Munro Sonic Egg 150 Review


Munro Sonic Egg 150Since undergoing a rebrand, the Munro Sonic Egg 150’s have improved upon the original model with the refinement of the amplification stage. Aesthetically, the Egg’s may not be to everyone’s taste, and there is some question with regards to the choice of cable, but their sonic capacity is undeniably excellent and, largely, on point for their intended purpose. The inclusion of a dedicated headphone amp is also pretty handy.

Review Preface:

When announced in 2011, the Munro Egg 150 monitor speakers were amongst the first of their kind to take advantage of the acoustically optimal ellipsoid shape. To arrive at such a radical design wasn’t necessarily the original intention, but the design trio, James Young, Phil Smith, and the legendary acoustics expert ‘Andy Munro’, soon begun to understand that the traditional ‘box’ speaker cabinet design had a detrimental impact upon the output sound quality. Turning to nature for a way to minimise the cabinet effect, specifically the Egg, was the ‘Eureka!’ moment where the measurements suggested that they may be onto something. Soon, in both theory and practice, the shape categorically proved that it was able to afford the designers with ultimate control over the output sound quality; where the drivers would be able to speak for themselves with minimal cabinet effect. The result was a pure output transmission with massive resolution, and consequently the Egg 150 monitor speakers went into production.

Before continuing, it’s important to understand that when the Munro Egg 150 monitor speakers were announced in 2011, they were marketed under sE Electronics. In 2015 this all changed when the monitors became a brand of their own, known as ‘Munro Sonic’. Both brands are owned by Sonic Distribution and the difference between the old Egg’s and the new Egg’s is that the midrange EQ control on the amplifier has a much more subtle approach at 2kHz, where you can push or cut the frequencies by ± 1.5bB, with a broader fixed Q-point. Munro Sonic have also added a centre alignment notch to the Main and Auxiliary volume potentiometers for reference, they’ve also added a circuit to protect the Egg’s during power down, and they’ve redesigned the amplifier circuitry to apparently deliver more bass impact. As there are no physical differences to the monitors themselves, if you have the previous generation Egg’s, you are able to upgrade the amplifier by contacting Sonic Distribution for an extra £699, with a complimentary two year warranty. But, speaking of warranty, when you purchase the Egg 150 monitors from new, you are afforded with a standard one year warranty which can be extended, free of charge, if you register online. In comparison to the competition, this appears very generous, although the only part that is not covered by this is the drivers themselves.

Finally, the only thing left to say with regards to the differences, is that, in early 2015, Munro Sonic announced a smaller and more affordable ‘Egg 100’ monitoring system. Where the Egg 150’s currently retail at £1999.00, the Egg 100 retails at £1299.00. If you are unsure of which pair of Egg’s will best suit you, Munro Sonic offer a free seven day evaluation period so you can test them out in your own listening environment without any pressure from a salesman, or the uncertainty of online purchasing.

Unboxing, Build Quality, Features, and Presentaton:

When the Egg 150’s arrive, it’s clear that Munro Sonic have gone for the efficient approach as everything is packaged into one large box. My problem with this is that it requires the muscles of Thor as its sheer 36kg dead weight is an absolute pig to wrestle into the unboxing position, and has the potential to put your back out for a week or two. The moral of the story is; you’ll need two people to safely locate it into position. But now that we’ve cleared that up, the Munro Sonic team have definitely thought about how to best protect their Egg’s. Nope, the internal packaging doesn’t reveal an egg box carton that you can repurpose as acoustic dampening for your control room, but instead you have separate compartments for each component, where everything is suspended within a modular plastic foam cradle – excellent, no wrestling here. What you will have to bare in mind is that the Egg 150 monitors themselves are technically passive, so you will have to make room on your desk, or rack mount (2u), for the power amplifier to sit. It’s also best that you play around with the position on your desk to find a space that’s convenient for your workflow, instead of leaving it in a rack behind you where quick volume adjustments, especially with the RCA input, are inhibited. This is always a big no-no.

In terms of the package contents, Munro Sonic have made it so that the Egg 150’s have a complete set-up and go ethos where everything that you need, except for XLR and RCA cables, is provided. If we break this down, apart from the monitors and amplifier, we have a pair of rack ears, two [unbranded] 3m Speakon leads (for between the power amplifier and speakers), an 1.5m kettle lead, an ‘Operation Manual’, and finally, but rather strangely, a single surge protected universal power adapter. This last inclusion seems, to me, not all quite there for the retail price of the eggs. The build quality of it seems cheap, and I’m 99% sure that most people would have just preferred a region specific kettle lead instead of having to use this. Regardless, that’s what we’ve got in the package. However, something that is much more reassuring to know is that Munro Sonic manufacture all of their Egg 150’s within the UK and, from what I’ve been told by an employee that I won’t name for obvious reasons, the parent company, Sonic Distribution, are very critical of the outsourced quality and often reject the finished product. Keeping the product development and manufacturing in the UK allows Munro Sonic to have ultimate control over the finished article so failure rates and small aesthetic inconsistencies are kept to a minimum. In fact before each pair of Egg 150’s go out of the door, an engineer is assigned to inspect the Egg’s and test their performance; a process that reportedly takes around 45 mins.

Now that we’ve naturally progressed onto a discussion about the build quality, it’s best to continue, but I’ll first begin with something controversial – cable quality. Whilst I understand that, within the Pro Audio world, there is a large dismissal of the benefits of premium audio interconnects, I feel that the Speakon cable that Munro Sonic include with their Egg 150’s is under-par, and unpractical. After connecting and disconnecting the monitors only a few times, the connector now fails to lock into position, subsequently I have to manipulate the cable in order to gain a consistent connection. Within the ‘Operation Manual’ Munro Sonic claim that the cable is “very high quality”, but I doubt this in the grand scheme of things; there’s no ‘real’ information to back this up. Put it this way, if they used standard binding posts, like most passive studio monitors, the user would be afforded with the availability to swap the cables for the one that they feel best comfortable with, and could even extend or shorten the cable. Sure the LED alignment feature would not be possible, but I don’t feel that this isn’t a massively necessary feature for most. For example, my Audiofilia AF-SM1 and Chord Electronics ‘Scamp’ rig uses The Chord Company’s ‘Epic Twin’ speaker cable, and I would say that I’ve gained a 10% performance increase. In certain situations this will be a worthwhile improvement, so the proprietary Speakon connection is a definitely downside in my books.

The Amplifer:

With my [minor] frustrations aside, we’ll begin by taking an in-depth look at the amplifier and, for the large part, it’s clear to see that this 50w quad Class A amplifier has been built well. By attaching the optional rack ears and removing the feet on the bottom, you can easily rack mount the amplifier if you have two units free. What you do have to remember is that if you rack mount the amplifier above or below an existing one unit rack device, you will have mildly inhibited access to its controls because the 1cm thick aluminium faceplate stands proud. Again you will ideally want to keep this amplifier with a space above and below it to minimise the chance of overheating, so this should be noted. On the other hand, if you intend to use it free on your desktop, then you will have to take into account the large 31cm (12”) depth and the bulk of the connections on the back, which could mean that you’ll have to move items around to maximise your workflow and have quick access to front controls.

Other than the thickness of the brushed aluminium faceplate, access to all of the controls appears logical and they are all appropriately labelled. With the new amplifier design the potentiometers now have a centre point for reference and they feel slightly loosely smooth to the fingers. However, if you cast your eyes over to the centre of the amplifiers faceplate you’ll notice that there’s an unlit red LED just above the on/off button. This LED is an indication that the monitors are peaking (aka. overloading) and means that the user should take immediate action to protect the monitors from being damaged. Unlike many other monitors on the market, Munro Sonic have chosen to not to implement any intelligent DSP, ie. limiting, in the signal path to automatically protect the monitors. Limiting obviously has an impact on the sound quality, which is not ideal in a reference environment. Some may see the lack of this protection circuit as a downfall, but ultimately these are professional monitors that should be used in the correct manner and never driven to excess. You also have to remember that, ideally, the tracking, mix, and mastering process should be performed at a modest volume to stop ear fatigue, maintain good clarity, and balance that will translate well. Likewise the danger is that mixing at high volumes can mask critical errors. There’s just no point in having super sensitive monitors, such as the Egg 150’s, and not using them for what they were designed for. If you do intend to blast the Egg 150’s then do this in the presentation phase, the bass player will appreciate this.

Moving over to the far right section of the amplifier we notice that there is a ¼” headphone output socket. Munro Sonic have handily built in a separate headphone amplifier into the Egg 150 monitoring system and, when headphones are connected, this will mute the speaker output. There is no way to allow the monitors to play at the same time, which is slightly annoying if, for some reason, you want to tap off a ‘how you doing’ signal for the live room. When the headphones are connected the respective selected output potentiometer becomes the headphone amplifier control. If you are using high impedance headphones then you will have to remember to unplug them after you turn down the volume otherwise you could get blasted by the monitors, and potentially damage them without any of that DSP protecting them. It probably would have been better to provide a separate headphone output control that can be set to your comfortable listening volume. There is, also, little information provided as to the specifications of this headphone amplifier, but I have tested it with my 250Ω Beyerdynamic DT250’s and 250Ω Beyerdynamic T90’s, to which the amplifier performs admirably with more than sufficient headroom. As it is not a critical component of the playback I won’t be providing an in-depth look at it’s individual sonic capability. What I will say is that it ticks all the right boxes and the only minor criticisms that I can pick with it is that there is some bass ‘pumping’ going on and it can iron over the micro details, still it’s really nice as an extra feature.

Munro Sonic Egg 150 AmplifierTurning to the rear of the device is a fairly standard affair showing us the crucial ins and outs, and even an extra little treat – a switch to turn on the LED alignment indicators. Personally I don’t think that I’ve come across this simple system to help tweak the optimal placement before, but still it’s handy. The system is just as simple as it sounds, flick the switch and each monitor speaker displays a small blue LED at the end of a recessed tunnel, just above the tweeter. After observing Munro Sonic’s 1:1 ratio (speaker distance and distance to user), all you need to do is look over towards the LED and if the light becomes brilliant blue then the angle of the speakers is in the correct position… Simple! Another excellent feature of the Egg 150’s amplifier is that you don’t just have a standard ‘main’ XLR input, you also have an RCA ‘Aux’ input. Switching between the two is as simple as turning the switch on the faceplate, and I’ve found this really useful for switching between a HiFi setup and a reference setup. I’ve found that it’s almost always worth checking a mix with a second, consumer based, DAC because it helps you to gauge translation, so this feature is something that I find particularly useful. Although now we only have one final feature to discuss, and this is the HF and LF trim pots. Having access to these ‘tuning’ pots affords you with the ability to match the Munro Sonic Egg 150’s to your rooms environment. As standard the Egg 150’s obviously come tuned to a typical ‘flat’ factory setting, but you can have a go yourself at making the Eggs sing for their supper. There is a problem though, and this is that the pots are constant and are not ‘stepped’. Other monitor speakers have a series of flick switches on the rear which allow you to accurately switch between predefined attenuation values, but the Munro Sonic Egg 150’s are much more complicated because of those pots, their size, and the need for a flathead screwdriver to adjust. With the HF pot you’re able to attenuate the high frequencies past 10kHz by up to -5dB, and with the LF trim you’re able to attenuate the roll off below 63Hz by up to -10dB. You do have to remember that there’s no reference marks, so undertaking this task is not as easy as you think, and you must proceed with caution.

The Monitors:

With the Eggs being, well, egg shaped, you might wonder as to how Munro Sonic make them, and what material they actually use to create their ellipsoid shape. The answer to this question is injection moulded ABS plastic… Now don’t go letting out the worlds longest sigh yet… Yes, we know that monitor speakers in this price range typically use high density woods and wood materials (usally MDF with a veneer), or injection moulded metal (typically aluminium) for their ‘superior’ acoustic qualities, and that plastic enclosures are usually used for cheaper monitor speakers, but Munro Sonic have created something ‘out of the box’ here. You have to remember that the shape of the cabinet has been implemented to minimise cabinet effect, and inside Munro Sonic have created wave guides along the inner surface, which are then dampened an acoustic material. The result is an annoyingly impractical shape for everything else, that, arguably, performs much better than traditional box housings. Needless to say that they are cheaper (in the long run) to manufacture, and some will find them pretty ugly – myself included. If this is the case Munro Sonic manufacture the Egg 150’s in three colours to soften the blow and suit your tastes; Red, White, and Black. Coming back to that terribly impracticable shape, Munro Sonic have soothed your woes with permanently affixed stands to keep everything ship shape. These stands keep the Egg stable and have a clamping mechanism that can be tilted up or down dependant on the listening position. In use I’ve found the stands to be very stable and I’ve experienced no long-term difficulties. In general I’ve found the cabinet to have a great solid build quality, and there appears to be no inconsistencies in the finish. Finally, it might be interesting for some to know, particularly those intending to use the monitors in high risk environments (ie. educational institutions) that the Egg 150’s do not come with any protection grilles, and neither are there any available.

LMunro Sonic Egg 150 Systemet’s forget aesthetics now, because you probably want to know what makes these near-field monitors tick. What we have here is a single 6 ½” mid/bass driver, a 1” mylar dome tweeter, and 2” front firing bass reflex port, kicking out a 45Hz to 20kHz frequency response. How this compares with the new Egg 100 system, is that the 100 has a 4” bass driver, the same 1” tweeter as the Egg 150’s, and another front firing bass reflex port, but this time with a 60Hz to 20kHz frequency response. On paper the Egg 150 seems more suited to a professional, or larger workspace, environment, whilst the Egg 100 would be more suitable for the project studio or a compact workstation. As both have the front firing bass reflex port, typically you’re able to place the monitors closer to walls without experiencing any bass imaging problems, what you will have to remember is to give the monitors some space around them. Thankfully if you are a bit confused as to how to lay out your workstation, Munro Sonic will provide a guide to room acoustics to those who request it, and will offer some advice.

Previously we mentioned that the amplifier doesn’t really have any protection circuits to prevent overloading. Whilst this is the case for the amplifier, it isn’t strictly true for the monitors themselves. Inside the Egg 150’s is a thermal cutout fuse for the high frequency driver (the tweeter) which passively monitors the temperature and cuts the signal if overheating is detected. Munro Sonic advise that the amplifier has enough juice to heat the voice coils inside the monitors if used at volume for long enough, or if there is a short period of excessive volume. The tweeter cutoff is used as a protection, but there is no protection on the mid/bass driver so if this happens you’ll need to stop using the monitors for a number of minutes to protect the drivers as they are not covered by the warranty.

Multchannel Systems:

Unfortunately the Munro Sonic Egg 150’s are not available in a surround sound, multichannel, configuration. You are unable to buy the Egg 150’s individually, nor does a dedicated subwoofer exist. You cannot use any external amplifiers with the Egg 150’s, and you cannot use the amplifier with any other speakers. This may come as a disappointed to some and I doubt that a multichannel system is in the works as the demand for a surround sound system may not be large enough.

Review Technology:

Lossless tracks varying from 44.1kHz to 192kHz and 16bit to 24bit, Pro Tools 9, Apple ‘Logic Pro’ X, MacBook Air Mid 2013 i7, Lynx ‘Hilo’, Chord Electronics ‘Hugo’, ARCAM ‘irDAC’, Epiphany Acoustics ‘Astratus IEC’, The Chord Company ‘Chameleon XLR’, The Chord Company ‘Chameleon RCA’, Channel D ‘Custom TRS to RCA’, The Chord Company ‘Signature Tuned ARAY RCA’, The Chord Company ‘Cadenza RCA’, Tilbury Audio ‘Passive Preamp, and Computer Audio Design ‘USB’.

Please note that these monitor speakers should be burnt in for a period of at least twenty-four hours before you attempt to judge their performance, or put them to use.

Sound Quality:

As expected, the Munro Sonic Egg 150 monitoring system is an excellent and effective package for delivering a [mostly] faithful reference signature with superior resolution, and a clean naturalistic edge. Having just said the word ‘natural’, or at least its synonym, I think that this is probably the best way to describe the general aura of these monitors even if they try to be on a level playing field. Apart from this general vibe, what’s also most immediately noticeable about the this Egg system is the smoothness and clarity that it delivers across the entire frequency spectrum. You never have the sense that these are a pair of monitors that are hard to listen to, or would take their toll on your ears for prolonged periods of use, simply put they have no aggression or edginess. However, the Egg 150 system is also capable at delivering huge amounts of detail without the veil attached, but it doesn’t choose to do this with saccharine brilliance or an overly dry cold presence, it does this by being an energetic, musical, and a slightly rounded confident beast, which is why I feel that the ‘natural’ descriptive only seems appropriate here. Don’t get me wrong, I’m not saying that the Egg 150’s lend themselves more to a Hi-Fi tone (unless you play with that midrange balance switch), I’m trying to make the point that they just sound right, and near on perfect, where your ears aren’t unduly drawn to any particular frequencies. There is one minor caveat here, and that is the fact that I do feel that the visceral bass presence is ever so slightly north. It’s not so defined that it makes your mixes inaccurate, it’s more that it’s articulate punchy presence forces you to make the right decision as to how much bass you should have in the mix, which is possibly why they translate so well. Coming back onto that midrange tonality switch, I’ve have found that it can be very useful at helping you identity the vocals in a congested mix even if it’s effect is minor. The switch affords you with the ability to zoom in on elements such as vocals, or lead guitars, keeps them central, and helps you make minor amendments that would otherwise be much more difficult. Overall I can report that the Egg 150’s are a confident clean, honest, clear, and uncongested pair of monitors, that can certainly be trusted with the most complicated of mixes. What I will also say is that I believe that some of the HiFi nuts who will read this will also appreciate the Egg’s for what they are.

At the top end, the Egg 150’s appear to sufficiently extend, but they don’t appear to go super high. In terms of super high frequency presence, it’s certainly there, it’s just not there in spades. It’s best to say that it harbours a smooth, silky, airy presence with superb cohesion that allows various elements to come together and not sound fragmented or hyper-real. It’s definitely doesn’t sound massively dry, it has a fluid like edge which eliminates harshness. Likewise, I’m unable to detect any super top end distortion, but there is an occasional very very low level grainy feel that’s practically undetectable. As we come down the spectrum and arrive in the midrange, the Egg 150’s exhibit a luscious smooth balanced body with no evidence of smearing, in fact the texture and imaging in this range is very impressive; it exhibits massive depth. In the low end we have that visceral punch that we described before and it seems to extend very low with impact. It seems as if the top end of the bass isn’t quite as defined as the lower bass registry, although down in the sub-bass area there is some body missing, but not enough that’s notable or will have any impact on your mixes – typically, in most situations, you’ll cut that area out of the mix for clarity. It doesn’t feel as if the bass articulation is accented, it does have a solid punch behind it and is full, although it doesn’t come across as over-engineered or ‘hyped’ or woolly in the slightest. The bass region maintains good control and, again, doesn’t appear to have any distortion as the resolution is very good. All in all, the layering in between all of the frequency boundaries is consistent and there is massive coherence and clarity at all levels. Likewise, I’ve found the Munro Sonic Egg 150’s to have great transient contrast and this does help with combating the loudness war, as well as making your job easier and almost removing the need to keep referencing against a pair of cans.

In terms of projection, I’ve found that the 6½” mid/bass drivers punch well above their weight and are, surprisingly, more than capable of filling a mid to large studio with limited effort and will still retain the bass impact. In fact the amplifier still has a surprising amount of headroom past the average listening volume and I seriously doubt that you’ll ever be able to max it out, not unless you wish to loose your hearing completely, or loose all credibility as an engineer. If you are worried that your room is too large, then it might be best to look at an alternative monitor with an 8” driver to really fill the room because, currently, Munro Sonic do not offer a larger monitor design. If we come onto the stereo image now, I’d have to say that the Egg’s project a slightly wider than natural image that is highly pleasing to the ears. I’ve personally found that this image is consistent across smaller or larger rooms and the sense of width still appears to be carried well. In use, the transparency across the range and its brilliant resolution makes pinpointing the spot you want to occupy or amend a breeze. It even translates well and I would definitely say that the image is exceptional for a pair of monitors in this price-range, nothing appears to be left unchecked or patchy, and the central domain is clear and concise with no textural difference. If you’ve previously experienced a pair of monitors where the imaging is ‘smeary’, then you’ll be surprised with just how well the Egg’s allow you to get in there with scalpel blade accuracy and create a complex image where you can hear each individual instrument occupying its own position within an organic three dimensional space.


Now that the Egg 150 monitoring system has undergone a number of notable improvements it seems as if the Munro Sonic team have, in many respects, hit the nail on the head. In general the package appears to be well executed, even if there are some ridiculous limitations in terms of physical flexibility (ie. no user replaceable signal cables), and it offers a whole host of additional features (headphone amp, AUX in, midrange balance, room equalisation, etc.) that go a long way to help the engineer get the perfect mix that will translate well, and sound good in most environments. Whilst some will find the look of the Egg’s garish, I personally feel that they offer substance over style and, in terms of build quality, they are solidly made even if the Egg material is a little cheap, and should last for years to come, but if you run into any difficulties that two year warranty helps. Having discussed the superior sound quality of the Egg 150’s, I feel that they project well, are competitive at their price point, offer a coherent naturalesque stereo image, are highly agreeable, and are ultimately ideal for use in a professional studio. All in all The Pro Audio Web Blog feels that it just scrapes into the four and a half star region.

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