Bose 901 Series V Questions

Please no Bose bashers.

#1. Has anyone ever listened to these speakers backwards ?

( with the 8 woofers facing you )...interested in your opinion regarding sound ...good or bad ?

#2.  Can the color of the drivers be black as well as blue ?

I am running my Bose Equalizer between Amp and Preamp...Is that a good way ?

Thank you 


Here ya go!

Three ways to connect the Bose 901 EQ to your stereo system

It’s a good time to be a Bose 901 owner, as there are many solid choices for amplification that make it easy to integrate the 901’s equalizer. This wasn’t the case just a few years ago, when it seemed like no home electronics had the capability to integrate with the Bose 901 system, unless you went with a separate preamp and amplifier combination. They were practically unusable with most integrated amps, stereo receivers, and of course, home theater receivers.

So, you have a pair of Bose 901 speakers, and you have the equalizer they came with. Here’s what you need to use them:

The Bose equalizer has a pair of analog RCA inputs, and a matching pair of outputs. You need to connect a pre-amplified signal to the inputs, the Bose EQ does its thing, then the outputs go to your amplifier. Once amplified, your music is sent to the speakers through speaker wires.

Connect to a separate preamp and amplifier

The most straightforward way to make the connections described above is to use separate components. You’ll need a stereo preamp and a stereo amplifier, two sets of RCA cables and some speaker wire. You can see how this works in the diagram below.


How to connect the Bose 901 EQ to a separate amp and preamp

Connecting the Bose 901 EQ to a separate amp and preamp lets you customize your sound system. But it also means you need space for three different components.

One benefit of using separate components is that you can mix and match different amps and preamps to achieve the sound you want. And you can also replace one or the other if you want to upgrade, or if one of them goes bad.

Connect to a single stereo component

Using separates isn't super common these days as many people prefer a more integrated system. This can come in the form of an integrated amp or a stereo receiver. Both of these options include the preamp section and the amplifier in one component. Using an integrated amp or stereo receiver built to a high standard is a great way to condense your stereo system without sacrificing sound quality.

If you were using an average set of speakers (not the Bose 901s), you'd simply connect them to the amplified, speaker-level outputs of your integrated amp or stereo receiver. However, if you want to use the Bose 901 speakers and equalizer, you’ll need an integrated amp or stereo receiver with a special set of variable analog RCA preamp outputs AND a set of analog RCA inputs that go straight to the amplifier. These connections let you hook the Bose 901 EQ up in-line between the preamp and amp, even though the preamp and amp are in the same box.

There are two connection combos that make it possible to use the Bose 901 EQ with a single stereo component: a tape monitor loop, or a pre-out/main-in loop. Many of today’s integrated amps have the pre-out/main-in loop. The tape monitor loop is no longer very common, because, you know…tapes. I'll explain both below.

Pre-out/Main-in loop connections

Some components have pre-out/main-in loop connections specifically for hooking up a separate EQ. Back in the '70s, equalizers were commonly used in higher end home audio systems. An EQ could make analog sources (like tapes and vinyl) sound better. And it could also fix problems with the sound of the room that the system was in. Today we no longer use separate EQs, thanks to most sources being digital, sophisticated signal processing, and room correction software.

How to connect the Bose 901 EQ to an integrated amp with pre-out/main-in loop connections

It's possible to connect the Bose 901 EQ to a single stereo component with pre-out/main-in loop connections.

The pre-out sends whatever source is being played to an outboard EQ, like the one included with the Bose 901s, using stereo RCA cables.

The main-in part of the loop receives the music as it comes back from the EQ and sends it on to the amplifier section of the component.


removable jumpers covering unused pre-out/main-in connections

Stereo components with pre-out/main-in loop connections often come with jumpers that connect the pre-out to the main-in when no EQ is going to be used. These jumpers are removed if an EQ is used.

Tape monitor loop connections

A tape monitor loop works in a similar way. In fact, the connection requirements are identical. However, a tape monitor loop functions slightly differently than a pre-out/main-in loop. A tape monitor loop, as the name implies, allows you to monitor a recording, live, in real time.

Say, for example, you were recording a record from your turntable to a cassette so you could play the cassette in your car. The tape monitor loop would allow you to listen to the tape as it’s being recorded onto rather than listening to the record as it’s being played.

This is simply not needed with today’s digital solutions for recording vinyl onto a more portable digital medium. However, if you have an older integrated amp or stereo receiver with a tape monitor loop, your connections for the Bose 901 speakers and EQ would look like this:

How to connect the Bose 901 EQ to an older component with tape monitor loop connections

You can connect the Bose 901 EQ to an older stereo component with tape monitor loop connections.

When Bose stopped manufacturing the 901 speaker system, the number of integrated amps and stereo receivers with compatible connections dwindled down to almost nothing. But many manufacturers have begun to add those pre-out/main-in loops back onto their integrated amps. Stereo receivers, not so much.

So, if you are looking to use a Bose 901 speaker system with modern electronics, you’ll want to look for a separate stereo preamp and amplifier combination that suits all your other audio needs, OR an integrated amp with a pre-out/main-in loop that does not exceed the maximum RMS power handling for your series of Bose 901 speakers.

+1 @yogiboy Awesome writeup and spot on.

Back in the early 80’s, I ran my 901 equilizer and dbx 3bx range expander through the signal processing loops in my SoundCrafsman SP4001 equalizer/pre amp.  Those were the days.  

I had the original 901’s with the chrome stands.  I would sometimes turn mine around for direct sound when we partied like it was 1999.  But most of the time I played them in the reflex position.  I also found they sounded like crap without the Bose equalizer.  

Don’t run them backwards; they were engineered more carefully than given credit.  The walls and placement make the difference between amazing and gawd awful.  You either have the right room or you don’t.  Use the supplied equalizer; again, tied more closely to the drivers and enclosure than folks realize.  Don’t be fooled by the simplicity of everything.  Last, separates give the best opportunity to make them shine.  They love power…I’m running mine with 650wpc mono blocks.  The head room really lets them perform.  

Bose used one ohm speakers, wired in series. Replacement speakers are available. You might try reusing the cabinets and putting a modern, two way speakersetup in them. The equalizer was necessary because their "natural" frequeny response was definitely not flat!  Enjoy the music!

The PA version of Bose speakers has 8 speakers facing out of course, and sound bad without the EQ.