CBM-170SE Tweeter - damaged or manufacturing variance?

[Shike]

Hey everyone,

Just a quick question. I took a grill off while listening the other day and noticed an odd mark on my center channel tweeter when light caught it at an angle. I was hoping someone could give an educated guess on whether this is damage, variance, or defect.

https://i.imgur.com/3gilFmG.jpg

Since it has a hard time showing:

https://i.imgur.com/gUnUhWg.jpg

Slightly going over it with a finger I can feel a very slight ridge. I had assumed physical damage but I'm not completely sure. I don't have kids and don't think any guests would have done anything, but there's something definitely there - I just can't place the "what" it is.

I have touched base with Ascend CS and was asked for pics in additional to a quote for a 170SE tweeter - I haven't heard back on the pictures yet but thought others may have insight as well.

Thanks

[davef]

Hey everyone,

Just a quick question. I took a grill off while listening the other day and noticed an odd mark on my center channel tweeter when light caught it at an angle. I was hoping someone could give an educated guess on whether this is damage, variance, or defect.

https://i.imgur.com/3gilFmG.jpg

Since it has a hard time showing:

https://i.imgur.com/gUnUhWg.jpg

Slightly going over it with a finger I can feel a very slight ridge. I had assumed physical damage but I'm not completely sure. I don't have kids and don't think any guests would have done anything, but there's something definitely there - I just can't place the "what" it is.

I have touched base with Ascend CS and was asked for pics in additional to a quote for a 170SE tweeter - I haven't heard back on the pictures yet but thought others may have insight as well.

Thanks

Hi Shike,

Dina received an email from you on 04/22 and replied to you with a price quote on a replacement tweeter on 04/23. We haven't received any pictures from you but I can have Dina resend the email if you like.

A crease like that is caused from the dome being pushed in which I would categorize as physical damage. However, it looks like the dome cleanly popped back out and to be perfectly honest, I don't feel it is necessary for you to replace the tweeter. With a small crease like that, there will likely be a very slight high frequency loss but up in the range that is well out of human hearing (you couldn't possibly hear it)

If it were my own personal speaker, I wouldn't replace it but I can understand if the sight of it bothers you or just knowing it is there.

Simply call Dina again if you would like to order a replacement.

[Shike]

Hi Shike,

Dina received an email from you on 04/22 and replied to you with a price quote on a replacement tweeter on 04/23. We haven't received any pictures from you but I can have Dina resend the email if you like.

I responded 4/23/2018 at 8:00PM to Dina, it included the pictures I had here.


A crease like that is caused from the dome being pushed in which I would categorize as physical damage.

The thing is I've never seen an outward arc like this on a dented tweeter. Initially I thought the same as you but I would expect the arc to be going inward, and even if going outward typically you don't get a such a uniform arc? Additionally it cannot be seen head-on without strong light from the side . . . the more I think about it the less sense it makes to me. Maybe I'm just in denial, but it's rubbing me wrong.


If it were my own personal speaker, I wouldn't replace it but I can understand if the sight of it bothers you or just knowing it is there.

Simply call Dina again if you would like to order a replacement.

Thank you for the additional info, I will have to call to confirm the price but if the email was right I may hold off to part out a second-hand set. Half the cost of the speaker is a bit much for me . . .

Thank you.

[davef]

I responded 4/23/2018 at 8:00PM to Dina, it included the pictures I had here.

I see the email from you now... Strange, the from name is different on this email so that likely caused some confusion.


The thing is I've never seen an outward arc like this on a dented tweeter. Initially I thought the same as you but I would expect the arc to be going inward, and even if going outward typically you don't get a such a uniform arc? Additionally it cannot be seen head-on without strong light from the side . . . the more I think about it the less sense it makes to me. Maybe I'm just in denial, but it's rubbing me wrong.

Please don't take this the wrong way, but how many creased soft dome tweeters have you examined? In a tweeter like this one, where the dome is very soft and heat treated to retain the shape - you are not going to get that typical hard crease line like you will see with more common Asian made domes. These domes are sealed - meaning there is a very specific amount of air-pressure beneath the dome that stays the same.

2 things will happen when the dome pushes in -- there will be an inward crease at the point of contact with the dome, and then there will be an outward crease as the additional air-pressure created by the depression pushes the dome outward. You can clearly see this on the attached pic I just took for you of my finger pushing in the dome on the same tweeter.

Because these domes are so soft, they typically won't ever leave that telltale hard inward crease line you mention, but - if the pressure against the dome causing the depression is sustained for a while - the dome itself will slightly deform around that outward bulge and you end up seeing exactly what you have documented here.

You have had the speakers for over 2 1/2 years now and, unfortunately, these things do happen sometimes no matter how careful one is (guests, cleaning people, general handling etc.)

Additionally, $54 for a fully custom made SEAS tweeter is very reasonable, but again, I really don't think you need to replace it.

I hope this made sense and we are here for you either way...

[Shike]

Please don't take this the wrong way, but how many creased soft dome tweeters have you examined? In a tweeter like this one, where the dome is very soft and heat treated to retain the shape - you are not going to get that typical hard crease line like you will see with more common Asian made domes. These domes are sealed - meaning there is a very specific amount of air-pressure beneath the dome that stays the same.

2 things will happen when the dome pushes in -- there will be an inward crease at the point of contact with the dome, and then there will be an outward crease as the additional air-pressure created by the depression pushes the dome outward. You can clearly see this on the attached pic I just took for you of my finger pushing in the dome on the same tweeter.

Because these domes are so soft, they typically won't ever leave that telltale hard inward crease line you mention, but - if the pressure against the dome causing the depression is sustained for a while - the dome itself will slightly deform around that outward bulge and you end up seeing exactly what you have documented here.

Dave, thank you for the additional explanation - that makes sense.


You have had the speakers for over 2 1/2 years now and, unfortunately, these things do happen sometimes no matter how careful one is (guests, cleaning people, general handling etc.)

Well, at this point I am considering replacing a full speaker anyway so this started solidifying it. I have one that has some finish issues on the cabinet so will likely pull drivers from it. Unfortunately the package deal v. single speaker cost is quite a bit different so I may wait and watch for second-hand still. It just makes more sense financially for me at this time.


Additionally, $54 for a fully custom made SEAS tweeter is very reasonable, but again, I really don't think you need to replace it.

I will admit that I'm compulsive and this will continually bother me.

The problem for me on the cost is that $54 and $20 shipping is still roughly 50% of what I paid for one of the speakers. I'm concerned that there's likely profit margin on the tweeter which combined with the shipping doesn't make it economical for me looking at the speaker price itself. It can be an amazing deal, but all I can see is 50% - a little more and I'd have a spare cabinet, woofer, etc. I don't want to sound crass or like I'm criticizing - and I understand I got the speakers significantly less by taking advantage of a sale and package deal - but it's something that rattles in my head.


I hope this made sense and we are here for you either way...

Yes it did, and I don't want to sound like I'm criticizing - I'm the type of person that tends to flog myself when something gets damaged. It has been and will continue to be a bad habit of mine. Thank you for your patience with me.