Boston Acoustics A100 Woofer ID (Pics)

[Boss302]

I picked up a pair a BA A100s the other day for $90 from a Craig’s List seller who told me the woofers were not original but exact replacements he found somewhere and had them professionally refoamed. These speakers look brand new with not a nick to be found on them. I believe these speakers are the original A100 series from the early eighties. Serial numbers on the cabinets are A100J111173 & A100J111166 and have the woodgrain vinyl finish.

The only marking I can find on the woofers are the small white stickers that are marked with a red dot and the date "June 11, 1981". I am hoping a BA fan out there can ID these woofers and verify that they are indeed correct for these speakers. See pics.

 

[dc270]

The concentric rings on the front look correct but that square magnet not so much. There should be a number stamped on the back of the woofer and it can be tracked to the mfg.
DC

 

[Boss302]

I did just find a number stamped on the back of one of the cones...12-001-1. This number and the white dated sticker are the only markings on these speakers.

 

[kgginslc]

The white sticker with red dot and date certainly look like all the other BA drivers I've pulled from my speakers, along with the terminal connectors and the spider fabric. All my A400 woofers have square magnets, but I'm afraid I don't know whether the a100 should or not.

 

[abpeep]

The white sticker with red dot and date certainly look like all the other BA drivers I've pulled from my speakers, along with the terminal connectors and the spider fabric. All my A400 woofers have square magnets, but I'm afraid I don't know whether the a100 should or not.

Everything about these does look original. In addition to what kgginslc mentioned the baskets also look original. I've got A100's and A150's, as well as a pair of A100's that I gave to my son - they all have square magnets.

Went to look and I even have a spare 10" driver in there that looks exactly like the picture.

Newer drivers and current replacement drivers from BA do have the round magnet.

I say............Carry on!

Alan

 

[mwicks]

I have a pair of A400's from 81 or 82 and the drivers have square magnets on the back like your picture. They don't have that "O" like thing on the back though.

 

[Boss302]

Man, I appreciate all the info! abpeep, looks like we have a match here. The jury is still out for me as to how I like the sound of these speakers though. They don't sound bad, but then again they seem sort of bland in the bass & mid-range department. Maybe it's the room or maybe it's the new surrounds on the woofers are not broken in and just need some exercising.

Should I decide to experiment with different woofers, can someone recommend suitable aftermarket replacements? I have no idea what the specs are on this system, so I'm in the dark. I did email BA, but got a reply that had nothing to do with the question I asked!!!!!!!!

Thanks!

 

[dieter14c]

I recently got a pair of A-150's with one woofer that wasn't original.
This post http://www.audiokarma.org/forums/showthread.php?t=170253 discusses a suitable non-Boston replacement for the stock woofer (the A-100's and A-150's use the same woofer).

As for the mid-bass and bass sounding weak, this could be due in part to the acoustic suspension design of the speaker. This design allows for tighter and in some cases, deeper, bass extension than a ported speaker might have. The trade off is that a fairly powerful amp is required to make them sound their best. As you said, they may also require some more break-in time due to the refoam.

 

[terra1]

Man, I appreciate all the info! abpeep, looks like we have a match here. The jury is still out for me as to how I like the sound of these speakers though. They don't sound bad, but then again they seem sort of bland in the bass & mid-range department. Maybe it's the room or maybe it's the new surrounds on the woofers are not broken in and just need some exercising.

Should I decide to experiment with different woofers, can someone recommend suitable aftermarket replacements? I have no idea what the specs are on this system, so I'm in the dark. I did email BA, but got a reply that had nothing to do with the question I asked!!!!!!!!

Thanks!

I have a pair of A100s and they are great for subtle delicate instruments like Jazz percussions and Jazz vocals. But I would have to agree if you are looking for searing vocals and guitars or thumping bass then bland may be appropriate. I like my Advent 5002s a little better. But my Polk 10Bs with 2 midranges even better.

Also I refoamed my Boston A100 with a unique smooth roll surround that matched the original and has a seamless look. It has a wider roll than yours and glued under the cone. But I don't know it that would make that much difference or require much break-in time to improve bass. I think what you are hearing is pretty much my impression when comparing. Maybe it does require more power. I know my Polks sound great on my 110 watt receiver, but they were at a whole different level when I heard them demo'd on a 250 watt amp.

 

[rsfmotoman]

I have a pair of A100s and they are great for subtle delicate instruments like Jazz percussions and Jazz vocals. But I would have to agree if you are looking for searing vocals and guitars or thumping bass then bland may be appropriate. I like my Advent 5002s a little better. But my Polk 10Bs with 2 midranges even better.

Also I refoamed my Boston A100 with a unique smooth roll surround that matched the original. It has a wider roll than yours and glued under the cone. But I don't know it that would make that much difference or require much break-in time to improve bass. I think what you are hearing is pretty much my impression when comparing. Maybe it does require more power. I know my Polks sound great on my 110 watt receiver, but they were at a whole different level when I heard them demo'd on a 250 watt amp.

I have the same thoughts as terra1 concerning the A100's. I recently refoamed a set and played them awhile to break in the the new surrounds. After all was said and done...
1. The high-end was very pleasing and easy to listen to.
2. Killer imaging, I was very impressed.
3. I was unimpressed with the bass, not very low and hard hitting.

I enjoyed my time auditioning them in my system but ended up bringing my NLA's back into play.

My two cents.

 

[Boss302]

I knew going in that the A100 is a speaker system for great detail and not best suited for the seventies classic rock that I mostly listen to (Rush, Boston, Heart, ect.). I was just hoping that being in a small and hard room and not needing to crank the volume knob past 11 or 12 o'clock, the A100s would have been a lot closer in sound to my old Genesis Physics Model 10s (solid performance across the board).

I am not going to give up on these just yet though. I'll give the new surrounds time to break in and I might try those Dayton drivers dieter14c linked above ($26 ea. is a bargain these days). I also have a little un-powered subwoofer from a Cambridge Soundworks New Ensemble II system in the closet. Might just hook that to the remote speaker terminals on my Technics SU-8600 and see if something blows up.

Thanks for all the input...rock on!!!!!!!!!!

 

[bumperboy]

I have a pair of series3 A-150's.
The woofer in mine looks just like the one "botrytis" posted, ie round magnet. Mine has the date sticker on the cage "10-7-88" with the name "Boston" moulded into the magnet.
The replacements from Boston are exactly the same in all respects, only without the "Boston" name moulding and the cris crossing on the cone face is slightly more pronounced.

 

[Jayrosc]

Reviving this old thread because I ran into the same question as the OP this morning when I took the woofer out of a pair of A100's I picked up yesterday on a trade. I feared it was a cheap replacement because there is NOTHING on it to indicate it is made by Boston. Quickly did a search and found this thread and discovered that all is well. Yay AK!!!! My woofers look exactly like the ones posted up top of this thread and are from 1982. Got to do something I've never done before: remove a brand new, well installed foam surround. Previous owner did the refoam on them, but one driver has a tiny rub.

 

[peerson]

Hey, Love your Avatar! My wife had one of those when I married her. Identical to your pic. Sorry, off topic.

 

[bcbud3]

Those surrounds on the original picture are the incorrect type. That might be causing part of the problem. Another problem could be lack of a good air tight seal around the woofer and tweeter. I redid mine and put new gasket and I can tell you the bass is plenty loud for the rock and metal I listen too. Had to turn the loudness button off.