Passive soundbar


Looking to de clutter and move my current second system to become a third system and in doing so am looking to replace my pioneer elite Andrew Jones Dolby Atmos L/C/R towers and center with a passive sound bar being driven by marantz 7007 receiver. I have multiple zones and things hooked up so a powered soundbar is not an option. Guessing I will need to add a sub or two as well given physical limitations of the sound bar.  I have about 43” width and somewhat varying height and depth let’s say 6 to 8 inches high and 7 deep. Not looking to break the bank but doesn’t seem like there are many cheapish options out there.  Am I missing a quality speaker somewhere ?  Would like to keep under $500. 
esthlos13
If your Marantz 7007 receiver can setup without a center channel speaker, you can get two matching "center channel" speakers instead of three, use it as left and right front speaker as @auxinput suggested.

https://www.crutchfield.com/p_107SIGS30/Polk-Audio-Signature-S30-Washed-Black-Walnut.html?awcp=&...

Interesting suggestions. I see Dayton audio has a relatively cheap center and 10” powered subs for just a few hundred- anyone have any experience with those?
I have used Dayton parts (such as a full-range or a woofer).  They are actually very nice for the money.  However, don't go for the ultra cheap stuff.  If you are looking at the Dayton center channel speakers for $50 or less, they are pretty much crap.  Also, the packages that have sub and speakers for $300-400 are also going to be crap.  The idea that you can get more product for "less money" is not a valid one.  In the end, you get what you pay for.
Yep fully aware of the get what you pay for!  The system that’s impacted is a super casual-need-better-than-tv-sound with occasional two channel as background to fill a large space (48x16).  Looks like monitor audio and def tech also have some passives.