Quote Originally Posted by Audie Oghaisle
I recently came across a recent episode of the never-ending to and fro re: the 901s...let me say to all and sundry, and I'll use a line I've read countless times in other forums @this site, "You don't know how to listen!"

Most members ot the "boom and tizz" brigade (long-time readers of the late, lamented "AUDIO" mag will recognize that phrase) are so use to hearing "in-your-face" hi freqs, they believe it to be a hallmark of accurate sound...and the low freq humps designed into most loudspeakers to disguise their rapidly-falling off, below mid-bass reponses...well, let's not go there!

I have owned 901 Series lls since 1974. I auditioned Allisons, Advents, Dahlquists(pre-mirror imaging mods) etc., etc. and chose Bose.

Why? To me, all the reasons pertaining to their design and execution made perfect sense. Multiple small drivers producing the output of a single 12" woofer with less mass, no hangover, none of the drawbacks of the larger cone. They theoretically can and, in practice do, provide crisp and accurate transients and do extend well into the nether areas...talk about basso profundo!

On a wide range of low freq-rich program material, whether it be the tympani in Copland's "Fanfare For The Common Man" , E. Power Biggs pedal work on Bach's organ pieces, synth work on some of Heart's or ELPs cuts...it's there, deep, accurate, clean and visceral.

Highs? Have you really(and I mean really) listened to live music? They(the highs) drop off quite distinctly depending on distance from the source. Do you really listen to trumpet, et al with your ears to the bell? On a close-miked recording with conventional loudspeakers, that's exactly what is happening...hardly realistic, IMHO.

Indulge me, if you will...Placement is critical, I built a side wall to be sure the installation parameters would match side to side. My power amp is an HK Citation 19 rated @100W/side and I use an SAE 2700B half-octave equalizer. My system is EQd from stylus to listening position. Using a calibrated source( a Crown third-octave test record) and a borrowed pro SPL meter(which by-the-by, the RS unit compares favorably with in side-by-side usage). Multiple room plots and adjustments resulted in near-flat response...but, flat ain't where it's at...a gentle roll-off above 10k provides the most natural sound to me and most of the pots are in the "cut" mode; the few that aren't are +3db max. The Bose eq is used to tweak lesser recordings and the tone controls on my pre-amp are bypassed with the "defeat" switch.

The sound is neither bottom-heavy nor shrill, the net result is smooth sound, uncompromising in its' candor. Good recordings sound as they should and poor ones are revealed...Listener fatgue does not apply and the catch-phrases are all at the ready: imaging and depth, inner details, articulation...an acoustic bass sounds as it should, brushes on a drum kit, ditto. But, only if the source can provide these things.

Comparing Bose to anything else is like the proverbial "apples and oranges" and those who base an opinon of their sound on a Bose-equipped system that has not been set up correctly don't know what they are missing, how unfortunate. And, don't think they are properly set up in a Bose store, quite curiously they're not!

Audie
Sir,

I am sorry, but your arguements in favor of the 901 are hollow at there very best.

Most members ot the "boom and tizz" brigade (long-time readers of the late, lamented "AUDIO" mag will recognize that phrase) are so use to hearing "in-your-face" hi freqs, they believe it to be a hallmark of accurate sound...and the low freq humps designed into most loudspeakers to disguise their rapidly-falling off, below mid-bass reponses...well, let's not go there!
This is a huge sweeping inflammatory generalization that is made to give foundation to your point. However this doesn't describe 80% of the speakers that are in the 901's price catagory. If the 901 was measured in the same fashion as other speakers in this price catagory, it would measure worst than at least 90% of them because of the comb filtering, and phase/frequency aberrations caused by the mixing of the direct and reflected output.

I have owned 901 Series lls since 1974. I auditioned Allisons, Advents, Dahlquists(pre-mirror imaging mods) etc., etc. and chose Bose.
None of these speaker companies exist anymore. Try a comparison with Dunalavy, Thiel, Aerial Acoustics, and as much as I dislike this kind of speaker Martin Logans. These are todays companies turning out speakers that would put the 901's to absolute shame.

Why? To me, all the reasons pertaining to their design and execution made perfect sense. Multiple small drivers producing the output of a single 12" woofer with less mass, no hangover, none of the drawbacks of the larger cone. They theoretically can and, in practice do, provide crisp and accurate transients and do extend well into the nether areas...talk about basso profundo!
There is only one problem with your theory. It takes mass to reproduce bass under 40hz. The size of the drivers, and the internal volume of the 901 makes anything under 40hz impossible to reproduce without a great deal of distortion. What is worse is the 901 suffer from a problem of its design, and its interaction with small room acoustics on a couple of levels. By the way, according to Stereophile, the 901 does suffer from hangover. The worst kind of driver hangover. All of its 9 drivers suffer from hangover in varying degrees which is worse than a single driver with the same effect. Now let's talk about the basso profundo that you say is a 901 strong point.

Room resonances:
The fact that, in a living room of typical size, the strongest standing-wave resonances usually occur at low frequencies, is the main reason why putting a speaker in a corner will produce the most bass-heavy sound. Once we get out of the corner, though, the efficiency with which each standing wave is stimulated will depend on the speaker's precise location relative to the room corner.
The crucial factor seems to be the location in the room from which the woofer(s) are feeding energy into it. Thus, it is often (usually, in fact) possible to obtain flatter overall response with a single relatively small woofer, which radiates from a small area, than from a multi-woofer system whose low end radiates from a general area that may be several feet wide.
By the same token, loudspeakers which radiate their lows in one direction (they are nondirectional after they leave the speaker) seem less prone to excite all the room resonances than ones which radiate from front and rear or front and sides. True omnidirectional (360-degree) bass radiators make it harder still to control standing waves, and that appears to be one of the problems with the Bose 901
Thus placement and the quality of the bass ouput of the 901 is totally inconsistant from room to room. No good CONSISTANT results can be obtain from the 901's bass output because instead of outputting from a single point in a corner like a good subwoofer, it is coming from a VERY wide point at that corner which definately excites standing waves at a much greater degree than a single driver subwoofer. Therefore in some rooms the 901 can sound passable, but in MOST rooms it will sound one notey and indistinct. This does not bode well for a speaker that is supposed to go into many different rooms, with many different room deminsions.

Room reflection and Concert hall ambience:

Dr Bose seems to operate on the principle that his speaker are designed to simulate(very important word here) the multiple reflections of a concert hall. This is a flimsy premise for small rooms which are too small to support concert hall size reverberation(or reflections). Let's face it, my listening room does not have the deminsions of Boston Symphony Hall. It therefore CANNOT produce a reflection pattern that resembles that hall. Hall reverberation requires a long decay for which my room, nor most listening rooms can support. Keep in mind that it is up to the recording to convey the recorded ambience, not up to the speaker to create some. The multiple reflections emited from the 901 does nothing more than to create a frequency comb filter which alters the natural timbre and tonal qualities of the recorded signal. If accuracy is your main goal, then the 901 fails from the jump. What is worse it that the driver facing the listening position emits very little signal directly to the ears, while the sound of the rearward facing drivers produces the most output. Once the rearward output reflects off the walls and into the room, it is out of phase with the signal from the front panel. The combination of these two signals at the ears produces an unwanted phase shift and time smearing. These phase shifts produce short notches in the frequency response depending on frequency. This is what the 901 uses to broaden the sound source at the expense of small detail and tonal shadings. The 901 does this to EVERY recording regardless of whether it was recorded that way. If a Steinway grand was mean't to be heard spread in between the speakers, with the 901 it will sound like it is as wide as the room itself. This effect while very noticeable with solo instruments, makes mass instruments lose image definition and true scale. In other words proper placement between the speakers.

In these days of hometheater and 5.1 audio, these speakers have outlived their usefulness. There is no need to scatter artificial reflections all over the room to simulate a live concert hall. A well calibrate 5.1 system of tonally matched speakers and a VERY good sub can do this with ease.

Indulge me, if you will...Placement is critical, I built a side wall to be sure the installation parameters would match side to side. My power amp is an HK Citation 19 rated @100W/side and I use an SAE 2700B half-octave equalizer. My system is EQd from stylus to listening position. Using a calibrated source( a Crown third-octave test record) and a borrowed pro SPL meter(which by-the-by, the RS unit compares favorably with in side-by-side usage). Multiple room plots and adjustments resulted in near-flat response...but, flat ain't where it's at...a gentle roll-off above 10k provides the most natural sound to me and most of the pots are in the "cut" mode; the few that aren't are +3db max
With all due respect to you, a half octave equalizer is useless in trying to eq a speaker where all of the drivers face foward. It is LESS than useless in dealing with the output of a speaker where the majority of the output is scattered everywhere. A third octave test disc has a smoothing effect of a speaker that exibits as much of a combing effect as this one. 1/6 and 1/10 octave anaylsis is much more revealing of a speakers frequency response. I highly doubt that you attained a flat response from this speaker at any point whether in front, sides, or rear.(according to a stereophile review of the speaker, it could NOT be made flat in four different rooms). A SPL meter, and a test disc is an EXTREMELY crude way of measuring a speaker. It tell you nothing about what is going on in the time domain. It also has no way of gating out room reflections which can alter what you measure by a great degree. Based on my understanding of room acoustics(Acoustics was my graduate minor), and my experience measuring speakers for installation in my clients homes, there is no way you can get a near flat measurement from a 901 even if you were to overlay the different plots you measured and average them together. With a speaker of this type, it is virtually impossible.

Highs? Have you really(and I mean really) listened to live music? They(the highs) drop off quite distinctly depending on distance from the source. Do you really listen to trumpet, et al with your ears to the bell? On a close-miked recording with conventional loudspeakers, that's exactly what is happening...hardly realistic, IMHO.
You are correct in your first sentence. However the distance it takes for the highs to drop off in comparison the the 901(without eq) is alot further than the distance to the rear wall of the typical listening room. Since we listen in the near field, high should remain the same as the recording provides at the common distance that most of us sit from our speakers. If a trumpet is close mike, it should sound close mike. That's called accuracy, and it is indeed as realistic as the recording conveys. That same trumpet will bell will sound 2-3ft wide on a 901, which is WAY less realistic when the bell of a trumpet is perhaps 7-10" wide at is widest flare. Since you are normally sitting 6-10ft from your speakers, I can hardly see(or hear if you will) how it would soundlike your ears on the bell. Huge exaggeration here I must say.

I believe I can stop right here. I have made my point. I believe that you have been a victim of Dr. Bose's brainwashing. I have several magazines with reviews of the above mention speaker, and none of them even remotely report a flat(or even a near flat) frequency response from them. Most applaud them for their spaciousness, but say they are weak at best in every other measured area. If I where you, in the future I would choose a more conventional speaker to blab about. There is VERY good chance it would measure better than the 901, and therefore offer you some cover from your audacious claims of merit for this speaker. In the plain language of my people of Manhattan, you could lie and hide!