How do I put in a volume control on this wired phone headphone set?

Question

I have this headset which I use with a cordless handset. The problem is the volume is way too loud even if I turn it down all the way on the cordless handset. There are no controls on the headset. I really like this headset, it's just too loud. I wish there was a volume control on it. How can I make this happen?

Equipment list: Uniden Phone – model D3580 (standard 2.5 mm telephone headset) Plantronics headset which uses the standard 2.5 mm telephone headset

I assume I could buy a volume control (Potentiometer) but I don't know which one. How do I match it up to the specs? Remember, I only want to turn this down I don't need to make it louder so no amplification is needed.

What parts do I need exactly? How should this he assembled? Is it required I use a soldering iron or can this be done another way I'm not aware of? Thanks!

Answer 1

I have this headset which I use with a cordless handset.

I'm assuming you will use (or want to use) this headset exclusively with the cordless handset so it isn't a problem modifying it.

If you can get to the speaker terminals then try putting a 100 ohm resistor in series with each speaker. This should attenuate things a bit. If still too loud then try a 330 ohm resistor, Hey they're 3 pence each (at most) so experiment a bit.

If potentiometers are your ultimate aim then experimenting with the resistors will get you an approximate value for a pot ohm wise. Without the little experiment you might be needing a ten ohm pot or a 1k ohm pot.

You ought to consider soldering this modification.

Answer 2

Andy's answer is a good one, but I would go for the opposite approach of starting with something oversized like a 10k pot in series with the speaker (assuming a one-earcup headset with one speaker - you'll need two potentiometers for two speakers) and adjusting until you're at a level you're happy with. At that point, you can use a digital multimeter to measure the resistance the pot is set to and decide if you want to replace it with something at a smaller range to give you better "resolution" around your target loudness, or with discrete resistors to make it permanent.

Audio pots sometimes have a "log taper" instead of a normal "linear taper", meaning that the resistance changes logarithmically as you adjust the dial. This has something to do with mimicking the way the ear interprets relative audio volume, where a log taper pot will appear to have a linear effect on perceived volume. This may or may not be of interest to you to consider for your application.