.TRS0&_nkw=bluetoothy+module&_sacat=0

https://www.ebay.com/sch/i.html?_od...lifier.TRS0&_nkw=bluetooth+amplifier&_sacat=0

 

[audioguru]

When the microphone hears the speaker then it will produce acoustical feedback howling. A cheap intercom or speakerphone prevents feedback by using half-duplex push button to talk or "voice switching" where it detects incoming sounds from the line then it cuts off your mic. When the distant end is quiet then it cuts off your speaker then you can talk. It cuts off your voice and/or the distant end if there is noise or if you both talk at the same time. An expensive intercom or speakerphone uses full duplex where you can both talk at the same time or with noises by a very complicated digital echo-canceller and a memory of the acoustical environment.

 

[kinarfi]

These head phones were expensive, and work very well, the only real problem was after a few hours, the got uncomfortable, it was interesting that while driving on the sand dunes, whenever the other guy got out of sight, we lost communication - definitely line of sight - but that's just RF.
The head sets have to be paired and they can be paired to more than one unit, so maybe I can use use a bluetooth module to feed the speaker.
The head sets are full duplex and so far, I have had no feed back problems, which was one of my concerns about going to a speaker instead of an ear piece.
Thanks,
Jeff

 

[audioguru]

Headsets are full duplex because there is no way the mic can hear the earphone. Replace the earphone with a speaker and you will have acoustical feedback howling, especially if both ends have a speaker:
Sound goes in mic #1 is amplified and comes out the other end at speaker #2. The sound from speaker #2 is heard by mic #2 and is amplified and passed to the other end's speaker #1. Then that same sound is heard by mic #1 again and the sound goes around and around.

About 30 years ago, Motorola made two speakerphone ICs that used voice switching. They worked fairly well and were cheap. For the past few years, Polycom makes some very expensive full duplex speakerphones that use an echo-canceller IC. Sometimes the echo-canceller gets confused and makes a funny noise.