Vol. 1
(Other volumes: 2  )

InterconnectTM is a forum for the opinions of Carl Marchisotto and will mostly consider the use of NOLA speakers and related matters. Hopefully it will encourage further thought.


But first I would like to shed some light on Carl Marchisotto, for those unfamiliar with me. I was brought up in a musical family. My father played piano and violin. I studied piano for 12 years. My mother used to drag me to the original Met to see Franco Corelli!

I was amazed at the musical talent I was exposed to. The sound of live music became part of my soul where it remains to this day.

I attended all the NY hi fi shows while in high school. I built my first loudspeaker in 1956.

After working part time selling records I finally was able to afford one Stentorian 12" coax. This driver had a massive zamak cast zinc frame and a giant 11 lb. Alcomax III Magnet system! I then saved enough for a second Stentorian. My father and I built two massive 12 cubic foot bass reflex cabinets for the speakers. I was very happy with the sound most of the time, driven by a Pilot SA260 stereo amp. However, an occasional hardness in the sound I attributed to the horn tweeters, which were crossed over at 3000 Hz. I decided to replace them with two Wharfdale Super 3 cone tweeters per side crossed over at 1000Hz. My first crossover was one capacitor and one inductor! I was now very happy with the sound and this system served me well for many years.

Then I met Marilyn - the love of my life. We decided to get married, we moved into an apartment, but the Stentorian 12 cubic foot cabinets did not move with us. So I needed a much smaller system. I chose AR3A speakers driven by Marantz solid state electronics.

I have had the privilege of experiencing many of those "audio defining moments" in my life. I would like to share a few:

It was about 1973, I walked into a room at the NY HI FI show labeled THE SAUL MARANTZ COMPANY. Inside I saw Saul and another much younger man. I was told his name was Jon Dahlquist. They were playing a speaker, which had the shape of the Quad 57 yet it was a dynamic speaker! There was a big sign that stated: "This is not an Electrostatic Loudspeaker." They were playing a tape of a live recording of a marching band through a Tandberg 64X. The sound was so "live" I could not believe my ears. I decided there and then that this guy Jon Dahlquist must know more about speakers than anyone else.

About 1976 I grew tired of my musical instrument electronics business designing electronic units for Gibson Guitars. I wanted to get into hi fi. I designed and built a super quality phono stage known as the Alltest phono stage. It measured great with distortion about .0005%. I then ran into a guy who worked for the new Dahlquist company. He invited me over to his home as he wanted to hear this new phono preamp. At his home I ran into another pair of these special speakers now named DQ10. He played a record through my Alltest phono preamp. It sounded OK - very clean. He then played the same record through his preamp, a Fisher 400CX tube unit. I could not believe I was listening to the same record! The Fisher was brimming with life while my Alltest was dead! I hated my preamp because it killed the music. This began my love affair with the vacuum tube, which burns brightly to this day.

In 1976 I got a job with the Dahlquist Company. I was hired as chief engineer. Jon wanted to diversify into electronics. It became known that this great speaker (DQ10) had limited bass. I was asked to design an electronic crossover for the new in-development Dahlquist subwoofer.

Now I came up with a concept- a passive hi frequency section combined with an active low frequency section. This would allow the high frequency signal to avoid degradation by active electronics, which was very audible through the very revealing DQ10s. Now the real thrilling part of the project was that I was to work directly with Jon's partner - the great Saul Marantz. Saul was a graphic designer by training. He would design the look and I would design the electronics. It was a great collaboration. The resulting product was named the LP1 Variable Low Pass Filter.

At Dahlquist, I was allowed to experience many great sounds and projects. There was the Quad II amps- one of my all time favorites. We made it even better by replacing the power supply 'lytics with mylar film caps!

I also got involved in speaker design. I was responsible for the Mylar cap kits and the mirror image mods for the DQ10. By that time, I designed all of the company's products. This included the DQ12, DQ8 and the DQ20 and DQ20i, among many others. The great Sid Smith (of Marantz fame) was now working for me as well. He was working on his amplifier project. I was the "ears" that had to evaluate it. I had great fun with Sid and learned a lot from him. I also was able to teach him a lot about listening. He would say to me "Carl I do not understand. When we had a tube amp that sounded bad at Marantz-there was always an obvious problem with a part not working. But with this new amp I cannot find anything wrong-yet it sounds bad." "Sid," I said," welcome to the world of solid state!"

Then there was the time I got to visit the great Harry Pearson. He had put together a system from several parts- the ribbon top section from the Infinity QRS and the Magnapan 1D bass panels. He wanted to use my LP1 to cross the Magnepans to the QRS panels. I helped him do this. He called the resultant speaker the QRS/1D. This was the first loudspeaker to generate a complete sound stage! This also was the first speaker in my experience to reproduce "image height". Very scary! Harry was breaking new ground in describing reproduced sound.

Toward the late 1980's Jon had a severe car accident. His family sold the business and in 1990 Marilyn and I went on to start Acarian Systems (ALON).

In 2004, we left Acarian to start Accent Speaker (NOLA), where we are today.

Sometimes I think that the point of the high-end industry and its original goals have been forgotten. With NOLA Loudspeakers, we are trying to recreate a listening experience as close to the "live one" as is possible. NOLA speakers are different. They look different and they sound different from other loudspeakers. However, they do not sound different from the sound of "live" music. I think that is the point.

I was recently at a dealer demonstrating the Viper Reference II. I chose a "live recording" of Shirley Horn in a small jazz club. I figured this type of program would best illuminate the difference between the Viper Reference II and its competition. The competition was a highly regarded floor standing forward-firing box speaker in the same price range. This speaker has a beautiful design and a world class finish. Its sound was very high quality and smooth. While this speaker has many attributes, it just could not make a live recording sound live. After playing the same Shirley Horn CD on both speakers, I asked the dealer what he thought. He said, "With the Vipers the sound was very much like what you would expect to hear live at a small jazz club. The other speaker," he said, "has a completely different sound."

I thought to myself, the competing speakers have two different sounds? That's it?

I said to him, "but the recording is one of a live performance!" I showed him the cover of the CD. I felt like asking him, "Is this your final answer?"

Now, if we were testing two cameras with an outdoor shot, and one camera gave a picture that looked "indoors", could both be correct? Not likely.

Anyway, here are some questions for thought:

Assuming we are trying to reproduce the sound of "live" voices and instruments:

  1. What instrument radiates sound only towards the front?
  2. What human voice radiates sound only towards the front?
  3. What natural sound radiates only to the front?
  4. What natural sound changes a great deal as you move your head a couple of inches?

The answer to the above 4 questions is of course NONE.

Regarding the important directional characteristics of instruments and voices (from Harry F. Olson's Music, Physics and Engineering):

In the midrange @ 1000 HZ - the amount of sound radiation to rear compared to the front:
Piano: -10 dB
Violin: -8 dB
Bass Drum: 0dB
French Horn: -15dB
Human voice: - 10dB

So we can see that 'live' sources produce mild reductions in rear radiated sound of 10-15 dB compared to the frontal sound radiation.

Regarding possible mid range speaker designs and resulting radiation patterns:

Omnidirectional: provides equal sound pressure in all directions and therefore cannot accurately reproduce how most "live sources" radiate sound into a room. Except for a couple of examples like maybe the triangle and the elevator bell - this pattern is not accurate.

Mono-pole: or front firing (typical box speaker). This is how most speakers are built. This also cannot reproduce reality as NO sound is radiated to the rear and there is no relation to the real world of "live sound".

Dipole: This design radiates front and rear-from the same diaphragm. So front and rear radiation is time coherent-but out of phase. It automatically cancels sounds to the sides and to the floor and ceiling-so it involves less of your room sound in the playback. With its 4.8 dB reduction in room power response, this provides the best match to the characteristics of the "live source" mid range room response and is why we use this in the best NOLA speakers. Examples- open baffle dynamic mounting of drivers, planar dipole designs.

Notice regarding the above - the wrong speaker radiation pattern cannot be fixed by any or all of the following:

  1. Making the enclosure very heavy.
  2. Making the enclosure out of plastic.
  3. Making the enclosure out of metal.
  4. Bolting the drivers to the baffle-really tight.
  5. Special Voodoo crossovers.
  6. Complicated mechanically adjustable enclosures.
  7. Use of Teflon© capacitors.
  8. Using many drivers in a mono-pole line array.
  9. Computer aided room correction.
  10. Beveling all sides of an enclosure.
  11. Using diamond, beryllium or ceramic diaphragms.

--- to be continued ---

© Carl Marchisotto August 2009
Cannot be reprinted without written permission