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Reviewer: Glen Wagenknecht
Financial Interests: click here
Source: Audio Upgrades modified CD player, originally a Luxman Brid, now tubeless with a zero times oversampling DAC whose output goes straight out via a volume pot.
Preamp/Integrated: none
Amplifier: Bel Canto 200.4
Speakers: Apogee Duetta Signature, Paradigm Servo 15 subwoofer
Cables: Signal Cable Silver Reference interconnects and speaker cable
Stands & Footers: Solid Tech, Equarack, Superspikes and Black Diamond
Powerline conditioning: Noise Destroyer power filtration
Room size: 12' x 17'
Review Component Retail: $2,650/pair, matching stand $700/pair

Getting to know any audio component is always a long-term affair. System break in and setup take time and patience. The Mark and Daniel Diamond + represents a full-fledged assault on the limits of what a small speaker is capable of doing. Excellent design and execution have yielded a speaker that will confound and impress even the most hard-hearted of audiophiles.

The Parts
There is no getting around the abilities of the woofer. It goes down further in frequency than any driver that small has a right to. It does so without the misguided trickery of front port augmentation. It is controlled, articulate and exhibits dynamic power that has to be heard to be believed. This is no shrinking dynamic violet of a mini monitor The woofer approaches subwoofer territory here with the kick of a mule. A seasoned audiophile who dropped by was convinced that my 15-inch Servo sub was being employed in the listening session. It wasn't. No faint praise.

Mark and Daniel's execution of the Heil is immensely articulate and only the best drivers out there can match it. Control, detail, dynamic nuance. All here in spades. The cabinet material is artificial marble. Suitably dense and well suited to vanishingly low cabinet coloration. One of the only intelligent approaches for this ambitious a design. Plus a very high WAF factor in terms of cosmetic appeal.

The Whole
Of course, all comments below should be taken in the context of performance within my specific system. The hallmark of this speaker is wide bandwidth clarity. It refuses to behave like a small speaker. Macro and micro dynamics are handled throughout the range of both drivers with a precision and control that put it in the top tier of compact speakers. The Heil illuminates like a searchlight. Resolution is the proper term here.

Imaging is wide and deep. Stage width is limited to between the speakers unless off-stage information exists on the recording. Basic depth information begins at the plane of the speakers and conveys accurate distance information from that point back. Ideal seating position for spacial immersion would be equilateral triangle.

Voicing. In the context of my setup, the Mark and Daniel tended towards the analytical side of neutral. The Heil is a little predominant in the crossover range. The woofer takes a bit of horsepower to achieve its full range so the difference is most apparent at low-level listening. The proper blend is achieved as the volume level rises. At lower volume levels the speaker is still extremely articulate because of the efficiency and dynamic character of the Heil. At higher volume levels the woofer seems incapable of running out of steam. In fact it is the Heil that begins to lose composure (I suspect due to the ambitious low crossover point.)

The two drivers have different characters but make no mistake, they blend well if you pay a little attention to detail. The Heil is a folded ribbon but like its planar brethren, has virtually no vertical dispersion. The blending will depend on getting the height and/or angle of the speaker aligned so that a composite of the two drivers reaches your ear. Get it wrong and the Heil will be either invasive or dull.

Resolving power. The speaker will easily tell you the differences between different recordings, equipment and performance. It will not gloss over the "mistakes of others" but it will not render any recording unlistenable due to exaggeration. As a point of observation, the speakers favored analog recordings over most digital. Perhaps merely a case of good taste?

With such unbridled go-for-the-gusto performance, the Heil can be pushed into compression faster than the woofer. Something to be careful about.
The previous is one limitation. The woofer represents the other. It takes a bit of level for the woofer to come into the picture because of air coupling and differences in mechanical efficiency. It raises the limit of the dynamic floor since the speaker must run at higher levels to achieve full-range capability.

Resonances. Not the woofer in this case but rather the Heil. A folded ribbon will due to mechanical limitations have a few peaks and valleys in the response curve. For the most part however, the low mass will generally dissipate those resonances faster than the ear can recognize them. Occasionally not and the speaker will draw attention to itself with an analytical flavor. Call it hyper detailing if you will.

Now, to put these caveats in perspective, remember that I'm being very critical. I work to find fault. There is no perfect speaker. The faults listed are minor against the virtues these speakers exhibit and most would not hear or acknowledge the things I have spoken of. In the financial perspective alone, there are many speakers far more expensive which exhibit more flaws and far less ability. The Diamond+ will hold its own against the best of them.

Ideal System
If I were to assemble a dream system around these little wonders, what would I choose? A good tube amp in the 45 to 100 watt range would do the trick. The natural compression characteristic of the amplifier would be an ideal synergy for both the dynamic floor and Heil caveats. It would precondition the signal in exactly the same way analog signal is preconditioned. Results? Better low-level performance. Ideal dynamic range. Midrange palpability. No tradeoffs in that match. Choose your favorite front end (good digital or ideally, analog here) and a little slice of sonic nirvana should ensue.

Some audiophiles will never be convinced to check out a bookshelf-sized speaker. After all, the Mark and Daniel speakers take up the same real estate and require similar positioning as a floorstander. That attitude would be a mistake. The Diamond+ will dynamically outperform and out-resolve many high-pedigree floorstanders with more sheer gusto than most could believe. Not giving the Mark and Daniel speakers a serious listen is a missed opportunity to have your preconceptions shattered (and also to remove your jaw from the floor.)

Mark & Daniel website