Perhaps we should stick with midfi...

I think it helps to have a sound you're trying to recreate in your head. You may be unaware that you are sensitive to missing high end information in a perfectly acceptable sound system until you hear it and it bothers you to the point that you'd rather not listen to music at all as long as the offending sound continues. I was like that when I finally switched speakers after 17 years. The new outrageously well reviewed pair I bought had excellent defined bass, good dynamics, very nice incisive midrange--BUT the highs were closed in like a slightly padded object was covering the tweeter and no matter the position of the speaker, messing with the considerable adjustments one could make on the outboard crossover, I could not get rid of the slightly to markedly closed in highs. I didn't know this even bothered me until I heard it. Others may be bothered in various other ways--lifeless dynamics, not enough or tubby bass, dynamics constricted, etc. You may not even know that it bothers you until you hear it. Man, I'm glad I took a chance on one more set of speakers after that disappointing venture on what I thought would be my last pair from reviews I'd read. Same thing happened with speaker cables. When it's right, it's enjoyable and you can quit anal/oh, analyzing your system and just enjoy the music. After reading another OOH BABY review of some outrageously good cables, I bought a used pair and inserted them in my system. The joy was gone, even after running the system for 2 straight weeks non-stop. Put the other cables (cheap, but also well reviewed) back in and the smile returned to my face. Same thing happened in my basement built dedicated room. I had stuffed the ceiling with 6" fiberglass batting that was a good sound absorber. The sound inside that room was incredibly the moment you walked in the door, clear with zero recognizable defects to my ear, anyway. My brother, in the trades, told me to get glacier ceiling tiles for that room and it will sound even better. I put in a slightly angled drop ceiling where behind the speakers was a little lower and sloped slightly upward to behind my seat. I laid all the glacier tiles in the grids and turned the music on. All the live illusion of music diasppeared and I was left with dull, flat, uninvolving music like a cheap table radio. I couldn't believe what those tiles did to the sound. I replaced most of the glacier tiles with Armstrong's highest articulation tiles that you can only get if you know someone it the trades and 98% of the magic returned like before I put in the ceiling tiles. It's a woefully long post and I'm sorry this lasted so long, but my main point is you'll know when something really bothers you. Try to fix the problem and also, when your system sounds great to you in all areas, QUIT reading about new stuff and just enjoy your system and the fact that you have been fortunate enough to take many different electrical devices connected together so that a very pleasing approximation of live music is coming out and you get to enjoy it most any time you choose. Reading the high fi rags just gives you the itch, the desire to acquire. Then you stay on the neverending treadmill of upgrades and ultimate dissatisfaction that goes with it. Music truly soothes and stirs the soul, wanting something more only stirs the wallet and your degree of unrest. Right now I thank God that I've been one of the lucky ones in this hobby to assembly a reasonably affordable system with outstanding sound. I intend to be very content for years to come and maybe help others reach their lucky point, also.

Good comments all around. I agree with Paperw8 that impedances have to match; but "trust your ears" just means that at the end of the day you have to be happy with your system; and synergy is that intangible (I guess intangibles could be considered "mushy"...) that gives you a little more for your hard earned ducats by giving you that sum-of-the- parts (components)-being-better-than-the-whole thing.
I guess there are some who would have heard the system I disparaged and liked it. I know, because I go to the audio shows, and there are some rooms that are very popular that it just blows me away that people like the sound in them. So everything is relative to the listener's ear. Although we have something of a "fellowship" as audiophiles (for the most part we agree for instance that Bose is crap), there are different schools of thought among us.
I'm lucky to have found an audio cohort that likes pretty much what I like: All tube, vinyl only, SET pretty much exclusively. Ya, I'm that guy.
But that guy considers himself pretty fortunate. I've paid my dues; my system is tits, and even my instincts are pretty good today.

Tough crowd. The guy hopes to get a big lift from securing a second hand system of high end gear and is not impressed. Then he's chastised for not knowing ahead of time. A great way to get more newbies into the High End...

I can understand why Gonglee3 would be disappointed. If you've never dropped more than $1-2K for some gear and poured out several $K for a rig, but it didn't do it for you, wouldn't you be put out?

Regarding him knowing better, you have to hear the respective brands of gear to know enough that it will potentially sound poor with other associated gear. If you've never visited for years as a guest of a high end shop or been to a show how would you know that? I did cringe when I saw the equipment listing of the rig, especially if it's older gear. Perhaps it was at one time $60k of stuff, but now is worth about $10K? That's still a lot of money to most people to dole out for a rig. If it doesn't perceptually sound two or three times better then he'd have some reason to be upset.

Anyway, if the sound is harsh and unforgiving at least one or two component changes are in order. The system obviously is so deficient that tweaking will not resolve it. I would experiment with different cabling, even used much less costly cables to attempt to soften the sound. If aftermarket power cords are not being used I'd snag some from the classifieds here. I would check every piece of equipment to ensure that I've tried every feasible setting in an attempt to moderate the problems. I would get some tubes or, as a distant second option, a very warm sounding SS component into the rig asap. If the bass was boomy I'd try stuffing the speaker port with a sock or foam to turn it into a quasi-sealed cabinet design; it may make it much more pleasant. Maybe a home made sound panel or two would help. It doesn't have to take a lot of money to spiff it up.

Do not be afraid to swap components from your other rig into the new one to see what it does! Get a feel for as many component combinations as you can. I would double check to see if the Quad amp can drive the speakers, then put it into the mix and see what it does to the sound. I would try the Parasound player with the new rig. I would probably try the NAD/Onkyo combo if deemed sufficient to drive the B&W. You may love the rig a lot more with just one or two changes. In any given rig the synergy between components may more than offset the removal of a slightly higher quality component. All things equal you want the highest quality stuff in the rig. But, if you can't stand the sound of those components, switch things around! I have made many systems with mostly higher end components and just one, and definitely no more than two, moderately priced components and gotten good results. No, not SOTA sound, but very nice sound.

Think in a fluid way about forming systems; don't compartmentalize your rigs. You don't like the main rig's sound now, so mix it up. Putting one different component into the rig may have profound influence for the better. You have enough gear that moving cables, amps etc. might get you a lot closer to something you like on the big rig. No matter the result you will learn a lot about how incredibly variable the sound can be with different gear. My guess is that you'll stumble onto a combo that you like a lot more than the current one.

Keep at it, Gonglee, because that rig has potential - a lot more potential than you think, perhaps a lot of potential. But it will take time and effort to coax the best out of it. You invest the time and an perhaps a bit more money and it might become a dream rig for you. If that happens you won't be so quick to sell it back. :)

Douglas - I like you suggest to mix and match with the OPs other system. I'd probably take one of the new components and hook it up in the old system and see if the sound improves. The next step might be to take one component from the old system and hook it up in the new and see if the offending component could be identified. If it turns out that changing a single component makes a nice difference, it could give some direction for a higher end replacement unit.

Everyone here is very kind and offering sage, well thought out advice to the OP. You are all to be commended.

I'll still bet that this person is a Troll, although I hope to be proven wrong when he posts some pictures to 1 of his 4 systems.

Again, I contend he's just tossing this group as the equipment he mentioned simply doesnt compute. Krell, Audio Research, McIntosh fronted by a Sony CD player feeding 802d's. Maybe if he would post pictures and describe the setup I would feel less like he's yanking our chain.