Tech: PCB amp and speakers. basic electronics.

[erikthecat]

[ukvac] Tech: PCB amp and speakers. basic electronics.

night all,

would anyone be able to answer a simple PCB amp, speakers and basic electronics question?

i believe that the standard speaker used in a typical mono non JAMMA cabinet would have been 8 ohm.
any idea how many WATTS RMS would have been the typical?
any idea what speaker a typical on board PCB amp would be capable of driving?

the reason i ask...
i'm in the process of knocking up a Pacman style table top style cabinet,
and am toying with the idea of adding two speakers, one per end.

am i wasting my time? would one fitted the base of the cabinet, firing down be sufficient?

if i do add a second speaker, i'm not sure if that should be in series or parallel
8ohm + 8ohm =16 ohm
or
1/8 = 1/8 = 4 ohm

if that's right neither of these look like the basic 8 ohm, perhaps it's neither

should just i just give up?

if anyone could spare the time to supply an answer or other suggestion that would be much appreciated.

TIA,

GaRy)

-------------------------------------
www.SplatThatCat.com

 

[favouredson]

[ukvac] Re: Tech: PCB amp and speakers. basic electronics.

 

[John Bennett]

Re: [ukvac] Tech: PCB amp and speakers. basic electronics.

Your correct on both counts, 2 speakers in series would give you 16 ohms impedance and in parallel you would get 4 ohms impedance. An amplifier designed to drive 8 ohms would be fine driving 16 ohms, it just would'nt be as loud. Fitting an 8 ohm amp with a 4 ohm speaker could blow the amp. If you want to match the amp output impedance with 2 speakers IN SERIES you could fit a 16 ohm (nearest prefered value 15R) resistor in parallel with BOTH series speakers or if using parallel speakers use a 4 ohm (nearest prefered value 4.7R) IN SERIES with them.

In short, 2 8 ohm speakers in series should be fine.

Mike

========================================
Message date : Oct 17 2004, 10:16 PM
From : "GaRy"
To : ukvac@yahoogroups.com
Copy to :
Subject : [ukvac] Tech: PCB amp and speakers. basic electronics.

night all,

would anyone be able to answer a simple PCB amp, speakers and basic electronics question?

i believe that the standard speaker used in a typical mono non JAMMA cabinet would have been 8 ohm.
any idea how many WATTS RMS would have been the typical?
any idea what speaker a typical on board PCB amp would be capable of driving?

the reason i ask...
i'm in the process of knocking up a Pacman style table top style cabinet,
and am toying with the idea of adding two speakers, one per end.

am i wasting my time? would one fitted the base of the cabinet, firing down be sufficient?

if i do add a second speaker, i'm not sure if that should be in series or parallel
8ohm + 8ohm =16 ohm
or
1/8 = 1/8 = 4 ohm

if that's right neither of these look like the basic 8 ohm, perhaps it's neither

should just i just give up?

if anyone could spare the time to supply an answer or other suggestion that would be much appreciated.

TIA,

GaRy)

-------------------------------------
www.SplatThatCat.com



DATA Imported from archives: originally posted by Mike Hawkins (mike.hawkins@fsmail.net)