Boston Kortec tweeter substitution - suggestions?

I'm experiencing a tinitus like ring in my ears from the kortec tweeters in my Boston A-series, and that even at moderate volumes - mind you I never play quite loud. Funny as the A-series sound so sweet and polite in every other respect.

So the quest I'm on is to substitute these tweeters for something that retains the lift centred at around 10-12kHz but sounding ping:ier and not this tsss like white noise.

I'm basically open for suggestions. No clue what the specs are for the kortec ones, but one out of an A26 measured 5.7 re. They have rather small magnets and are plotted at 89dBs in this region, but the X-over may have adjusted these levels to match.

Any input on the matter welcome.
 
Boston A26 is a sophisticated design, but has a soft dome tweeter, which is not to everyone's taste.

I see designs like the Boston RS-260 use what looks like SB Acoustics ring radiators, and possibly SB woofers too.
SB29RDNC-C000-4 :: SB Acoustics

I've no idea what the mounting issues will be on that bespoke plate. You will also need to work out the crossover schematic to know how to adjust levels and maybe add a 2.2R series resistor to the 3R tweeter.

Lot of work, and somewhat trial and error but doable.
 

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Well, the tinnitus like ringing in your ears might be exactly that - tinnitus- and if so, no amount of futzing around with the drivers or crossover in the Bostons or any DIY build are likely to resolve the issue.

If you do decide to pursue modding these speakers, be aware that there's a lot more to the process that just subbing a driver with similar Re and sensitivity, and different dome/cone material/profile .
 
Well, the tinnitus like ringing in your ears might be exactly that - tinnitus- and if so, no amount of futzing around with the drivers or crossover in the Bostons or any DIY build are likely to resolve the issue.

If you do decide to pursue modding these speakers, be aware that there's a lot more to the process that just subbing a driver with similar Re and sensitivity, and different dome/cone material/profile .
Well if it is indeed tinitus and not some ringing of the tweeter these specific tweeters are obviously likely to accentuate some frequency of my ears' distaste.

You see I'm not at habit of playing speakers quite so loud to introduce any discomfort of that sort. E.g. yesterday I was sitting in the adjecent room with some music playing in the background at talking level and they still hit that nasty, tinitus-y frequency, which needless to say was quite fatiguing.

Obviously I don't want to subject myself to sounds that could be damaging to my hearing so all the more reason to try and adjust it if possible. What ever damage thay may be done already noone man can fix. But this obviously being frequency dependent I would do my best to remedy that.
 
Boston A26 is a sophisticated design, but has a soft dome tweeter, which is not to everyone's taste.

I see designs like the Boston RS-260 use what looks like SB Acoustics ring radiators, and possibly SB woofers too.
SB29RDNC-C000-4 :: SB Acoustics

I've no idea what the mounting issues will be on that bespoke plate. You will also need to work out the crossover schematic to know how to adjust levels and maybe add a 2.2R series resistor to the 3R tweeter.

Lot of work, and somewhat trial and error but doable.
The word is that Boston make their own drivers, but rumours has that they have somebody make the drivers for them to their specs. Could be SB as that tweeter design bears evidence to.

That specific driver seems to be lower impedance and quite a bit higher sensitivity, though, so chance is I have to rebuild the X-over w. various links and dampers from scratch if going with that driver.

I believe this driver is what makes the M25 4 ohm and the A25 8 ohm (although the latter seem to average at 6 ohm actually - unless that's some tweaks made to the x-over).

I've been using soft domes for as long as I can remember but never ones this fatiguing. These seem rather rough from 3kHz on, and not only peak at 12kHz but also at 16kHz. Yet they're described as smooth and they are in that they do soften with frequency.

Perhaps I'll just try them with those from my HS line speakers which may just perform a bit differently while hopefully being electrically similar to those loaded into the A-series ones.
 

joeytruelove

Member
2016-06-08 10:28 pm
Maybe it's that old boom and tizz balance you are up against, you know, sounds good in the shop, but after an hour of it at home, you hate it! It's why a lot of people slope the tweeter down a few dB. The BBC dip. :D

I don't see much useful in that FR for the A360. Except it's bright at the top.

You do need that crossover layout to make sense of any possible changes, but putting 7.5R in series with 0.68uf, a zobel, across the tweeter usually tames the top end. You can even try it across the speaker inputs to correct impedance at the high end, which some amplifiers are sensitive to.

I don't like soft domes at all. Just me, but they just sound wrong to me, especially when I am tired, and the old brain isn't correcting stuff. Hissy, spitty, I don't know the word.
 

richard12

Member
2011-06-12 10:33 pm
Boston tweeter replacement

Seems the tweeter in the A series is easy to blow up. At least I blew up mines in A360 and when I recently bought A250 occasions the tweeters were also blown. But I replaced with Visaton FRS5x and noticed improved highs. This FRS5X is 8 ohm broad band unit, so not specific tweeter. But it is lovely in the highs and very cheap ~10 Euro. The only point is it needs a separate chamber. I built these in A360 and A250. For A250 it's relative easy to do. For A360 rather difficult to built since the mid has a separate chamber what limits the access to the back of the tweeter. But with some patience, silicone kit and small wooden panels i managed to built a small chamber.

Unfortunately I also suffer Tinitus. With the FRS5X much less irritation as with the standard tweeter.
 

Lojzek

Member
2012-02-10 12:12 pm
Croatia
Joey is in an ideal position to remedy the tweeter issue by deploying a cone tweeter. I have been listening to one in a recently developed project made from scrap pieces of a mini hifi system. The dispersion is very much different from the usual dome types. Steve would remember the model by Monacor that suits fine. It is not a very high quality solution but some people are not burdened with that and it's cheap.
 
The word is that Boston make their own drivers, but rumours has that they have somebody make the drivers for them to their specs. Could be SB as that tweeter design bears evidence to.

That specific driver seems to be lower impedance and quite a bit higher sensitivity, though, so chance is I have to rebuild the X-over w. various links and dampers from scratch if going with that driver.

I believe this driver is what makes the M25 4 ohm and the A25 8 ohm (although the latter seem to average at 6 ohm actually - unless that's some tweaks made to the x-over).

I've been using soft domes for as long as I can remember but never ones this fatiguing. These seem rather rough from 3kHz on, and not only peak at 12kHz but also at 16kHz. Yet they're described as smooth and they are in that they do soften with frequency.

Perhaps I'll just try them with those from my HS line speakers which may just perform a bit differently while hopefully being electrically similar to those loaded into the A-series ones.

I know it's an old thread, but I can't help but wonder if Boston has someone make their drivers. I'm guessing so, since they USED to make them on a highly automated assembly line next door to me in Peabody, MA, but ever since they started making their stuff in Asia, I can't see a small company like Boston Acoustics having their OWN factories, rather just farm it out.
 

LSmith4285

Member
2020-05-19 10:36 am
I know this is a really old thread but I'm wondering if you could let me know which tweeter you ended up going for joeytruelove? I'd also be interested to hear how easy the install was. I've got a pair of A26s with a blown tweeter. I was hoping to get a direct replacement but I haven't managed to source one so I'm looking at other options.


Thanks.
 

Consolez

Member
2020-06-01 9:42 pm
I also run into this tread.

I have a pair of A25 speakers with blown tweeters. Also the radiator of the crossover got really hot but survived. Any ideas for replacements for the Kortec softdome tweeters?

I live in Europe and can’t find dealers of Boston Accoustics anymore.

Thanks in advance !