ML-1C Dampening Material ?Question?

[Refugee]

I have a pair of ML-1C speakers acquired last year that I plan to recap the crossovers on. I have the caps and resistors and material to put the woofer back in with a proper air tight seal. When reading Roger Russell's page I saw that the speakers are an 'overdamped' design. I believe this has to do with the sealed cabinet and also the fiberglass stuffing inside to keep the bass driver 'tight' and reduce any movement of the cone that is not caused by the magnet and coil...to stop any reflexing action from the surround.

Before I open the speakers to get to the crossover I would like to know you guys thoughts on the replacement of the 'stuffing' inside the speaker.
Should it actually touch the rear of the speaker?
Should more be added?
Am I right to think that the stuffing is there to mechanically restrict the movement of the cone?
Any insight into properly replacing the stuffing and the part that plays in the speakers performance would be greatly appreciated.

 

[TSmith8605]

I have a pair of ML-1C speakers acquired last year that I plan to recap the crossovers on. I have the caps and resistors and material to put the woofer back in with a proper air tight seal. When reading Roger Russell's page I saw that the speakers are an 'overdamped' design. I believe this has to do with the sealed cabinet and also the fiberglass stuffing inside to keep the bass driver 'tight' and reduce any movement of the cone that is not caused by the magnet and coil...to stop any reflexing action from the surround.

Before I open the speakers to get to the crossover I would like to know you guys thoughts on the replacement of the 'stuffing' inside the speaker.
Should it actually touch the rear of the speaker?
Should more be added?
Am I right to think that the stuffing is there to mechanically restrict the movement of the cone?
Any insight into properly replacing the stuffing and the part that plays in the speakers performance would be greatly appreciated.

Should it actually touch the rear of the speaker?

If the stuffing touches the back of the woofer cone, you might get some buzzing of the stuffing against the cone. Also, the stuffing should not be allowed to interfere with the cone movement.

Should more be added?

I would assume McIntosh added a designed-in amount and so I can see no reason to change that.

Am I right to think that the stuffing is there to mechanically restrict the movement of the cone?

No, the air pressure inside the sealed cabinet damps the woofer movement. The stuffing raises the density of the interior of the sealed cabinet which makes the cabinet work like a larger non-stuffed cabinet - with the stuffing you get the same performance with a smaller box.

OK, the stuffing is not there to physically press up against the woofer to restrict it's movement and the woofer should remain clear of the stuffing.

 

[jlovda]

Usually, the combination of driver and cabinet parameters for an overdamped system is such that without equilization F3 will be quite high and sound thin. The speakers are meant to use equilizers such as the MQ101.

 

[twiiii]

The stuffing also prevents back energy from reflecting off the back of the cabinet and sides modulating the cone blurring the bass and prevents standing waves and internal echos. The ML series woofers have less than 3% distortion at 30 Hz at rated power. Any changes will increase the distortions and effect optimum performance. You could take a very very open synthetic weave screening type material and place one layer over the woofer to prevent the fiberglass from touching the cone. Always where gloves when working with the fiberglass.