One for the techies.....
I have bought a cinema system which has 3 ohm satellite speakers. I am not going to use 4 of the satellite speakers and am instead going to get 4 ceiling recess speakers which are already wired for. My problem is i can only seem to find 4, 6 or 8 ohm ceiling speakers online. As i understand it, the wattage of the ceiling speakers does not have to exactly match the ones i will not use from the cinema system but the different impedance (ohms) could result in me blowing the in-built amplifier that comes with the cinema system. Can anybody confirm re this ? I couldn't get a definitive answer from the sony centre i visited.
2nd problem/question ..... i am using the 4 satellite speakers from the cinema system as standalone speakers in a high ceiling living area. These are going to connect back to a 2 way stereo amplifier (thus the speakers can only be controlled in pairs) to which i will connect a small radio/CD player. Given that the satellite speakers are 3 ohm, does this mean each channel of the stereo amplifier which will be each supporting 2 speakers would have to be 6 ohm ?
Finally, i am presuming the wiring that is done on the house will not in anyway change the impedance / ohms and thus the 2 scenarios above are the only 2 i need worry about ?
Quote from: blast05 on August 29, 2007, 08:57:10 PM
I have bought a cinema system which has 3 ohm satellite speakers. I am not going to use 4 of the satellite speakers and am instead going to get 4 ceiling recess speakers which are already wired for. My problem is i can only seem to find 4, 6 or 8 ohm ceiling speakers online. As i understand it, the wattage of the ceiling speakers does not have to exactly match the ones i will not use from the cinema system but the different impedance (ohms) could result in me blowing the in-built amplifier that comes with the cinema system. Can anybody confirm re this ? I couldn't get a definitive answer from the sony centre i visited.
If speakers have a higher impedance than spec'ed for, the power output will suffer (downwards), and the higher frequencies might take a hit. (Only if the ohm rating were lower would you risk blowing the amp, ohm = electrical resistance, which become impedance in an A/C set-up, which speakers are).
Quote from: blast05 on August 29, 2007, 08:57:10 PM
2nd problem/question ..... i am using the 4 satellite speakers from the cinema system as standalone speakers in a high ceiling living area. These are going to connect back to a 2 way stereo amplifier (thus the speakers can only be controlled in pairs) to which i will connect a small radio/CD player. Given that the satellite speakers are 3 ohm, does this mean each channel of the stereo amplifier which will be each supporting 2 speakers would have to be 6 ohm ?
It seems like each speaker will be connected in parallel from each channel (not one wire going from one speaker to the next, but two coming from the channel), therefore 3 ohms is all that will be 'seen' on each channel.
Quote from: blast05 on August 29, 2007, 08:57:10 PM
Finally, i am presuming the wiring that is done on the house will not in anyway change the impedance / ohms and thus the 2 scenarios above are the only 2 i need worry about ?
Correct, and good luck with it!
Cheers F an SB.
So based on replacing ~120 watt cinema system 3 ohm satellite speakers with ~80 watt 4 ohm recess ceiling speakers, you reckon i should chance going with it ?
For my second scenario, i have it wired both ways, i.e.: i can have each speaker independently controlled (4 separate cables) this requiring a dearer 4 way amp or the way i am going to go - 2 speakers to the front of the living area (cable going from amplifier location to the first speaker and then on to the second) going through 1 of the stereo channels and the other 2 speakers to the rear going through the other stereo channel.
I am sure i am mixing up all the lingo here :-[
Welcome Blast.
Quote from: blast05 on August 29, 2007, 11:01:38 PM
Cheers F an SB.
So based on replacing ~120 watt cinema system 3 ohm satellite speakers with ~80 watt 4 ohm recess ceiling speakers, you reckon i should chance going with it ?
I'd be a little nervous here -- the power rating of your replacement speakers is lower than the original speakers (assuming both are a measurement of 'RMS' or 'Average' power?), therefore the power that's being fed into the 80W speakers could be too powerful. I wouldn't chance it.
Quote from: blast05 on August 29, 2007, 11:01:38 PM
For my second scenario, i have it wired both ways, i.e.: i can have each speaker independently controlled (4 separate cables) this requiring a dearer 4 way amp or the way i am going to go - 2 speakers to the front of the living area (cable going from amplifier location to the first speaker and then on to the second) going through 1 of the stereo channels and the other 2 speakers to the rear going through the other stereo channel.
I am sure i am mixing up all the lingo here :-[
Lingo good ;)
Can you have a look at this link: http://colomar.com/Shavano/spkr_wiring_sp.html, it gives a good pictorial breakdown of serial and parallel amplifier-speaker wiring arrangments, and also how the impedance is calculated (added for in series, split for parallel).
f**k i dont understand a word of that! :-\
Quote from: hardstation on August 30, 2007, 02:29:12 AM
I know nothing about speakers but here's something about Ohm.
This means that the current is equal to voltage (potential difference) divided by the resistance.
I = V/R or V = IR or R = V/I.
This may help you.
You're not wrong there HS, except that this is, strictly speaking, for Direct Current (D/C), not Alternating Current (A/C), which brings in phase considerations (hence the use of
impedance instead of
resistance), i.e., the voltage won't always peak with the current.
An additional equation is P = VI, where P is power, therefore P = I
2R
Edit (just copped this now):
Quote from: hardstation on August 30, 2007, 02:29:12 AM
I know nothing about speakers but here's something about Ohm.
http://en.wikipedia.org/wiki/Georg_Ohm (http://en.wikipedia.org/wiki/Georg_Ohm)
He had a law you know. I can't remember the name of it, it wasn't catchy but....
Yes, it is/was
Ohm's Law! ;)
Quote from: blast05 on August 29, 2007, 08:57:10 PM
One for the techies.....
I have bought a cinema system which has 3 ohm satellite speakers. I am not going to use 4 of the satellite speakers and am instead going to get 4 ceiling recess speakers which are already wired for. My problem is i can only seem to find 4, 6 or 8 ohm ceiling speakers online. As i understand it, the wattage of the ceiling speakers does not have to exactly match the ones i will not use from the cinema system but the different impedance (ohms) could result in me blowing the in-built amplifier that comes with the cinema system. Can anybody confirm re this ? I couldn't get a definitive answer from the sony centre i visited.
2nd problem/question ..... i am using the 4 satellite speakers from the cinema system as standalone speakers in a high ceiling living area. These are going to connect back to a 2 way stereo amplifier (thus the speakers can only be controlled in pairs) to which i will connect a small radio/CD player. Given that the satellite speakers are 3 ohm, does this mean each channel of the stereo amplifier which will be each supporting 2 speakers would have to be 6 ohm ?
Finally, i am presuming the wiring that is done on the house will not in anyway change the impedance / ohms and thus the 2 scenarios above are the only 2 i need worry about ?
But a seperate amp them built in things are useless
QuoteBut a seperate amp them built in things are useless
I know, ideally i would but they are 3 times the price and given the level of use i will knock out of it then i couldn't justify it.
What i am going to do is bring back the cinema system (haven't opened it yet) and get one with 70 watt satellite speakers with 4 ohm resistance (142 watt 3 ohm satellite speakers on the one i am bringing back). I can get similar spec'd ceiling speakers to replace these no problems so all should be grand.
Apologies for bringing this up again but could anyone comment on the following spec of gear for my scenario:
Cinema system: http://www.superfi.co.uk/index.cfm/page/moreinfo.cfm/Product_ID/3431 (http://www.superfi.co.uk/index.cfm/page/moreinfo.cfm/Product_ID/3431)
Ceiling speakers: http://www.cybermarket.co.uk/ishop/923/shopscr162.html (http://www.cybermarket.co.uk/ishop/923/shopscr162.html) .... is it ok to buy 2 pairs of these as replacements for 4 of the satellite speakers in the cinema system ?
Stereo amp to be used with the 4 satellite speakers from the cinema system: http://www.sony.ie/view/ShowProduct.action?product=TA-FE370&site=odw_en_IE&pageType=Overview&imageType=Main&category=HFC+Amplifier (http://www.sony.ie/view/ShowProduct.action?product=TA-FE370&site=odw_en_IE&pageType=Overview&imageType=Main&category=HFC+Amplifier)
My latest problem/confusion from reading up about this and only half understanding it all is that satellite speakers from the cinema system that i will be deploying with the sony stereo amp may not have any crossovers built in, with the crossover being provided internally in the DVD/amp in the cinema system. In this scenario, bass would be sent to the satellite speakers and damage them ...or something like that :-\