Sleek SA6 "Bass Ports"?

[Spyro]

I have only recently been catching up on the threads on these but it is hard to ignore the praise. I personally have not yet heard them but am shocked that they can hold their own with triple drivers or even ER4's.

The part I don't understand is the bass port. As far as I know they don't really work on armature drivers. Bass ports introduce a controlled amount of "leakage" to your seal. That's how we've always lost bass in any IEM. And now they think someone would want to do that purpose? If armature drivers have no vent port in the back, true bass-porting can do nothing to alter "bass response." Only a purposely introduced leak can cause a drop in bass compared to the driver's original performance in a perfectly sealed ear. That 12dB difference at 20Hz claim is fantastic if it was a boost from the driver's original output, but after a bit of thought, I can only come to the conclusion that they only allow a drop of 12dB there, not a boost. And no one wants that, really, do we? A drop at 20Hz? In an IEM? We don't have enough there to begin with.

But I DO want to hear a pair...

[channum]

The "port" is not so much a port, but rather a plug that changes the size of the chamber around the driver and thereby alters the perceived character and amount of bass. Even on the bass+ there is almost a pinhole but unless you break it with a needle or something, it's still very much sealed.

As someone who just mailed triple.fi 10 pro back to keep SA6, I can assure you that it works.

[ClieOS]

Imagine a dynamic transducer mounted on a sealed wooden box and you play your music on it, how would it sound? You will get muffed bass, right? Now you put a hole in the box to vent, than you got a very common 'bass reflex' system used in most loud speaker these days - Your muffed bass is all gone and now the bass is strong.

The bass ports (namely Bass+ we are discussing here) uses the same idea as bass reflex system. The hole is on the back of the transducer, therefore it doesn't affect the sealed ear canal as only the front (or should I say the nozzle + the inner chamber) of the BA transducer is used to create the seal (think of it as the front and back of dynamic drive).

For Bass= and Bass-, there is no hole at the back for venting. Instead, the space within the port (Bass+ has a small space, Bass- has no space) controls how much bass resonance can be generated within.

You will be interested to know that Shure already utilizes the same technology (using a control space to generate bass resonance) in their SE310 and above models to get the bass response they wanted. Instead of calling it 'bass port', Shure calls their version the 'Tune Port' technology, without the ability to customize of course

Originally Posted by channum

Even on the bass+ there is almost a pinhole but unless you break it with a needle or something, it's still very much sealed.

You uses the needle (to clean the clot) if the port is blocked. If it is sealed, than it won't have much use.

[channum]

Originally Posted by ClieOS

You uses the needle (to clean the clot) if the port is blocked. If it is sealed, than it won't have much use.

I'd say the opposite: you use the needle if you want to change the character further, it does just fine as is and seals out moisture and debris, which is why they're very explicit you shouldn't be using these with no port in place. It's rather obvious to me by the complete lack of mold marks and the perfectly flat interior surface that there is no "clot" going on here.

[ClieOS]

Actually, once the hole is open (as it is on arrival), increase the hole's diameter further brings very minor effect to the bass response. I have both needle cleaned Bass+ and brand new Bass+. You can't see if there is a clot or not. I cleaned mine the first time because I noticed the bass on one side dropped to almost Bass= level.

Note that I didn't try to widen the hole, just cleaning. I have done different mod on my SA6's bass ports (see my sig.) and one thing I notice is a needle can not easily punch a hole in the bass port. They are made out of a very elastic plastic material, if you punch a hole with a small needle, the hole will just seal back. The only way I was able to make a hole is by applying a bit of heat to the needle to melt just enough plastic to form a small hole.

[robojack]

Originally Posted by ClieOS

Imagine a dynamic transducer mounted on a sealed wooden box and you play your music on it, how would it sound? You will get muffed bass, right? Now you put a hole in the box to vent, than you got a very common 'bass reflex' system used in most loud speaker these days - Your muffed bass is all gone and now the bass is strong.

The bass ports (namely Bass+ we are discussing here) uses the same idea as bass reflex system. The hole is on the back of the transducer, therefore it doesn't affect the sealed ear canal as only the front (or should I say the nozzle + the inner chamber) of the BA transducer is used to create the seal (think of it as the front and back of dynamic drive).

For Bass= and Bass-, there is no hole at the back for venting. Instead, the space within the port (Bass+ has a small space, Bass- has no space) controls how much bass resonance can be generated within.

You will be interested to know that Shure already utilizes the same technology (using a control space to generate bass resonance) in their SE310 and above models to get the bass response they wanted. Instead of calling it 'bass port', Shure calls their version the 'Tune Port' technology, without the ability to customize of course


You uses the needle (to clean the clot) if the port is blocked. If it is sealed, than it won't have much use.

ClieOS, any idea whether if after enlarging the hole with a needle/pin, the hole will start to shrink? The soft material of the bass port leads me to wonder whether the hole will contract over time.

[ClieOS]

Originally Posted by robojack

ClieOS, any idea whether if after enlarging the hole with a needle/pin, the hole will start to shrink? The soft material of the bass port leads me to wonder whether the hole will contract over time.

I think I just answered your question with my previous post.

[channum]

Originally Posted by ClieOS

Actually, once the hole is open (as it is on arrival), increase the hole's diameter further brings very minor effect to the bass response. I have both needle cleaned Bass+ and brand new Bass+. You can't see if there is a clot or not. I cleaned mine the first time because I noticed the bass on one side dropped to almost Bass= level.

Without official word, I don't see much point in this argument, but I'll just say unequivocably that there is no hole in my bass+ ports. There is a thin membrane across where you are making your hole and either it's the most intentional appearing, most perfect manufacturing flaw I've ever encountered, or it's not supposed to be open. Given that these function exactly as I would expect relative to the bass= I started out with, unless I hear differently from JasonK, I'm not about to go jamming hot needles into them based on the assertion that there's supposed to be an actual port hole.

[robojack]

Originally Posted by ClieOS

I think I just answered your question with my previous post.

Heh, I was already typing out my question, by the time you posted. Thanks

I think mine arrived with + bass ports that were somewhat clogged, because after I stuck a pin through each of the ports, my bass response increased dramatically. The bass slam I had wanted, but didn't get initially, appeared as if out of nowhere.

[tadad1]

Originally Posted by channum

Without official word, I don't see much point in this argument, but I'll just say unequivocably that there is no hole in my bass+ ports. There is a thin membrane across where you are making your hole and either it's the most intentional appearing, most perfect manufacturing flaw I've ever encountered, or it's not supposed to be open. Given that these function exactly as I would expect relative to the bass= I started out with, unless I hear differently from JasonK, I'm not about to go jamming hot needles into them based on the assertion that there's supposed to be an actual port hole.

From Post #583 of the "Sleek SA6" thread.

Originally Posted by JasonK

Bass - and Bass = do not have a hole allowing air to exit. They do however have varying cavity sizes to change the bass response.

The + bass port looks similar to the - but it has an extremely small opening allowing air to port completely out of the SA6.

Hope this helped.

Jason

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[channum]

Originally Posted by tadad1

From Post #583 of the "Sleek SA6" thread.

Interesting. I may pull out the microscope and see if my eyes are playing tricks on me or if there really is no hole in mine.

[robojack]

Hold it up to the window, or a light. The hole is so small, you can sometimes barely make it out in normal lighting.

[channum]

I am wrong, there are holes, DOH! It took a microscope to confirm it to me, but they're there. When he says they are "extremely small", he's not kidding, comparatively, they're less than 1/4th the diamer of the width of the "1" on the date on a U.S. penny

[ClieOS]

Originally Posted by robojack

I think mine arrived with + bass ports that were somewhat clogged, because after I stuck a pin through each of the ports, my bass response increased dramatically. The bass slam I had wanted, but didn't get initially, appeared as if out of nowhere.

Yeah, I had that problem when I was swapping in and out different bass ports. It was probably clogged by the dust on my table or finger. Since the hole is so small, a little obstruction can restrict the air flow enough to lower the bass.

[Taterworks]

I've thought a bit about the reason behind bass porting in an in-ear headphone, and here's another idea: Perhaps the tight seal between an earphone driver and the ear canal may apply an excessively high acoustic impedance to one side of the driver, causing its very deep bass output to be compromised. By opening a tiny leak in the seal of controlled size, it may be possible to decrease the acoustic impedance encountered by the transducer in the small air volume of the ear canal, allowing the transducer to move more freely. This would also allow other bass enhancement techniques like bass-reflex loading to work more effectively, as the action of the reflex vent wouldn't be overwhelmed as quickly by the ear canal's high acoustic impedance.