Bose 901 VI

[Erik Mandaville]

"this .... from people that frown on ...... Tone Controls ...."

Maybe some people. I have always liked tone controls, and have never been one to yank them out of a circuit in the name of hoped-for better sound.

Erik

[Erik Mandaville]

Gary:

A speaker that makes a greater number of recordings sound good ("musical"), albeit with a little veiling, even if they are not recorded too well. This category would include the Bose 901 series (with big amps and well-suited rooms), and many speakers of the "sweet and gentle school" that audiophile magazines tend to like. As I said in a former email, the Bose 901s in Alphonso's Mercantile, with their 1,000 wt amps, don't seem to veil, but all others I've heard seem to.

I'm sure I must stand corrected. I had no idea what amps were being used when I heard them, but I got the *impression* that speakers were fairly efficient from their very punchy and clean quality. Despite the fact that there aren't more conventional passive crossovers used the EQ, as I've heard from a very reliable source, must eat up gobs of power. But, that fact notwithstanding, they did in fact sound very good, and I sometimes ponder the idea of taking this whole thing in the opposite direction of how it's been going for the past bunch of years. In other words, using much less efficient speakers powered by substantially more powerful amplifiers; which as Max mentioned, really would be a pretty funny thing for someone like me who has spoken so glowingly in the past of amps in the 1.5 watt range. It's crazy, I know, but so what!?

I have some small monitors I made years ago, very carefully cut from 2 inch thick ceramic chimney tile, that are just incredible. Really, these are something special. I rebuilt the network to the most simple I could get away with, and they are truly, truly superb with the right amp. With a 3 watt single-ended triode feeding them, they are terrible, and start to sound congested and distorted very fast with those amps. I tried them with our Teac a few months ago and the match was outstanding. Most speakers I've tried with the Teacs seem pretty happy about it.

I was going to go listen to the 901s again today, but was just too tired. I love the way those things look, and maybe that's something that's influencing me in some odd way, but I don't think so.

What's a good 1,000 watt amp?

Erik

[garyrc]

Erik.

I believe McIntosh makes a good 1,000 wts per channel (2 channels) amp, and they also make a three chassis unit that produces 2,000 wts RMS for each of 2 channels, and claims to provide 8,000 wts peak (per channel??, both operating??) ... but I don't know how they are measuring / defining "peak."

I don't think BOSE provides the usual standard figures for dB SPL at 2.83 volts at 1 meter, but I believe the version of the 901 of the early 1970s has been rumored to be about 93 dB, with wall reflection (not anechoic). This would mean that 100 wts into a Klipschorn would be the equivalent of about 1,333 wts into a BOSE 901.

Don't get me wrong, I have always liked the sound of the Bose 901s at Alphonso's, so I know they can sound very good.

P.S., I have no objection to tone controls -- I especially loved the ones I used to have on a Luxman, with several choices of turnover frequency and slope.

[Erik Mandaville]

Gary:

93dB? really? Maybe that impression of higher than average efficiency wasn't too far off the mark. It seems you're right about the SPL figure as being left out in the specs they give. I really have no idea of how things were set up at the store to make the speakers sound as good as they did (there), and, just like with virtually everything in this hobby, is something that needs to be tried for oneself in one's own home.

The information and opinions on this subject you provided were helpful -- I appreciate it.

If you don't mind my asking, is Alphonso's and audio electronic's store? When I first read your reference to *him* I thought you were talking about a friend who owns 901s.

Erik

[DrWho]

It really doesn't matter that the lower octaves are synthesized. It sounded good to me.

Simple enough?

Yep, you like the sound of distortion and either don't know what live music sounds like or don't care that your system doesn't sound like live music.

Just outta curiosity - can you hear the "tremelo" induced on flute passages when there is bass material present at the same time? I find the same effect totally destroys any hope of accurate reproduction of piano as well. In other words, I can't stand piano concertos or really any complex passages being played back on 901's. I don't like notes to be present that were never played and notes to be missing that were played. PWK didn't like intermodulation distortion either - oops, I used a technical term. I don't like wobbly notes!

[tparker1]

Erik;Bose sounds ok If you have the right one's.What I don't understand is why they have Nine drivers on one side and two woofers on other side.

To me I think they would sound much better if you had two speakers left and right with the Nine Drivers in each and add a Sub for the Lows.

A friend bragged How Loud His 901's played and said they were the best I talked Him into bringing them over which He did and fired them Up We sat back and used My Sony DVPS-7000 DVD/CD Player/@ Carver TFM THX Amps bridged mono into My Yamaha RX-V2090 used as a preamp for front speakers and in Unbridged mode other times.They sounded pretty good and he had this SEG on His face so We unplugged His 901's all the time he kept saying Man those Bose speakers are awesome.

I hooked up My CF-4 Klipsch Front Speakers and blowed Him away.He couldn't believe how good the Klipsch's sounded.

His speakers sounded good but were no match for Mine but Cf-4's cost more and outweighed His so it was not a fair fight.

Bose makes some excellent Speakers but they are Pro series .Check them out and I think they should use them for Home Speakers myself.

A pair of MB4-BLACK Modular BOSE Bass Loudspeakers with Panaray LT 9702 Loudspeakers or the 802 Series lll Loudspeakers (Professional)

They aren't that expensive either and have better drivers and Cabinets.

[Erik Mandaville]

"Yep, you like the sound of distortion and either don't know what live music sounds like or don't care that your system doesn't sound like live music."

You pegged it! That you were able to excavate the true intention behind that 15 minute experience is remarkable.

I don't like wobbly notes either, unless they're intended to sound wobbly. Some opera singer's I like make their voices wobble once in awhile, and sometimes it sounds appropriate for the piece, other times just too wobbly. I'm with you in that sense.

Erik

[Erik Mandaville]

"oops, I used a technical term."

Oops! Gotta watch those!

Erik

[Erik Mandaville]

Tparker1:

"Erik;Bose sounds ok If you have the right one's.What I don't understand is why they have Nine drivers on one side and two woofers on other side."

I might be wrong, but I think they have a grand total of nine drivers: four in each section at the rear of the cabinet (for 8) and one in the front baffle for a set of 9 drivers.

I'm sure your Klipsch speakers sounded great; we really enjoyed the La Scalas we used to have, and now have a pair of Klipschorns and 2 pair of Heresies.

Here's the thing again: Forget that these were Bose 901s or any other brand, for that matter. I happened to have a chance to listen to some speakers I've never heard before, and in the 15 minutes or so of listening, discovered that I liked the sound I heard more than I disliked it. Whether I know what live music sounds like (which I do) or whether I like the sound of various types of distortion that may or may not have been present, does not change the fact that I was impressed by them in that short space of time. There have been other occasions where I heard conventional dynamic drivers and dome tweeters in boxes that were immediately uncomfortably bright. The 901s sounded much more balanced in that respect, and also had great presence at the same time.

If you go back through this thread, it might become evident that others mentioned something positive about the sound of 901s in the right application -- factors associated mainly with the listening area and adequate amplification.

Dee: You're right, it's just a little story.

Erik

[Cut-Throat]

Yup, I've taken many a 901 apart and repaired their rotten foam drivers. There are a total of 9 drivers. 8 on the back and 1 in front. All about 4 1/2 inches - the same. No internal crossover, just the equalizer. I still own 1 pair and keep them for people that visit me and ask me if I have ever heard of the amazing Bose 901's. I then let them hear the 901's and then a SET driven Horn System. No one has preferred the 901's yet.

The 901's can sound pretty good, if they have plenty of clean power, are postiioned correctly and played extremely loud. They will impress you with their small size and incredible loud but clear sound. If played at a party with enough booze in me, I can get my toes tapping. I don't believe that anyone in history has replaced their SET amps and Horn speakers with Bose 901's however.

I do have a custom pair of Bose 901's that I refoamed the drivers on. I also made solid walnut panels to cover the sides and front of the speakers and finished them with about 6 coats of varnish. They are simply stunning looking. I actually got them free from some guy that said they did not work and was junking them. I keep them in my 'audio museum' with my Solid State Crown, Hafler, Marantz, Pioneer gear. It all looks cool, but sounds marginal, but reminds me of all the stuff I could not afford in the early 70's.

[johnyholiday]

Nothing new in the "aural optics" twilight zone.......

[jt1stcav]

Interesting thread, Erik.

Haven't auditioned any 901s since '89, but I agree with your assessment on their sonics as well. Regardless to what type of drivers are used and how many, how their specs are achieved, and how they sound without their supplied equalizer is totally irrelevant IMO...what's important to me is how decent they can sound with a properly set EQ in the right room with the right amplification with certain music. And love 'em or hate 'em, the fact that they're still manufactured since the early '60s has to say something about their aural design.

[DrWho]

And love 'em or hate 'em, the fact that they're still manufactured since the early '60s has to say something about their aural design.

...or the home audio market []

[Erik Mandaville]

"I don't believe that anyone in history has replaced their SET amps and Horn speakers with Bose 901's however."

Well, I guess that depends on how far back you want to go.

I thought that's what the big brawl in the Pompeii amphitheater was over, wasn't it? Took place in 59 or 60 CE, I think. One team was called the SET-HORNS, the other the 901s. Both had their equipment organized so that spectators had the best listening experience possible. The Velarium (that's a big cloth awning that could be rolled out over head to protect against sun and rain) was in place in order to provide some small amount of reflected sound, but the problem was that both sides seemed to have an equal number of fans. Those cheering for the 901s complained that horns and SET amps tended to beam and lack dynamics; the SET crowd thought the 901s were overly diffused, didn't have clean, crisp highs, and that bass notes sounded 'wobbly.' Despite the fact that the majority on both sides tended to stick with what they knew and liked as far as the kind of sound systems they used in the atriums of their homes and villas, there were accounts of a few, less overtly illustrious listeners who quietly exchanged thoughts, ideas, and feedback over the merits of both. Some even went as far as becoming friends, and getting together to listen to music at one another's homes just for the -- if you can believe this -- pleasure of it.

Actually, now that I think about it, I think that whole unfortunate event was over something else -- a gladiatorial contest, I believe.

Kevin: It sounds like you took some time and care refinishing those 901s of yours.

Erik

[maxg]

Close Erik but actually I think it was the all new Vesuvius Sub woofer that was designed to really shake the walls down - and it was in Herculaneum where they refused to play such old designs as horn loaded woofers and reflected sounds.

Horn-loading was actually started by the Greeks some 500 years before in their theatres so you could hear a stage whisper in the back row. Which amps they were using is not recorded.

[Erik Mandaville]

We were talking last night how it would be neat to one day invest in a new pair of Heresy IIIs for downstairs stereo system. I would move the Is we are using now up to the big rig as rear surrounds. They would be perfect for that!

The 901s were fun to listen to, though.

Erik

[Erik Mandaville]

Max: Thanks for the correction on that!

LOL!

[Erik Mandaville]

Jim:

"what's important to me is how decent they can sound with a properly set EQ in the right room with the right amplification with certain music."

Totally agree with that, and it was an interesting experience. I have no idea about what may have been going on in terms of how everything was set up in the store, and wonder that it might be hard to duplicate at home, here -- meaning our home. Nevertheless, the sound of those things was pretty nice, and I loved the way they look. Aesthetics *ideally* should have little influence, but I admit to being sometimes drawn to components in terms of what they look like.

Thanks for your thoughts on this!

Erik

[jt1stcav]

You're welcome, Erik.[]

[garyrc]

Erik,

One more bit of indirect evidence that the BOSE 901s may have an effective efficiency of about 93 dB is that when Stereo Review (August 1984) reviewed the 901 Vs, they reported a sensitivity of 87 dB, but pointed out that their quasi-anechoic testing set up was not really valid for testing speakers like the BOSE that depend on reflections from the room walls. In most of the 901 setups I've seen, the speakers are close to the wall behind them, therefore get a lot of reinforcement for all those speakers aimed right at the wall, and the outermost speakers shoot sound into, or toward (depending on room size), the corners. PWK pointed out that any speaker in a corner would gain something like 6 dB over the same speaker out in the room, but fairly near the back (or front, it's all relative) wall. 87 plus 6 equals 93! Considering all the talk about the inefficiency of the 901s in the magazines, 93 may be a bit generous to them. The irony is that most of those articles were written in the 70s, when there were still a ton of efficient JBLs, EVs, ALTECS, and the like, around, so by comparison, the 901s were inefficient, indeed. Times have changed. Nowadays, even JBLs are declining in efficiency in their top models. My impression is that the mean (probably the median and mode, too -- causally observed, the distribution looks like it approaches normality) of speaker efficiency is around 90 dB now. If that is true, everything else being equal, 100 wts into a Klipschorn would be about the equivalent of about 2,000 wts into a typical (90 dB) speaker.

Alphonso's Mercantile [where the 901s, with powerful amps, sound good, and are always on] is not an Audio store. Alphonso runs a store in a sort of artist's colony on the Mendocino [Northern California] coast that carries local arts and crafts, CDs, many imported at his request, and some vinyl. He is incredible knowledgeable in music and music history, and has reference works, such as the unabridged Oxford encyclopedia of music. He introduced me to many obscure works, such as Kabelac's Mystery of Time. Someone asked him if he ever considered moving into the city. He raised his wine glass toward the front window, overlooking an inlet in the sea, and said, "No, I need that."

He is getting older, as are we all, so I hope he is still there.

Maxg,

Isn't an amphitheater, Greek or otherwise, a horn of sorts? If so, acoustical horns are ancient.