Probably not the best place to ask, but Im after a speaker of quite specific dimensions.

This isnt for a car, its for a project Im pricing up, and Ive had no luck finding a speaker that is the right size.

Must be 120mm diameter, and a MAX of 25mm depth (less is better!). Ive searched around but as Ive never really been into audio stuff Im not sure where to look. Anything Ive found in the 120mm range is waaaaaaay to deep for what Im looking for.

The reason I ask here, is that maybe some kind of car speaker would be suitable, or someone could suggest somewhere I could start to look? (Replies of www.google.co.uk / .com will get a slap).

Sound quality isnt important, however it being shielded (?) and passively powered are almost mandatory.

If anyone has any suggestions, or even knows what Im talking about (as Im not sure I do), a reply would be appreciated.

My Googling skills once again amaze me.

http://www.maplin.co.uk/module.aspx?ModuleNo=37984&doy=26m4#overview

5 inches, so near enough 120mm ( I can be slightly flexible with diameter, but depth is the problem).

Assuming it is less than 25mm in depth (which I doubt), could I somehow rig it to run from the output of a standard PC soundcard? Also what about power? You see where this is leading . . .

*edit - Volume control, how would that work? Via PC I assume?

Its a speaker... itll have two solder tabs, or two wires.

you connect one lead of an audio cable to one tab... one lead to the other.

Plug jack on other end of cable into the speaker socket, and pray your pc soundcard is beefy enough to drive it.

Failing that youre better off feeding the output of the PC through an amp, and then plowing that output into the speaker.

At least those are my first 5 minute thoughts.

If you want to introduce a simple volume control, shove a POT in the middle of one of the leads to the speaker. Sorted.

Cool, ta for the info.

I cant have an amp for this project, so I best get praying!

I assume the smaller the speaker, the better chance a sound card would have of driving it?

Quote from: White GiantCool, ta for the info.

I cant have an amp for this project, so I best get praying!

I assume the smaller the speaker, the better chance a sound card would have of driving it?

In theory, and by my reckoning yes... but Id imagine some crazy small speaker with an insanely strong magnet in it, could cause issues, however likelihood is next to nil that that will be an issue.

no room for a little IC amp ?

Quote from: M3ta7h3adIts a speaker... itll have two solder tabs, or two wires.

you connect one lead of an audio cable to one tab... one lead to the other.

Plug jack on other end of cable into the speaker socket, and pray your pc soundcard is beefy enough to drive it.

Failing that youre better off feeding the output of the PC through an amp, and then plowing that output into the speaker.

At least those are my first 5 minute thoughts.

If you want to introduce a simple volume control, shove a POT in the middle of one of the leads to the speaker. Sorted.

Speakers arent all the same, living room ones are almost always 8 ohm while car ones generally use 4 ohms.

This also means there can be issues connecting them up.

Quote from: Serious

Quote from: M3ta7h3adIts a speaker... itll have two solder tabs, or two wires.

you connect one lead of an audio cable to one tab... one lead to the other.

Plug jack on other end of cable into the speaker socket, and pray your pc soundcard is beefy enough to drive it.

Failing that youre better off feeding the output of the PC through an amp, and then plowing that output into the speaker.

At least those are my first 5 minute thoughts.

If you want to introduce a simple volume control, shove a POT in the middle of one of the leads to the speaker. Sorted.

Speakers arent all the same, living room ones are almost always 8 ohm while car ones generally use 4 ohms.

This also means there can be issues connecting them up.

Just because you may have seen a word on the back of a speaker cabinet doesnt mean you must post about it.

Youre talking about impedence. Not really an issue with any IC based amp/feed, as feedback circuits should allow a range of load impedence values to be catered for.

Its certainly not an issue to be worrying about with the speaker he has chosen.

Quote from: Markno room for a little IC amp ?

Mark has a point, you can buy "amp" kits from maplins ready to go just requires a little solder... failing that you can buy them as pre-printed PCBs with a parts list so you can DIY it from different online places.

Im sure I have one I made (only mono feed in and out however ) in a drawer upstairs somewhere, its always handy to have around... spesh if you just want to listen to some music occasionally on the go.

hmm, what sort of size are we looking at for one of these amp kits?

teeny

Excellent, thanks.

Still looking for a suitable speaker though.

Quote from: M3ta7h3ad

Quote from: Serious

Quote from: M3ta7h3adIts a speaker... itll have two solder tabs, or two wires.

you connect one lead of an audio cable to one tab... one lead to the other.

Plug jack on other end of cable into the speaker socket, and pray your pc soundcard is beefy enough to drive it.

Failing that youre better off feeding the output of the PC through an amp, and then plowing that output into the speaker.

At least those are my first 5 minute thoughts.

If you want to introduce a simple volume control, shove a POT in the middle of one of the leads to the speaker. Sorted.

Speakers arent all the same, living room ones are almost always 8 ohm while car ones generally use 4 ohms.

This also means there can be issues connecting them up.

Just because you may have seen a word on the back of a speaker cabinet doesnt mean you must post about it.

Youre talking about impedence. Not really an issue with any IC based amp/feed, as feedback circuits should allow a range of load impedence values to be catered for.

Its certainly not an issue to be worrying about with the speaker he has chosen.

It can reduce the quality of sound severely and damage either your amp or speakers if they are badly matched.

Damage isnt going to be a problem with that small amp tho.

No... impedence matching is old. It would only be a problem if the equipment he was using to drive the load (in the case a speaker) was made perhaps 30 years ago.

Welcome to active discrete electronics... or rather welcome to the latter quarter of the 20th century.

Dont be so dismissive and condescending, my brother ruined one of a pair of Celestion Dittons because he thought it would be a good idea to run them through his car, it seemed highly likely to me it was the impedance mismatch causing the problem.

Youll also find a lot of top end hifi kit will ask you not to try to drive speakers of unusual impedence (like 4ohm or less) without checking if it is compatible first.