2 things that kill bass with that setup. First a speaker will return more bass if it is rigidly mounted. If the frame can move it will lower the impact of the cone. Second, a speaker will return more bass if you separate the front soundwave from the back soundwave.

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Paul Niwranski
1966 Cadillac Superior Crown Royale Limousine Hearse

If you're mirrors ain't shakin...you got taken...
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