A Hifonics coaxial speaker? I understand that you don't want to spend a lot of money, but IMO, you got exactly what you paid for..
If you run 1500watts to a dual subwoofer sub stage, don't think a set of cheap coaxial speakers will be able to keep up with their SQ or SPL of your sub stage..
If you want to have a balanced sound system, spend as much on your front stage as you spent on the sub stage. Subwoofers are cheap anyways and dime a dozen. You can get have great SQ with a $100 subwoofer. The front speakers on the other hand will cost you a lot more if you want SQ and SPL
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There are a few decent oval speakers:
Hybrid Audio Mirus coaxial speaker (the 5x7 version, this is based on the popular Hybrid Audio Imagine line woofer)
JL Audio C5-570x coaxial speaker
JL Audio C5-570 component version of the same
Image Dynamics XS-57
If these are not satisfactory, look into components with round woofers. One good example is Massive Audio CK6 series, though you probably want to budget >100watts channel for these. A lot of people have been praising recently JBL's MS-series MS-62C speakers, and being priced at under $200 these should be a good value based on reviews.