Bose speakers with Yamaha receiver

willis7469 said:

Well, all of it I guess.
As an exercise in academics, sure why not see what you can do. But “bread and butter”? Not even close. It’s neat that you could make it work. But I can’t imagine why anyone would bother.
Junk.

Click to expand...

The Bose hate, I understand many people suffer from this. I'm a DIY speaker builder for 40 years now, and the reason I kept this little bass module was because of the reasons cited in my original post. Although in no way approaching a true "subwoofer," it's a pretty decent little passive bass unit that has several interesting design features. I'd have to agree that most Bose products are substandard, cheaply made mid-fi, using press-board covered in vinyl, ****** electrolytic capacitors, etc. but marketed as something "more." But that doesn't mean they have never had good ideas or note worthy designs. Bose pretty much pioneered the sub/sat speaker system, which has been copied thousands of times over the last 30 years or so. This particular unit has been sitting in my garage for the last 7 years, as I was given a broken Lifestyle system (which I parted out, repaired and sold on Ebay). but I thought I would go ahead and save/refurbish this little bandpass woofer rather than trash it. Yes, for academics as well as actual application. And then post my results on a HT forum, in a thread talking about exactly this type of project.

Hope my little endeavor helped someone else who had a similar interest.

Not that anyone is actually following this thread, but I thought I'd update my post with a review of the refurbed and converted Bose Acoustimass bass unit. We moved into our new home and I finally set up the downstairs TV/Theater. Since we have a dedicated HT upstairs, this one was for casual TV watching and movies when the kids are in the game room/HT playing video games or watching their stuff. I used the refurbished Bose Acoustimass module, which I converted to work with my receiver as detailed in the prior post. I like vintage equipment, mainly because I'm old, and cheap. And if it's not broke, don't fix.

So, for reference here's the cheapo downstairs theater where the Bose Acoustimass bass unit is being used:
55" Insignia F30 Series LED 4K UHD Smart Fire TV
Panny SA-XR55 receiver (circa 2005, still love it and will use it forever or until one of us sheds this mortal coil)
Pinnacle QP9W speaker bar (left - center - right passive speaker, circa 2013 or so. Pinnacle is no longer in business)
Bose Acoustimass bass module (converted from amplified to passive, circa 1990s)
Bose "Doubleshot" dual cube speakers (surround, circa 1990s)

The idea here was to please the spousal unit with a system that is nearly invisible in the living room but sounds far better than the tv speakers. This was easily attained, but not without some issues.

First off, the bass module is very "mid-bassy," and the roll-off on the high end doesn't happen until around ~250Hz or so. This is problematic for HT in that I have the module bi-wired with the left/right on the speaker bar and there is no active crossover available on the receiver in this mode. I have the center & surrounds crossed at 150Hz / 12db per octave at the receiver and the left/right also 150Hz / 6dB per octave using a pair of caps, but the bass module is on it's own and rolls off naturally at the higher than desirable 250Hz. I used the bi-wire balance setting to lower the output of the bass module, and this helps some but I may purchase/make some coils for this unit in the near future. Speaker bar and bass module are located behind the TV (slightly raised so the bar passes all sound). The only indication of a HT is the tiny surrounds behind you (mounted high on the wall) and when you open the cabinet to operate the receiver.

Sound is as expected - far superior to tv speaker, but falling short of real LFE effects for HT (the Acoustimass rolls off rapidly lower than 50Hz). Once dialed in, music is actually pretty nice with the warmth of the Pinnacle silk domes and dual 3" drivers for each channel. Bass from the Acoustimass is efficient (have to turn it down, as noted) and is smooth and not "one-note" like so many critics claim. That 6th Order bandpass is still an amazing thing for a mass market consumer product IMO. HT is fine for casual movie nights. The awesome: the Panny will combine amps in parallel in stereo, and when bi-wired you have 6 amps total power for music since center/surround aren't needed. Such amazing tech and still sounds fantastic. <<3

So, mission accomplished - happy wife, happy life, and I'm pleased with the end-project and overall sound signature. The Acoustimass conversion to passive fills in from 150Hz down to 45Hz, but the lower octave is vacant. It's fine for what it is, and when it's serious movie night we go upstairs. Fun and cheap makes daddy happy.