Amplified mulitple speakers....

[affirmirror]

i have no background in electronics but am currently undertaking a project that requires multiple amplified speakers.

about 2 weeks ago i purchased a text book and have been studying some of the more basic principles of electricity; curcuits, amplification, et cetera. so i can' really say i know much, but...

my project requires an amplifier to power 6 small seperated speakers (3 Left, 3 Rigt), specs of the speakers are: 2.5w RMS 5w max 8ohms, as ascribed on the back, there are probably like 60 ways to do this for someone who knows what they are doing, but can anyone point me in the right direction?

:?:

thanks much for any help.

 

[Gene]

The amplifier has speaker terminals on the back. There should be two terminals for the right channel and two for the left. Each pair of termina;s should have an indication:

1. if there are only two terminals per speaker connection, they should be marked + and - OR colored red and black. There should also be an indication of ohms . . . such as 8 ohms. If there is no indication, check the manual for the amp or look for a switch on the rear panel that gives you a choice. Sometimes ohms is not spelled out but shown by the Greek omega (like an upside-down U.

2. if there are multiple connections for each speaker they should be labled as - and a choice of 4, 8, or 16 - or all 4 connections.

The terminal on each speaker should be marked + and -, red and black, or have a red dot next to one of the terminals.

You will want this information before you select a wiring design for your 6 speakers.

 

[affirmirror]

not sure i follow you?

i have two terminals per speaker, each speaker is 8ohms, as is stamped on the back...

i will need to go from one amp to 6 seperate speakers, using 3 speakers as a left channel, and 3 speakers as a right channel...

such that the

____|_________|________|_( AMP )_|______|______|_____
speaker_1 speaker_2 speaker_3 speaker_4 speaker_5 speaker_6

i have had no luck when looking for schematics to output to 6 speakers. OR should i be thinking more along the lines of just having a single output (+)(-) and then having a spliter dividing the wire into 6?

:?

 

[bogdanfirst]

since you have 8Ohm, you could simply use 24 Ohm speakers in paralel, but i dont think you can find 24Ohm spakers.
one idea is to use 2 Ohm speakers in paralel and in series with a 4Ohm speaker. or use 3 speakers of 16 Ohm and with a series resistor, but this way you will loose power. i'll think of other ways to connect them. what type of speakers do you have available?

 

[Gene]

What I was getting at is that - to design your hook-up, I need the ohm value of the amp output.

 

[Gene]

The idea is to match the impedence of your amp's output by configuring the speakers in a way that will closely match (low/no loss). Here is the way I would do it. It presents 5.3 ohms to the amp which should work well if your amp is 4 or 8 ohms. On another note, the power handling capacity of these speakers is quite low - they are not built for high volume.

 

[affirmirror]

well, the amp is what i'm working on building...so nothing is set in stone other than the speakers 'cuz i got a lot of them for free.

my current task is to figure the out best way of approaching the construction of an amp to power the speakers,...so the amp is a variable at this point?

 

[stevez]

It would be helpful to indicate if you want to be able to vary the volume in each of the speakers independently of the others.

You might connect the source to three small stereo amplifiers with independent voume and balance controls. An alternative is to connect the output of one larger amplifier to appropriate variable resistors (used to be called L pads) with speakers for adjustment. While power is not high it may be harder to find volume controls for the output.

There are numerous ICs that are low cost and available for audio work - many are stereo and external parts requirements are low. TDA2002 comes to mind but it's been a while since I fooled with this stuff. Others who post may have ideas on low cost ICs that will work.

There are modest cost kits available from Vellman and others. I think MCM Electronics or Jameco handle some of this stuff.

Anyway, good luck. Sounds like a fun project.

 

[stevez]

It looks like a TDA2005 might work - 3 of them on the same board with common power supply and appropriate external components. The result would be 3 stereo amplifiers. I noticed a "kitsrus" website and from that it seems that they have put things like this together in kit form. They appear to distribute all over the world thru various dealers. There are probably numerous ICs like this that would serve your needs quite well. Datasheets give you a good start on design.