DIY AGC and Bi-quad filtering

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Hello
First my goal is to build a small portable stereo speaker having a "okay" low end and a sound which can fill a small room.

Active Drivers in consideration
1. Dayton Audio CE42p-4
2. Dayton Audio CE56p-4

Amplifier
1. PAM8403: 3W class d

Power source
1. Single 3.7V 2600mAh cell

To complement the low end, a passive can also be used, Peerless 830878.

But the target volume is less than 0.03ft3. Need two drivers in a small enclosure.

Simulating in WinISD Pro, I applied Linkwitz transform to both speakers, in a sealed enclosure, with a Butterworth Highpass filter at 100Hz, respectively. Signal at 3W.

1. For CE42p-4
Box Volume - 0.015ft3
Fsc - 169Hz
Qtc - 1.020

2. For CE52p-4
Box Volume - 0.017ft3
Fsc - 240.45
Qtc - 1.091

The low end, more specifically at 100Hz, the excursion looks no good. Quite damaging. You can see it in the attached image, the white circled region.

Since, these drivers are not capable of wow bass, I am looking for something around 100Hz but definitely less than 140Hz.

Can someone suggest me the corrections to be applied to manage the high excursion at just about the new Fs? Again wouldn't mind a passive.
Is it possible that an AGC would help to control the power delivered in the low end, and thus contain the over excursion problem?
Please note the power source is a single li-ion cell.

Thank you.
 

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