Question on re-gaussing (L300).

[Steve K]

Hi everyone,

I currently am enjoying a pair of L300s (foilcal says 'Model L300'). Overall, it sounds great to my ears, except for one thing. In vocal sources, or others, where it's expected that a certain sound be centered between the speakers, it's offset slightly to one side. This is true, too, when I switch over to the mono mode. As the LE85 mid, in this model, seems to have the greatest effect on how vocals, pianos and guitars sound, I am thinking that re-gaussing these drivers would have the greatest effect in helping correct the offset. Otherwise, I'm quite happy with the overall quality of these 25+ years speakers.

Does anyone here have experience with re-gaussing the magnets, and if so, what results have you realized? I'm planning on holding on to the L300 for at least 5 years, so I'd like to get the most out of its potential.

Thanks for your feedbacks in advance.

Steve K

[Robh3606]

Used in a home setting I doubt they need to be regaused. What's happening could be as simple as an oxidized potentiometer. Before you even atempt to open them up you should turn the controls through their full range several times and return them to where they were to see if that fixes it. You could also just turn down the midrange on one side and see if that works before you do anything else.

Rob

[Hofmannhp]

Hi Steve,

another idea comes to my mind......pls check the mid drivers dias....maybe there's an aftermarket dia with different impedances....

my 2 cents

HP

[Steve K]

Thanks for your comments, Rob & HP.

First, the L-pads on both speakers have been replaced with equivalent ones from Alps, obtained from JBL service, so oxidation is not the problem.

Adjusting the L-pad dials fixes the offset, but the difference between the L and R is about 2 steps on the 0-to-10 gauge: '7' on the left, and '5' on the right. I suppose I can live with that. But is it normal, or within the range, for the pair to have that kind of difference in their SPLs?

Also, am I right in targeting the LE85 in making the corrections? I mean how do the 077 tweeters stand up after all these years in existence? Not having heard original L300s when they first appeared on the market, I have no comparison to make to help me know if what I'm hearing is how it should sound, not that I could remember an acoustical imprint even if I did hear a pair back then.

And what about the network? Could it be that time has taken its toll on the efficiency of the electronics inside the crossover? If so, what steps can be taken?

Like I said before, I think the L300s are wonderful speakers for my current environment. I like the way it sounds in almost all the types of music I listen: jazz, rock & classical. To me, these speakers are more appealing to my ears than a Thiel CS2.4, for example. If it can be made to sound better, I'd just like to know what options are available. Thanks.

[DavidF]

"...except for one thing. In vocal sources, or others, where it's expected that a certain sound be centered between the speakers, it's offset slightly to one side. This is true, too, when I switch over to the mono mode. As the LE85 mid, in this model, seems to have the greatest effect on how vocals, pianos and guitars sound, I am thinking that re-gaussing these drivers would have the greatest effect in helping correct the offset. Otherwise, I'm quite happy with the overall quality of these 25+ years speakers...."
Steve K

Be certain that the driver connections are all the same on each system. That is the mid-driver is not out of phase with its mate in the other system, the high frequency driver, etc. This could create an out-of-balance stereo image.

Since you mentioned that the Lpads have been replaced, it may be that you have to trace the connections through the crossover, as well, to be sure the connections are correct.

DavidF