Martin Logan Prodigy & Descent Sub

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former MLO owner/operator
Dec 27, 2004
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Rancho Mirage, California

[size=+3]The Martin Logan Club - Member Product Review[/size]



[size=+2]Martin Logan Prodigy & Descent Sub



Reviewed By Member Steven Haycock
January 2004


This review takes place some 10 months after having taken delivery of both the Prodigies and the Descents. Previously owned speakers (which help serve as a reference) include Apogee Diva’s and KEF Reference 4’s. However this is my first experience of owning and living with a pair of Martin Logans and I am therefore approaching this review as a relative newcomer to the world of electrostatics.

[size=+1]Principal Associated Equipment[/size]

•Krell KPS 20i/L CD Player and pre amplifier

•Krell FPB700cx Power Amplifier

•Transparent Ultra Bi Cable speaker cables

•Transparent Ultra balanced interconnects

•Transparent Ultra RCA interconnects (pre to sub woofers)

•Power supplies to Prodigies and Descents & other electronics: Transparent Reference power cords & power conditioners.

[size=+1]Listening Room Size and Characteristics[/size]
Overall room dimensions are 25 feet wide by 32 feet deep with a 10 foot high ceiling. The room has a solid floor with ceramic tiles and is acoustically on the bright side. The brightness is countered by curtains along the length of one long wall and books along a large portion of the opposing wall, together with the usual assortment of soft furnishings and rugs. The complete system is located along the room’s 25 foot front wall.

[size=+1]Purchase Considerations[/size]
Aside from price, my personal criteria for speaker selection is driven firstly by the type of music I listen to, and second according to room size and practical considerations. Essentially I wanted a loudspeaker which does everything well, on any type of music (not much to ask) and given that around 50% of my music collection is classical it was a pre-requisite that the Martin Logan’s reproduce this type of music well. The remainder of my collection is roughly divided between electronic, new age, jazz and rock. My pre-purchase research suggested that Martin Logan’s do not give the same outright performance on rock material as a well designed cone – or mono pole – design can and hence I had set my expectations on this front a little lower (but more on this later).

From a practical point of view I am fortunate in having a large listening room which, although not a dedicated room, has permitted a great deal of freedom in the set up of the system and in the placement of the loudspeakers in particular. Based on some ten months of almost daily listening experience with these speakers I have no doubt that they benefit enormously from being sited well away from room boundaries.

[size=+1]Set Up Considerations[/size]
Set up for both the Prodigy and the Descent is crucial. Get this wrong and you will never realise the full potential of these speakers. The product manuals provide clear and comprehensive instructions and guidelines for set up and it is strongly recommended that these are followed.

[size=+1]Prodigy Set Up[/size]
I started with the speaker panels around five feet from the front wall, some 8 feet apart and with around 2 – 3 inches of toe-in. Over the ensuing months I have moved the speakers many times and think that I now have them close to optimal: six feet from the front wall, ten feet apart (centre to centre) and with 2inches toe in. My most preferred seating position is roughly 12 feet from the front line of the panels, although near field listening also works well with these speakers on more intimate material. My overall preference though, taking all music genres into consideration, is to have the seating position further back, where I find the overall imaging and sound staging to be at their combined best.

[size=+1]More on toe-in[/size]
The right degree of toe-in is also a critical factor in optimising the set up of the Prodigies. Small changes in toe-in (say half an inch) yield noticeable differences. In my overly bright room a degree of extra toe-in has helped to tame the impact of that room brightness on the mid to upper mid range which, on some material, can otherwise sound a little forward or strident. However the downside to increasing the toe-in is that the sound stage starts to becomes more compressed. The answer is to experiment until you find the right balance. In my case 2 inches of toe-in is about right. However the better solution is to ensure that appropriate room treatments are applied to get your acoustic listening environment optimised.

On a purely practical level I do not recommend installing the spikes on these speakers straight out of the box. I found that during the first few weeks of use two things happened: first, through experimentation, I learned to appreciate how these speakers sound in different positions and second, the sonic characteristics of both the Prodigy and the Descent change as they run in. Martin Logan supply gliders which it make it easy to move the speakers around during this initial phase.

The spikes provided by Martin Logan are heavy duty and of top quality. My only criticism is that the locking bolts have a smooth, rounded profile making it difficult to really tighten them down – and once tightened down can be equally hard to release.

[size=+1]Running in[/size]
It took at least 100 hours of run in time before the performance levels of the speakers started to plateau, by which time I had a reasonable idea of how best to set up the system. Even so, for several months after this I continued to make fine positioning adjustments before arriving at what I now think is the right set up for my room.

The Prodigy is bi-wirable and this review was conducted only in bi wire configuration. Lastly, on the reverse of the Prodigy, next to the binding posts, a switch is located which provides the option of attenuating the bass response by +3 db, according to room variations and personal taste. In practice, whilst I found the difference between ‘flat’ and +3 db to be quite subtle, I finally settled on the +3db position.

[size=+1]Descent Set Up[/size]
My system consists of two Descents, one for each channel, driven via the RCA outputs from my Krell pre amp. In time I intend to bi-pass the passive cross over and drive the Descents using balanced interconnects through an external electronic cross over, something which the Descents provide for.

In my view (and allowing for the fact that mine is a music only system) the Descents provide an adequate degree of tuning flexibility with the controls conveniently located on the front panel of the sub, behind the easily detachable grill. The Descents permit level control, four phase settings (0, 90, 180 and 270 degrees) and finally a 25HZ control which allows this frequency output to be modified by up to +/- 12 db.

The subs are crossed over in my set up at 40HZ (as recommended) but can be crossed over at 70HZ when partnered with smaller, main speakers. I finally located the Descents behind and wide of each of the main panels, some 10 inches forward of the front wall, angled slightly towards the listening position and set about 14 feet apart. There are those who will argue that bass frequencies exhibit no directional characteristics so that you can’t really tell from where the signal originates, but I personally think that this is an over simplification. With two Descents in stereo configuration my impression is that the subs not only integrate more effortlessly with the main speakers but they also integrate the bottom octave more accurately to the rest of the musical program.

After much experimentation I have settled on the 90 degree phase setting, ‘flat’ at 25 HZ and an output level setting of 4.5 (out of 10). On most material this gives deep, well extended bass support to the musical program, without intruding or colouring any aspect of it. On a few recordings it is necessary to back off the gain a little, but this is hardly an inconvenience.

[size=+1]Build Quality[/size]
I would rate build quality for both Prodigy and Descent as ‘excellent’ and the final finish as ‘very good’ - but not up to the best standards offered by some other high end manufacturers. Apart from the optional finishes offered on the trim rails (which are of very high quality) no options are offered for the bass cabinets which are finished very simply in matt black. It suspect that this strategy has enabled Martin Logan to maintain a relatively competitive price for their speakers and I can only imagine the added costs involved of applying an exotic finish, which begs the question: would it be worth the extra outlay?

The electrostatic panels themselves are very well constructed and finished so that the overall impression when walking into the listening room and seeing the whole set up is extremely impressive (I might have said ‘jaw dropping’ but I think I have to reserve this metaphor for the E2’s…).

[size=+1]Listening Results[/size]
Straight out of the box the Prodigies gave an almost lightweight impression which is in no way representative of their true performance capabilities. Hence this review is based on listening sessions which have taken place with the speakers fully run in and well sited in the room. All source material is CD based.

One characteristic of the Prodigies which strikes me more than any other that I have heard (at any price) is their ability to disappear when the music is playing. They are incredibly open and transparent throughout the mid-range, with no hint of colouration, giving the very real impression that you are not actually listening to a pair of loudspeakers at all, but to the music itself. Beware however that poorly produced material is exposed for what it is: in other words I have not found the Prodigies to be especially forgiving.

Across all types of music these speakers very convincingly reproduce the air and the ambience of the recording venue which is a critical part of any listening experience. Equally impressive is the way the panels are able to handle the decay of notes so naturally; it’s another subtle but very important detail which you may not realise you’re missing on less capable (cone) speakers.

Volume setting is important when listening to music and one of my criteria for a good loudspeaker is its ability to perform well at any volume setting, from low background to high, concert hall levels. For me the Prodigies fulfil this criteria with ease, exhibiting no signs of fatigue or compression at high volumes whilst still retaining a complete sense of proportion in terms of imaging and soundstage – and this is maintained across the frequency spectrum. Having said this, I have not skimped on the power amplification and regard the Krell 700cx as an excellent match for the Prodigies, demonstrating to me at least that these speakers respond well to large, current capable, high quality amplifiers.

[size=+1]Light Classical Music[/size]
On light classical music such as Decca’s recording of Albinoni’s Opus 9 Concertos, the full spectrum of the performance is produced evenly with no discernible under or over exaggeration at any frequency. Bass lines blend especially well, exhibiting no difference (to my ears) in sonic characteristics to those of the main panels.

String instruments are reproduced with excellent tonal accuracy and texture. What I would describe as the ‘air’ surrounding each instrument and the decay of each note are captured more convincingly than I have heard on some far more costly systems (I recall auditioning a monopole speaker system costing $70K coupled with equally impressive downstream electronics and wires which could do no better than this).

Solo performances, for example piano and cello, are reproduced very realistically: imaging is holistic, sizing life like and the subtle sounds associated with the playing of those instruments – the performers physical interactions which are plainly observed at a live event - extremely well conveyed by the Prodigies, principally thanks to the transparency and sensitivity of the panels. Furthermore, in my estimation, the full dynamic range of the piano is achievable with these speakers although I strongly believe that this ability is very much dependent on the amplifier being used to drive them.

Turning to voice I played selections from the Anonymous 4 repertoire starting with ‘A Lammas Ladymass’ recorded at Le Feuillet Paroissial de Saint Augustin, Montreal (Harmonia Mundi 907222). Every nuance of voice and intake of breath is placed before you, in your listening room, surrounded by the scale and ambience of the venue. Once again decay of notes is absolutely first class, convincing me beyond doubt of the Prodigies unparalleled strength and subtlety in this area.

I was however aware on this recording of what I can only describe as a degree of mid range stridency on some passages which I felt intruded on parts of the performance. To examine this further I turned to another of A4’s recordings – Le Bele Marie, performed at St. Patrick’s Cathedral, New York and experienced the same effect, again on just a few passages, albeit a little less marked.

On just about all other vocal material, male or female, voice reproduction is truly first rate in all respects. The A4 issue could be attributable to many things (e.g. the recording, the CD format, cables, room effects and so on) or it may simply be a characteristic of the panels. During the course of this review however I found that it was possible to ameliorate the mid range stridency by increasing the toe-in of the Prodigies by about an inch (any more than this and the sound stage became too compressed for my liking); it is also notable that mid-range stridency is only observed in isolated instances. Putting all of this together suggests to me that the issue is most likely connected with the brightness of my listening room and its concrete front wall. I am also inclined to lay part of the blame with the limitations of the CD format.

[size=+1]Full Scale Orchestral[/size]
Full scale orchestral pieces such as Mahler’s second symphony (Simon Rattle, EMI CDS7479628, 1987) are reproduced with tremendous power and control, and yet with an equal measure of delicacy and refinement on quiet passages. Dynamic range is simply ‘par excellence’. Stage width and depth are huge and layering is evidenced with great conviction. Complex passages are handled with ease. With the right material, try as I might, these speakers are very hard to fault with large scale pieces such as this.

Turning to Jazz, for which ML’s are famed, I can confirm beyond doubt that this genre is reproduced to great effect. One of my own favourites: Diana Krall’s ‘Live in Paris’, is reproduced with the most life like verve and energy, revealing the ability of the Prodigy to connect the listener with the recorded event. The sound stage is not just large scale but is also full of air and ambience, giving a very realistic rendition of the live performance. And each component of the performance is equally impressive – drums, bass, piano, guitar and, not least, Diana Krall’s wonderful voice which is literally ‘there’ in the room. Each instrument is well defined and solidly placed on a broad, deep soundstage. Drums are particularly well rendered in all respects, not just in terms of character of but in terms of size, three dimensionality and dynamic impact.

In short, pick any well recorded Jazz CD you care to think of - you will not be disappointed with these speakers.

This was a crucial test for me since rock makes up about 20% of my CD collection, which is significant enough to be an important purchase consideration. As noted in the introduction to this review I had ‘managed’ my expectations for how the Prodigies would handle rock music, but as it turns out I needn’t have bothered. My first surprise came when playing Pink Floyd’s ‘Momentary Lapse of Reason’ and ‘The Division Bell’ where the overall sound and presentation is quite noticeably different than that obtained on conventional loudspeakers. Initial impressions hint that the Prodigies are somehow a little more laid back than a conventional speaker, but as you listen you begin to realise the real truth: that the Prodigies actually create a very well balanced, very even handed performance which lacks for nothing in terms of dynamic impact. Personally I find this not only more palatable but ultimately it’s a more rewarding listening experience than can be obtained on conventional speakers.

And what a fantastic experience the Prodigies create: for the first time I can really appreciate the production work which must have gone into these two albums. The layering and detail mixed in with the music is presented in a wholly coherent way which, combined with a huge soundstage which extends well beyond the speaker boundaries, creates a rich and involving experience. Other rock CD’s which I especially like and used in this review include Led Zeppelin II, Joe Satriani’s ‘The Extremist’ and Roger Waters ‘Amused to Death’. Take the track ‘Summer Song’ from the Extremist – when the gain is turned up it’s clear beyond doubt that nothing is lacking in terms of power and impact both of which are delivered with enough force to wake the dead. But as with every other type of musical genre I have listened to through these loudspeakers, there is also a wealth of micro detail which helps to paint a so much more complete picture than I have heard before. The micro details themselves are also reproduced without in any way overwhelming the presentation: instead the effect is one which simply makes for a more involving experience.

It has to be mentioned that in all cases the Descents were on line and of course they add a fundamental bottom end foundation which I personally could not do without now that I have experienced it. Even so, the Prodigies on their own should in no way disappoint on this type of material.

[size=+1]More on Bass and the Descent[/size]
I can state without any reservations that once run in the Prodigy has exceptionally good bass which, as far as my ears are concerned, integrates seamlessly with the panels. The bass goes deep and is both taught and well defined. Equally importantly timing is a great strength of the Prodigy. I have been repeatedly surprised and delighted by the way the bass keeps pace so precisely with the rest of the performance. Furthermore I have heard reputable cone speakers whose bass integration is notably slower and less well integrated than is the case with the Prodigy and this is surely a great testament to the thought, design and engineering which has been put into these speakers.

Why then add a sub woofer? And in my case not one, but two Descents in what is a music only system…

Firstly the Descents are built to the same design standards and using the same cabinet materials as those used for the bass units of the Prodigy. As I understand it, a key design criteria for the Descent was that it had to blend well with ML speakers – implying that it must be fast, articulate and must exhibit the same sonic characteristics. On this basis alone the Descent for me was a natural and obvious choice.

Second, there is no shortage of musical program which includes bass below 35HZ (the approximate lower response limit of the Prodigy bass). The Descent will reproduce bass flat down to 18HZ – leaving no doubt that if it’s been recorded then this system will reproduce it.

So what effect then does the inclusion of the Descent have on the overall performance of the system? To try to illustrate the answer to this take a recent recording such as Peter Gabriel’s ‘Up’ which has plenty of bass content. Without the Descents this album unquestionably has powerful, extended bass - but bring the Descents on line and you realise how much deeper that bass actually goes. It’s enough to shake my listening room of 8,000 cubic feet, the walls floor and ceiling of which are built from concrete. But again subtlety and finesse also play a big part in the magic which the Descent can create: overall definition is increased making bass lines easier to follow and the soundstage of the overall performance is somehow amplified – it has noticeably greater width and depth.

The overall impression then is one of significantly greater weight and power of performance and this is achieved without in any way compromising the work done by the panels. Very careful set up is however critical to gain this effect: if the level setting is too high then the music is quickly overwhelmed; get the phase wrong and the performance loses a degree of focus and solidity. With patience and experimentation it is not difficult to get the balance right and the effort is well worth it for the added power and overall sense of palpability that is achieved.

[size=+1]Summing Up[/size]
Both the Prodigy and the Descent are extremely fine, solidly engineered products which, once run in and correctly set up, have delivered beyond my expectations with just about all types of music. After almost a year of living with them I am still amazed at their capabilities and I am sure that I have yet to realise their full potential.

So transparent and truthful are these speakers that I now find myself re-appraising not just the other components in my system (especially the front end), but the source format itself. In time I will re-install vinyl replay into the system and I have already begun to build a small collection of SACD’s.

Patience is needed whilst the speakers run in and they do require considerable time and care with set up. Another major factor to keep in mind is the listening room itself – both acoustically and in terms of size. However, taking these factors into account I would personally, wholeheartedly recommend both the Prodigy and the Descent to anyone who is serious about music.

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