what impedance to use with new speakers help ?

[Meridius]

Hi all

I just bough some cambridge audio sl30 to go with my A2 amp.

my amp has 2 settings for imedance

upper setting (Main
if you use one pair of main (A or B) the impedance of each speaker must be 4ohms or higher

if you use two pair of main(A & B) the impedance of each speaker must be 8ohms or higher

lower setting (Main
if you use one pair of main (A or B) the impedance of each speaker must be 8ohms or higher

if you use two pair of main (A & B) the impedance of each speaker must be 16ohms or higher


now the cambridge audio sl30 say the impedance are 4-8ohms

so which do i use on my amp ? i am only use 1 pair of main on B i do not have any other speakers pluged in as its for stereo only.

can anyone help me as it seems that i can use upper and lower but i was woundering if it would make any difference to the sound quality from 4 or 8ohms

cheers for any help

 

[njedpx3]

Hi all

I just bough some cambridge audio sl30 to go with my A2 amp.

my amp has 2 settings for imedance

upper setting (Main
if you use one pair of main (A or B) the impedance of each speaker must be 4ohms or higher

if you use two pair of main(A & B) the impedance of each speaker must be 8ohms or higher

lower setting (Main
if you use one pair of main (A or B) the impedance of each speaker must be 8ohms or higher

if you use two pair of main (A & B) the impedance of each speaker must be 16ohms or higher


now the cambridge audio sl30 say the impedance are 4-8ohms

so which do i use on my amp ? i am only use 1 pair of main on B i do not have any other speakers pluged in as its for stereo only.

can anyone help me as it seems that i can use upper and lower but i was woundering if it would make any difference to the sound quality from 4 or 8ohms

cheers for any help

Cambridge Audio are great speakers, but you are going to be driving them with very little of the Anthem's A2 power. The lower/higher settings are designed to protect the amp from having too much current. Obviously, if you have lower nominal impedance (remember impendace vaires with frequency and is not a single value) you will have higher current. Almost every amp that has mulitple output impendance setting has a resistance shunt for lower impedances to protect the amp.. not to enhnace sound. So I would surmise the A2s higher setting is actually adding and internal resistance to limit the current and protect the A2. Now to further support my statement the A2 is rated at 200 watts per channel into 8 ohms and only 300 watts per channel into 4 ohms. Actual power if not shunted and assuming no power phase loss would be 400 watts per channel.

Bottom line, either setting will work fine because you have more power than you will ever use with you Cambridge Audio SL 30s. However, I personally would use the lower setting.


Peace and Good Sound,

Forest Man

 

[Meridius]

thanks for that why would you use lower setting over the high setting if both are ok to use ?

 

[Codifus]

thanks for that why would you use lower setting over the high setting if both are ok to use ?

I have a similar switch on my Yamaha integrated amp. What the switch did was tap 2 different areas of the transformer.

In 8 ohms or greater mode, the switch set itself to access the full voltage output of the transformer, and hence, the full capability of the amp.

In 6 ohms or less mode, the unit tapped a lesser voltage output, thereby never energizing the voltage rails fully, so to speak.


Basically, in 6 ohms or less mode, you never get the full potential of the amplifier's power, a protection to prevent from burning itself out.

The safe answer would be to use the low setting, but the high setting is the only one which will give you all of the amplifier's true capability.

I would try the high setting and watch if the amplifier gets warm/hot too easily when playing music "enthusiastically"

CD

 

[Meridius]

cheers for that

i dont play music very loud at all as i am in a room that is 8ft by 10ft and i dont need to go past 30db, I play music at 50db to 35db no more no less.

i have it set to

upper setting (Main
if you use one pair of main (A or B) the impedance of each speaker must be 4ohms or higher

at the moment, so this should be the safer option ? would it make the amp last longer do you think as its 10 years old and the main A left side has gone and i am using the main B as left and right a fully working.

 

[Codifus]

cheers for that

i dont play music very loud at all as i am in a room that is 8ft by 10ft and i dont need to go past 30db, I play music at 50db to 35db no more no less.

i have it set to

upper setting (Main
if you use one pair of main (A or B) the impedance of each speaker must be 4ohms or higher

at the moment, so this should be the safer option ? would it make the amp last longer do you think as its 10 years old and the main A left side has gone and i am using the main B as left and right a fully working.

Yes, that is the safer setting. As for longevity, I really don't think that impedance switch helps your amp last longer either way. Rather, longevity would be more determined by how well the circuit components are soldered to their PCB or what state your capacitors etc are in. In other words, longevity is determined mainly by how well the device holds up physically. Also, by choosing the safe setting, you have pretty much guaranteed that the amplifier won't have any electrical longevity issues because it will not push out too much current.

CD

 

[j_garcia]

Because of the current limiting in 4 Ohm mode, I would set it to 8 ohms. It will handle a lower impedance load just fine in that mode; that is most likely the default setting anyway. As has already been mentioned, you won't be using all of the available power so it should not be an issue.

 

[Meridius]

Because of the current limiting in 4 Ohm mode, I would set it to 8 ohms. It will handle a lower impedance load just fine in that mode; that is most likely the default setting anyway. As has already been mentioned, you won't be using all of the available power so it should not be an issue.

strange if it can handle 4ohm in 8ohm mode why even have a 4ohms mode then ?

but even if i am not using the full power what is the harm in leaving it set to 4ohms would this not be safer ?

why would cambridge audio sl30 say the impedance are 4-8ohms why not just pick one or the other ? does it mean if a amp does not have a switch the speakers would work on a amp that has 4ohms only or an amp with 8ohms only without the switch ?

dos it mean that these speakers will work on a amp set to 4 or 8ohms ? if thtas the case it should not matter where i have the switch correct ? only that setting the switch to 4ohms is limiting the power to teh amp wheres 8ohms gives me full power

so these speakers willl work on both settings is this what cambridge audio sl30meain

cheers sorry for all the questions

i also have a pair of kefs on another amp a yam 3900 and they say there 8ohms only which i have set it to on the amp so some speakers must be only 8ohms and work on amps that have 8ohms or higher wheres some must be both 4ohms and 8ohms and these cambridge audio sl30 would work on amps that are 4ohms only

is this right

 

[Codifus]

strange if it can handle 4ohm in 8ohm mode why even have a 4ohms mode then ?

It can handle 4 ohms, but not fully. If you have 4 ohm speakers, the switch is set to 8 ohms, and you like to play music loud, using the full extent of the amplifier's power, then the amplifier may burn out.

but even if i am not using the full power what is the harm in leaving it set to 4ohms would this not be safer ?

It is safer, but you are also making a sacrifice: you are not getting the amplifier's full capability. It's a trade-off, and you have to make a choice.

why would cambridge audio sl30 say the impedance are 4-8ohms why not just pick one or the other ? does it mean if a amp does not have a switch the speakers would work on a amp that has 4ohms only or an amp with 8ohms only without the switch ?

Speakers are complicated. When called on to play a 50 Hz tone, the resistance of the speaker will be different than when it is called upon to play a 5000 Hz tone. Music contains the full range of frequencies from 10 Hz all the way to 20,000 Hz and beyond. The speaker will play most if not all of those frequencies but it's resistance will vary.

dos it mean that these speakers will work on a amp set to 4 or 8ohms ? if thtas the case it should not matter where i have the switch correct ? only that setting the switch to 4ohms is limiting the power to teh amp wheres 8ohms gives me full power

Yup.

so these speakers willl work on both settings is this what cambridge audio sl30meain

Yes, but be careful in the 8 ohm mode if you have 4 ohms speakers and play it loud. Like I said earlier, if the amp gets warm, chances are that the 4 ohms speakers are making the amp work very hard, and it may be close to burning itself out.

i also have a pair of kefs on another amp a yam 3900 and they say there 8ohms only which i have set it to on the amp so some speakers must be only 8ohms and work on amps that have 8ohms or higher wheres some must be both 4ohms and 8ohms and these cambridge audio sl30 would work on amps that are 4ohms only

is this right

It just means that 8 ohms is only what Yamaha will guarantee to work and not stress it out. If you connect 4 ohms speakers and don't play it loud, they will probably work fine.


Hope this helps!

CD

 

[yepimonfire]

from experience leave the amps impedance switch alone, it reduces the amount of power your amp can put out and makes it not sound as dynamic. i doubt you will turn your speakers loud enough to draw enough power from your amp to ruin it because it would be so unbearably loud before you get to that point.

 

[j_garcia]

strange if it can handle 4ohm in 8ohm mode why even have a 4ohms mode then ?

but even if i am not using the full power what is the harm in leaving it set to 4ohms would this not be safer ?

To protect the amp, but the Anthems are more than up to the task.

why would cambridge audio sl30 say the impedance are 4-8ohms why not just pick one or the other ? does it mean if a amp does not have a switch the speakers would work on a amp that has 4ohms only or an amp with 8ohms only without the switch ?

It means that it likely drops to no less than 4 ohms.

i also have a pair of kefs on another amp a yam 3900 and they say there 8ohms only which i have set it to on the amp so some speakers must be only 8ohms and work on amps that have 8ohms or higher wheres some must be both 4ohms and 8ohms and these cambridge audio sl30 would work on amps that are 4ohms only

Home audio gear is 8 Ohm. Speakers are made lower impedance at the choice of the designer. More powerful gear is typically needed for low impedance loads, but impedance varies with frequency and with only two speakers, it won't be an issue.

is this right[/QUOTE]

It can handle 4 ohms, but not fully. If you have 4 ohm speakers, the switch is set to 8 ohms, and you like to play music loud, using the full extent of the amplifier's power, then the amplifier may burn out.

That is simply not true.

It is safer, but you are also making a sacrifice: you are not getting the amplifier's full capability. It's a trade-off, and you have to make a choice.

"Safer" is sort of the wrong term here. This amp should be perfectly fine driving a 4 Ohm load. Yes it will deliver more current into that load, but unless you actually hear it struggling at the levels you are going to listen at, it isn't an issue. The Anthem amps are well built.

 

[Meridius]

cheers for the help to u all

i will leave it set to the upper postion which is the 4ohms or higher mode as i only play music back at 50db to 35db which is not very loud byt in the small room they sound loud.

this system is only for my office work at home when listening to music as my other system for movies and music has my higher end gear on its just that i neve needed to look into the ohms of a speaker becasue all the ones i have have always been 8ohms untill i got these.

but thanks for the help.