• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

120 Ohm Speaker

Status
Not open for further replies.

Manu

New Member
Anyone know how much a 120 Ohm Speaker costs?
 

Sebi

Active Member
I've never seen a loudspeaker with higher impedance as 50ohm.
The 100V line amplifier output impedance is 120ohm, but need a matching transformer for each loudspeaker.
 

Sebi

Active Member
In this case no need transformer. Try out with 16ohm speakers. The cause of hi-ohms speaker requirement: in microphone mode produced more signal.
 

Gene

New Member
The problem with a 2-way, hands free intercom is that the speaker also must act as a microphone without feeding back on itself. Normally the best is between 8 ohms and 120 ohms. Commercial intercoms operate in the 45 ohm range. This seems to allow the speaker to act (somewhat) as a microphone and speaker without too much distortion. If you did a search for "speakers 45 ohm" you will find some suppliers like:

http://www.surplussales.com/Microphones-Audio/MicroAudio-7.html

This is one possibility.
 

Manu

New Member
Sebi said:
In this case no need transformer. Try out with 16ohm speakers. The cause of hi-ohms speaker requirement: in microphone mode produced more signal.

I tried it with 16ohm, wasn't that bad. Well, I am just gonna look around. and stick with 16ohm for the moment.

Thanks for replying guys. It helped alot.
 

Madmartin

New Member
Maybe you give a try to two telephones speakers.
(the old-style type with a mechanical dial)
I think I remember them to have resistances as high as 500 ohms
 

Sebi

Active Member
The phone is good idea, but as i remember the old telephone with dial contain 75ohm speaker with steel-membrane. The Taiwan-junk wall phone contain often 50ohm speaker, and (here in Europe) the door-phone systems working with 50ohm (plastic-membrane) speakers.
 
Status
Not open for further replies.

EE World Online Articles

Loading
Top