Cone drivers aging

[mica]

Dear all,

There is obviously some degree of cone drivers aging that depends on various factors but dominantly due to the cone degradation based on material fatigue and cone breakups as a consequence.
In evaluating speakers, we usually measure FR as well as THD or distorsion of various harmonics. Do these figures give us a reliable picture of driver quality or compared to the new one!?
So far, I haven't seen any measurement of intermodulation distorsion that, in my firm opinion, must be present due to the nature of cone transducers.
Are there any works on this topic? I suppose that many members would be grateful to hear the LH members opinions on this important topic, the reason is quite clear.
Thanks.

Mica

[ivica]

Dear all,

There is obviously some degree of cone drivers aging that depends on various factors but dominantly due to the cone degradation based on material fatigue and cone breakups as a consequence.
In evaluating speakers, we usually measure FR as well as THD or distorsion of various harmonics. Do these figures give us a reliable picture of driver quality or compared to the new one!?
So far, I haven't seen any measurement of intermodulation distorsion that, in my firm opinion, must be present due to the nature of cone transducers.
Are there any works on this topic? I suppose that many members would be grateful to hear the LH members opinions on this important topic, the reason is quite clear.
Thanks.

Mica

Hi mica,

If we want to present some older drivers FR, IMD, THD, it would be difficult to explain or confirm the level of cone transducer aging level, as ambient influence, number of "working hours", level of sound (or applied power) that have been 'applied', the quality of the used amplifiers, proper frequency response applied to the driver would have make their influence to the mentioned characteristics.

regards
ivica

[mica]

Hi mica,

If we want to present some older drivers FR, IMD, THD, it would be difficult to explain or confirm the level of cone transducer aging level, as ambient influence, number of "working hours", level of sound (or applied power) that have been 'applied', the quality of the used amplifiers, proper frequency response applied to the driver would have make their influence to the mentioned characteristics.

regards
ivica

More precisely: The questions raised in the thread relate primarily to the size and influence of intermodulation distortions, which have not been widely discussed so far.

Mica

[mica]

Could be interesting:
https://www.stereophile.com/reference/1104red/index.html

Mica