Review: Hedd Tower Mains Professional Monitors

Posted on 27th February, 2019

Review: Hedd Tower Mains Professional Monitors

Before heading off to The Bristol Hi-Fi Show, I attended the UK launch of the new HEDD Tower Mains, the latest and most impressive addition to the HEDD line-up.

The setting for this show-and-tell was Rimshot Studios, a remarkably lovely, purpose-built boutique recording and mastering facility set amongst the North Kent Downs.

HEDD Monitors at Rimshot Studios

The main live room of the studio was host to the demonstration. The ample, high ceilinged space was perfect for these formidably-sized monitors.

The father and son presentation was as technical as it was entertaining. Frederick Knop, Mastering Engineer, Musicologist and son of Adam Audio founder, Klaus Heinz, work well together as a double act which no doubt is excellent news for the company they have formed together, HEDD (Heinz Electrodynamic Designs).

HEDD Tower Mains

HEDD Tower Mains

Walking into the open space, the Tower Mains stood guard either side of a grand piano. A fitting situation for such stately proportioned speakers.

Would I class the speakers as attractive? Perhaps not as much as those domestic set-ups where aesthetics may have compromised pure engineering. However, it is because of their pure engineering that they possess a different cosmetic charm.

Every element of the HEDD Tower Mains modular design has been lead by the role dynamics play in audio reproduction. Additionally, they needed to achieve the highest degree of authenticity and realism.

The Extended Tower Mains are around seven feet tall and with their dual sub-modules set either side of the mid/top unit, they make for an impressive, not to mention imposing, sight.

Standard And Extended

Freddie and Klaus

The Tower Mains comprise two modules, and the system is available in two variants - Standard and Extended. The main difference between the systems is that the Standard has one subwoofer module, the extended has two.

Naturally, adding the second subwoofer adds headroom and dynamic range, but both systems deliver an identical frequency response.

The systems both feature the TM80 module comprising a single AMT (Air Motion Transformer) ribbon tweeter along with two 7.2-inch drivers and a pair of 4.7-inch drivers arranged symmetrically in a quasi d’Appolito formation. The drivers are in turn powered by 3x 300W class D ICEpower amplifiers. The crossover frequencies are at 250Hz and 2.5KHz.

The sealed box cabinet features heavily chamfered edges to avoid edge diffraction. The 3 dB lower efficiency compared to ported designs is compensated and even exceeded by having multiple drivers and enormous amplifier power. However, the TM80 isn’t designed to stand alone.

In Standard flavour, the TMS36 subwoofer slots in beneath the TM80. If you're feeling fruity, you can add a further TMS36 up top to create the Extended system.

HEDD Tower Mains rear

The TMS36 packs four 9-inch drivers and 2x600W of class D amplification, again in a sealed enclosure. It crosses over with the TM80 at 80Hz and in combination with the TM80 creates a monitoring system that's good to 120dB and covers from 20Hz (-3dB) to 50KHz.

Finally, the Tower Mains are fully HEDD Bridge compatible which means they can connect directly to a Dante-IP based playback device, or to a more complex multichannel hub based on Audinates IP technology. Also, the free HEDD Lineariser software plugin enables the Tower Mains to play with a
striking phase linearity of ±1°.

The Standard System costs £15,990; the Extended System is £23,990. HEDD told us that it had sold at least one system “off spec” to someone who hasn’t even heard them yet.

Sound Quality

Having spent a while in studios of varying budgets and, more recently, surrounded by hi-fi ranging from the affordable to “that's almost as much as my last yacht cost me”, the Tower Mains are incredible monitors, I was impressed by how revealing the big HEDDs are. This is in part due to the sealed box construction.

Of course, the whole point of studio monitors is to be revealing, but there was also a musical clarity to these tall speakers.

HEDD Tower Mains Extended Official

In their extended formation, the low end is subterranean. The choice of tracks proved that the Tower Mains could handle bass in a tight and controlled manner, but that doesn't mean that the set-up can't rattle your fillings should it need to. I put forward Sevdaliza's Human as a test track, and I was happy to hear it played back on the large system. Looks shot around the room when the song went from light, breathy vocals to staccato samples to prolapse-threatening lows.

Where the lows plumbed the depths the top end is capable of attracting dogs from miles around. The AMT tweeter really does the business, and it is a testament to that fact that the Tower Mains only needs one of these per side to balance out all those bass and mid drivers. Not only does the tweeter balance out the tonality, but it also keeps everything sharp, accurate and precise.

Speed and timing were also on point here. For big speakers, they remained agile and accurate throughout the demo. There wasn't great width to the soundstage, but that's not what studio monitors are about. What you do get is excellent focused audio.

That being said, when chatting with the other, mostly pro-audio, attendees at this exclusive bash, it was repeated that even though these are very serious professional monitors they could be repurposed as a very successful high-end hi-fi product if given a lick of paint.


Would I give the HEDD Tower Mains house room? You betcha! More to the point, I would gladly recommend that my studio-dwelling friends check out the HEDD Tower Mains at their earliest convenience. Should the main event be too much monitor for their space, and after hearing the monitors in the control room at Rimshot Studios, HEDD should definitely be on their list to check out.

For more information, go to HEDD.


    Jay Garrett's avatar

    Jay Garrett

    StereoNET UK’s Editor, bass player, and resident rock star! Jay’s passion for gadgets and Hi-Fi is second only to being a touring musician.

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