HEDD Type 20 by Arthur Stone
The HEDD Type-20 is a 3-way active studio monitor with analogue inputs and an optional digital connection module. A software component is also available – The Linearizer – which phase corrects the source which in turn places less stress on the hardware components and improves the sound.
Feed Your HEDD:
Sometimes the reviews write themselves...or present ideas, through chance and synchronicity.
I'd finished the review and packed away the HEDD Type-20's and decided they were the best monitors I'd heard in my room: dynamics, tone, soundstage. I wanted to double-check, so I re-unboxed and set them up.
The doorbell rang. It was the UPS guy come to collect the review pair of Kali LP-6's. Pleasant chap and looking at the box and reading the lettering, he said: 'Professional studio monitors eh?'
He was decent enough to say this in a non-belittling way, without any contempt but I judged his comment as from someone who knew something about audio and gear. My hunch proved correct.
I said: “Are you into audio and gear?” He laughed and told me about his high-end record deck, home system and penchant for classic vinyl re-releases. My opening gambit was that vinyl has 16 times the resolution of mp3 and we proceeded to discuss the resurgence of classic vinyl reproduction. We could have talked for hours and we both knew we were gear-buds for life.
In fairness to Kali, they deserve the title of 'pro' and that news was probably off UPS guys audiophile radar. I'm sure he googled them later anyway.
What sealed the deal, in establishing a shared passion for audio and gear, was when I said: “I've got some HEDD Type-20's upstairs.” UPS guy looked impressed at the mention of the HEDD name and he knew 'Type-20' too. I said: “HEDD have just released Main Towers and a huge smile came on his face. We nodded respectfully and UPS guy drove off into the vinyl sunset.
I keep mis-remembering my room dimensions and publishing different sizes in each review. Is it really important? I mean building materials, room shape and mass dampening, absorption coefficients of fixtures and furnishings, atmospheric and environmental factors, all come into play...and different rooms will sound different despite sharing dimensions whatever we interpret the laws of physics to say.
The actual dimensions are: 12' (3.7m) wide with an open door leading to a 15' deep hall with rooms off either side (my echo chamber) and a large window the other side (curtains used to sonically brighten or darken the room for tracking); the depth is 10' with 2 x 2' deep recesses on either side of chimney breast These recesses are part filled with books, vinyl and diffusers and resonators.
I'm sitting facing the wide section wall with the diffusers behind and mirror points covered with air-gapped acoustic fibre tiles and a ceiling cloud.
The 8' ceiling is thick plasterboard leading to a raised loft. The room is anchored to the mass of the small apartment building and the structure is formed from a solid reinforced concrete frame with concrete blocks forming partitions and room, all finished in plaster.
Good to go:
I mention this because the HEDD Type-20's 'reacted' with my room in a way that no other monitor I've tried has; energy did not seem to be wasted and transferred into the building/room structure. The bass appeared in a very structured, unforced way. Very clear and natural without the room responding as usual.
The soundstage was not as bright as other ribbon-tweetered monitors I've tried – a little less obviously present, more naturalistic, slightly-less fatiguing and kinda invisible as a source of the wide-expansive (but un-hyped) soundstage. This was a 5' nearfield triangle set-up close to the front wall. I think I could have set them back up to 6-8' further back – the power and stability of image was there – and I did some listening from the rear wall sofa spot which confirmed this.
The first thing to say is that the HEDD Type-20 is a professional instrument in terms of design and construction, features and controls, and also in that it is capable of conveying the same sonic character as a fine musical instrument.
Even with less well-produced or technically inferior source material there is still a sense of realism and plausibility I don't hear with other monitors I've tried/reviewed. Sound this good comes at a prime spot on the cost-benefit curve. In general, I had total confidence in the Type-20's; I didn't feel I needed a sub and there was plenty of SPL on offer.
That's not to say that you can't hear when something is wrong; you do – but equally what is right is clear.
As with other professional 3-way studio monitors it was impossible to determine which sound was coming from which speaker (or even from the speakers); the impression was of being immersed in a seamless, expansive soundstage: deep front to-back and endless sides. The mono centre was super-strong – magnetic – even with the monitors set wide. I noticed no 'high ceiling' or any cut-off between hearing and physically feeling the sub-bass in my body. There is enough physical depth and weight to effortlessly project bass and sub bass. It tickled sometimes!
My only real criticism of the HEDD Type-20's is the monitor self-noise (a pleasing or non-jarring white noise sound) that can be heard at around 3ft/1m in a quiet room; beyond that distance I wasn't aware of hearing or sensing it. In fact, that was the sound of the audio interface – a Focusrite Saffire. I switched to the KRK Ergo monitor controller and the noise was only audible at around 12”/0.3metre and well under the noise floor of my 'quiet PC.'
I guess that the only other minor (but important) gripe is the undetented control dials on the rear which are difficult to calibrate unless the monitor is turned around; a piece of tape attached to a flat-head screwdriver shaft can be used as a marker for easier calibration. The potentiometer (Phillips Head-slotted) head is softish plastic – perhaps for electrical reasons? - and showed some signs of wear and tear; generally, the build-quality is robust but the finishings and surfaces are quite delicate and extra care should be taken when moving or adjusting. The Type-20 scuffs easily but the rubberised-coating has a velvety texture, softly refracts the light and it helps the monitor physically fade into the distance.
The power switch is on the rear, along with the IEC power inlet; the XLR/RCA inputs (as well as the digital option slot) cover most bases and enabling domestic home hi-fi or second set or remote use, or connecting with unbalanced professional gear; the XLR is balanced. HEDD have adopted the digital module as a way to keep technologically-current and widen application of the range.
The Air Motion transformer (AMT) is unique design that differs from regular tweeters/speakers in that it can exceed a 1:1 diaphragm-to-air-motion ratio by four times. Hand-wound by craftsmen. HEDD have further evolved this classic design by using a strong magnetic field to lower distortion and intermodulation; with a special wave guide 2-way monitors are capable of lower crossover points. I heard an unforced but natural and realistic soundstage with no borders.
Rather than cutting-and-pasting everything from the HEDD site, I'll post this one pic and recommend visiting this page for a fascinating and in-depth guide to the HEDD Air Motion Transformer and it's history.
The mid-range 4.7” (120mm) speaker basket and 1.25” (32mm) voice coil is punchy in that region. I mentioned the tickling sensation earlier and this felt like the top end of that – even at modest volume. Nice for 808's!
The woofer 7.2” (182mm) basket and 2” (51mm) voice coil does the deep sub thing especially with the Linearizer engaged. Beautifully-detailed low bass. Passed the Bob Katz-Rebecca Pidgeon test. Nice mono centre down deep.
The (silent) port is interestingly-shaped too; although it is a rounded rectangle or slot, it is also bevelled inside.
Again a lot of worthwhile info on the components and design specifics at the HEDD site.
In the Aston Shield reviews we saw how the honeycomb design – a hexagonal shape ubiquitous in outer space, nature and human tech/culture – offered advantages of strength, material and mechanical efficiency, lightness, in addition to the sonic advantage (in the case of a popshield) of distributing air pressure at an angle perpendicular to the force of direction.
HEDD have used the hexagon in their speaker material: they call the material/process 'UHC cone' (Ultra Honeycomb Composite). I couldn't find/fit in more info on this but maybe the subject of a future HEDD review.
The Linearizer software (plug-in and stand-alone) is a great tool and adds detail and dynamics to the music heard. The Linearizer plug-in is either placed on the final output of a DAW (post-Limiter) or in a stand-alone mode for use with computer audio via VB cable.
It took me some time to figure out what exactly how to integrate the Linearizer into the production workflow? It made the monitor give more detail, sharper dynamics but that wouldn't translate to the mix as Linearizer should be bypassed for rendering. Perhaps the Linearizer was helping make mix and phase decisions? Improvement would stay on the track for rendering.
In fact the HEDD Linearizer plug-in uses Finite Impulse Response (FIR) to compare the expected physical response of the speakers with the digital audio passing through and then delays and adds filters to that digital audio so that when it is output; so the speaker is not 'fighting against itself' in terms of simultaneously receiving a signal to push-out or relax, positive or negative signal.
By phase aligning the signal (as the last software component in the chain) for the perfect (speaker) component/driver 'work,' the maximum efficiency is achieved.
The monitor performs optimally with the Linearizer engaged. Consequently there is less inefficiency and stress on the drivers and electronics potentially improving the lifetime of the components.
The sonic advantage is that better mix decisions (and a sharper, clearer listening experience) can be had based on the sonic improvement of the monitor efficiency.
HEDD say that many (99%) of current DSP-speakers have only basic IIR filtering and it can be shown that FIR is better suited to matching particular frequency response requirements e.g. monitors. The advantages of IIR, namely, efficiency, is less of an issue especially when run on a current device and HEDD seem to have nailed the software with no CPU hit on my old PC.
Klauss Heinz of HEDD explains it superbly in this short video: The HEDD Lineariser(R) - Heinz Electrodynamic Designs
The HEDD literature, manuals and website are good. Clear and informative and with the Linearizer you get information and charts for the: HEDD alignment curve (for the Type- ) or Anechoic flat curve; and then a selection of phase responses: linear. Part-linear, and minimum phase.
It's interesting and educational to spend some time with different audio sources and test the different settings; differences can be heard and for me it was possible to set it (Type-20 alignment Linear full range) and really feel that the monitors had disappeared as a source of the audio.
I think this is why I found this powerful 3-way system a good fit in the nearfield position.
Really hearing bass and sub:
Working in a small room brings issues of noise transmission to family, friends and neighbours (unless they like it of course); also small rooms by their nature are not suited to the deep bass trapping needed to soak up and tame the bass energy.
Passive and active resonators are another aid but these also require space and cash.
I noticed the name Sonarworks being used by many people – something of a reference product of the time.
I noticed how boomy the bass and sub was on familiar tracks – some known to be boomy, even by design, and others with too much sub. The HEDD Type-20's revealed this immediately.
On many previous tracks (especially non-electronic) I've just HPF'ed at 50Hz as I had no confidence below that – but the Type-20's go down to 30Hz and it was clear I could begin to have some confidence in what I was hearing.
Probably best to make a distinction between professional studio use (which I know little about) and semi-professional home studio: I can see the HEDD Type-20's appealing to both markets particularly as it's possible to add connectivity cards.
The common denominators are: superb, accurate, comfortable sound; a reliable reference for production; good value for money; professional features and connectivity; and ease-of-use.
The HEDD bridge inter-connectivity modules (one of which can be mounted into a rear panel slot) opens up DANTE/Audio-over-IP via CAT.6 Ethernet for HQ audio streaming and multi-channel set-ups (Dolby Atmos, Auro 3D, etc.) also distributed networks in multiple workspaces and listening venues.
Equally (without the optional digital module) you can enjoy analogue inputs in a simple way. The Linearizer, which works on the playback device, is still available for use and it can also be used stand-alone with VB cable software.
I see the HEDD Type-20's on consoles in nearfield positions and I think I understand why: even up close the naturalistic soundstage, resolution and dynamics are perfectly conveyed without fatigue.
The best value for me was in the ability to trust them: for making decisions; as a reliable reference. Best monitor I've tried to date.
Sound Quality 5/5 There's a difference between sounding good and allowing to hear music that sounds good. No problem identifying issues in an analytical sense but not punished by fatigue.
Basically it does what a full-range monitor needs to do without making you pay for it; that adds to its value.
Ease of Use 5/5 No problems listening all day without fatigue. Shelving and gain controls do a good job of tailoring the HEDD Type-20 to specific rooms/positions. The speaker arrangement means that the Type-20's are physically unobtrusive (for 3-ways) and they have a good 'longshot' depth. They deserve good stands. One point of general caution: when connecting monitors digitally there is the possibility of 0dBFS and these go loud! Usefully the rear panel gain dial can set an appropriate peak level.
Features 5/5 Never felt like I needed a sub. The HEDD 3-way system is flawless. The Linearizer software is a genuinely useful and effective sonic tool and I learnt more about audio from the process of using it; an ear educator. The digital amplifiers can produce quite high levels when needed and the sound was very linear at different listening levels (or as linear as one would expect given listening/SPL curves).
Bang-for-Buck 5/5 The HEDD Type-20 sits at a good bang/buck point relative to the 3-way competition. In a sense it's not just the first-class physical monitor you buy but also the decades of design expertise and the passion for audio excellence behind the Type-20's.
Credits and Links:
The Type 20 studio monitor by HEDD | Heinz Electrodynamic Designs
HEDD’s modular input card system HEDD Bridge
The HEDD Lineariser(R) - Heinz Electrodynamic Designs
Infinite impulse response - Wikipedia
Photos used courtesy of HEDD; additional photos by Arthur Stone.
Thanks to Steve Barton for the extended review period.