Advice need about a defunct Bose system

undecided

Active Member
I have a Bose Acoustimass 15 home theatre system, driven by a Marantz 1506 receiver, but the subwoofer (SW) has failed. Bose stopped selling the system in 2006, and they don't make a powered SW any longer, so I have been looking for a replacement SW to use with the Bose wired speakers. At present, a ribbon cable is attached to the receiver and goes to the SW, and the speaker cables go from the SW to each speaker.
To use a new SW I would obviously have to relocate the speaker wires from where they currently enter the Bose SW to be directly connected to the receiver speaker outputs and run a SW cable from the 1506 to the new SW.
However, I have just noticed this caution in the Acoustimass manual which has completely thrown me.

CAUTION Never connect the cubes directly to a receiver output. Always connect the cube arrays to the Powered Acoustimass module, then connect the module to the receiver.

Why this caution? Is it just that turning up the amp might blow the speaker(s)? Some other reason? Can I ignore it and just use another SW?
If I can't just buy and use another SW, the system is (very expensively) useless.
We have a CD collection, so a soundbar system solution won't help, as almost all soundbars no longer have an audio input (and a hifi assistant told us that the sound would be rubbish, anyway).
We're looking for some advice, please, on how best to get out of this bind.
Thanks
Undecided
 

noiseboy72

Distinguished Member
The reason you cannot directly connect the speakers an amplifier is that there's a high pass filter that blocks bass frequencies from reaching the satellites.

The Bose system is a Sub-sat system as opposed to having larger full range speakers and a sub just for low frequency effects or to cope with the very lowest frequencies. In many sub - sat systems, the filtering is built into the speaker, so any amplifier and powered sub can be used, but this is not the case with Bose, who choose to build the filtering into the sub.

Your options are therefore to try and find a 2nd hand unit, get yours repaired or disconnect the power so it just does the filtering - which is passive and you then plug a powered sub into the receiver. I think there may be some modifications needed to the sub if you go down the latter option as there's a muting relay to remove that protects the speakers from turn on thump.
 

undecided

Active Member
Grateful thanks to both responders.
Graham14. As it happens, we found Electronics Partners over the weekend, have contacted them and are awaiting a quote. Also, we bid for a SW on E-Bay, but lost the auction. ☹️ Thanks for your suggestions. (but what on earth were you doing being up at 06:38 on Easter Monday? )
Noiseboy72. My wife and I are so appreciative of your reply. It answers our question, stops us blundering on with "*** it, let's connect them to the receiver anyway" and crystalizes our options on how to proceed. Repair is definitely the cheapest option; we'll see what Electronics Partners come up with.
Both your postings demonstrate how wonderful forums are for getting information from a more knowledgeable audience. We (76 and 74 yrs old resp.) are extremely grateful to both of you. 👍
Undecided and SWMBO
 

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