Solving the BOSE issue!

[Resident Loser]

...I keep seing references to the Sound and Vision article from 1999 from which those specs were quoted...and yet more recently in November '04 Ken Pohlmann did a review of the Lifestyle 38 system that seems to have no axes to grind...and didn't call into question Dr. Bose's lineage or ulterior motives in his supposed quest to dominate the A/V world...

Getting back to those numbers...I realize no loudspeaker exists in an anechoic vacuum, but putting any Bose loudspeaker in that test environment seems to be somewhat self-serving...Direct/Refelecting being the operative phrase, sorta' kinda' intimates that relections are what they are...well...a somewhat important , dare I suggest integral, part of the mix...Hmmm...anechoic...reflections...anechoic... reflections...DANGER! DANGER! This does not compute Will Robinson!!!

I've found nothing re: these specs that indicates the multiple cubes were aimed on-axis, the only available resource is here:

http://www.intellexual.net/bose.html

and if they were, given the fact that the Bose owners manual indicates they should be aimed to give a balance of direct and reflected sound, the test parameters are therefore suspect IMO. Might the fact that they are supposed to be off-axis to each other have skewed the numbers? and all the while, conveniently fitting in the apparent Bose-bashing agenda? If so, how convenient...

I'm not gonna' say the frequency plot as provided isn't ragged...bu-u-u-t...

That dip in the 200-300Hz region is at the crossover point between the bass mod and the satts...if the system was placed in a real room (not in a anechoic environment) would things have been more linear? Keep on repeating...direct/reflecting...direct/reflecting...

The rise to a +4 dB peak and subsequent fall @ 5-7kHz region...could the axis alignment (if that's how it was indeed done) have been responsible?

Answers? I have none...only questions...

I'll try to locate my pink-noise plots over the weekend, but at the very least I'll just re-plot the inverse of my current settings on my half-octave graphic and provide some further info...at least re: 901-lls...and they were done in a real-life living room and with the best of intentions.

jimHJJ(...now I think I'll have an apple turnover and some OJ...)

[Resident Loser]

...I'll try to locate my pink-noise plots over the weekend, but at the very least I'll just re-plot the inverse of my current settings on my half-octave graphic and provide some further info...at least re: 901-lls...and they were done in a real-life living room and with the best of intentions.

I didn't have the time to locate my originals, but the following graph is the inverse of the settings currently on my SAE 2700B half-octave equalizer...



It took a while even locating multi-cycle, semi-log paper I could download that could be re-worked from a .pdf to a .jpg for my purposes...and me being an avowed Luddite and computer-illiterate had a devil of a time at the whole venture...plus now downsizing to fit the site's requirements...anywho!!!

jimHJJ(...have at it...)

[Woochifer]

...I keep seing references to the Sound and Vision article from 1999 from which those specs were quoted...and yet more recently in November '04 Ken Pohlmann did a review of the Lifestyle 38 system that seems to have no axes to grind...and didn't call into question Dr. Bose's lineage or ulterior motives in his supposed quest to dominate the A/V world...

Uh, and that 2004 review that Pohlman wrote did not include any technical measurements, which is very unusual for S&V. Let's see, S&V reviews for other comparable HTIB packages DO include the technical measurements, while they are excluded from the Bose Lifestyle 38 review. No axes to grind evident, but I would hardly call this type of exclusionary cherry picking objective.

Getting back to those numbers...I realize no loudspeaker exists in an anechoic vacuum, but putting any Bose loudspeaker in that test environment seems to be somewhat self-serving...Direct/Refelecting being the operative phrase, sorta' kinda' intimates that relections are what they are...well...a somewhat important , dare I suggest integral, part of the mix...Hmmm...anechoic...reflections...anechoic... reflections...DANGER! DANGER! This does not compute Will Robinson!!!

And here's where the Acoustimass differs ... that direct/reflecting design is adjustable by the USER, and can in fact be positioned as a conventional direct firing satellite unit. This is very different from Bose's direct/reflecting bookshelf and floorstanding speakers, or dipolar or bipolar or omnipolar speakers, which have the radiating pattern fixed into the speaker design.

and if they were, given the fact that the Bose owners manual indicates they should be aimed to give a balance of direct and reflected sound, the test parameters are therefore suspect IMO. Might the fact that they are supposed to be off-axis to each other have skewed the numbers? and all the while, conveniently fitting in the apparent Bose-bashing agenda? If so, how convenient...

S&V conducts all of their speaker tests using on-axis measurements. That's why their results are comparable from graph to graph. David Ranada and more recently Tom Nousaine have been conducting these tests the same way for years. No Bose bashing agenda from them, and no Bose favoritism from them either, unlike Pohlmann's approach of only telling the good news, and leaving out the details.

That dip in the 200-300Hz region is at the crossover point between the bass mod and the satts...if the system was placed in a real room (not in a anechoic environment) would things have been more linear? Keep on repeating...direct/reflecting...direct/reflecting...

Nope, the wall reflections and room placement cannot create what isn't there in the first place. The existence of this frequency gap is audible during normal listening. As I noted before, male voices sound very strange on an Acoustimass system.

The rise to a +4 dB peak and subsequent fall @ 5-7kHz region...could the axis alignment (if that's how it was indeed done) have been responsible?

Another very audible phenomenon in a real world setup. Despite their steep dropoff in the highs, the Acoustimass systems subjectively sound bright much of the time, and that goes along very well with that peak that occurs around the 5 kHz mark. However, this brightness does not apply to higher pitched sounds like violins, trumpets, cymbals etc. With those sounds, the Acoustimass systems sound almost muffled.

I'll try to locate my pink-noise plots over the weekend, but at the very least I'll just re-plot the inverse of my current settings on my half-octave graphic and provide some further info...at least re: 901-lls...and they were done in a real-life living room and with the best of intentions.

jimHJJ(...now I think I'll have an apple turnover and some OJ...)

Interesting results that you posted. The most notable aspect that I spotted was the big difference in how the L and R speakers measured. Was this room asymmetrical?

[Resident Loser]

...being the dimwit that I am, on review I noticed the right-channel peak @ 10k...actually since my EQ controls are +/- 16dB max, that point in the plot should be 5dB lower...like this:



And in answer to your inquiry:

Interesting results that you posted. The most notable aspect that I spotted was the big difference in how the L and R speakers measured. Was this room asymmetrical?

Well, ostensibly the room (10x14 or so) is visually a rectangle and my speaks are along the longest wall...however, directly opposite the left speaker is a foyer, alcove, place to wipe your feet, roughly 4ft. square...standing in it is a sonic nightmare, and I'm fairly certain it has an effect...to say the least...and then there's the picture window in the short wall in between...

As if that weren't enough, there is a similar situation at the right speaker. That mirror-image "alcove"-like space actually extends into a hallway, which at least doubles that leg of the room...and then there's the archway that opens into the dining area...so sonically, the space is sorta' like a U-shaped affair...and then of course comes the furnishings...all in all, a great big pain in the (r)ear...

I had used a laundry-list of SPLs on a legal pad for the EQ set-up...Since transferring those numbers to the proper plotting medium, I think I can now visually account and correlate for nearly every blip and bloop in the response curve.

jimHJJ(...all-in-all, it's been a beneficial exercise...)