Danny Richie tears apart the Dynaudio Special 40s

[Puma Cat]

Literally and figuratively.

Danny Richie of GR-Research recently did his extensive analysis (including measurements with his Clio system) of the Dynaudio Special 40.

Looks like Dyn cheaped out on this speaker that originally sold for $2995.

The woofer measures suprisingly poorly with notable peaks at 1110 hz, 3400, hz and 10K. Danny refers to it as "rough".

Yowch!

There is also a significant ringing component to the woofer in the spectral decay. John Atkinson obtained effectively identical results when he measured the Special 40 in Stereophile.

The parts for the crossover, wiring and fill is also problematical.

Iron-core inductors, sand-cast resistors, cheap poly and electrolytics caps in the XO, and el-cheapo, 16 AWG PVC insulated clip-on leads for the internal wiring, and a poorly-damped cabinet with cheap fill.

Danny's reaction...

Danny did say that Dyn spent an extra 10¢ and used binding posts that are non-ferric, so..that's good.

Danny went through and fixed the issues with the drivers, their measured performance and improved the overall frequency response to be smoother and within 1-1.5 dB. Also knocked down the knee at 1100 Hz peak in the mids.

You'll also note that the behavior of the woofer is quite a bit smoother.

He also reduced the ringing component of the woofer to a considerably lower level in the spectral decay.

I'll leave you to watch the video to see how got these issues fixed with his mods. Needless to say, he improved it quite a bit. Most notable is the improvement in the vertical off-axis response with the drivers remaining in phase as you go up.

Dynaudio | How Special is the 40? - YouTube

Total cost of the parts for upgrading the Dyn Special 40 is $245. Having built one of Danny's speaker designs using his parts, wire, and drivers, I would think the Special 40 is quite a bit better with his modifications.

 

[apdoc2004]

Maybe Dynaudio should hire Dannie Richie since the company is clearly lacking speaker designing talent! All the money spent on their ultra expensive Jupiter measuring room has been wasted.

 

[Puma Cat]

Maybe Dynaudio should hire Dannie Richie since the company is clearly lacking speaker designing talent! All the money spent on their ultra expensive Jupiter measuring room has been wasted.

I didn't say that, and neither did Danny, so it's not accurate to generalize on Dyn's expertise based on a single speaker.

And in the interest of full disclosure, I'm a huge fan of Dynaudio, and have owned a pair of Contour S3.4 with upgraded Esotar 2 tweeters that were my personal reference for over a decade.

None of that changes the fact that the frequency response and spectral decay data for the stock Special 40 don't lie. That woofer with stock crossover clearly has some problems with respect to a very lumpy frequency response and ringing at 1100 Hz. This was independently confirmed by Atkinson in his testing as well: "I listened to the enclosure's panels with a stethoscope. While the top panel was quiet, the sidewalls were afflicted with several resonant modes that affected the midrange..." and "However, the touch of midrange congestion was something I'd first noticed from my listening chair."

The quality of parts, wiring, connectors, and damping materials used for the cabinet leave a lot to be desired as well, especially for....a $3000 speaker.

If Dyn had added all of...$125 to the cost of the BOM with better quality parts (assuming Danny is charging 2X his cost for selling the sourced parts, which he has every right to do, to make a profit) and used a better crossover design, this would be a been a notably better-performing speaker. But that extra $125 in better quality parts would have likely pushed the MSRP to $3500, if not more.

I know my Contour S3.4s have got some issues, too, because when I swapped out the Esotec tweeters for the Esotars, I was disppointed to see very cheap white foam rubber materials used in inside the cabinet for damping, and some Van den Hul "zip cord" for wiring the drivers. Ugh. At least they were soldered, on though. And I know for a fact the crossover board has sandcast resistors. Ugh, again. They sound good, but...they could have sounded better. At some point, I may ship one to Danny to map out a fix.

And as a long-time Dyn owner and fan, though, I'm disappointed to see how Dyn "cheaped out" on this speaker, a 40th Anniversary special edition, no less.

 

[apdoc2004]

I am not casting aspersions on Dannie Richie's technical knowledge and I do not claim to be an expert on how to design or measure loudspeakers. i just find it somewhat incredulous that a major company like Dynaudio would have a hard time designing a speaker that measures well (with all the resources at their command). Could it be differences in how they perform their measurements? I do not know. I put less stock in the cost of the crossover components as plenty of well know loudspeaker brands with great sounding speakers have pretty ordinary crossover components (TAD R1 speakers come to mind and I am sure there are many more).

 

[Puma Cat]

It's clear from Danny's analysis that the S40s were built to a budget with cheap parts, connectors, wire, and damping materials and R&D time. The data shows it; look at the rough response of the woofer and significant ringing component.

The crossover components have as significant impact on the quality of the sound as they would in an electronic component. You don't see ARC, CJ, Pass, etc., using iron-core inductors or cheap caps and sand cast resistors on their boards.

 

[Mr Peabody]

I find this very surprising. I wonder if it's du to the current ownership. I believe 3.4's would be under the original Dynaudio though, depends on which version I suppose.

I've heard stories of the original designer scrapping prototypes because they didn't sound the way he wanted them to, up to his quality, to his ear. Sad that corners were cut on a product from a company that once had such pride in their product.

I am a Dyn fan and find this a disappointing report

 

[Puma Cat]

I find this very surprising. I wonder if it's du to the current ownership. I believe 3.4's would be under the original Dynaudio though, depends on which version I suppose.

I've heard stories of the original designer scrapping prototypes because they didn't sound the way he wanted them to, up to his quality, to his ear. Sad that corners were cut on a product from a company that once had such pride in their product.

I am a Dyn fan and find this a disappointing report

Yes, I'm a big Dyn fan, and find this disappointing, also. I have get into my S3.4s and see what's up with them at some point. I wasn't impressed with the internal wire they used when I swapped in the Esotar tweeters. I found a pic of the crossover board online a while ago, and if memory serves, they used some sand cast resistors on the XO board. Gack!

 

[Puma Cat]

Found the photo of the S3.4 crossover. This looks pretty good, with Mundorf MKP caps and air-core inductors. I'd replace those sandcast resistors with Mills resistors, though, if I kept the XO's original circuit design. And I'd see if I could replace that electrolytic. Wire would have to go, though. I'd use Danny's wire, and would "braid" them as I did for my Encores, instead of that "zip cord" design.

 

[mep]

Found the photo of the S3.4 crossover. This looks pretty good, with Mundorf MKP caps and air-core inductors. I'd replace those sandcast resistors with Mills resistors, though, if I kept the XO's original circuit design. And I'd see if I could replace that electrolytic. Wire would have to go, though. I'd use Danny's wire, and would "braid" them as I did for my Encores, instead of that "zip cord" design.

You should team up with KingRex as he has lots of experience criticizing the crossovers in speakers he’s purchased and making them “better.” As for ARC not using iron core inductors in their products, can you tell me which ARC gear uses air core inductors?