Danny Richie tears the Special 40 apart
 

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".

https://photos.imageevent.com/puma_c...09.26%20AM.jpg

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.

https://photos.imageevent.com/puma_c...08.36%20AM.jpg

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...
https://photos.imageevent.com/puma_c...14.38%20AM.jpg

:worried:

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.

https://photos.imageevent.com/puma_c...24.11%20AM.jpg

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.
https://photos.imageevent.com/puma_c...24.25%20AM.jpg

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.

https://youtu.be/0TxorWiy78w

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.

Not so special? Someone needs to send him the Heritage

Yep, looks like Dyn cheaped out on the BOM, and the connectors, wire, and damping materials. That woofer's performance is pretty rough.

As for the Heritage, I was thinking the same thing. That would be interesting.

You need someone else to tell you whether some speaker is good or not? :)

I would be curious to know what he has to say about the Harbeth 30s series...

Yeah, me too, and I've thought about sending one of mine to Danny. My only hesitancy is that it is very difficult to remove the speaker "grilles" without damaging the cabinets. My understanding is that Harbeth uses a special tool to do this.

Please do, we need that one too, then I can safely order a kit for each of my crappy but beloved speakers :D