One is made in China by the thousands at a time right next to a line of umbrellas and another line of Barbie Dolls. The other is made by DD with the best parts that are available anywhere in the subs price range. Reliability and build quality as well as sheer grunt...all fall on the AQ side of the scale. It's probably considered a very biased reply by most here, but I install L7s regularly and DDs regularly. No real comparison. If you pit the Solo X version against the HD3, you may have a more fair comparison.
That is the honest truth you are asking of those who reply to your post.