Boston Acoustic A70's

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gfreek

New Member
So I revived a pair of BA A70's, kept in an attic above a garage, they were in freezing temps. I re-foamed the woofers. Hooked them up to my system, Thorens table with Red Ortofon cartridge, Hafler Pre-Amp,& DH 120 power Amp. To be honest not very impressed with sound, Highs are too high, harsh, I have to cut it back, not much low end..compared to my ADS or Pinnacle speakers..Wondering if freezing temps affected the dome tweeters or crossovers, from what I've read here capacitors on crossovers. Suggestions would help. Have another pair of A100's need redone,but have second thoughts..Thanks..
 
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Which ADS and which Pinnacle speakers are you comparing to? Freezing temps shouldn't do any permanent damage, as long as everything was warmed up before you started listening I can't image it having an effect. Which foam surrounds did you use on the woofers? Boston speakers use a very specific surround shape which a generic refoam kit will not match. Have you recapped the crossover?

I owned a pair of A150 and A400, both were excellent speakers IMHO, but even the 400s were not bass kings. However, I would never consider the tweeter to be harsh. In fact part of the reason the A400s left was because my Thiels had noticeably more detailed highs.
 
ADS L780's lows and highs, & Pinnacle BD500, just highs comparison since they are much smaller.. I used re-foam kit from Midwest Speaker, specific for A70's .. Have not recapped crossover, since i'm just getting back into this, I'll search for this repair..
 
You probably need a recap for the high end. And the A-70s want to be placed flat against a wall to get reasonable bass out of them.
 
Wow, I had my A70s A/B'd to smaller advent and could barely tell the difference. Something is wrong with your placement or speakers.. or amp.. or source.. or ears.. or...
 
MacNoob said:
the A-70s want to be placed flat against a wall to get reasonable bass out of them.
Click to expand...

A point worth repeating. Boston A-series speakers, unlike many other speakers, were meant to be placed against a wall.

Also, glad to hear you got a Boston-specific refoam kit. It probably doesn't make all that much of a difference but the OCD part of me gets unnaturally upset when I see Boston speakers with generic surrounds.
 
Check em with a battery and the woofers should both go the same way when you put the battery on the leads the same way. Doesn't take long to see the woofer move so don't leave that voltage coursing through the speaker.
 
I use a power supply to provide a less than 20 V DC signal to the woofer to raise it or lower it as needed to refoam the driver. It is not a lot of milliamps, though so a 9V battery will do the test fine and quickly.
 
I've been working on a pair of A70 to give my son. The crossovers were done a few years back but there was a rattle in one woofer. Replaced both woofers a couple of weeks back and now hate to give them up. Plenty of bass in these just sitting on top of my workbench. That tweeter should be pretty smooth.

Not sure what the problem might be - I wouldn't let this keep me from working on those A100.

Disclaimer: I listen to a pair of BA T1030 and have A100, A150 stored. Another set of A100 to one son, and CR8 to the other son. A pair of T830 passed through here once. There are two pair of A40 in the garage to refoam...
 
Followup, I Installed new caps, set them against a wall as mentioned above and they sound pretty good.. Thanks.
 
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