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<blockquote data-quote="newusername" data-source="post: 3049985" data-attributes="member: 562064">Haev a look around SSA.&nbsp; I&#039;m fairly sure that I&#039;ve covered it in some respects, either in an entire thread or piece-meal through a few different posts.&nbsp; I&#039;ll try and summarize quickly here...Cms: Progressive spiders.&nbsp; This is one of the easier ones to solve (within reason) by carefully designing the spider geometry and positioning.&nbsp; The surround has a little bit to do with this, but the spider is the predominant factor here.&nbsp; However, over huge stroke (like 40-50mm plus), it becomes a little more challenging.&nbsp; Remember, it&#039;s just a treated piece of cloth.BL: Utilization of <a href="http://www.soundsolutionsaudio.com/forum/index.php?showtopic=9421" target="_blank">linear BL gap treatments</a> can easily solve this.&nbsp; Of course, treatments like LMT, for example, require substantially longer voice coils due to the increased number of windings, which causes an increase in DC resistance, but that factor is not really power compression, perse.Thermal: This is a challenging one to overcome.&nbsp; It doesn&#039;t take long to double DC Re, which doubles Qes, which doubles Qts...I think you see the pattern here.&nbsp; This can be limited by utilization of larger voice coils (both in diameter and length, but more importantly, in surface area), various cooling treatments in the motor (see DD or Fi), or by using different materials.With all of them, it takes careful planning to steer clear.&nbsp; However, if you can stay away from Cms and BL power compression, you&#039;re in great shape.&nbsp; They are the big contributors to distortion (BL ~60% and Cms ~30%) and are very dynamic and immediate in nature.&nbsp; Whereas thermal power compression begins maybe 10-15 seconds into play and can remain fairly constant at a given power input, BL and Cms compression occur on every single stroke.&nbsp; So if you play a 50 Hz note (50 cycles with movement in the forward and rearward direction), you encounter BL and Cms compression 100 times in one second!&nbsp; Obviously overcoming these two are the most critical components of the three.</blockquote>

[QUOTE="newusername, post: 3049985, member: 562064"] Haev a look around SSA. I'm fairly sure that I've covered it in some respects, either in an entire thread or piece-meal through a few different posts. I'll try and summarize quickly here... Cms: Progressive spiders. This is one of the easier ones to solve (within reason) by carefully designing the spider geometry and positioning. The surround has a little bit to do with this, but the spider is the predominant factor here. However, over huge stroke (like 40-50mm plus), it becomes a little more challenging. Remember, it's just a treated piece of cloth. BL: Utilization of [URL="http://www.soundsolutionsaudio.com/forum/index.php?showtopic=9421"]linear BL gap treatments[/URL] can easily solve this. Of course, treatments like LMT, for example, require substantially longer voice coils due to the increased number of windings, which causes an increase in DC resistance, but that factor is not really power compression, perse. Thermal: This is a challenging one to overcome. It doesn't take long to double DC Re, which doubles Qes, which doubles Qts...I think you see the pattern here. This can be limited by utilization of larger voice coils (both in diameter and length, but more importantly, in surface area), various cooling treatments in the motor (see DD or Fi), or by using different materials. With all of them, it takes careful planning to steer clear. However, if you can stay away from Cms and BL power compression, you're in great shape. They are the big contributors to distortion (BL ~60% and Cms ~30%) and are very dynamic and immediate in nature. Whereas thermal power compression begins maybe 10-15 seconds into play and can remain fairly constant at a given power input, BL and Cms compression occur on every single stroke. So if you play a 50 Hz note (50 cycles with movement in the forward and rearward direction), you encounter BL and Cms compression 100 times in one second! Obviously overcoming these two are the most critical components of the three. [/QUOTE]

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