Japanese speakers to US receiver

The electromagnetic spectrum does not know a difference between the USA and Japan. As long as the speakers have the right impedence for the reciever, and will accept a little more power than the reciever is capable of putting out (so you don't blow the speakers) everything will work fine.

 

In general, conventional speakers are pretty much universal--that is, you can connect them to anything that will work electrically. My speakers are from the UK, and, over the years, they've been powered by amplfiers and receivers from the UK, the US, and Japan.

The only possible problem area I see above is with the impedance on the speakers of 4 ohms. That is too low for some amplifiers/receivers. Your owner's manual should have some indication what the minimum acceptable impedance is. Also the back panel of a receiver usually mentions something, most often around the speaker terminals. Something like "4 ohm minimum." They might use "Ω" instead of "ohm." Sometimes an amplifier/receiver will be OK with 4 ohms, but need some adjustment, like flipping a switch.

---------- Post added 7th Sep 2013 at 11:12 PM ----------

Actually it can be safe having more power than the speaker can take. Yes, there is a risk of blowing a driver, but as long as one doesn't push the speaker too hard, it should be OK. Hint: if things start sounding bad, you are going too loud, and you could destroy something.

My speakers are rated at 75 watts maximum. At the time I got them, the dealer suggested as one possibility an amp rated at 150 watts. The most powerful amp I've personally used was rated at 100 watts (steady power), and capable of far more in short term "burst" power. The speakers not just survived, but they actually outlasted the amp.

A bigger problem than too much power is way too little power. An amp that is too weak, and pushed too hard, can destroy speakers.

---------- Post added 7th Sep 2013 at 11:15 PM ----------

By this I mean, of course, having an amplifier/receiver that is capable of putting out more power than the speaker can accept. For example, 80 watts output power for a 50 watt maximum speaker.

 

First, actually JBL is an American company, not Japanese. (Even if your specific speakers are coming from Japan.) Secondly country of origin is pretty much irrelevant. Most standards are pretty much standard world wide, and the only times a company can get away with something radically different is if they have a high end product that is special enough that people who buy it are willing to adjust.

As I pointed out above, the one concern I see is the question of whether the Sherwood receiver can support a 4 ohm load. Chances are pretty good it can, but I have seen some receivers that will not go under 6 (or even 8 ohms). Again, this information should be in the receiver's owner's manual, or (usually) on the back panel.

If a receiver cannot handle a 4 ohm load, it could be damaged by using a pair of 4 ohm speakers.

---------- Post added 8th Sep 2013 at 01:09 AM ----------

Of course, past electrical compatibility, there is the question of how well JBL speakers will work with a given receiver. My main speakers have been powered by an amazing range of receivers and amplifiers over the last 20 years. Every combination has generated sound. But some combinations have sounded noticeably better than others.

 

I did some searching, and found the Sherwood RX-4109 manual on the Sherwood site. It appears that this receiver requires 8 ohms or more:

To get the manual, go to Sherwood's receiver page. Click on the RX-4109 link. That page includes the link for the owner's manual on right side.

 

it might be OK. might not. check the manual... maybe find user forums/etc.
if you do decide to run them, be very careful with the volume, dont just turn it up loud.
What you're eseentially doing is sending unused/unexpected current past the speakers and back into the amp... some amps are built to tolerate this, some are not.

I would recommend getting speakers with 8 ohm impedance

You could add 4 ohm resistors to each speaker, but they need to be rated for the power of the amp, and you'll effectively be halving the amps maximum strength so you need to be careful that you aren't distorting the signal in an attempt to get maximum volume if you do this.

 

Basically, to explain why an amplifier specifies a certain impedence is Ohm's law and Watt's law. Impedence is basically just resistance at a frequency. There is a complex circuit inside the amplifier, and, although this is not desired, all the parts of the circuit give off some heat, even the wires. For a given gain setting of the amplifier and a given input, a certain output will come out. For this example, let's say 8 volts. Let's say the last part in the amplifier has a rating of 10W. Your amplifier is probably going to have this same rating. Also, the amplifier says you should use an 8 ohm speaker. If you do, you will be getting 8 watts out of that ampilifier. If you change to a 16 ohm speaker, you're only going to get 4 watts. If you change that speaker out for a 4 ohm speaker, you're going to end up with 16 watts out, potentally damaging the parts with smaller ratings. (Note that these calculations are based off an ideal amplifier. Real life amplifiers are much more complex)

Ohm's law is Voltage = Current (Amps) * Resistance or Impedance (Ohms)
Watt's law is Power (Watts) = Voltage * Current
These can be combined to give you Power = Voltage squared / Impedence.

 

The only big difference between the U.S. and other places is frequency. In the U.S. it's 60 Hz, other places it's 50.

That won't matter for your speakers, but for example some computer power supplies might have problems. The best way to describe why is, imagine tying a rope to a building and pulling the other end up and down. If you do it fast, the rope goes higher and lower. The power supply has to take that wiggly rope and straighten it out. So if you buy something overseas and it's used to dealing with a rope that doesn't wiggle as much, it might not be able to handle being plugged into a power outlet in the U.S. But U.S. stuff should work everywhere.

Anyway nothing to do with your problem. To stretch the analogy a little further, imagine pulling on the rope. If it's attached to a loose brick, it'll pull right out. That's the only kind of impedance you have to worry about with your speakers. 4 ohm is a pretty loose brick in general, but then the current through a speaker wire doesn't pull very hard so it works out.

 

Or else a different receiver or amplifier.

---------- Post added 8th Sep 2013 at 03:04 PM ----------

The advantage of doing a different receiver or amplifier is that one could potentially get something that would work with a wider range of equipment. One reason I had that 100 watt amp was because it could work with a wide range of speakers. It had a lot of power (real world power), and was safe down to 2 ohms.

 

Put it this way: I personally wouldn't try using 4 ohm speakers with a receiver that is rated for speakers 8 ohms or higher. If that receiver is engineered for 8 ohm or higher speaker loads, it will probably not be happy with 4 ohms. There may be a risk of breakdown. Also, I'd think, the performance may suffer.

One thought: you might try e-mailing Sherwood and asking their advice