Receiver and 4ohm center channel speaker..help

[steyer9mm]

I just purchased a Marantz sr4600 receiver. The receiver can drive speakers that are minimum 6ohm.

The speakers i am using:
1)M&k k5 for the front left and right which are 8ohm
2)M&k k7 for the center channel which is 4ohm
3)M&k k4 for the rear left and right surround which are 6ohm
4)M&k vx1250 subwoofer

When watching a movie in 5.1, anything loud will cause the receiver to shut down. I am thinking the center channel at 4ohm is what is causing the receiver to shut down. Is this correct? Before the Marantz sr4600, i had an older pionner elite receiver (vsx-14) which also had a minimum 6ohm requirement for speakres but i had no problems driving all of my M&k speakers. Is there anything i can do to prevent the Marantz receiver from shutting down? Or do i have to return it and get another one? Its kind of lame to return the receiver because it can drive one center channel speaker at 4ohm if it is inded the problem. Please help....thanks

 

[tbewick]

It sounds like you are driving your amplifier and speakers too hard. You could try listening at a lower volume or buy some better speakers and/or amplifier.

It might also be worth double-checking all the speaker cable connections and receiver settings.

I've found this simple SPL calculator (linked to on the main Audioholics site) helpful in getting an idea of how loud you can play your system:

http://www.myhometheater.homestead.com/splcalculator.html

I run my 90 watt amplifier 3 dB lower than maximum volume for extra headroom (~half-power).

Another thing you could do is to roll-off the bass and treble slightly as this will relieve some load from the power amp. Activating cinema/THX eq. may also reduce strain on the amplifier.

 

[mtrycrafts]

I just purchased a Marantz sr4600 receiver. The receiver can drive speakers that are minimum 6ohm.

The speakers i am using:
1)M&k k5 for the front left and right which are 8ohm
2)M&k k7 for the center channel which is 4ohm
3)M&k k4 for the rear left and right surround which are 6ohm
4)M&k vx1250 subwoofer

When watching a movie in 5.1, anything loud will cause the receiver to shut down. I am thinking the center channel at 4ohm is what is causing the receiver to shut down. Is this correct? Before the Marantz sr4600, i had an older pionner elite receiver (vsx-14) which also had a minimum 6ohm requirement for speakres but i had no problems driving all of my M&k speakers. Is there anything i can do to prevent the Marantz receiver from shutting down? Or do i have to return it and get another one? Its kind of lame to return the receiver because it can drive one center channel speaker at 4ohm if it is inded the problem. Please help....thanks

Most likely it is the center speakers as it gets more action than you think.

 

[Jack Hammer]

Nice set-up, those tiny speakers really put out a lot of clear sound. I'm not familiar with your reciever. However, I was running the exact same speaker set up (K5 l/r,K7 ctr, K4 sr) with my Denon 2805 (100wpc) and never had a problem. Now I'm running M&K LCR851 (4 ohm & bigger) in l/c/r with the K4's as surrounds and the K5's as surround backs and a VX860 sub without any problems at all. The 2805 is also rated for only 6ohms.

I've also run the K5's and K7 in front on my older lower end RCA 60wpc (only rated for 8ohms) reciever w/o any problems. You may want to check the reciever out.

BTW even though M&K's website lists the K4's as being 6 ohm speakers, the owners manual, their catalog, and the product specsheets all list them as being 4 ohm speakers.

 

[j_garcia]

My brother runs a pair of LSi7s off a 4300 and it seems to do OK. All my speakers are 4 Ohm, but only my center and surrounds are being driven by the receiver. Prior to adding the monoblocks, the receiver struggled. A single 4 Ohm speaker shouldn't be a problem unless it is relatively power hungry. The key thing will be, if it starts to sound distorted, TURN IT DOWN.

 

[heroesunplugged]

M&K's

I have a pair of M&K s100b's (also 4 ohms) that I have connected to a Pioneer VSX-1015 and have never had any problems. M&K's are very efficient so it sounds like your amp. I would try disconnecting the center channel and set the center channel to off/no in your speaker settings on the 4600's speaker setup menu and see if it still shuts down. If it doesn't then it's the center channel amp that can't handle the 4 ohm load.

If you want to sell your center channel let me know!

 

[j_garcia]

Well, the fact that you also have the 6 Ohm surrounds combined with the 4 Ohm center means you are dipping into the range where this receiver can't handle it. It means your Marantz is less tolerant of low impedance loads than your previous receiver. Is the Marantz well ventilated? Maybe it's a thermal shut down? Low impedance loads will cause the receiver to heat up more. How high are you listening? What do you have the speakers crossed over at?

I agree with herosunplugged, you should probably turn off the center and see if the problem persists. Does it do the same thing if you just play music in stereo?

 

[Jack Hammer]

...Or you could try putting an 8ohm speaker in the center and see if that makes a differance.

I forget where i saw it, maybe secrets of home theater, but someone had some technical reviews of the M&K speakers that listed impedance across the spectrum. Most of the 4ohm rated speakers never dipped below 3.6ohms during the testing and generally averaged around 6-7ohms. I forget which speakers were tested and the exact numbers, but it was somewhere in that range.

Again, try any 8ohm speaker you can find in the center and see if it stops shutting down.

 

[steyer9mm]

Thanks for the great advice guys.

I had the marantz sr4600 for a couple of weeks so i figure the quickest and easiest way to solve is to get another receiver. I returned it and found an excellent deal. I just picked up a pioneer vsx-9300tx which is bascially the exact same thing as the pioneer elite vsx-56txi which sells brand new for 1700. I got the vsx-9300tx for 600 From what i hear, this receiver will have no problems driving all my m&k speakers

 

[Jack Hammer]

Cool,

Let us know in a few days how everything works out for you.