Upgrading a Leslie 120 (sow's ear -> silk purse)

[Guest]

Hello all:</p>

I've got a Leslie 120 and want to improve its sound. I know that it has just a 12"(?) loudspeaker, and that the high-frequency reproduction capabilities of a cone of this size are limited. I'm thinking of replacing it with a same-size loudspeaker with a coaxial horn high-frequency driver, like a Tannoy. </p>

Anyone have any suggestions about this (other than not to do it)?</p>


Thanks,</p>

Ben
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[bluetantra]

Re: Upgrading a Leslie 120 (sow's ear -&gt; silk purse)



Hey, Ben-</P>


Have you considered adding an amplifier to the cabinet? I see amps from 125's come up on ebay from time to time. I was planning to do just this to my own 120, to convert it to a 125, but I ended up finding a deal I couldn't pass up on a 222.</P>


John</P>

[toasterDude]

Re: Upgrading a Leslie 120 (sow's ear -&gt; silk purse)



I think this is a very promising idea. It seems to pop up on the forums now and again and everybody says, yeah that could work -- but nobody ever tries it! (or at least if they do they never post back on how it worked.) So I say, go for it, and please let us know how it turns out. Personally I think it's a much better option than trying to create a Franken-Leslie "145", as so many do.</P>

[Hammond101]

Re: Upgrading a Leslie 120 (sow's ear -&gt; silk purse)



I think this is a promising idea as well. Most of the coaxial speakers I have run across don't handle much power however. There is also the issue of crossover frequency. I don't think it will sound bad, just different, and not like a two rotor.</P>


I did, in another life build a two rotor Leslie 110. The cab was modified with a donor 110 cab cut down &amp; added to the top for the upper horn &amp; driver. I used a solid state amp to power it that just sat on top of the cab. It actually sounded pretty good looked OK painted black and made a nice guitar cab too. It was way too much work for what it was actually worth. It and a M111 brought about $475 on ebay about 3 years ago. </P>


A 125 amp and two way speaker would be reasonable solution I think.</P>

[toasterDude]

Re: Upgrading a Leslie 120 (sow's ear -&gt; silk purse)



Another thought on this question. I briefly owned a Leslie 120 -- familiar readers of this forum will have heard me complain about it before -- which I despised. The sound to my ear was very muddy and sort of muffled. However, I don't think the single 12" driver was solely to blame: I also owned (and miss now!) a Proline Leslie 820 (also a single 12" driver/rotor) -- which sounded comparatively fantastic. It was no 145/147, of course, but it really did put out a great sound. It seemed to have great clarity and projection, by comparison to the 120. So this is all a long-winded way of saying, maybe it was a case of a different 12" being able to project more highs... which would indicate your coaxial driver experiment may well be a big success. On the other hand, I also wonder if BT and H101 may be right in focusing on the amp - in advocating a 125 over the 120, since the 820 had the little solid-state amp in it, while the 120 was entirely passive. So anyway: all the more reason to go for it, with your 120 or a 125 if you can find one! Good luck with it-</P>


Scott</P>

[andyg]

Re: Upgrading a Leslie 120 (sow's ear -&gt; silk purse)



Gosh this takes me back to when I was a kid, trying to build my own speaker cabinets, including rotary ones.</P>


I can remember 120's sounding muffled too, but the 110 that I had on my Gulbransen at home wasn't muffled at all, and that was unpowered like the 120. I'd guess that it had the same 12" driver as your 820, as it was from the same era.</P>


Ido remember buying some 12" dual cone units. 8 ohms impedance and good for handling about 25-30 watts RMS. I think they were Celestion, and they sounded good to my ears back then.</P>


We also used JBL units when I was with Kawai and decided to seriously uprate our leslie 415's. 10" dual cones replaced the 6x9" stock units, IIRC.</P>


If you get the rating and impedance right, I'm sure a dual cone unit will give the 120 the luft it needs.</P>


Andy</P>


PS: that should have read 'lift' it needs, but it's a good slip, as giving it some luft would also help!</P>

[Guest]

Re: Upgrading a Leslie 120 (sow's ear -&gt; silk purse)



Thanks, all. I don't see a lot of value to incorporating an amplifier into the 120 cabinet. While I could add some high frequency lift in an amplifier, I could do this much more easily upstream of the volume pedal in the organ. My objective, after all, is to improve highs, not make the organ/loudspeaker louder. Am I missing something?
</p>

The shaping of the styrofoam rotobaffle, and the fact that the baffle pulley is holey, should help the mids and highs from a horn get out of the cabinet, even if they modulate in sync with the lows from the woofer. I'll post my results and any photos.</p>

Ben

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