Recently I purchased a pair of Bose 901's and 601's. I'm running the 901's with the Bose equalizer through speaker "A" connections. The 601's are through  "B" connections. I'm scared of the warning in the 901 owners manual that says the 901 equalizer may damage other speakers. Does anyone know where to set my unused  7 band graphic equalizer as to better duplicate the bose equalizer? it"s range is +- 12 db starting at 63Hz to 12.5kHz.



Thanks Cleeds. Yes, the 601 don't require an equaluizer, but I'm scared the 901 equalizer will damage them. I've been keeping the volume down when I listen to both 901 and 601, and turning 'off" my "tape monitor" at high volumes as to not run the 901 equalizer process through all speakers. can i just eliminate the 901 equalizer, and replace it with my 7 band equalizer?

The 901s need equalization, the 601s don't. The only way to run both properly would be with two stereo amps with the 901 equalizer only connected to the amp driving the 901s. It doesn't matter what equalizer you use, it can only be one or the other, not both. 


... do they still make the 901s

No, Bose stopped making them a few years ago. The 901s had a long run, though, even if many audiophiles didn't approve.

I think @russ69 is correct has to how to connect both the 901s and 601s at the same time.

A friend of mine had some 901s hanging by wires from the ceiling  in the mid 70s. For what I knew then, they were awesome. Enjoy.


The eq that runs the 901’s is a proprietary eq that nothing like a regular eq. A standard eq is increasing an incremental frequency. The 901 eq is adding gain across a wide spectrum. When they say it could damage other speakers they are talking about crossovers that can’t handle the gain or current it puts out. I still have my 901’s. They hang in my garage. They are good party speakers if you like loud with no soundstage or imaging. I hooked them up one day in my reference system and then hooked up my 301 (used for front surround) and the 301’s sounded so much better. Friend had 601’s in high school and always liked their sound for what we did. Smoked a ton of weed and hash, dropped some acid and cranked hard rock and metal. Great memories but not serious reference quality.

If adding a 2nd amp doesn't stall your adour, here's some curves from the 901s' eqs'...

Model 1~2s':

,,,and the 3~4s'...

Add the 7 band prior to the amp for the 601 'rears' ought to allow you to play about with the array to taste. *S*

....parametric eq’s are better at the slopes, the ’gain across a wide frequency’ as @sgreg1 notes....they ’look’ like such, at least to me...

(...shout out to retrovoltage.com for the graphs...👍)

Went to many a party where 901’s were present.  They were a huge seller.  The only advice is not to play them screaming loud! It’s not good for them or your ears!


I sold all these products back in their heyday.  To distill the various advice to clear instructions...

1. Your amp must have a "tape loop", "external processor loop", or pre-out/main-in jumpers in order to incorporate an EQ in the signal path.  

2. The amp that drives the 901s should not drive any other pair...speaker B can only be another pair of the same generation 901s!

3. If your amp has only one set of tape or preamp outputs, use a pair of Y connectors to double (1M>2F), or use duplicate outputs if it has them, to run into a second amplifier...preferably an integrated, to set relative volume.  Choose any line level input.  EQ with your graphic if desired and if amp 2 has a loop too.

4. Early generation 901s (SeriesI and II) had MUCH more severe EQ characteristics than all later models, so the danger of damage to another speaker is greater with those.  No graphic EQ is equipped with the boost to flatten the early ones' response...at 30Hz, they had over 20dB boost!

Hello 1perpet2.  An equalizer is an equilizer. Bose. DBX, whoever. The EQ is asking your amp to put out way more bass than usual for "normal" speakers. Any EQ trying to make the 901's sound good would do the same thing. You don't need a different EQ. Bose warns you because other speakers may not survive the boost required to make the 901's sing nicely. Think about it. The EQ feeds you amp that feeds the speakers, right? The amp is what you need to think about!  It is likely to be pushed into distortion which causes damage to the tweeter voice coils of other speakers. The 901 uses 1 ohm speakers in series with one another. It is the only speaker that can reproduce the sound of a nine foot wide solo violin. Of course, there are no nine foot wide violins. Have pity for the amp that drives the 901's. Happy listening.

OMG it's been the late 70's since it was the last time l heard my friends Bose 901's  I thought they where great, until l heard my other friends Infinity Kappa 9's