The best way to find out whether there are other speakers that you'll like better than what you have now is to actually go and listen to some. Where are you located? If you're in a higher population area, there are likely to be a number of options listed on your local Craigslist. I'm in Syracuse, NY, and there are always lots of them on my local Craiglist.
You'll be able to easily see what people are asking for them in your area; you can always negotiate prices for them. Go and hear them and see if there's anything that you like: nobody else can tell you what you'll be happy with. Just do some internet research on them first, look them over carefully, and make sure you hear them for yourself first.
How about a pair of Altec 604's? I think that might be an eye opening experience.
And you have been asked a few times, "WHERE ARE YOU LOCATED?"
Sorry, I am in Kentucky, USA. Feel no need to get super specific since IMO that is not a factor in sound.
Those pioneers are almost sure to be “better” speakers than the rack system ones, but that’s “better” in the sense that they reproduce sound more accurately. You may or may not like that. Your Kenwoods may very well have a sound that you prefer.
As to brands, each of the bigger brands made a wide range of speakers from really good to often really bad. You really can’t just pick a brand a day go for that one because it’s really pretty meaningless.
Those pioneers are almost sure to be “better” speakers than the rack system ones, but that’s “better” in the sense that they reproduce sound more accurately. You may or may not like that. Your Kenwoods may very well have a sound that you prefer.
As to brands, each of the bigger brands made a wide range of speakers from really good to often really bad. You really can’t just pick a brand a day go for that one because it’s really pretty meaningless.
I totally disagree Kenwood speakers sound quality is stealer , and are highly underrated. The one and only reason people say they are good at best is because of their low price ,, , Ask a professional songwriter or professional musician they more about sound then anyone , I know a few every well-known songwriters and musicians who swear by Kenwood speakers and will say they were a top brandAs pete's picks says above, start with the speakers. Replace them first with something you like, and see if you find the electronics inadequate then.
It's not that Kenwood speakers are bad per se, it's more that speakers weren't their strong suit -- their strength was the electronics. Some of the so-called Kenwood "rack systems" are clearly a cut above the typical cheap rack systems that were pretty common. I have a couple of power amps that were parts of such systems -- a KM-105 and a KM-205, which are essentially identical in appearance and in their published measurements. (It's the same amp with different numbers.) They are rated at 150 watts, which is quite a bit -- more than most receivers. Whether you like how they sound is completely subjective, but for what I paid for them, they were a bargain. I'm not familiar with your units, but they might be better than you think, and maybe you'll be happy with them if you had better speakers.