Cloth vs rubber surrounds

[TTS56A]

Hello guys, i wonder if different type of surround can really make difference in terms of bass quality. I heard some people who say that cloth surrounds are better because they introduce less distortion when moving out, but i also know that a lot of good subs have foam or rubber surround. The question is not pro subs vs home subs, but more related to the linearity of surround. What do you think about?

[Electrodynamic]

When people have commented on surrounds making a difference they are not comparing the same exact subwoofer with two different surrounds. They are always comparing two completely different subwoofers so their observation is a bit bias. But yes it comes down to the linearity of the surround, not the material, that makes the largest impact on sound. However, rubber surrounds are heavier and do suck up some sensitivity compared to foam or cloth. 

 

The majority of the quality of sound from your subwoofer happens in the linearity and performance of the motor. Second comes the performance from the soft parts (spider and surround). Of course the latter is a massive massive generalization. 

[SME]

My answer is that, yes, surround material can matter.  Which material is the best?  The material that suits the particular design best.  Another potentially relevant property of a surround is mechanical damping.  This is more of an issue for drivers used into the mid-range, but depending on design target of the driver, it could  still come into play in a subwoofer driver design as well.

[TTS56A]

When people have commented on surrounds making a difference they are not comparing the same exact subwoofer with two different surrounds. They are always comparing two completely different subwoofers so their observation is a bit bias. 

 

This is a good point, I also think that. But what i'd like to know is if really cloth/corrugated surrounds can generate the least amount of distortion compared to rubber one. I always knew that rubber surrounds are needed for long excursions and deep bass due to a lower fs. So i would think that what they told me is only a false myth 

[Contrasseur]

This is a good point, I also think that. But what i'd like to know is if really cloth/corrugated surrounds can generate the least amount of distortion compared to rubber one. I always knew that rubber surrounds are needed for long excursions and deep bass due to a lower fs. So i would think that what they told me is only a false myth 

FS can be lowered by adding mass to the cone or voice coil as well. Like Electrodynamic said, it's the surround's linearity that matters. It seems that rubber roll surrounds can be scaled up very large, and the tall profile gives it a lot more room to stretch than a cloth accordion (generalization of course). Look at some of his own drivers. The HST11 has WAY more surround than any other 11-12" driver, and consequently way more linear throw! Ultimately it's about the right tool for the job. The TC Sounds Pro-5100 and BMS 18N862 are designed for a very different task than the Stereo Integrity HST-18 or RE XXX that sport rubber half-rolls.

[Electrodynamic]

This is a good point, I also think that. But what i'd like to know is if really cloth/corrugated surrounds can generate the least amount of distortion compared to rubber one. I always knew that rubber surrounds are needed for long excursions and deep bass due to a lower fs. So i would think that what they told me is only a false myth 

 

It comes down to the length of the roll(s) more than anything else. Length of and shape of the rolls. Rubber or foam does not determine "sound quality".  One material is not inherently more "linear" than the other. Material determines longevity and/or sensitivity goals. So does thickness. I.e., weight. 

 

Someone mentioned the HST-11/12 surround. Yes it is big. Yes it is foam. If it were rubber the senitivity would be reduced by at least 1 dB (even if made of Santoprene). But it is the size and profile of the surround that allows such massive linearity from the surround to accommodate the very high stroke motor...not just the fact that it is foam/rubber/cloth. Cloth would easily deform at those excursion levels. But on the flip side, cloth offers many benefits for higher sensitivity drivers compared to foam or rubber. 

[TTS56A]

Thanks for the clarification Electrodynamic 

[Ricci]

The biggest cloth accordion type surrounds that I've seen employed will only support about 2" peak to peak somewhat gracefully. I say somewhat because they are getting very tight by that point. If an extra roll were added (eating into cone area a bit) and the corrugations were made a bit deeper they could improve on that. The new surrounds employed on the MTX 9500 seem like a blending of the 2 styles as does the Alpine HAMR surrounds. Tooling those pieces costs a ton of money though. I actually like the accordion style surround better simply because it acts more like a spider and seem to be easier to make it behave similarly in both directions. It's also lighter and does not protrude above the frame which makes it easier to use and more stable in horns. Anybody ever seen a half roll surround get sucked inverted due to cabinet vacuum? Just depends on the app. If excursion needed isn't really high I like the accordion surround. If you need a big VD stroker you'll need a big half roll or Hi-roll. Different tools.

[Johnny2Bad]

I won't address the replies already posted here except to say I largely agree with the replies so far. What I do want to mention, however, is an aspect of the rubber (or synthetic rubber) surrounds that may or may not be an issue for a builder / buyer.

 

(I use the term "rubber" as everyone else here does, noting that a true rubber surround is unsuited for a loudspeaker application but synthetic types are what is commonly found).

 

Cloth surrounds tend to be more durable than rubber / rubber-like materials, which can deteriorate at a much higher rate. The "rubber" types are generally much more susceptible to environmental degradation and generally tend to incorporate a chemistry that is designed to keep the material supple; the problem being that this softener can dry out, change chemically to a lees effective form, or be attacked by dressings that are sometimes, rightly or wrongly, recommended ( some waxes, silicones, WD-40, etc) and UV light.

 

Compounding the problem is that different rubber / rubber-like formulae have different characteristics with regard to longevity and it is not easy to assess at the as-new state, where they all tend to be just fine. Over time is when you learn whether one driver or another tends to fail. Re-coning is hardly a crisis but none the less is best avoided.

 

For some this is a non-issue (who cares what ends up happening with your sub built into a car you no longer own) but everyone should decide for themselves what weight to put on it when choosing a driver.

[MemX]

I won't address the replies already posted here except to say I largely agree with the replies so far. What I do want to mention, however, is an aspect of the rubber (or synthetic rubber) surrounds that may or may not be an issue for a builder / buyer.

 

(I use the term "rubber" as everyone else here does, noting that a true rubber surround is unsuited for a loudspeaker application but synthetic types are what is commonly found).

 

Cloth surrounds tend to be more durable than rubber / rubber-like materials, which can deteriorate at a much higher rate. The "rubber" types are generally much more susceptible to environmental degradation and generally tend to incorporate a chemistry that is designed to keep the material supple; the problem being that this softener can dry out, change chemically to a lees effective form, or be attacked by dressings that are sometimes, rightly or wrongly, recommended ( some waxes, silicones, WD-40, etc) and UV light.

 

Compounding the problem is that different rubber / rubber-like formulae have different characteristics with regard to longevity and it is not easy to assess at the as-new state, where they all tend to be just fine. Over time is when you learn whether one driver or another tends to fail. Re-coning is hardly a crisis but none the less is best avoided.

 

For some this is a non-issue (who cares what ends up happening with your sub built into a car you no longer own) but everyone should decide for themselves what weight to put on it when choosing a driver.

 

I guess it's a similar situation to foam surrounds of the late 20th century - they will suit their purpose for a certain length of time but will ultimately degrade. 

 

How long is that period of time, though?  Do we know at this stage in time? 

 

If rubber surrounds are good for 10 years then I think that's pretty reasonable, although longer is always better (or so the ladies tell me... ) 

 

 

Is it not fair to say that any woven material may ultimately deteriorate as well?  After all, if we wear items of clothing for long periods of time they will ultimately wear through - so if a subwoofer cone is going back and forth in a repetitive motion for years, I imagine that a material surround may finally wear out?

 

 

Just some uneducated thoughts anyway

[radulescu_paul_mircea]

I don't know what the material is but it seems like rubber, in an S form. The thing with it is that it has to support a very large moving mass, but it doesn't have to be that linear because of the magnetic centering inherent in the motor