Originally Posted by ss3740
Originally Posted by kbarnes701
Thanks, and I think we are zeroing in on this
M&K B1600 Bookshelf Speakers
IMPEDACE: 4 ohms
MINIMUM POWER: 10 watts RMS
RECOMMENDED POWER: 25 - 200 watts RMS or more
MAXIMUM POWER: 200 watts RMS unclipped peaks
FREQUENCY RESPONSE: 30 Hz - 20 Khz [+ or -] 2db
MAGNETICALLY SHIELDED: yes
DIMENSIONS (H x W x D): 11-5/8" x 7-1/2" 10-1/4"
WEIGHT: 12 lbs.
Here are my speakers. There are 7 of them. And 2 MK subs. I could not find any efficiency specs. I think the 4250 just does not have enough butt to run them as the Marantz 7500 did. The current draw is coming from my Furman Elite 15-DM. It is registering all current, TV, OPPO, and Denon. I think one of the subs goes thru it to, but nothing has changed ,other than the swap in receivers, and the current draws are as I specified. With the Marantz in place ,it drew 12 and the Denon 4. The old Marantz was rated at 105.. Something is telling me the Denon is overrated. What else could it be
You left out the sensitivity of the speakers. M&K usually go for around 89dB/watt/metre - I googled briefly but couldn’t find the info. The 4530 is definitely capable of driving 4 ohm speakers and there are many users here doing just that without problem so it isn't the impedance that is the issue. Similarly, the 4520 has more than enough grunt to power these speakers to decent levels. If my estimate of 89dB sensitivity is correct (I have a lot of experience with M&K speakers) then you need just 1 watt to hit 89dB at 1 metre, which is pretty loud anyway. 40 watts from a listening distance of 9 feet will give you about 100dB, which is louder than most people listen. As the 4520 is more than able to deliver 40 watts to all channels, then you are not lacking power, assuming you are not sitting 20 feet from the speakers of course. If you are, move closer.
WRT to the current draw it is what it is. There is a simple rule of physics which determines the relationship between volts, amps and watts as you probably know. The Marantz cannot draw 12 amps, end of. I am not disputing what your gizmo tells you, just that it is not possible unless we break the laws of physics, and Scottie was right on that one even if he was so often wrong about dilythium crystals. I am not sure what is going on there but an amp rated at 105 wpc (2 channels driven) cannot draw 12 amps. Typically it would perhaps run about 70 watts with 7 channels driven, so that is 490 watts total - on a 110 volt mains, that would give a current draw of about 4.5 amps. Like I said before the marantz would have to be on about 1,300 watts to do 12 amps - or close to 200 watts per channel. No way.
Bottom line is this IMO: you do not have an amplifier problem. Whatever problem you feel you do have is difficult to diagnose at distance. You have good subs so you should be getting plenty of mid-bass slam.
You haven’t mentioned the crossover setting you are using. If it is the commonly used 80Hz, try upping it to 100Hz and let the subs do more of the heavy lifting. I have the much bigger M&K S150s and I cross them at 100Hz for the same reason - to let my dual Submersives do what they were designed in heaven to do...
Edited by kbarnes701 - 2/24/14 at 3:22am