ScanSpeak MUN-17, built by Alex

Copyright 2021 © Troels Gravesen

Hi Troels,
 
I finally completed my lengthy build of your MUN-17s and have had them in my living room for about six months now. They replaced my SEAS 3-Way Classics, which I finished about five years ago. The Classics were lovely speakers, having the combination of a nice open midrange and great listenability; unfortunately, they weren't an ideal match with my zero-feedback 300B amplifiers, despite the friendly impedance and sensitivity of the speakers, and the bass was a little woolly and poorly defined. I stress that this was a matching issue, rather than a fundamental weakness of either speakers or amps.   
 
This was a very extended project: it took me well over a year to collect the crossovers and drivers, and a further year or so between buying the first batch of timber and applying the last coat of lacquer to the veneer. The MUN-17s are constructed of layered plywood with MDF baffles - the dimensions are identical to yours, except that I have extended the covers down over the woofers, necessitating a reduction in the width of the lower baffles and hence an increase in depth by about 3cm to maintain the same volume for the woofers. The outside of the cabinets are veneered in American oak veneer, while the baffles are finished in ash veneer, sprayed satin black, and everything was  finished off with four coats of clear satin spray lacquer.
 
The mid-treble is driven by my 300B monoblocs, of Kevin Kennedy's design, and I installed the Hypex PSC2.400D plate amps for bass duties, as described on your original project page. The rest of my system is a Funk Vector-modified Pink Triangle with Funk Firm FX-R arm and Lyra Delos; Marantz CD6005; and DIY Vacuum State RTP3C preamp. 
When I started adjusting the bass levels and equalisation I found that, because the speakers were perforce installed only about 15cm from the back wall, the low-frequency boost supplied with the default filter settings made the bass slightly overblown, so I deactivated it. I found I had to invert the output of the Hypex amps, since the valve amps have inverted polarity. I plan to make some proper measurements over the next few weeks.
 
What can I say about the sound? I might say the MUN-17s are easy to listen to, since there is nothing to object to about the sound, no bass boom or over-emphasised frequency ranges, nor are they tiring over an extended listening session. At the same time, they are really hard not to listen to - there is so much happening in every recording that my attention is constantly being drawn to the music. On good recordings, the sound is huge with plenty of realistic presence and detail, as well as great imaging. I don’t know whether it is the beryllium tweeters, but I find that with these speakers vinyl surface noise is less intrusive than with any other system I have had. In summary, I am very pleased!
 
Best regards,
 
Alex