Both channels shut down immediately. And a red light in the power button of the amplifier turns on.
Here in Chile i have 50 hz 220 volt outlets. I want to test with a transformer from 220 to 110. Probably the spaekers was in the incorrect voltage because the speaker said that is 110 volt, but i dont know if the store changed the voltage of the speakers, because is very weard that the speaker dont burned down.
Best regards
Best regards
My amp have only two channels. what i can do is bi-wire the speakers. I dont know if that is going to solve the problem
Have you ever heard these working for more than a few minutes?
Apparently if a USA 60Hz version (yours?) is played on 50Hz (even with correct voltage stepped down to 110VAC), the mains-frequency detect circuit causes the HV to shut off after a while...
They just need an amp that can deliver current not just voltage. SL3 are wonderfully sweet and articulate with an 40 year old 200 watt Threshold amp played to near clipping. They are wonderful with a 25 watt Nelson Pass designed DIYAUDIO BA3 that I built played comfortably loud. With these amps they are lightning quick with transients that will make you an electrostatic fan for life. Most of the time I'm using them with only about 1 watt of juice. But even at reasonable volumes the SL3 sounds dreadfully harsh and thin with no dynamic range with my wife's Yamaha and Sony integrated amps. They just can't deliver the current. They have dinky transformers and weigh nothing. SL3 are not easy to drive but they can reward richly if fed properly.
When you measure impedance of the speaker(s) did you just use a multimeter to measure the DC resistance or did you have equipment to measure impedance over the full frequency range ? Speakers that are so called difficult loads can drop very low at certain frequencies. Most amplifiers can't handle this. Some do better than others, for instance I have a have a Hafler DH-500 amp that I accidentally shorted the speaker banana jacks once and it kept playing into almost a dead short, albeit at greatly reduced volume from the speaker. The old Hafler MOSFET output transistor amps (DH-200, DH-220, P-230, DH-500) have been reported to do pretty decent with some difficult load speakers and I've seen some NAD amplifiers that also did pretty decent too. FYI the old Hafler amps had no problem putting their full current at high frequencies into low impedance loads.
If your problem is the amp, you ideally want an amp that can double or nearly double the power into 4 ohms. a modern example is the Vidar amp from Schiit.com
As a trouble-shooting option, you could try some 4 ohm high power resistors in series between the amp output and the speakers. That will alter the frequency response based on the impedance variations and reduce the volume, but it will limit the current to a safe value that the amp should be able to handle without shutting down. This will tell you if the issue is the current limit of the amp. Some of the so called "competition" car amps can handle very low impedance loads of 2 to 0.5 ohms. If you can borrow one with a car battery it should also be able to handle the load at least up to its fairly high current limit. This should help trouble-shoot what the issue might be.
The general rule is the more difficult the load, the more current you need from the amp to handle it properly. An example of this is some of the old Infinity speakers that were known as "amp killers" because they had impedance dips that sometimes were at 2 ohms or lower ! They tended to fry amps !
If your problem is the amp, you ideally want an amp that can double or nearly double the power into 4 ohms. a modern example is the Vidar amp from Schiit.com
As a trouble-shooting option, you could try some 4 ohm high power resistors in series between the amp output and the speakers. That will alter the frequency response based on the impedance variations and reduce the volume, but it will limit the current to a safe value that the amp should be able to handle without shutting down. This will tell you if the issue is the current limit of the amp. Some of the so called "competition" car amps can handle very low impedance loads of 2 to 0.5 ohms. If you can borrow one with a car battery it should also be able to handle the load at least up to its fairly high current limit. This should help trouble-shoot what the issue might be.
The general rule is the more difficult the load, the more current you need from the amp to handle it properly. An example of this is some of the old Infinity speakers that were known as "amp killers" because they had impedance dips that sometimes were at 2 ohms or lower ! They tended to fry amps !
Hi,
low ohmic load values are not the real problem here. If the load is ohmic the amp simply will run out of current at some point. The current clipping is a sudden and clearly audible limit.
The problem is rather the range of phase shift of the load (that was exactly the Infinity's burdon, not that its impedance dropped to 2R). It not only requires considerable reactive power to be delivered by the amp, but it also eats up the amplifiers phase reserve (stability margin). Due to it influencing the feedback of the amplifier it alters the amps behaviour long before current clipping occurs. The amp beginning to sound harsh.
The majority of all amps doesn't seem to cope well with phase shifts >45° and only very few can handle 60° plus.
jauu
Calvin
low ohmic load values are not the real problem here. If the load is ohmic the amp simply will run out of current at some point. The current clipping is a sudden and clearly audible limit.
The problem is rather the range of phase shift of the load (that was exactly the Infinity's burdon, not that its impedance dropped to 2R). It not only requires considerable reactive power to be delivered by the amp, but it also eats up the amplifiers phase reserve (stability margin). Due to it influencing the feedback of the amplifier it alters the amps behaviour long before current clipping occurs. The amp beginning to sound harsh.
The majority of all amps doesn't seem to cope well with phase shifts >45° and only very few can handle 60° plus.
jauu
Calvin
Calvin is correct. The stability margin is the bigger problem when dealing with this kind of load. Feed-back free amps have the potential to work better but it still depends on the particular amp design. with a difficult load it would help to use some kind of impedance correction circuit with the speakers to make the overall load to the amp a little more friendly. Zobel networks are one example of this type of circuit used to correct (flatten) a speaker impedance - typically so the crossover network works better.
Unfortunately the best way to design some impedance correction to ease the amp load would require using some sort of loudspeaker measuring equipment as a start. Most people don't have access to this type of equipment. I have A loudspeaker Measuring System (LMS) made by LinearX which is one such system but I don't have any of these speakers to measure to attempt something. If anybody has the Dayton Audio test set available from parts express or one of the other systems that can measure impedance over frequency, and access to these speakers, we could attempt to do something to ease the difficult load a bit.
Lacking that, you'll have to look for an amp that can handle that brutal load. I've heard of some people using an autotransformer to transform a very low Impedance load into higher impedance but I don't know where you would find such a thing and it would probably be significantly costly.
Look at amps that other people have had success with driving these and similarly difficult load speakers.
Unfortunately the best way to design some impedance correction to ease the amp load would require using some sort of loudspeaker measuring equipment as a start. Most people don't have access to this type of equipment. I have A loudspeaker Measuring System (LMS) made by LinearX which is one such system but I don't have any of these speakers to measure to attempt something. If anybody has the Dayton Audio test set available from parts express or one of the other systems that can measure impedance over frequency, and access to these speakers, we could attempt to do something to ease the difficult load a bit.
Lacking that, you'll have to look for an amp that can handle that brutal load. I've heard of some people using an autotransformer to transform a very low Impedance load into higher impedance but I don't know where you would find such a thing and it would probably be significantly costly.
Look at amps that other people have had success with driving these and similarly difficult load speakers.
How about trying a PA amplifier, like the one attached? It handles tough loads and has "impedance compensation"....
This is more of a question than a suggestion, since the OP will surely consider that PA Class D is not "Hi End" ....
Behringer | Product | NX3000D
This is more of a question than a suggestion, since the OP will surely consider that PA Class D is not "Hi End" ....
Behringer | Product | NX3000D
That's certainly an interesting and powerful option that should work very well. While PA amps are not considered "hi-end", they certainly are not bad and normal consumer amps exhibiting current limiting, clipping, etc are certainly far worse that the slightly higher distortion or whatever slight degradation you probably get from a PA amp.
You just have to be careful about fan noise on some of them, but most class D amps don't generate much heat to really need fans running all the time.
You just have to be careful about fan noise on some of them, but most class D amps don't generate much heat to really need fans running all the time.