Jump to content

Boston Acoustics A100 Versions

Pete B

Recommended Posts

The original version of the A100 employed several versions of a 1" poly dome tweeter from SEAS.

The woofer has the same Fc (42 Hz) in the 1.6 cuft enclosure and probably had a similar Qtc as the

Large Advent.  The woofer looks like the 10" used in the Advent Legacy so I think that there was a

lot carried over from Advent.  It was sound engineering after all.

I don't like this crossover because there is no crossover on the woofer and the tweeter is driven

rather hard due to the large capacitor and minor attenuation.

sba2 on Audio Karma wrote: 

The original A100s (series 1) used several Seas tweeters:
H 211
H 241 L
H 253 (with ferrofluid)

I drew this schematic for the Series 1 version based on pictures, it seems 

that there were revisions within the Series 1 model.





Link to comment
Share on other sites

BA started making their own tweeters for the Series 2 version of the A100 and they 

look very similar to the SEAS version that they replace.

The crossover is improved with an inductor (looks exactly like the OLA inductor) and 

cap forming a 2nd order network on the woofer and also a 2nd order network on the


sba2 on Audio Karma did all the work reverse engineering this version and I just 

entered it into Xsim to draw the schematic:

Note the reverse polarity on the tweeter.




Link to comment
Share on other sites

This crossover was drawn from a picture on the thread at AK and we are not sure if

it is another revision of the Series 2 or the Series 3 version.  I like this version more 

since it adds damping on the woofer section and a bit more attenuation on the tweeter:

Note reverse polarity on the tweeter.


Link to comment
Share on other sites

  • 9 months later...
  • 2 months later...
On 11/8/2019 at 8:09 AM, Billy_Shears said:

Thank you for posting the circuit diagrams.  

Where can I buy replacement woofers?

Do you think it is worth replacing damaged woofers to rebirth 25+ year old speakers? 

look for the A100 I/A150 I/A200 woofer. (if you have series I) Or A100 II/A150 II for series II< and A100 III/A150 III for the series III.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...