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Why this capacitor in my Bose satellite speaker ?
Old 26th January 2017
  #1
Gear Head
 

Why this capacitor in my Bose satellite speaker ?

Hi ! I'm going to unite a bunch of Bose satelite speakers to make a poor man's L1..... I opened up the se-5 speaker and found a 4.7 MF capacitor connected from one speaker to the other... ( The two speakers are connected in series). The capacitor is connected to the two positive terminals of the speakers... My other Bose satelites...The model 7 ones , the cubes, have no capacitor.... What purpose does that capacitor give, and can I just take it out ?? I have a BBE crossover which will only send 200 Hz and above to these satélite arrays... I see no reason to have a capacitor in there..... Do you ? I will have 8 of these Bose se-5s per side (16 speakers per side)... That means 8 capacitors.... Can I just take them out ? I'm a newbie , so pardon my lack of knowledge in this.....Thanks for tips !
Old 26th January 2017
  #2
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mikefellh's Avatar
Suggest you study speaker design, the capacitor is there as a high-pass to the tweeter.
Old 29th January 2017
  #3
Gear Maniac
 

well this is what I called sudo two-way back when I was playing with building speakers in the mid 80's. interesting that Bose used it in a commercial application. what it does it shunts all the highs to the other speaker. this causes the loading of the hi pass frequencies to be of just one speaker and the lower frequencies are in series and observed on the two full range drivers electrically, they are -3db but acoustically, they are +3db thatr results in a 0db penalty for putting two speakers in series (theoretically). A secondary result would be reduced high frequency distortion compared to two clock radio speakers either in series or parallel.
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Old 30th January 2017
  #4
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Richard Crowley's Avatar
There is nothing pseudo about it. The capacitor and the impedance of the tweeter form a high-pass crossover filter for the 2-way speaker system. It has been used in simple speaker circuits for many decades. And likely still popular today for its low-cost and simplicity.



Of course a Bose L1 system is a very sophisticated mechanical and intelligent active circuit system. It is not just a collection of speakers in a column. Attempting to make something like an L1 out of a bunch of cheap computer speaker drivers is exactly like that old saying: "You can't make a silk purse our of a sow's ear." The concept is preposterous.
Old 30th January 2017
  #5
Gear Maniac
 

Quote:
well this is what I called sudo two-way back when I was playing with building speakers in the mid 80's. interesting that Bose used it in a commercial application.
Huh? Are you suggesting that Bose copied your ideas? I've got a '50's radio that uses the same thing. We all like to copy from those who came before!
Old 30th January 2017
  #6
Lives for gear
Quote:
Originally Posted by rfnoise View Post
Huh? Are you suggesting that Bose copied your ideas? I've got a '50's radio that uses the same thing. We all like to copy from those who came before!
I think its pretty obvious that I'm the 80s he is saying that he called this cap use a sudo. Not that he "invented" it, but that the 80s was when he was interested in playing around with the application. He pretty clearly NEVER said it implied what you are suggesting...
Old 30th January 2017
  #7
Gear Maniac
 

This is what audiospacific is talking about. It's an interesting idea but not what the OP described.
Attached Thumbnails
Why this capacitor in my Bose satellite speaker ?-psuedo-2way.gif  
Old 30th January 2017
  #8
Gear Maniac
 

Quote:
Originally Posted by enginefire View Post
I think its pretty obvious that I'm the 80s he is saying that he called this cap use a sudo. Not that he "invented" it, but that the 80s was when he was interested in playing around with the application. He pretty clearly NEVER said it implied what you are suggesting...
Perhaps I was a bit too sharp with my wording. Apologies!
Old 30th January 2017
  #9
Lives for gear
Quote:
Originally Posted by rfnoise View Post
Perhaps I was a bit too sharp with my wording. Apologies!
I've been there too for sure.
Old 30th January 2017
  #10
Gear Maniac
 

Quote:
Originally Posted by rfnoise View Post
This is what audiospacific is talking about. It's an interesting idea but not what the OP described.
that is what I was thinking when he was describing it but with the cap across the upper speaker vs the cap across the lower speaker.

it may be just a 6 db crossover for one speaker like Richard said too. Without pics, the correct answer will be uncertain, unclear.

Also a lot of these designs that Bose came up with have a lot of phase issues. So badly indeed that in some of there designs they had to actively process the signal and induce phase shifts just for them to be undone at the crossover. Clever, but the way I look at it over engineering for a flawed design always lead to mediocre which does describe most of their speakers.
Old 30th January 2017
  #11
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Richard Crowley's Avatar
Quote:
Originally Posted by rfnoise View Post
This is what audiospacific is talking about. It's an interesting idea but not what the OP described.
That circuit is just a "variation on the same theme". The capacitor "bypasses" high frequencies across to the tweeter so that they aren't lost in the impedance of the woofer voice coil. The woofer is designed mechanically so that it can't move fast enough to reproduce high frequencies, and likewise with the tweeter that can't effectively move enough air at low frequencies. There really is a lot more physics and electrical engineering here than meets the eye.
Old 30th January 2017
  #12
Lives for snowflakes
 
12ax7's Avatar
 

.
Wait...

I'm more than just a little unclear about exactly what's inside these "Bose satelite speakers" (as described in the OP):

The OP speaks of "a 4.7 MF capacitor connected from one speaker to the other" (but does NOT specifically say that they are a woofer & teeter combo), so...

...Are we talking about a cap between a "woof & tweet combo (as described by Richard Crowley)?

...Or maybe something more akin to what is alluded to by "rfnoise" in his take on "audiospecific"'s post.

Now that I've re-read the OP, I see that it says: "(The two speakers are connected in series). The capacitor is connected to the two positive terminals of the speakers..."

...So it would appear that it would be NEITHER of these, but rather something else; perhaps something like this?:
Why this capacitor in my Bose satellite speaker ?-bs-cap.gif
(...But that doesn't really make any sense, does it?)

Does anybody know (for sure) exactly what's in there?
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Attached Images
Why this capacitor in my Bose satellite speaker ?-bs-cap.gif 
Old 30th January 2017
  #13
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Richard Crowley's Avatar
No. It makes no sense at all. Without a photo or a proper schematic, I put essentially zero credibility in the verbal description. Unless it is simply a high-pass filter for the "satellite speakers" to limit their low-frequency response (which is presumably handled by the "sub-woofer")
Old 30th January 2017
  #14
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12ax7's Avatar
 

Quote:
Originally Posted by Richard Crowley View Post
No. It makes no sense at all.
Well, at least its not just me being "dense" here.
.
Old 30th January 2017
  #15
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12ax7's Avatar
 

Quote:
Originally Posted by Richard Crowley View Post
[...]
Unless it is simply a high-pass filter for the "satellite speakers" to limit their low-frequency response (which is presumably handled by the "sub-woofer")
Yeah...

...But that would yield a HPF at 4229Hz (8 ohms) or at 8457Hz (4 ohms), so...
.

Last edited by 12ax7; 30th January 2017 at 09:17 PM..
Old 30th January 2017
  #16
Gear Maniac
 

Quote:
Originally Posted by audiospacific View Post
that is what I was thinking when he was describing it but with the cap across the upper speaker vs the cap across the lower speaker.
Drat! audiospacific was right the first time. I must have been blind last night, just re-read now. This exactly fits the OP description. I guess it makes some sense as it MIGHT reduce hi freq. comb filtering of spaced drivers.
Attached Thumbnails
Why this capacitor in my Bose satellite speaker ?-psuedo-3way.gif  
Old 30th January 2017
  #17
Gear Maniac
 

Quote:
Originally Posted by LukeAndListen View Post
Hi ! I'm going to unite a bunch of Bose satelite speakers to make a poor man's L1..... I opened up the se-5 speaker and found a 4.7 MF capacitor connected from one speaker to the other... ( The two speakers are connected in series). The capacitor is connected to the two positive terminals of the speakers... My other Bose satelites...The model 7 ones , the cubes, have no capacitor.... What purpose does that capacitor give, and can I just take it out ?? I have a BBE crossover which will only send 200 Hz and above to these satélite arrays... I see no reason to have a capacitor in there..... Do you ? I will have 8 of these Bose se-5s per side (16 speakers per side)... That means 8 capacitors.... Can I just take them out ? I'm a newbie , so pardon my lack of knowledge in this.....Thanks for tips !
It sounds like you want to use the speakers for surround channels? Like a home theater or big game system, right? If the two speakers inside are the same, like two identical full range speakers wired exactly as above, then I see no real harm in taking out the caps. But, why bother? What is bothering you about them?
Old 30th January 2017
  #18
Gear Maniac
 

yes, @ rfnoise , they did! With the price of the 90 degrees phase shift that comes with using a 6db filter.
Old 30th January 2017
  #19
Gear Maniac
 

without regurgitating their marketing nonsense, the l1 is a vertical line array with 180 degrees horiz pattern . the speaker radiation of a full range speaker is 90 degrees. So how is the op going to build his column. Logic dictates tilting the speakers 45 to the left and right, and allow the evils of comb filtering up the centrer vertically.since the comb filtering effect would be 1/2 the radius of the driver, then theoretically, the only ones that will complain is the trained ears of professionals and instrumentation and not the general audience.
Old 30th January 2017
  #20
Lives for snowflakes
 
12ax7's Avatar
 

.
Well, its been 4 days since the OP.

It would be nice if "LukeAndListen" would post a revealing photo of the innards of this satellite speaker box.

...Without that, we're all just kinda wastin' our time here.
.
Old 31st January 2017
  #21
Gear Maniac
 

lol, nice one! @ 12ax7
Old 19th February 2017
  #22
Gear Head
 

Sorry for not responding earlier... The Bose satelite speaker I'm using is the se-5... It's one speaker cabinet with two 2.5 inch full range drivers which are offset about 45 degrees, I think.. the two little speakers are connected in series, and the capacitor connected from the positive of one speaker to the positive of the other....like one of the diagrams above.... Any ideas ?
Old 19th February 2017
  #23
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loujudson's Avatar
Quote:
Originally Posted by LukeAndListen View Post
Sorry for not responding earlier... The Bose satelite speaker I'm using is the se-5... It's one speaker cabinet with two 2.5 inch full range drivers which are offset about 45 degrees, I think.. the two little speakers are connected in series, and the capacitor connected from the positive of one speaker to the positive of the other....like one of the diagrams above.... Any ideas ?
WHICH of the diagrams?
Old 19th February 2017
  #24



This looks to me like the woofer section of a two and a half way. Yes not what the OP posted because his description does not include a tweeter. But if it did.....................

The two woofers would be connected like this to give more preference to the low frequencies on the woofer with the cap across it. It would shunt the HF around the bottom woofer and therefore its only contribution to the overall sound would be mostly LF while the mids and highs would be mostly sent to the woofer on top.



Also some dual VC drivers are connected this way to accentuate the bass.
Old 19th February 2017
  #25
Lives for snowflakes
 
12ax7's Avatar
 

Quote:
Originally Posted by LukeAndListen View Post

[...] the two little speakers are connected in series, and the capacitor connected from the positive of one speaker to the positive of the other....like one of the diagrams above.... Any ideas ?

If what I've emphasized in bold above is indeed true, here's what you have:
...But that would mean that the two speakers are wired OUT of PHASE. (Note the + and - signs.)


This would make absolutely no sense whasoever, and I'd be willing to bet that some dumbass with a soldering iron has done this to your speaker.
Is the other speaker wired in the same way?

...Again, please post a picture!!!
Old 19th February 2017
  #26
Gear Maniac
 

Quote:
Originally Posted by 12ax7 View Post

If what I've emphasized in bold above is indeed true, here's what you have:
...But that would mean that the two speakers are wired OUT of PHASE. (Note the + and - signs.)


This would make absolutely no sense whasoever, and I'd be willing to bet that some dumbass with a soldering iron has done this to your speaker.
Is the other speaker wired in the same way?

...Again, please post a picture!!!
I think he has this:


I think they did them this way since one was more treble than the other, and both speakers were full range. But for them to sound good you had to splay them about 45-90 degrees. That is what I remembered about these bose clock radio speakers. since they lost zenith and rca they had to do something with those clock radio and tv speakers. I did laugh when they came out. Because all of those systems like that never sounded good and people fell over them. Granted at the time Kloss wasn't doing much, and KLH wasn't marketed as good as bose ( btw klh made a couple of nice speakers that were nice to mix on )
Old 20th February 2017
  #27
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Richard Crowley's Avatar
It seems much more likely to me that the speakers are wired like this.



This protects the tweeter from damaging low frequencies and meets the requirements of the OP:
Quote:
the capacitor connected from the positive of one speaker to the positive of the other.
But, of course this is all academic as the original premise is dead in the water.
Old 20th February 2017
  #28
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I'll admit that I'm completely befuddled here, as it seems to me that the best course of action has nothing to do with the capacitor or how it's wired . . .

1. NO piece of equipment can be "improved" by merely cutting out a part that was in the original design, when having not even the remotest clue of how it works or what the part was for.

2. The fact that an ostensibly similar model from the same manufacturer doesn't have the part is of no logical bearing on #1 .

3. If you have such distain for the product as to disregard points #1 and #2 , then perhaps you should choose another for your application.
Old 20th February 2017
  #29
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Gearslutz, where techs come to debate what the long gone OP meant.
Old 20th February 2017
  #30
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loujudson's Avatar
Quote:
Originally Posted by enginefire View Post
Gearslutz, where techs come to debate what the long gone OP meant.
'Zakly! I was going to suggest he use this instead:
Tectonic Elements TEBM35C10-4 BMR 2" Full-Range Speaker 4 Ohm
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