How Ohm Speakers Are Designed? Part 2.

Last week, in Part 1 of “How Products are Designed,” we discussed how and why Ohm develops a new speaker model. In Part 2, we take a look at how the objectives get realized. Do we start from scratch or build on what’s available? And, again, that depends…

While the Walsh driver assemblies are Ohm-made and unique, we do believe that it makes no sense to spend time and money to recreate the wheel – or even a good part. Today, there are a lot of high quality off-the-shelf parts available. So, our designing process looks at utilizing what we may be able to use from those sources. In fact, the super-tweeters we use in all models from the MicroWalsh through the Walsh 5000 are almost off-the-shelf units. They are modified only slightly for our needs. Of course, we had to test hundreds of tweeters to find the best for our needs (and this search continues). This change and a few others made such significant improvements; we felt the need for a change is the series name. They became the Thousand Series and the MicroWalsh SE’s: an evolutionary – not revolutionary – change. Now we have upgrades for all the prior Walsh speakers.

There is no “silver bullet” in audio, but new materials are being developed and utilized at a fast clip. We try to get information on those as quickly as possible. We are particularly looking for materials or techniques that will:
• deliver wider dispersion,
• extend treble response,
• allow greater sensitivity,
• increase power handling capacity and/or
• lower distortion.
And, just for good measure, do all of that in a smaller package if possible. Neodymium magnets give many of these benefits, although at a substantial cost penalty. We have used them in our super-tweeters for several generations of Walsh speakers, then in the Walsh 4000/5000 inverted transducers and now also in the Walsh 3000. We first investigated Constrained Layer Damping (CLD) for our cabinets after using it in the drivers for Ohm As and Ohm Fs almost forty years ago. In 1982, the Walsh 2 cabinet used CLD. We came to use CLD in all our Walsh cabinets as we grew to understand the cabinet as a major influence on the sound.

Complicating the quest is the fact that, not infrequently, these goals conflict with each other. A material that promises an advance in one area does so at a performance sacrifice in another. An example is metal and ceramic dome tweeters: they extend the treble response but add an un-damped high frequency resonance. Another is line-source tweeters like ribbon and accordion styles. They, too, extend the treble but their frequency response varies with distance, so the sweet-spot is very tiny. In speaker design, as in life, there is no such thing as a free lunch.

Finally, and most importantly, in our consideration, is how the various components work with each other and particularly with our Walsh drivers. It does not matter if the new materials, drivers, or other components are the finest of their breed if the overall synergy is not a seamless fabric of music reproduction. So, whatever the specific design goals we have for a new speaker, the target is to provide a natural, enjoyable and accurate musical experience for the listener. The area where we are investing a lot of energy at the moment is getting our quality and dynamic range out of smaller speakers. If you are going to have up to thirty-two speakers in your Dolby Atmos system, you will not want thirty-two large speakers. Our process is a series of tiny and not-so-small steps in that direction.

Enjoy & Good Listening!
John

John Strohbeen Author

John Strohbeen was the President and Chief Engineer of Ohm Acoustics from 1978-2023.