Home stereo installation

[boomdart]

Nevermind

 

[f95toli]

It does not matter, it is perfectly ok hook up a pair of "6 ohm" speakers to a "8 ohm" amplifier.

That the speakers are rated 6 ohm simply means that their impedance is 6 ohm at 1kHz, the real impedance of any speaker varies with frequency and can drop to values as low as 1 ohm (even for "normal" speakers).
A 6 ohm speaker might be (but not always) a bit more diffcult to drive properly than an 8 ohm speaker but that is all it means.

 

[Mday]

it wil work fine. there are power consumption issues if your input and output impedances dont match, but that's about it.

matched impedances are more of a "audiophile thing" so unless you are spending a few grand, meh.

 

[f95toli]

Power consumption has nothing to do with it, the output impedance of the amplifier is definitly not 8 ohm (In a good amp it should be well below 1 ohm, i.e. close to an ideal source) , and as I pointed out the impedance is far from constant anyway so impedance matching is not an issue.

It is simply related to how much current the amp needs to supply, even a 200 W amp will have problems with a speaker with a very low impedance because there are limits to how much current it can supply.
The rating of the speaker is just suppose to give you a rought idea about how difficult it is to drive. In a modern system is almost always irrelevant.

 

[drag]

The only side effect is that your reciever will run slightly hotter.

 

[uart]

Yes, as others have said you can connect the 6 ohm speakers without any problems.

The reason they specify 8 ohms on some amplifiers is that the THD (total harmonic distortion) is often better with a slightly higher impedance load. As long as you dont plan to drive those speakers too hard then 6 ohms should be fine.

 

[Mday]

Originally posted by: uart
Yes, as others have said you can connect the 6 ohm speakers without any problems.

The reason they specify 8 ohms on some amplifiers is that the THD (total harmonic distortion) is often better with a slightly higher impedance load. As long as you dont plan to drive those speakers too hard then 6 ohms should be fine.

yeah, definitely dont run the speakers too loud. depending on wattage, your max volume on your receiver can blow the speakers.

 

[f95toli]

That is actually something of a myth. You CAN of course blow your speakers but if you have speakers with "normal" sensitivity (aorund 89-21 dB) then you are more likely to blow your ears than your speakers.

The main reason why speakers are destroyed is actually clipping, and that is due to the amplifier not having enough wattage, if the amplifier can not supply enough current it will "clip" which means that a DC current will flow through the coil, and that will destroy your speaker very quickly.
The point is you are more likely to blow your speakers with a low wattage amp than with a good 200W amp.

 

[boomdart]

If I hook the 6 ohm speakers to the receiver, it cuts off after about 8 seconds of play.

So I need to learn how to hook them to 8 ohm. :/

 

[brentkiosk]

Do you have 8 ohm speakers to try? If so, does it NOT cut off with those? As f95toli said, the real output impedance of the amp should be very low - well below either 6 or 8 ohms and the amp should not care. How loud are you playing it when it cuts off in 8 sec? Both high volume and low? It sounds a lot like it might be something other than the speakers.

 

[uart]

If I hook the 6 ohm speakers to the receiver, it cuts off after about 8 seconds of play.

That's surprising. Most amplifiers are current limited or even power limited, and those things can cause a trip, but I've never heard of speaker impedance being monitored and protected in it's own right.

Well if you really want 8 Ohms then just get yourself a coulple of 2.2 Ohm 5W resistors and stick them in series with the speakers.

In the mean time (just to test it) why don't you put your 2 existing speakers in series (giving 12 Ohms) on just one channel (either left or right) and leave the other channel unconnected. Test this to make sure it doesn't still cut out.

 

[boomdart]

I'm using 8 ohm aiwa speakers right now, but my 6ohm aiwa speakers are much better sound quality. I was planning on hooking all four up, if at all possible. (Reciever has four channel output in surround mode) Otherwise it gives 80w x 2. In surround I believe it's 60w x 2 and 40w x 2 rear. (All RMS)

The 8 ohm speakers will turn about half way up, but they're not powerful enough to get any louder without distortion. If my dad hadn't destroyed my Marantz speakers I wouldn't have this problem >_<

I rarely use my stereo for playing music, I have the receiver hooked up to my game cube, xbox, ps2. I mainly use my computer for music right now; no cd changing and 4.1 klipsch's don't sound bad at all, had these puppies since they came out...Although the damned volume control pod keeps going out, that pisses me off. I'm on my fourth one now!

I'll try hooking both to the same channel here in a second. Hopefully it doesn't *have* to be 8ohm or nothing.

 

[f95toli]

What is the sensistivity of your 6 ohm speakers? The fact that the amp cuts off probably means that it is overheating (protection circuit), are you trying to play very loud, or? What happens if you just play at a very low volume?

And I don't understand what you mean by "powerfull speakers", how load you can play has nothing to do with the speaker wattage rating, it is mainly related to the sensistivity (using speakers with very high sensistivy, for example a horn-loaded speaker, you can play extremely loud even with a 5 W amp)

 

[boomdart]

Read my newest edit to the original post...

Actually, just looked, and the ones I thought was 8 ohm, are 6 ohm too... wierd...

I guess it was just the wire I was using to extend the speakers that it just didn't like?

i've got all four hooked up now, but they sound really wierd in surround mode...

Two pairs of speakers, one is 15w the other is 40w.

By "powerful enough" I meant that the speakers didn't aren't good enough to be played @ any louder of a volume. I need more powerful speakers to get more volume out of them; how could that be taken any other way?

I have no clue what the sensitivity of the speakers are.

 

[uart]

So you had a short circuit in your wires or what ?

 

[f95toli]

I van assure you that you can play very loud on a speaker which is rated 15W. Again, it is usually not the wattage but the sensitivity that is relevant (15W of continuos power is LOUD), if the sensitiviry is high enough. What is the sensistivity of the speakers? It should be in the specifications.

 

[boomdart]

I don't have a clue what the sensitivity is, i've had these speakers for years. Aye, it'll play very loud though. But not as loud as my good speakers used to be, and they don't have much bass at all.

I still have a slight problem with playing all four at once though... Oh well, I've stopped worrying about it...

 

[PrinceXizor]

All you ever wanted to know...and a little bit more.

This article is written from an audio studio (thus "audiophile") standpoint. But it has a section on speakers (for those that don't know, they're called monitors in the studio realm) and amps and the problems/non-problems involving impedance.

Linky

P-X