Bose 901 Series V Speaker Review!

[audioresearch]

I believe the distortion was high because the speakers you tested were old and most likely the spiders, and/or surrounds, and/or cones had deteriorated with age.

In the case of the surrounds, it is a known fact that the foam surrounds would often completely rot away with age and quite likely the ones in the speakers you tested were well on the way to failing totally. I believe that somewhere in the production run of the series V, the foam was changed to a different type of foam that would not rot.

Those problems would likely also affect the frequency response.

I have no idea how much the old foam surrounds contributed to the high distortion numbers, but at least the first two editions of the 901 (original 901 and series II 901) did not have the foam rot problem because they did not use foam, so perhaps they will have much better distortion numbers and maybe even frequency response also if you are able to test them one day.

I used to run 4 pairs of 901s which really took care of any limited output capabilities quite nicely at least until the day when all their drivers failed due to foam rot.

Nobody ever mentions one fantastic improvement made by the 901s: finally, at long last, a speaker system where blowing tweeters is not a problem when listening to loud music.

 

[audioresearch]

Let me add that it is nice to know old 901s can probably deteriorate a lot, at least the ones with foam surrounds one series of which you tested and so if your tests are representative of all Bose speakers that used the original style of foam(see what follows about that) then maybe one would wish to avoid buying used series 3-5. I'm not sure about the series VI original or series VI updated. I heard from a highly placed engineering source at Bose whom I personally knew that once the foam rot problem became known, Bose switched to a foam with a different molecular structure that supposedly would not rot somewhere during the production run of the series V and so the series VI should supposedly have the newer "good" foam.

 

[GXAlan]

If you look at my signature, I have done some non NFS basic measurements of the VI, VI ver 2 and original 1968 model.

 

[Everett T]

I believe the distortion was high because the speakers you tested were old and most likely the spiders, and/or surrounds, and/or cones had deteriorated with age.

In the case of the surrounds, it is a known fact that the foam surrounds would often completely rot away with age and quite likely the ones in the speakers you tested were well on the way to failing totally. I believe that somewhere in the production run of the series V, the foam was changed to a different type of foam that would not rot.

Those problems would likely also affect the frequency response.

I have no idea how much the old foam surrounds contributed to the high distortion numbers, but at least the first two editions of the 901 (original 901 and series II 901) did not have the foam rot problem because they did not use foam, so perhaps they will have much better distortion numbers and maybe even frequency response also if you are able to test them one day.

I used to run 4 pairs of 901s which really took care of any limited output capabilities quite nicely at least until the day when all their drivers failed due to foam rot.

Nobody ever mentions one fantastic improvement made by the 901s: finally, at long last, a speaker system where blowing tweeters is not a problem when listening to loud music.

From the review: "Funny side story: he was going to send the Series IV he owned but had issues when it came time to refoam them so he sourced a very good condition pair of Series V’s and shipped them to me."

So the surrounds were not an issue with the measurements FWIW.

 

[audioresearch]

From the review: "Funny side story: he was going to send the Series IV he owned but had issues when it came time to refoam them so he sourced a very good condition pair of Series V’s and shipped them to me."

So the surrounds were not an issue with the measurements FWIW.

Ya maybe, I was just guessing. But it does seem that old speakers can age differently from speaker to speaker so it might be best to test a few pairs if ever you have that luxury. In the last year, I bought 2 pairs of original 901s and at least one of the drivers seems bad as I can hear serious distortion/rubbing/whatever from one particular location on one of the speakers. I have a spare original 901 and whenever I get around to it, I'll narrow down the problem to whichever driver(s) is the cause and replace it and also check the state of the sealer around the drivers and also clean up the connections where the internal wiring attaches to the internal speaker terminals that are on the bottom of the cabinet since in the past I have found those to sometimes be corroded enough to badly ruin the sound.

 

[ahofer]

An acquaintance is staying in a place on Long Island. Sent this pic

Place is owned by a well-known electronic musician.
Another pair of 901s in the closet, apparently.

 

[egellings]

I just have a problem with a 4" or so diameter paper cone doing justice to frequencies usually reproduced with small dome or ribbon drivers. I can see how 9 of the drivers could cover bass & midrange frequencies adequately, however. I heard a pair once and was impressed by how good the LF performance was, and midrange did well, too. HF output, not so good, despite the EQ provided with the speakers.

 

[GXAlan]

An acquaintance is staying in a place on Long Island. Sent this pic

Place is owned by a well-known electronic musician.
Another pair of 901s in the closet, apparently.

Nice! If I just saw one, it would have been chosen for looks. With a second pair, the musician must really enjoy the sound.

I just have a problem with a 4" or so diameter paper cone doing justice to frequencies usually reproduced with small dome or ribbon drivers. I can see how 9 of the drivers could cover bass & midrange frequencies adequately, however. I heard a pair once and was impressed by how good the LF performance was, and midrange did well, too. HF output, not so good, despite the EQ provided with the speakers.

It very clearly drops above 16 kHz, which makes it less ideal when you are younger but less of an issue as you get older. It does give a bit of a vinyl/less detailed and less fatiguing sound.

That said, I have MG-III’s and multiple generations of the EMIT tweeter. The 901’s are still an enjoyable speaker. Adding a super tweeter to fill the upper most octaves works great. I have used the JBL UT-405 with my Bose 901’s and gotten great results.

 

[egellings]

Nice! If I just saw one, it would have been chosen for looks. With a second pair, the musician must really enjoy the sound.


It very clearly drops above 16 kHz, which makes it less ideal when you are younger but less of an issue as you get older. It does give a bit of a vinyl/less detailed and less fatiguing sound.

That said, I have MG-III’s and multiple generations of the EMIT tweeter. The 901’s are still an enjoyable speaker. Adding a super tweeter to fill the upper most octaves works great. I have used the JBL UT-405 with my Bose 901’s and gotten great results.

I did like the room filling effect of the speakers on some music. On other music, the effect seems overblown.

 

[GXAlan]

I did like the room filling effect of the speakers on some music. On other music, the effect seems overblown.

It's definitely not your "girl-with-guitar" speaker choice. It really does work great with anything you'd hear in a concert hall, or a "big band" type of sound.

In my home, I've found them to be exceptional for my home theater since the high frequency roll off isn't a big issue. I should have ridiculous amounts of comb filtering, but I don't think it matters in practice. I have four Bose 901 running at L/R front + rear. I have two JBL S/2600's flanking the television as my dual center channel. That has the asymmetrical horns which preserved a center image for vocals even when you are silly-off-axis.

I feel like it's the difference between listening to headphones vs. speakers and speakers vs. the 901 room-filling sound.

 

[audioresearch]

I just have a problem with a 4" or so diameter paper cone doing justice to frequencies usually reproduced with small dome or ribbon drivers. I can see how 9 of the drivers could cover bass & midrange frequencies adequately, however. I heard a pair once and was impressed by how good the LF performance was, and midrange did well, too. HF output, not so good, despite the EQ provided with the speakers.

The 4.5" drivers will beam the higher frequencies unlike a small dome tweeter. The dome tweeter does not avoid beaming because it is a dome, but only because it is small. If the driver is too large compared to the wavelength, it start beaming. The 901 handles this problem by having most of the drivers on an angled "V" shape in the rear so that the sound is spread out and "un-beamed" so to speak. Some acoustic scientist/audio engineer once did an experiment that showed high frequencies were totally masked out above a certain frequency in the range of 12KHz to 14KHz according to one of Dr. Bose's lectures. The main goal of that experiment was not that finding and so nobody ever bothered to find out just where between 12KHz and 14KHz the point was where highs got totally masked. Sure, if you are listening to a movie sound track and it is of a signal generator sweeping up to 20KHz, then you will notice that the 901 drops out some highs you should have heard (if you knew they were there).

A very long time ago, I sold the AR-3a speakers I owned and replaced them with the original 901s. Despite what others have said elsewhere about the 3a's having rolled off highs, I always thought mine sounded too pronounced and that the 901s deadened them back down to reality.

I went over to Boston Symphony Hall a few times and carefully listened and the highs from the real orchestra were also subdued compared to the 3a and sounded more like those from the 901s. I was waiting for some audiophile to walk up to the orchestra and demand they stop playing because they didn't sound accurate!
Yes, it would have been a better test if I set up my 901s on the stage next to the orchestra and switched between my speakers and the orchestra, but who was going to let me do that? I was also a stereo salesman and it was common knowledge in the business that some speakers would unrealistically boost the highs. It gave them so-called "presence" and fooled customers who did not know better. When the customers heard a more realistic sounding speaker, they thought it was missing the highs and they would be getting cheated if they bought it.

 

[GXAlan]

I went over to Boston Symphony Hall a few times and carefully listened and the highs from the real orchestra were also subdued compared to the 3a and sounded more like those from the 901s.

+100

I really like my Bose 901 VI’s even though I have fancy Meyer Sound gear and really do enjoy my Magnepan full-height true ribbons too.

I went to SF Symphony last year when John Williams and Anne-Sophie Mutter were performing. By pure luck, I happened to be sitting at THX style distances (where my FOV of the stage matched the width of a movie theater screen) and dead center to where Anne-Sophie Mutter was playing (so left of center in audience, stage right) and at the height of Anne-Sophie. Again, perfect position through dumb luck.

I have always associated recordings of Stradivarius violins to have a little bit of a bite, but in this actual performance, the treble was far more subdued than a typical audiophile speaker. Imaging was not pinpoint but the expansive nature of the 901 soundfield truly replicated the experience at the symphony.

What is great is that I could then compare the same artist and conductor on a modern premium recording. Since the violin is allowed to shine, I was able to compare the live experience with the home experience.

There is something to be said about the hyper-real experience of many audiophile speakers but I think the Bose 901’s came incredibly close to the true experience.

In contrast, while the Bose 901’s does well with vocals, I much prefer my Meyer Sound’s.

I do think that the 901’s could be improved with modern speaker manufacturing techniques in terms of the enclosure and driver itself and running full DSP. It’s on my “if I win the Powerball” hobbies I would take on.

Last, the Series VI and Series VI ver 2 measure differently so I would also expect the Series V to differ from the VI.

 

[anmpr1]

Some acoustic scientist/audio engineer once did an experiment that showed high frequencies were totally masked out above a certain frequency in the range of 12KHz to 14KHz according to one of Dr. Bose's lectures. The main goal of that experiment was not that finding and so nobody ever bothered to find out just where between 12KHz and 14KHz the point was where highs got totally masked. Sure, if you are listening to a movie sound track and it is of a signal generator sweeping up to 20KHz, then you will notice that the 901 drops out some highs you should have heard (if you knew they were there).

A very long time ago, I sold the AR-3a speakers I owned and replaced them with the original 901s. Despite what others have said elsewhere about the 3a's having rolled off highs, I always thought mine sounded too pronounced and that the 901s deadened them back down to reality.

I went over to Boston Symphony Hall a few times and carefully listened and the highs from the real orchestra were also subdued compared to the 3a and sounded more like those from the 901s. I was waiting for some audiophile to walk up to the orchestra and demand they stop playing because they didn't sound accurate!

No one attending a live symphony orchestra really hears anything like what comes out of their loudspeakers. The question of imaging, front to back depth, and all the other stuff audiophiles find worthy of talking about is lost at the concert hall (of course a lot depends upon the seats you can afford). Plus, rhythm and pace depends upon the conductor, and not your amplifier or cables!

Highs being 'masked' is also a function of the large auditorium. For example, up close and personal a music lover unfamiliar with real instruments could find that an E string on a violin might make them cringe. I remember being told that the sound was 'steely and unpleasant'. "Steely" I thought! "Hmm... I wonder what the string could be made of!?" LOL

You likely recall (or have read about) how AR in conjunction with Dyna conducted 'live versus recorded' demos, using in a large auditorium. According to reports, casual listeners really couldn't reliably tell the difference between a chamber group and the AR (I think at the time it was the original AR3 model). A large open venue tends to 'blur' localization and homogenize the sound. At least that is my experience. Of course with repeated trials one could likely learn to spot the difference between live and a loudspeaker, reliably. In a smaller closed space (like a living room) there is no problem recognizing differences, immediately.

FWIW, the best 'high school auditorium' type reinforced sound I ever heard was from a set of Bose pro loudspeakers that looked like 901s, but with the angled backside (with all the drivers) facing the audience. I decided that if I ever found myself living in an auditorium I'd buy overhead 901s facing outward.

As far as AR sounding 'bright'? I wish I had a pair to compare. Memory is not the best arbiter of past reality, but my long lost impression of their 'sonic signature' was that they were pretty smooth across the FR band, but suffered horribly from the 'box' sound. Almost as if the music was 'struggling' to get out of the box. Not pleasant for me, yet many (maybe most hi-fi fans) didn't mind, either overlooking or not recognizing that effect. AR, KLH, and later Advent sold a ton of the design, for sure.

The 'box' was an effect that IMO was typical of acoustic suspension designs. Also, from my experience AR really needed a lot of amplification to 'come alive', and in their day watts were never a cheap commodity. 60 watts/ch was about the minimum you'd like.