Hi folks, I see this thread hasnt had some activity for a while, but I am experiencing a similar problem on my Marantz SR 6004 - no mid bass.
Basiclly, the symptoms are like that of connecting a big speaker on a small low power amp that just seems to not be able to 'drive' the speakers.
Granted, I am currently playing with old pioneer speakers which most certainly dont come close to B&W 683 Im pondering buying, but there is definitely something weird about the Marantz receiver.
In my case, yes I have read the manual & also played with the settings, positions & speakers. I am trying everything in 2ch stereo mode as its all about the music performance, & for the purposes of that performance, I dont use the sub.
Sure, my B&W 608 Subwoofer takes care of the low bass, but booming isnt what we want here. Im currently having to crank the LPF crossover from the receiver to 160Hz (which is a lot higher than my preferred 100) just to compensate for the complete lack of bass from my floor standers.
Thats not too bad, but then the overlap between 160 to the 400 odd mark makes the base sound quite hollow & not clean fast punch.
Once again, I iterate, I dont want a cerwin vega boom box, I want flat response, but not at the cost of dull performance.
I dont want to use all 7 speakers & so engaging audyssey doesnt change much.
Ive tried by increasing the bass to max +6 but it doesnt make it better. Its +6 is already bad enough!
Also tried the user EQ & cranked the 60-250hz up but that isnt elegant either. No bass is no bass, cranking the eq only gerates distortion & it isnt going to fix it.
Also, in pure direct or DTS direct modes, the eq is pointless, so the sub will shake the room but the floor standers wont do anything & your system sounds like one of those cheapo sony that come with 5 tiny satellites hanging on a wall
My Pioneer 3 way speakers perform really well on my old pioneer amp.
A friend has (what we would call crap) yamaha rx-v363. I took my speakers over, & the mid base was actually very nice, it worked the woofer. Yes, the receiver wasnt as flat & a tad bright to my taste, but at least we can tolerate that for a $400 device.
Not having any mid bass in my $2000 device is a much bigger problem than having a tad of brightness.
I tried my friends (again crap) Wharfedale speakers on my Marantz, & yes I agree that being a newer design they are probably more responsive & did sound better than my pioneer speakers, but no where near as good as what the yamaha was doing to them.
Also, the marantz SR6004 is 110W discrete. Yet, I had the crank the volume up 10db more that the puny 65w yamaha to get the same level of sound on either speaker, not sure why.
After paying 5 times the price, one expects a lot more out of a receiver.
The review on whathifi.com for the 6 series seems to be very much along the same lines for the mid bass as what im experiencing.
I wold appreciate any tips or experiences you experts may have, & if any one else has noticed this about the Marantz. I sometimes feel like taking it back & actually asking them to fix it as part of the warranty, I get the feeling this is just defective.
Cheers