Need a subwoofer for FR10 bookshelves.

[50AE]

I've been offered for very cheap small bookshelves fullrange speakers with Visation FR10 8 ohm drivers. Visaton - Lautsprecher und Zubehör, Loudspeakers and Accessories

Of course, they struggle on the lows, so I'd like to build a subwoofer for them. My questions are:
-What should be cut off frequency?
-What should be the order of both of the crossovers?
-What should be the nominal power and sensitivity compared to the drivers - subwoofer to satellite ratio?
-Because of availability, I'd like to use a visaton speaker. Can you recommend me one?

The crossover of the sub could be made active with a variable cut off frequency, in case I get a bad frequency response.

 

[bjorno]

I've been offered for very cheap small bookshelves fullrange speakers with Visation FR10 8 ohm drivers. Visaton - Lautsprecher und Zubehör, Loudspeakers and Accessories

Of course, they struggle on the lows, so I'd like to build a subwoofer for them. My questions are:
-What should be cut off frequency?
-What should be the order of both of the crossovers?
-What should be the nominal power and sensitivity compared to the drivers - subwoofer to satellite ratio?
-Because of availability, I'd like to use a visaton speaker. Can you recommend me one?

The crossover of the sub could be made active with a variable cut off frequency, in case I get a bad frequency response.

Hi,

Why not build a low footprint sub using the 8” Visaton AL 200 driver using a ported design.

IMO, best SQ if converting the most promising box(70L BR) recommended by the manufacturer to a T-TQWP.

My suggestions are: XO somewhere between 120-145 Hz using a 24 dB LP filter for the sub and for the FR 10 use a 12dB HP filter.

When placing the sub somewhere at 1 - 0.5Pi space angle: One Visaton AL 200 driver in a T-QWP will match the two FR 10:s sensitivity well.

b

 

[tb46]

Hi bjorno,

Interesting design. You may want to check, but I think in your drawing you swapped the S1 and S4 designations.

Regards,

 

[bjorno]

..I think in your drawing you swapped the S1 and S4 designations..

Thanks tb46, for being observant!

Agree, You're right, In the picture S1 and S4 should be swapped

b

PS: The driver offset distance is not correctly predicted in HR as the crude picture is depicting but this discrepancy is IME of minor importance...obvious noticed if simulated in MJK:s program using appropriate amount of damping material.