Bose 601 has less bass on one side

[anti-doom]

My Bose 601 speaker has less bass on right side than left side. What would be a problem? How to fix? Any thought/comment would be appreciated. Thanks

 

[Tetrode]

If all the cones are working try swapping them right to left.

If the problem remains it's likely an amplifier or room issue.

 

[Biggreenford]

Is one of the speakers in a corner?

 

[anti-doom]

Tried to swap everything (left speaker to right output and right speaker to left output) but still the right side has less bass.

 

[Tetrode]

You physically swapped the speakers locations right?

 

[BillyTheKid]

if you swapped the outputs and the problem is still on the right side, then it sounds like a right speaker problem.
have you opened it up and checked out the woofer yet ?
Is it woofing at all ?

 

[anti-doom]

Physically swapped the locations of two speakers then swapped two woofers from left to right and two from right to left. Problem still there on the faulty one. One speaker has really nice sound while the another one still has less bass, no matter what I have done to it, still less bass. I touched the woofer it seems have sound coming out but not as good as on the good one. Could it be a crossover problem? Help

 

[anti-doom]

Is one of the speakers in a corner?

No they are located away from the corners.

 

[Tetrode]

Physically swapped the locations of two speakers then swapped two woofers from left to right and two from right to left. Problem still there on the faulty one. One speaker has really nice sound while the another one still has less bass, no matter what I have done to it, still less bass. I touched the woofer it seems have sound coming out but not as good as on the good one. Could it be a crossover problem? Help

There is no crossover on the woofers.

If they are series one they are wired in parallel,series II and III are series connenected.

 

[Dan ʕ•ᴥ•ʔ]

Check for air leaks and make sure the foam surrounds are still good on all bass drivers.

 

[mikeybc]

A dirty bass pot on the amp ? A dirty loudness button?

 

[BillyTheKid]

still sounds like a bad driver to me....like maybe the foam is gone.
I'd take it apart, closely inspect the bad one. If it looks ok, then swap it with the good one...make sure the problem travels with the driver and not with the cabinet.

 

[uxwbill]

Have you checked your speaker wiring?

If + and - are not connected properly on both speakers and the amplifier, you'll get strange effects like a lack of bass (bass cancellation) due to one speaker being out of phase with the other.

 

[4seatPilot]

Check your magnet strength.

I have a bad woofer in one of my speakers.. (not bose) I pulled both woofers out, and the magnet on the bad one is about half as strong as the good one. It does produce sound, just not as loudly as the good one. I just tested with a piece of metal and judged how much pull each one had... it wasn't a precise test, but it was pretty clear that one had a weak magnet.
Further inspection of the woofer revealed that it had been re-mounted at some point, likely when it was re-coned many years ago. My guess is that they dropped it in the shop - dislodging the magnet and necessitating a re-cone. Rotten thing is, they charged me for the re-cone if I remember correctly. Back when I didn't know what I know now...

 

[half_speed]

Low bass

Bought a set of Bose 601 series ii this weekend. Hooked up a boombox at the sellers home to verify all speakers worked (they had no stereo to connect to). Got them home and hooked up only to find that they had almost no bass even though the woofer cones moved a lot. Put my fingers on either woofer to hold the cone from moving and then it had good bass! Guessed the woofers were probably out of phase. Found the service manual on the internet and it said to test the phasing by connecting a 10V DC battery across the terminals on the back of the speaker. I used a single D cell battery across the +/- terminals for a second or two. The manual said both cones should move out. Found that one woofer moved in and one out on both the left and right speakers. So they were out of phase. Reversed the wires on the woofers with the cone that moved in. Now have tons of bass! The woofers were marked Bose so don't know if someone messed with them or they came that way, but working great now.

 

[brokenbodyma]

As all already have said check your wiring and make sure your left right oriention is ok.That should not induce a no bass problem but just start off right.There is a switch on the rear termanial cups that say symmetrical or asymmetrical.Make sure these are set the same way.One is to produce generally front firing sound and the other asymmtrical is to bounce the sound off the closest wall and give you that sound all around effect.I had series 1 and there were hundreds of staples to get to the top and front woofers.If so inclined you could pull and switch out woofers or at the very least make sure they are internally still connected.Before I sold mine I thought they were great speakers ,they did take up a lot of space but w/ the right amp could shake the walls and have no distortion.

 

[Clunt]

Apologies for resurecting this partially decomposed thread, but did you end up finding the cause? I'm having the exact same issue with the output on my left speaker. Swapped side channel on amp and cables, still on the left. Both the woofers and all the tweeters vibrate to the music, just not as hard as the right side. Could there be a cap or resistor or something faulty in the terminal wiring?


Edit:spelling

 

[zaibatsu]

I had to repair a pair of 601 Series II for a gentleman recently and fixed the same (seemingly common) issue as in this thread so I thought I'd share what I found:

• Main drivers (at least in the Series II) are wired in series, do not use the crossover, and both appear to be the same
• Both drivers (in working condition) will measure around 3Ω across the woofer terminals

If bass response seems low in one or both speakers, the first thing to check is that the drivers aren't dead, and then that they are wired in correct polarity. As mentioned above already, there is a high likelihood that by this age the speakers will have seen previous work, and as a result a good chance someone will have wired some of the speakers out of phase. In my case one of the speakers had one of the two bass drivers replaced earlier in its life (with the genuine Bose part), however the installer had wired the woofer back to front.

If you look closely at the woofer terminals one of them will have a + sign (and on the tweeters the same is indicated by one coloured/painted red), this was marked correctly on all the drivers in my case, but the test mentioned by half_speed (applying small DC voltage and noting which direction moves the cone "out") will show correct polarity also. You don't need 10V, I used 2 AA 1.5V batteries, even one should be fine, don't apply for more than a second.

If one woofer is wired correctly and the other out of phase, the bass will indeed cancel out, even though both drivers continue to work.
Swapping the wires on the incorrect woofer fixed mine.

The original issue with this pair was with the tweeters however, so I'll add that info here too:

• Tweeters should also measure around 2.8 - 3.0 Ω each
• The blown tweeter on this unit measured very high resistance (in the MΩ)
• Tweeters on 601 Series II are compatible with 301 Series II (and Series III) as well as 601 Series III. You cannot use Series I or IV.
• In my case I used tweeters from the 301 Series II and they worked perfectly
• The cones are fragile so make sure you handle them with care, and if being shipped, that the seller packs with care
• The crossover is used for the tweeters only, these parts were all in spec on both of these speakers in my case

Finally, binding posts had come loose which was causing the sound to drop out when they were moved sometimes, I pulled them apart and reassembled tightly using a tiny drop of loctite on the part of the threads where the nut clamps the bolt to the speaker - so that in future use turning the finger nut outside won't be likely to unscrew the terminal nut/s. Don't get any loctite on plastic if doing this.

Hope it's useful to someone in future.