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bose 901 mods?!

It's not that hard to figure out, the 901's need the active EQ...simple. Whether the rest of your system can deal with the EQ is not the speaker's fault.

I would liken it to some of the electrostatic rigs or whats the other one, Braun's top of the line? Both need electricity to operate and without it don't do what they are intended.

I really don't care as I got rid of mine, they just didn't do it for me that's all. The 501's seem to do HT well enough for my family so they stay taking the abuse.
 
My biggest problem with the 901's is mostly theoretical. Here's how I see it. Imagine looking at two speaker systems with the intent of purchasing one of them:

System A:

System A is from one of the premier names in Audio...both high end, studio and stage. They have many many years of proven experience, and this particular speaker was built by carefully assembling the finest drivers in their lineup and meticulously engineering the crossover, and understanding that efficiency, next to linear response, is the most important specification in building speakers. These speakers are built to sound full and wonderful, whether hooked up to a Sansui 221 receiver or dual behemoth monoblocks, and they do indeed sound full, natural and wonderful. All things being equal, in an ideal room situation one wouldn't need to touch the tone controls, let alone have an equalizer in the mix.

System B:

System B operates on the principal that anything will sound good if a) you equalize the bejeesus out of it, b) throw enough power at it, c) cleverly market it with flashy full page adds showing nifty color coded arrows that suggest an enormous soundstage, and d) add credibility by painting a mental picture of a brilliant doctor/scientist slaving away in his laboratory for 20 years to come up with a 'breakthrough'. System B takes 9 small, full range drivers, similar to most factory car speakers, sticks them in a futuristic (for the early 70's) cabinet, shoves an active eq ahead of them that has boosts on the bass and treble ends of the spectrum to Himalayan proportions to make them sound unlike factory car speakers and in the process sucking power from the amplifiers like an enormous sea sponge, all the while requiring that the buyer install them in a room that has symmetrical acoustic properties, Left and Right, for any sort of positive result whatsoever.

Knowledge is everything. Hype is nothing.
 
What kind of speakers are you referring too in System A? I'll give them a listen.
Also where does everybody see all this 901 marketing going on? I do not recall ever seeing or hearing an ad for the 901.
 
Sansui Louie said:
a) you equalize the bejeesus out of it, b) throw enough power at it
Click to expand...

That statement is very true. I've listened to some really really crappy speakers using a 901 EQ and it makes them sound surprisingly good.
 
Jim B., I was referring to the mid-70's hype for the 901's, which established them as a 'premier' speaker. These ads ran in audio mags, but also in places like Playboy, Penthouse, Popular Mechanics and other men's magazines. They had a pair of 901's on their VERY 70's looking stands, and blue, red and yellow funky arrows depicting how the "Direct Reflecting" sound reflects off the walls and corners to the listener's ear like a 3-rail pool shot. That's all fine and dandy, if you have a symmetrical room that's dedicated to just running the 901's, with a chair in the sweet spot. But, like a pool table with one rail removed, what happens when on one wall there's a window that's open, or has a thick drapery over it? Even at age 14, I studied that ad and posed that question.

I haven't seen that ad in over 30 years but remember it like it was yesterday.

Bose had a clever marketing department. By flooding media and basically declaring themselves king of the heap, along with these impressive looking colored arrows and the mystique of Dr. Amar Bose, it was hard to counter with mere mortal specs and performance.

The brand that I referred to in Speaker A could be any number of brands...JBL, ElectroVoice, Cerwin Vega, Klipsch, others. I think I had JBL in mind when writing it.
 
The pedestals for the 901's are Eero Saarinen designs that date to 1957 and were offered with the first 901's in 1967. He was a great modern architect who did the TWA terminal at Kennedy, the IBM research center in Yorktown Hieghts NY, Dullus Airport in VA, and the Gateway Arch in St. Louis among many others. I really like the mid century architechture and style, It represents an incredible era in our history and none of todays ugly digital CAD designs can come close to the originality and style.
 
Guess some of you straightened Tim in PA out....even if he asked that you refrain from those type of responses. Nice job. (All audio. No Attitude)?
 
kcollins4 said:
Guess some of you straightened Tim in PA out....even if he asked that you refrain from those type of responses. Nice job. (All audio. No Attitude)?
Click to expand...

I don't see one post here where anyone has bashed Tim in PA.

If you happen to own 901s then you have every right to get them working the best they can.
I stated it right here that 901s can and do sound quite nice under the proper circumstances and when hooked correctly.

If Tim or my brother can get their 901s sounding great in the systems they have then thats fine by me and most of the others in this discussion.

Bose has created their own empire and for many of us they are deserving of some criticle discussion where many feel Bose left us hanging.
This entire EQ box deal may have been fine back in the mid 70s when stereo ruled and most systems could easily employ the box.
With todays HT receivers and 5.1, 6,7 & 9.1 set ups, the 901s are a nightmare.
I still don't have a clue how to make them work in my brothers system as the rears hooked to his new Denon 2807 receiver. With just about any other good quality speaker it is mearly a matter of connecting wires but not so with the Bose 901s and I am not sure we can even use them in his system.
That speaks volumes and points directly to a failed concept in my book.

The sad thing is I might have to tell my brother to bring his 901s down to his garage Stereo system and use them the way they are designed and then go buy a set of REAL speakers for the rears of his new system.
If Bose had some allegiance to their customers they would design a fix so these speakers could be used in the new systems.

Gary
 
kcollins4 said:
Guess some of you straightened Tim in PA out....even if he asked that you refrain from those type of responses. Nice job. (All audio. No Attitude)?
Click to expand...

You've got a point there. True, nobody bashed Tim, but they did hijack his thread, which asked for help, and turned much of it into long-winded Bose bashing. Tim, I hope you got some useful stuff out of this as well as being reminded that some people don't like Bose speakers or the Bose company.
 
gamalot said:
Bose has created their own empire and for many of us they are deserving of some criticle discussion where many feel Bose left us hanging.
This entire EQ box deal may have been fine back in the mid 70s when stereo ruled and most systems could easily employ the box.
With todays HT receivers and 5.1, 6,7 & 9.1 set ups, the 901s are a nightmare.
I still don't have a clue how to make them work in my brothers system as the rears hooked to his new Denon 2807 receiver. With just about any other good quality speaker it is mearly a matter of connecting wires but not so with the Bose 901s and I am not sure we can even use them in his system.
That speaks volumes and points directly to a failed concept in my book.

The sad thing is I might have to tell my brother to bring his 901s down to his garage Stereo system and use them the way they are designed and then go buy a set of REAL speakers for the rears of his new system.
If Bose had some allegiance to their customers they would design a fix so these speakers could be used in the new systems.

Gary
Click to expand...
Bose 901's are stereo speakers designed for music reproduction. They were introduced in 1967. They have other newer products that are designed for home theater surrond sound applications.
I know many people who use the 901's to listen to their movies and TV shows in stereo and enjoy it. The stereo everywhere effect does not become tedious like surround does.
 
gamalot-here's a possible solution for your brother.
Run the outputs from the multi channel receiver to a 2 channel amp or receiver-some old thing one of you have lying around idle-with line level inputs.
Then hook the Bose EQ and speakers to that receiver/amp.
 
andy said:
That statement is very true. I've listened to some really really crappy speakers using a 901 EQ and it makes them sound surprisingly good.
Click to expand...

If they sound really good afterward.. Does it really matter what was done to get them there?
 
it's ok!

i know that speakers are the part of the stereo that make it or break it. and everybody has an opinion. my opinion is that nobody is wrong when it comes to what they like to hear. this is a great forum. like all forums,you have to do a little filtering as you read. i think i would like to get some ar3 or ar4 though.
 
Greetings,
The problem is not with the speakers but with the application. As mentioned previously, the speakers were designed for stereo and not multi-pair utilization. The simple solution is to use a surround processor/preamp. This is what Im doing. I have two pairs of series II that will hang in my theater/family room. Its unfortunate but there arent any budget HT receivers with the pre-out capability and most processors are fairly pricy. But Adcom, Technics etc have produced them and are readily available used.
BTW, I also own Magnepans, Quads and several Fostex based speakers and although I dont consider the 901 a high resolution speaker, I have always liked them. Small and fun for just blasting. And the reflected sound and ability to hang them is excellent for HT IMHO. My kid cant get them and they are almost impossible to blow up. Im going with a phantom center and I think that with the refective nature of the speaker, it should be a decent illusion.
This is my first post here. Hope its of some benefit.

taylor
 
HI All,
Having been a former owner and around 901's since 1967, I have a couple of things to say.

First, everyone who says the equalizer is required are right. No one has mentioned why this is true. The design of the 901's feature multiple small full range drivers overdamped by the cabinet volume. Unaided by the equalizer, the low frequencies are hugely rolled off and the high frequencies are also rolled off. This is intentional. The alignment of the box is typical accoutic suspension with more than average damping.

The equalizer changes the frequency response of the electronic signal to exactly compensate for the non-linear response of the speakers. In the room, we hear the combined frequency responses which is hopefully linear. But the correction is not perfect so the result still has frequency anomalies.

The original 901's required the most compensation from the equalizer. I don't remember the exact numbers but the bass was increased on the order of 15 dB at 30 Hz. This is a huge amount. Most power amplifiers don't have enough power.

Next, some care is needed when replacing surrrounds. The surround is the spring that suspends the cone. The mass of the cone and the compliance of the surround form a resonant system. Being a resonant system it has a resonant frequency. The speaker box is designed around the resonant frequency of the speakers in open air. This is a critical relationship and it is carefully controlled.

If you change the "springiness" with a new improper surround, the resonant frequency of the drivers is changed. The match of resonant frequencies of the bare speakers and the box is now mismatched. The performance of the overall system will suffer. Not good.

Not knowing the compliance of the new surrounds, or even the originals, it is a crap shoot. It's impossible to predict the amount of performance reduction. It may not be much at all.

The best way around this is to have the manufacturer do the surround work. I just wanted to warn you.

Sparky
 
Karma16 said:
The best way around this is to have the manufacturer do the surround work. I just wanted to warn you.

Sparky
Click to expand...

The closest Bose will come to doing this is to have you trade in your speakers for new ones.
They don't even sell complete drivers.
 
gearhead said:
The closest Bose will come to doing this is to have you trade in your speakers for new ones.
They don't even sell complete drivers.
Click to expand...

Agreed!
When the foam on my original 901s failed they had a program! Send the old ones in with $350 plus shipping and they sent me back new series VIs.

I have no idea what they do with returned sets but you don't get your originals back. I found this very disheartening as I expected to have my Vintage speakers repaired and returned.
This is also why I feel justified to flame Bose.

Gary
 
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