best 3.1 speaker system
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swapnilvz
I have a 5.1 channel home theater system, all the 6 channel jacks are connected to speakers of 3 ohms each. I have 4 old speakers from a previous system. two main speakers are 6 ohms each and the other two satellite speakers are 16 ohms each. and to top it all my home theater system does not have a line out jack at the back. How do I go about wiring these 4 speakers to my existing system?
Answer
Strongly unadvised... I'm with the others on this one... Don't do it.
Guessing with this sort of thing, voids your warrantly... has the potential to fry things that are at this point working. However, since you're asking...
3 Ohms, I'll also agree is a rather peculiar load... it's usually 2,4 or 6 Ohms... regardless... this is what you posted... so...
If for instance your amplifier is Class AB and running 50% effiency at 3 Ohms, and say 50 Watts... when you double the Ohms rating you've lost power ouput capability by as much as 1/2... So at 6 Ohms the given channel is now only capable of producing 25 Watts. When you half your power you've halved your effective dB levels by half. It takes twice the power to increase output by +3 (+10 db SPL's) which is a doubling of effective loudness to the average listener.
Typically, you don't want to step up or down more than a single impedance load level... I've yet to see a standard amplifier that'll drive 1.5 Ohms, stabily for your average home theatre system, so that leaves you with going up a level, or trying to stay as close as you can to the existing impedance load... so the maximum target impedance load would be 6 Ohms, and the minimum would be 2. I guess what you're asking, are there any combinations that I can safely wire so I don't fry my gear.
-=[The math...]=-
I don't know if you have a Philips HTR 5000, but it was the only one I could find with 6 channels, and a 3 Ohm load on all those channels... so... we'll work off that one... for examples.
http://www.p4c.philips.com/files/h/htr5000_01/htr5000_01_dfu_eng.pdf
Running Series we Add... running Parallel we take...
1/(1/a+1/b+1/c+1/...)
Where a,b,c are the differnt speakers wired in parallel. Another things you need to make sure, is that the RE (Thiele-Small Spec - RE is the actual DC resistance of the drivers voice coil) be matched to all the other drivers. I'll guarantee you this is not the case... and you'll find that on the satellites, and the mains that were shipped with the system will be working harder than the other drivers at the increased output levels. The high impendance drivers that you're attempting to wire in are more resistive, so the drivers are going to be handling different power levels, and now you risk underpowering scenarios to the motors which is far more likely to fry speakers. Anyways... warnings aside... And you can pretty well guarantee, as mentioned above this this just voided your warranty... ;)
Front speakers...
checking them in series... 3+6 = 9 Ohms... that's likely not going work... or if it does, it'll sound very quiet.
parellel... 1/(1/3+1/6) = 2 Ohms... that might work... but make sure you're watching heat levels on your gear...
So on a hypothetical, you can run your mains in Parallel... and still be able to hear something... at the servere risk of, you guessed it... 'cooking your gear'...
Rears...
> What you could do is run the sats as a
> second set of surrounds in SERIES.
I have to directly contradict The Sound Broker on this one...
> You now have 4 speakers running off the
> rear surrounds at a higher impedence which
> is easier on the amp as far as load.
I'll agree with you to a certain extent... but let's do the math on this...
Running the Satellites in Series... 3+16 = 19 Ohms...
If the amplifier is functioning at 3 Ohms stable, or likely recommended optimum... this just critically underdrives the speakers. 3 Ohms, doubled... becomes 6 Ohms, to 12 Ohms... to nearly 24 Ohms...
If the Channel has a maximum output of 50 Watts... we just went to 25, to 12.5 to 6.25 Watts... Over two speakers... 16 Ohms, suggests they were possibly driven from a Class A, or AB, Tube at some point. The liklihood of hearing much of anything out of those speakers is slim... as the output stages of the Reciever probably aren't functioning at much past 6 Ohms... This is more likely to cook the speakers, and disable the output capabilities of the amplifier stages.
If you run them parallel... 1/(1/3+1/16) = 2.52 Ohms... that's pretty close to 3 Ohms... but... it's obvioulsy pulling more current, something you have backwards, as you state here, that current is stable, indifferent to the impedance load.
> What it won't do is lower the current demands
> since you now have double the drivers to control
This really makes it sound like you know what you're talking about... but come on???
You've got is totally backwards... almost all amplifiers are VOLTAGE DRIVE... NOT CURRENT DRIVE... the difference? A big one... I see an awful lot of crap posts being dished out to unsuspecting people expecting to receive a decent answer... This is nonsense...
Voltage Drive - As the impedance falls, the load voltage will remain constant, as the current increases, and more power is created...
Current Drive - As you are suggesting... a majority, if not all Solid-State amps do not work this way... As the impedance rises, voltage increases, to maintain the same level of current. So as the current rises, the power output level increases...
No matter how you look at this, varying the impedance on a Voltage Drive circuit will alter it's current! Sheesh... for an audio guy, I find this flabbergasting.
As for the last part of the question...
> so watch the heat and listen for audible signs
> of clipping. You will obviously have to
> recalibrate your surround channel levels.
As you have suggested to wire this up, heat is not likely the issue, as there's way to much impedance to even pull any current to the speakers.. so the output power has been critically damped. Without current draw, there's no amplification, so there logically wouldn't be any heat, because no work is being done... Clipping? Huh? And then to suggest recalibration of the surround channel levels... Too funny, I haven't laughed this hard in a long time.
> and to top it all my home theater system does
> not have a line out jack at the back. How do
> I go about wiring these 4 speakers to my existing
> system?
I'd say at this point, unless you understand what's been written so far, I wouldn't even attempt it... Otherwise...
http://en.wikipedia.org/wiki/Series_and_parallel_circuits
http://www.rocketroberts.com/techart/spk_wire.htm
There is little chance this will increase the overall productivity of system. And the above mess is why... ;)
What's the best surround sound system for music in a small room?
Z
I am completely new to surround sound systems, and all the terminology is so confusing. I need a surround sound system that works well for music, is around $100-$200 (new or used), and is good for a 10x12 bedroom. It may end up getting used for a TV down the road, so it would we be good if it also sounds okay for television. I'd really appreciate any help I can get, I feel so clueless!
Answer
are you looking for a 5.1 or 7.1? for $200, well you're in a very tight budget, so you might as well get a entertainment system. try this HT-D550ZA - samsung. it's under $200 in bestbuy. if you are really looking for a very good surround system, forget about bose. i mean, bose is so overrated and the sound quality really sucks. the best speakers out there are defeinitive, martin logan, b&w, vienna acoustics to name a few. i have only a 3.1 set up, all martin logans and i already spent about $4000 just for the center channel speaker, left and right spearkers, and the sub. i want to set it up for a 5.1 but, i don't have enough room to put the 2 speakers, but, i tell you this, i only have 3.1, but the sound quality is superb.
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