Bose 901 VI

[Erik Mandaville]

Neil:

"Its interesting to note that many of the subjective strengths and weaknesses attributed to 901s have also been leveled at Klipsch Heritage."

Good point. I tried to raise that same fact much earlier on in this thread, because there are indeed those who dislike horn speakers in general, and the Klipsch Heritage series in particular.

Erik

[Deang]

"...like most other Heritage product owners have re-capped, replaced standard xovers with univesals, replaced universals with extreme slope, changed my mid drivers, changed my tweeters, changed my woofers, etc.....however, I have never had to do anything to my 901's..."

Well, it's not like there's much you can do to 901.

Looks like you've done everything except try a better midhorn (exluding the stuff you just picked up off of eBay). What other midrivers have to used on the Klipschorn -- I only know of a few 1 inchers that go down to 400-500Hz cleanly. I wish Klipschorn owners would quit dinking with gear and order a set of Trachorns from Al. Anyone that says the Trachorn isn't better than K-400, "just different" -- should probably throw in the towel and order a nice set of those supeb 901's.

[Erik Mandaville]

"Well, it's not like there's much you can do to 901."

But remember, the 901 combined with the EQ device is what constitutes the system, just like Klipschorns or virtually any multi-driver system requires crossover networks to divide the frequencies. Similarly, one could just as easily start replacing all the capacitors, resistors, and other parts in the 901 EQ with 'audiophile-grade' passives. Every cheapo electrolytic could be ripped out and replaced with a Hovland, Auri, or Mundorf in order to build it the way it should have been done.

Erik

[maxg]

"The multiple small speakers in a small box, heavy electronic equalization, and the direct-reflected sound path produces massive amounts of harmonic distortion and spectral reinforcement/cancellation that results in the schizophrenic sound reproduction you mention. "

What happens to the air vibrations produced by the many different instruments of an orchestra?

Erik

Busy Sunday thread this one. Just had to respond to this one Erik - listen to a single violin and then listen to massed violins - there is almost nothing in common on the face of it (yet obviously enough for the ear to recognise many violins - one wonders how?). I think there is little doubt that air vibrations from many instruments affect the sound of the individual instrument. We could have a whole thread on the evolution of the orchestra as we know it today - the instruments that made it and those that didn't, possible as a dirct result of tonal imbalances caused by the position and impact on the orchestral whole.

As for the - do 901's play classical or not? It is going to depend very much on what is being played - and the consistency of the sound source (in my opinion). To explain that - if you are listening to massed choir music - continuously - I would imagine the 901's would be fantastic. Opera, on the other hand - may have part massed choir in the background - but switches to foreground single voice both lone and overlaid, with an without orchestral accompaniment from bellow usually.

I think it is these changes that affect the 9 driver dispersion of the 901 more than with other speakers (although let us not forget there are many speakers out there that fall over with any large scale classical or operatic work) and would lead to the odd sonic experience I refered to.

It is also worth bearing in mind that there are many listeners out there that do not care one jot for soundstaging, imaging and the rest. For these people the 901 might also be excellent.

Interesting to see what parts of my mini review people have picked up on. At the price and size of the 901 it has, IMHO, no right to do anything THAT well. That is does do some things better than ANYTHING else is incredible.

Erik - if they are additional to what you have - go for it. I think you will have a blast with them - I know I would. Might be a good idea to go second hand - that way if you ever change your mind the financial hit would be minimal and you could sell them pretty much for what you bought them for.

[Deang]

"Well, it's not like there's much you can do to 901."

But remember, the 901 combined with the EQ device is what constitutes the system, just like Klipschorns or virtually any multi-driver system requires crossover networks to divide the frequencies. Similarly, one could just as easily start replacing all the capacitors, resistors, and other parts in the 901 EQ with 'audiophile-grade' passives. Every cheapo electrolytic could be ripped out and replaced with a Hovland, Auri, or Mundorf in order to build it the way it should have been done.

Erik

You can't dress a turd. No passive part, no matter how good -- can overcome the deficiencies found with low quality drivers or poor design.

[Guest " "]

"What other midrivers have to used on the Klipschorn "

Aside from the Klipsch drivers....I like the ACR/FOSTEX D400 and D450. I like the D450 moreso. The D450 comes in at 12 lbs each. It has a titainum diaphragm with a clear mylar surround. The result is a metal driver that can perform well in the Khorn mid range. I have owned a set of D400's and D450's for 21 years and always go back to them. I recently sold them upon purchasing some k-1132's. In 1986 I paid 900 german marks for the d450's which at the time, was about 600 dollars.

Horn wise Intially, i had the d450's attached to some wooden bi-radial horns. These wooden bi-radial horns where able to easily go down to 300hz. Also tried the 511's and some old altec biradials with out the fins.

Had i not bought the top sections I recent got off ebay I was cooking up a plan to use some k-1132's I bought for 300 a pair on a set of sawed off k-401's. You old k-401's were going to get sawed off. Saved by the bell....for now anyway.

I'm told by a reliable source that the k-1132 can reach lower than the k-69-a. So I replaced the set of k-69-a's that came with the top sections with a set of k-1132's.

In the long run, I'm heading for some mini Jubilees for in-house use and a set of LaScala's with k-45's, k-1132'a and k-70-g's for my out door and mobile requirements. The k-703 and the k-510 fit into the LaScala horn section if you turn the 703 sideways and push the k-510 to one side.

"Anyone that says the Trachorn isn't better than K-400, "just different" -- should probably throw in the towel and order a nice set of those supeb 901's. "

AL said he would consider a 2" version if there was enough intrest.

[Duke Spinner]

Sorry all ....

but them little drivers absolutely suck

just listen to the IM distortion, say w/ heavy bass , and say, Piano

NO amount of EQ ... can fixit ....!!

[Deang]

There's no fixed standard for accuracy because you can't make one. Just like the loudspeaker -- a live, unamplified instrument will sound different depending on the room it's in and where you're sitting in relationship to the instrument. The goal of audio reproduction should be to make the music pleasurable to listen to. At the level most around here inhabit, the sound is reasonably "accurate", and more times than not the weakest link is the recording itself.

[Guest " "]

Duke...you need the 802's instead of the 901's.

[Duke Spinner]

Naaaah ...

I need ... more Altec's .....[]

[DrWho]

"It has to do with accurate

reproduction." What's that, and when do you know you've got it? When

it sounds good? Accurate reproduction of what, the original recording

event? What was that like, and were we even there? You must know that

EVERY SINGLE COMPONENT in the chain influences the signal in some way,

so when is the decision made that we have in fact obtained an accurate

as possible representation? Should we invite others over to decide for

us? What if the recording engineer came over to listen and found that

while the overall sound was very good, the result wasn't even close to

what he/she heard in the recording studio. A few EQ adjustments are

made here and there, and the engineer nods in approval. Much better --

to him. The engineer leaves, and you sit down, frowning, to listen to

the now much more 'accurate' sound. To use a term some seem to have a

better understanding of -- Pure Crap. (as opposed to what? the diluted

version?)

Again, you miss the point and continue

masquerading in your little world of inexperience. Have you actually

had a recording engineer over to your house? Or are you just playing

out some psychotic scenario in your head? Your analogies never cease to

scream that you just have no clue.

Nobody in their right mind would presume to quantify when accurate

reproduction is actually obtained and to presume to imply that as my

meaning is hilarious. I will however never hesitate to describe

attributes that deviate from accurate reproduction. Frequency

intermodulation distortion, comb-filtering, and insane power

compression are just three readily apparent attributes of he 901's. Are

you going to argue that a system with such distortions is going to

sound more like real live music?!?

Arguing that you

can enjoy music on a heavily compromised system does not make you an

audiophile, nor does arguing that you can enjoy the sound of

distortion. Might as well go to a wine tasting seminar and proclaim the

awesomeness of your fake $1/bottle wine from Wal-Mart. Better yet, go

ferment some grape juice in your fridge and boast about the importance

of learning to enjoy its flavor because it too is wine. (And while

you're at it, denounce all the science involved in making the good

wines because you have learned to enjoy your home brewed crap.)

Ya know, I have absolutely no issue with someone enjoying music on a

compromised system. But to claim a crap system as good because you can

find a way to enjoy music on it is absurd. I know you disagree, but I'm

not the deaf one trying to claim that my Optimus Minimus 7's are on par

with a pair of Khorns simply because "they are speakers too!"

My goodness man, get out and listen to some live music sometime!

[DrWho]

Sorry all ....

but them little drivers absolutely suck

just listen to the IM distortion, say w/ heavy bass , and say, Piano

NO amount of EQ ... can fixit ....!!

lol, except the magical recording engineers in Erik's head!

[Def Leper]

What happens to the air vibrations produced by the many different instruments of an orchestra?

Erik

Even a row of violinists playing the same notes never really reproduce an identical acoustical signal, we can still tell that more than one violist is playing and if we are close enough, should be able to hear them individual. What I'm talking about is nine drivers all radiating the same signal, and this signal is interacting inside the box as well as interacting outside the box with both direct acoustical waves and those radiated back with a short time delay from the reflecting surface.

[Erik Mandaville]

"And while you're at it, denounce all the science involved in making the good wines because you have learned to enjoy your home brewed crap"

[]

Okay, I'm sure you're right. Good point.

Erik

[Erik Mandaville]

And Max:

Once again, I do appreciate your take on all of this. I haven't been in the position to listen to the 901s in a more home-like envrionment, but I do think very highly of your review, your observations, and your clear-minded advice.

Erik

[DrWho]

What happens to the air vibrations produced by the many different instruments of an orchestra?

Erik

What I'm talking about is nine drivers all radiating the same signal, and this signal is interacting inside the box as well as interacting outside the box with both direct acoustical waves and those radiated back with a short time delay from the reflecting surface.

Comb-filtering and the laws of superposition can describe all of that behavior...A quick google search would provide a lot of information on the topic.

[Erik Mandaville]

"Comb-filtering and the laws of superposition can describe all of that behavior...A quick google search would provide a lot of information on the topic."

Oh, okay. I will make a point to check that out when I have the time. The laws of superposition sound...edit: (very) important!

Erik

[maxg]

What happens to the air vibrations produced by the many different instruments of an orchestra?

Erik

What I'm talking about is nine drivers all radiating the same signal, and this signal is interacting inside the box as well as interacting outside the box with both direct acoustical waves and those radiated back with a short time delay from the reflecting surface.

Comb-filtering and the laws of superposition can describe all of that behavior...A quick google search would provide a lot of information on the topic.

I would presume that this is also applicable to any "normal" speaker where there is more than one driver performing the same job. This list would inclue the KLF range, the RF 7, the RF 63, 83 etc. etc.

One would also wonder if this effect is not present in a live performance where sound waves are being reflected off multiple surfaces and arriving at the ear at different times - or at the same time with slightly less power?

Whilst I think it is clear that there are pitfalls to the 901 approach to sound reproduction I think there are also advantages. It is the individual listener's decision as to what compromises they are prepared to live with that should decide what speaker they eventually end up with. Remember that a Khorn implementation also carries a number of compromises. They just happen to be ones that people on this board choose to live with. I would imagine the same is true of the Jubilee clone - although I have not heard it.

Certainly, when it comes to the Jub - sheer size is an issue for many, not to mention its appearance which, shall we say, might not suit all tastes.

Obviously - this is a Klipsch forum so one might expect some bias towards that speaker manufacturer - but I see no reason to harp on about the supposed weaknesses of another brand to justify choosing this one. When I originally bought Klipsch I did so because I liked the sound more than I did from other manufacturers in my experience. That others might have chosen differently does not, imo, make them better or worse than me.

Here we have a long time member who is an owner of a variety of Klipsch product that happens to have heard and been impressed by another manufacturer - one, apparently, that dare not speak its name. He is not suggesting, at this moment, that he will immediately dispose of the Klipsch products in favour of this one, merely that he might append this speaker to the list of products he currently listens to and enjoys.

No amount of de-crying the speakers he has heard is going to change the fact that on first listen he rather liked them. He may, or may not, ultimately buy them. He may, or may not, ultimately come to regret that decision down the road. The pro's and cons of the speaker design are not really relevent now - he heard them and rather liked them and wants to investigate them further. I would guess such investigation will be based upon listening more than specifications.

To my mind the 901 - whilst obviously different from any other speaker I have experienced, does have some similarities to a composition of speakers (now that I have had some more time to digest the experience).

That they are without crossover and that they have but a single driver facing the listener does give them some traits of a single driver implementation - ala Lowther for example. As Erik has Lowthers he might be in a better position to comment on this than I.

That they have multiple drivers facing rearwards does give the sound something of the flavour of a panel speaker. Depth and spaciousness did seem particularly strong.

The equalizer is unique in my experience (being specific to the speaker - and in fact the model). In some ways this might make as much sense in a single driver implementation as it would in this one. Were one to take a single driver and to boost the highs and lows - even without touching the midrange then one might well end up with a full range speaker - or close to it.

Obviously - as a vinyl lover who is accustomed to the RIAA curve in phono stages I have less of a religious aversion to equalization than an all digital owner might have. Boosting bass response (at least) is something I am kinda used to.

Interestingly the equalizer with the 901 does not limit itself to bass and high boost - but also offers tailoring of the mid-bass sound - presumably in an attempt to moderate the speaker to better match given room responses. We can discuss the pro's and con's of that approach at infinitum but I can tell you from my one off experience that the mid bass slider makes a huge difference to the sound - one that appeared on first use to be fairly easy to "dial in".

All I can conclude at this stage is that with the amplification we tried and in the room we used what this speaker did well - it did very well indeed, and what it did bably - it did badly. In another room - with other amps and sources that picture might be very different - it might even out for all I know and be suitable for general purpose listening. True, as it happens for many speakers I have experienced, although maybe a bit more true in this case.

[Erik Mandaville]

"Are you going to argue that a system with such distortions is going to sound more like real live music?!?"

Not exactly, because (1): I haven't seen any data where the distortion you attribute to the 901s is indicated, and (2): It wouldn't make any difference. For me there is only one thing that matters.

I'm experienced enough to be able to identify the qualities of artificially reproduced music that sound good to me, and I'm comfortable with that. These related speculative distortions aside, I will argue that there are those for whom the enjoyment of music is paramount, and for whom scientifically measured response is of academic importance, only. Moreover, if you read with close atttention some of the observations of others who have contributed to this subject, you will note that I am not the only one who was impressed by the sound of this non-Klipsch loudspeaker system. If that makes them equally inexperienced in your view, I would suggest that what would possibly benefit from a certain amount of alteration is not their or my choice of transducer or other hardware, but rather the breadth of your understanding and acceptance of the importance of individual choice and preference.

Erik

[Erik Mandaville]

"No passive part, no matter how good -- can overcome the deficiencies found with low quality drivers or poor design."

That sounds similar to something I used to suggest in the past. Remember?

In any event, please discuss the shortcomings of the drivers in question, and indicate the specific parts to which you're referring.

That you think the design is poor doesn't make it a poor design.

Erik