Ohm Walsh Micro Talls: who's actually heard 'em?

Greetings.....

Never  got got back to you last night as we decided to watch something fun, so the last Jason Bourne movie it was. It's amazing what a little bit of speed, Transparancy and tweeter extension will do for the whole experience. Gun shots are so crisp and dynamic, voices are clear and intelligible, all the micro dynamics of surround effects gives the experience a much higher feeling of being there.
As for the movie....my wife and son, said good night half way through the plot...😵

Back to the speaker (4/5k's) after removal I took some time to look over the construction around the drivers, the filling/wadding looks out of control so I sheared some of and gave it a better look.
Could I hear a difference.....NO

The actual platform that the crossover and tweeter assembly is resting on is made from some simple 1/4" plywood, tapping on the forward edge gives out hollow woddy ring that can't be good as vibrations will either ring away when played, or vibrate the tweeter
in multiple axis.
I have to say that the crossover was very well thought out and looked very tidy indeed. 

So the idea was to dampen the platform, but there's only so much room vertically and room was a big issue as most tweeters
in the style I was looking for was in the 5"-8" height and I needed something in the 4" range.

Digging  out the tweeter was easier said en done, as everything was
hot-melt glued or potted in some black semi hard epoxy. 
The black "stuff" prevented me from seeing the wiring, but with
my incredible perseverance they were finally relieved of their gooey
prison. I do think JS personally made the crossover and possibly assembled the unit as he signed the plywood.

Finally I have the tweeter in my hands and I can run a proper impedance test on the unit, 4ohm's give or take so with that I knew
what to look for.

The problem...
The tweeter I wanted was 5 ohm not four, so what to do?
I first bought one unit, soldered it on to the center ch to see if anything would  blow up, implode or possibly burn down my house. Nothing of the sort happened, but what I heard was everything previously missing, not perfect but as I previously said it had to do with the size of the Walsh driver not the tweeter.

So 5 ohm works like a charm, but I'm lucky that the main cans have 
options and adjustability for different presentations and room sizes.

More to come soon....

Here's some more changes and ideas to make the Ohm's really, really amazing...


One thing I've been realizing is that the higher I cross over the main speakers the better they sound, my theory is that the Walsh driver
likes to be un-loaded a bit as bass could possibly swamp the midrange and some tweeting signals.
 I will continue to look in to that aspect of the sound. It could also be the reason the smaller speakers sound as good in the upper range.

In the next few days I will try an open cell foam plugg in the vent port to see if it changes the quality of the bass. This is of course a guessing exercise and who knows I might hate it.

I have also wondered why there's no tweeting in the back, so I'm planing to take the original tweeters, build a simple crossover loaded directly from the speaker wire posts, that way I don't have to hack the original crossover. If this works and I don't see why not, as I had some Von Sweikerts VR4's which used a back firing tweeter to great effect, and I did love those speakers a lot. To control the tweeter I will use a volume control in the circuit....

Back to the tweeter platform build on the 4/5k's....
After considering the options to dampen the (circular) plywood
part I decided to use 1/16" thick (3" wide) basswood in three layers with dampening material on the first layer and semi rigid glue between the slats to dampen any further vibrations. All this was glued to the edge of the platform and clamped.
So when you look at the platform it now looks like a birthday cake 
made from plywood covering all the dampening material. After the edge was cleaned up I covered the whole thing with dark grey felt,
contact cement made the whole affair super easy and very clean looking :) Sudenly no vibrations just a thud when I tap it.

The original set up had a pice of white cardboard glued (hot melt)
to the tweeter, in the shape and size of half the platform, the bottom front edged hot glued in on the bottom and then folded backwards in a soft arc to a standoff in the middle of the crossover.  As I changed the tweeter I wanted to cancel as much of a possible back wave so the the felt got folded in towards the back, semi mimicking 
the original folded cardboard. Any protruding edge got a open cell
foam edge to cancel unwanted reflections...

The speaker cover is the old style so called black fabric, but to me it looks like faded black anodized aluminum, kind of a purplish color that needs to go, so I found some black, real black stuff that should go a long way to modernize the look.

That will do it for now, and I look forward to share the rest of the project very soon...🇸🇪

Peter whatever the outcome yours is a very unique and interesting DIY endeavor. You are starting out in a very good place sound wise compared to many in my humble estimation. Your findings poking around inside the OHMs is also very interesting for me.

I have an older pair of OHM Ls that I bought for a couple hundred dollars new back in 1978 that I have endeavored to upgrade and maintain myself.   I use these currently in a smaller room where my main gear resides.  

I have these sounding  very competitive with much more expensive modern alternatives, better than ever these days.   I replaced 8" bass drivers with Morel units that cost as much as the speakers pretty much originally.   I also added sub-bass activation circuit JS uses in most of his newer units to help keep bass extended and managed.

These still use original paper tweeter and super tweeters and high end sounds very good once properly balanced.   I've considered upgrading the high end drivers as well but have not felt compelled to do it quite yet.   I need to investigate some more but would definitely like to consider trying a folded ribbon tweeter in those just for fun.

 Hey Mapman....
Nothing feels better than improving on a concept, might it be mechanical, electronic or aesthetic wise. Those OHM L's could be 
improved in stages, and every time there's an improvement you get closer and closer to the edge of possibilities.
Last night as I was listening to some great 24/96 tracks, something
magical developed, suddenly I could tell that the tweeters started to relax and got sweeter and lusher......I think they're broken in.

Sweet Jesus, Guitar strings were so amazing sounding, I was closer to how my Audiostatic electrostatic speakers sounded like, precise tons of air and incredible speed......You can tell I hate these speakers :))

As I said before I will add tweeters on the back of the speakers and 
I might re-purpose the Original tweeters, but if I want to use a L-Pad
(volume control)  I'll need to go with an 8 ohm  unit. Tried finding a pre made cross over but I might go with the Behringer electronic cross-over if I can't find a solution.

I will try to get a test going with foam plugs tomorrow, but I'm starting to build a home automation system around the Amazon Echo (Alexa) so I have to install new wall switches etc. so I can surprise my darling on Christmas morning....🇸🇪

Back for a small update...

Had an hour to spare to fiddle with the port and the foam plug.
I had a square of egg-crate foam that I cut in to 5x10" strips rolled them up
and inserted the plug in to the bottom port of each speaker.

vewy vewy interestiiing....
First I was concerned about closing of the port as it changes the back pressure, but
what it did was smoothing down the heaviest bottom frequencies making the package a little less boomy. I used an amazing CD from the movie "Tha last Samurai" tons of high frequencies, and lots of deep deep Japanese Kodo drums with amazing impact and depth.
was it better? I will run some tests tomorrow and see how the room responds to the changes. I will also run a frequency sweep and see what it looks like.

As mentioned earlier I am adding some tweeters to the back of the speaker, and I was vasilating about active or passive crossover network, I slept on it and decided to make a simple passive xo that I can use the L-Pad to dial in the effect.
Should  be exiting as it could add some extra dimension to the sound.

I know some people wanted to change the wing-nuts to something more modern and
cool looking. Go to www.mcmaster.com click on NUTS and there you go, I'm ordering the 
THUMB NUTS in SS pretty cool stuff. If you are looking for hardware it the best place ever.

Peace....out