How much bass is enough?
This age old question has divided mankind for centuries, since the days when stone-age audiophiles would fiercely debate the properties of drums made from Sabretooth Tiger pelts vs Mammoth hides.
How much bass you require will be influenced by a variety of factors.
Your preferred musical genres for instance, your average listening volume, which digital audio player you use, and even the geometry of your ear canals may alter your lower-frequency preferences.
Or it may come down to mood – at times you may prefer to
feel instead of hear the music.
ISN Audio have created an IEM for such occasions… the
EST50s.
Earlier this year I was very impressed by
Penon’s Impacts, and they must’ve felt similarly about my review because without asking they sent along a pair of complimentary ISN EST50s to review. I’d barely heard of ISN to that point, and was dimly aware they sold cables but had to google the EST50s just to see what they were!
Of course I immediately felt a pang of guilt – you see one of the Impacts’ few drawbacks is their absence of a dynamic driver, so although their bass is excellent by BA standards, it remains BA bass nonetheless. Having commented on this, could Penon have sent the EST50s to prove they do indeed sell IEMs with bountiful bass slam?? Remind me to complain they aren’t expensive enough to see what happens next…
The
ISN EST50s are USD $449 tribrid IEMs containing a single DD for bass, one Sonion BA for mids, one Knowles BA for highs and two Sonion ESTs for ultra-highs. It’s a delightfully minimalist configuration that keeps shell sizes small whilst giving you that juicy EST goodness.
They’re bundled with ISN’s S8, a relatively thin 8 wire silver-plated OCC cable with 2pin connectors. A multi-plug version isn’t offered so instead you’ll choose between 4.4mm, 2.5mm or 3.5mm terminations. The IEMs also come with an 18 month warranty.
The EST50 shells are vented so pressure build-up isn’t an issue, and the first thing you’ll notice is how incredibly shapely they are. ISN have attempted to imitate a Custom-IEM form factor in a universal body as much as possible here, and the end result is uncommonly comfortable– so much so they deserve special praise for how easily I forget their presence in my ears, coupled with the excellent isolation their deep fit provides.
Packaging
The
EST50s arrive in a fairly small & very light cardboard box with a leather carry case, leather accessories case, three sets of eartips, shirt clip & IEM cleaning tool, and the aftermentioned ISN S8 cable & leather cable holder.
Many audiophiles pay quite a bit of attention to packaging and “unboxing experiences”, and after spending thousands of dollars on a luxury product that’s perfectly understandable. Obviously the EST50s lack that sort of pricetag, making a more modest collection of accessories acceptable.
I fall into the camp of preferring minimalist packaging that’s less costly to ship so the EST50 ensemble doesn’t bother me, particularly as it lends assurance that as much of the purchase price has been devoted to the earphone as possible. However some might argue the quality of the box & case leave room for improvement.
Sound Impressions
Upon listening to the EST50s for the first time you’ll be immediately struck by their deep, resonating bass presence. It is more heavily biased towards sub rather than midbass and thus is especially satisfying for electronic music, of which I have a particular fondness.
Having tested them with Spinfit W1 tips via a Cayin N8ii DAP (solid state mode with P+ enabled) using local files stored on a Micron i400 micro-SD card, I found bass is very much north of neutral, and you’ll feel as well as hear that pounding bass slam!
Bass quantity isn’t quite as extreme as FatFreq’s more expensive
Maestro SE which remain the most over-the-top set of IEM bass cannons I’ve heard, but it isn’t too far away either. There is ample rumble, slam and impact down low, which will serve any bass-dominant album or genre extremely well. Bass texture could be improved, but remains satisfying.
The really good news is the EST50s have been tuned extremely tastefully, demonstrating a controlled aggressiveness that generates plenty of excitement without excessive fatigue. You’ll hear all that bass without it overpowering the midrange, nor is this the kind of slow or bloated bass we can experience with budget DD IEMs.
In fact the EST50s’ dynamic driver is responsive enough to do fast-paced music with busy passages justice, without ever creating coherency issues with those faster BAs & ESTs. Indeed coherency is one of the EST50’s great strengths, with all five drivers combining harmoniously.
There’s enough bass & treble to qualify the tuning as tastefully V-shaped, with the midrange avoiding any recession or dryness common to poorly tuned V-shape IEMs. Both female & male vocals demonstrate plenty of presence, but may not quite convey the refinement we see from IEMs worth thousands of dollars. To be fair, that sort of smoothness would probably impede the visceral rawness that makes the EST50s such fun in the first place.
Treble performance is excellent thanks to the presence of those two ESTs, with plenty of sparkle and commendable resolution without the need to hunt for detail. I did feel nuances were presented slightly more effortlessly by IEMs with vastly higher pricetags, but the relative difference was quite small. Indeed the EST50’s treble prominence has proven to be fantastic for classical music, not something I expected from IEMs with basshead DNA.
Technical Performance
With regard to technicalities the EST50s are capable, but perhaps not exceptional beyond the constraints of their cost. Dynamics are superb, perhaps aided by their superb coherency. Soundstage is wide but not spectacularly so, but isn’t the deepest with layering a notch down from multi-thousand dollar IEMs, and imaging is solid without calling attention to itself. This is where swapping to a more expensive cable helps.
Resolution is well above that of budget IEMs, perhaps only a very small step below earphones worth thousands of dollars, and this difference rarely asserts itself without actively straining to pick up minute changes.
Overall the EST50s straddle a wonderful line between being brash enough to evoke a feeling of raucousness, without being so raw they fail to perform well with most genres. In terms of nitpicks, I wouldn’t call them cold or sterile but a touch more lower midrange warmth would occasionally be nice for vocals, and if you listen at high volumes you may find their treble prominence excessive. I’d also love an even wider & deeper soundstage without having to pay more for an upgraded cable.
IEM Comparisons
Penon 10th Anniversary –
2xDD, 2xBA, 2xEST (USD $499)
It’s only natural to start here given my recent
10th Anniversary review.
Unquestionably the best IEM all-rounders I’ve heard under $1000, the 10th Anniversaries are more relaxed & refined than the EST50s, with a more polite presentation that’s less bombastic and excitable. Physically they’re slightly larger and not quite as comfortable, though the difference in comfort wouldn’t discourage me from using them.
10th Anniversary bass is certainly enough when called for but lacks the over-the-top quantity & slam of the EST50s, and is biased towards midbass rather than sub instead. 10th Anniversary treble is also not as prominent, resulting in them possessing a much milder V-shaped signature. They also have a significantly richer, smoother midrange, but I find the EST50s to have slightly better coherency.
The EST50s are significantly more upfront with a feeling of being closer to the performers, and this gives the 10th Anniversary the impression of having a wider soundstage though perhaps not quite as deep.
The 10th Anniversary remain the better all-rounder choice, but simply aren’t as fun or exciting as the EST50s, particularly for bass-dominant genres like electronic music.
Dunu SA6 MK2 – 6x BA (USD $579)
I was loaned the SA6 MK2 by my friend
Neweymatt and was surprised to find they’re much larger than the EST50s despite containing only 6 BA drivers. They certainly stick out quite far but are comfortable regardless, being very sculpted to the ear like the EST50s, and thanks to their larger shells isolate even better.
Being BA-only, the SA6 MK2s bass is something of a surprise being extremely impressive by BA standards… but lacking the added texture, slam & punch of the EST50s. The SA6 MK2s midrange is little dry, and although they demonstrate the pleasurable sensation of speed & precision achieved by omitting a DD, that slightly plasticky BA texture is present. Nor can the SA6 MK2s emulate the EST50s effortless resolution, perhaps due to the lack of EST drivers. Dynamics are also poorer.
The SA6 MK2s do possess a wider stage than the EST50s, but it is not as deep. They’re more easy listening IEMs that are very well balanced, and it’s unfortunate a comparison to the EST50s paints them as a poor choice because they’re actually quite good if you accept those BA-only shortcomings.
Kiwi Ears Quartet – 2xDD, 2xBA (USD $109)
The Quartets are surprisingly large for their driver count, but very sculpted & comfortable with build quality rarely seen at this price. They contain a pair of tuning switches, which I leave in the OFF position for pleasing results.
Most immediately apparent is how much of a step down their bass is from the EST50s, both in terms of quantity and quality. With less lower midrange emphasis they produce a dryer sound, that is tonally much flatter & more subdued, not helped by poorer dynamics. Their treble is also whispy, lacking body.
The Quartets’ resolution is very disappointing, but their one advantage is a slightly wider soundstage than the EST50s, although it has almost no depth to speak of. Essentially the Quartets are outclassed rather badly.
7hz Legato – 2x DD (USD $109)
My friend
o0genesis0o loaned me the Legatos which are certainly unique in their aluminium construction, being quite possibly the most slippery IEMs I’ve ever struggled to handle without dropping. They’re also physically large & heavy, but lack the ear-hugging contours of the SA6 MK2s or Quartets.
With their double DD’s the Legatos have also been touted as basshed IEMs, and indeed their bass quantity is north of neutral – greater than that of the Quartets, but lacking the quality of slam & impact of the EST50s, nor is bass quantity as high. Overall the Legatos are less V-shaped, being more polite and smooth but less exciting as a result.
Unfortunately the Legatos also suffer from poor dynamics, inferior resolution & soundstage depth compared with the EST50s, and though their treble is more substantial than the Quartets’ they lack the sheen & shimmer of the EST50s’ EST drivers.
Truthear x Crinacle Zero – 2x DD (USD $49)
As you might expect from a double DD IEM the Truthear Zeros are quite large, but very light. Their shells aren’t sculpted to ear geometry at all, so eartip choice is crucial for a comfortable fit. Physically they’re reminiscent of Fir Audio’s Frontier Series containing the XE6 – not uncomfortable, but perhaps lacking the rounded contours of other IEMs.
Requiring a humungous amount of power – almost double that of the EST50s to reach similar volume, the Zeros feature a very wide but flat stage, a somewhat thin & recessed midrange with fairly neutral bass biased towards sub. This creates the feeling of being seated a long way back from the performers, with a somewhat uninvolving sound.
The Zeros have a very flat treble presentation that sounds one-note in its’ simplicity, with a lack of weight behind those higher notes. Though the stage is very large, it feels artificially stretched in much the same way Sennheiser’s IE900 does to me. The Zeros are a relaxed & laidback IEM, the very antithesis of the EST50s.
Cable Comparisons
Do cables make a difference? Of course they do, but I’m sure you knew that already.
There’s absolutely nothing wrong with the EST50 stock cable, in fact the
ISN S8 is excellent value for what it is. However there’s distinct advantages to opting for something different, and I’ve never been one to pass up an excuse to roll cables so let’s give it a try and see where it leads us!
ISN S8 (USD $32.50)
The EST50 stock cable uses 8 wires of silver-plated OCC and is quite bright, accentuating treble and imaging. It’s also extremely light & comfortable, even by 4 wire standards.
The S8 doesn’t enhance stage dimensions quite as much as other cables, and its’ added treble sparkle & upper midrange accentuation contributes to the EST50s exciting presentation. This could potentially lead to fatigue if you’re very treble sensitive, in which case a copper cable may prove be a better choice.
Penon CS819 (USD $49)
The 10th Anniversary stock cable is similar to the ISN S8, with 4 of its’ 8 silver-plated wires replaced with OCC copper instead. Surprisingly on the EST50s this leads to better separation, with more lower midrange presence creating a sense of fullness.
Note weight is also improved, with vocals in particular having more substance behind them. However dynamics & treble sparkle are diminished compared with the ISN S8, but this could potentially result in less fatigue.
NiceHCK BlackSoul (USD $50)
This extremely comfortable 2 wire ‘5 element alloy’ cable creates a wide but flat stage, rolling off treble significantly to create a much smoother sound, but I do find bass is more muted compared with the stock cable and imaging also seems negatively affected.
A good option for anyone who finds the EST50s treble too hot & dynamic, though I don’t care for this pairing as I’d rather not having the EST50s excitement tamed.
Penon Vocal (USD $69)
This 4 wire silver-plated OCC copper & gold foil cable is sure to get you noticed in a crowd, and is a nice visual match for the flame-inspired EST50 faceplates.
As the name suggests Vocal pushes vocals forward and enhances midrange clarity & note weight, balancing out the EST50s natural V-shaped sound. Everything becomes smoother, calming the excitement to create a more mature sounding presentation.
A perfect low-cost pairing to turn the EST50s into more capable all-rounders.
Penon Obsidian (USD $149)
This heavier-than-expected 4 wire OCC copper & gold plated copper cable takes the improved refinement of the Vocal cable & kicks it up a notch. This is a testament to the importance of cable synergy – previously I’d found the Obsidian disappointing on both the Penon Impacts & 10th Anniversary, but it pairs with the EST50s extremely well.
It even manages to widen the EST50s soundstage, something it didn’t seem to accomplish with the Impacts. The lower midrange also feels more crunchy & visceral, with even better separation than the Vocal cable creating a greater feeling of cleanness & control. Bass seems slightly less impactful, but I don’t mind the trade-off.
Penon Leo Plus (USD $249)
The 8 wire gold-silver-palladium alloy Leo Plus again demonstrates it’s ability to accentuate treble, widen the stage, improve resolution & make things like cymbal splashes stand out even more.
However dynamics seem diminished, and bass doesn’t quite hit as hard. Although this creates a sound less likely to fatigue I’m not overly fond of the pairing.
Effect Audio Ares S 8 wire (USD $279)
With 8 thick wires of OCC copper the Ares S boosts the EST50s lower frequencies as it did with the 10thAnniversary, dynamics are also improved as are resolution & imaging.
This is an ideal choice in the unlikely event you fail to find the EST50s visceral & punchy enough, although shifting the focus towards the bottom end even more may leave the EST50s feeling like a blunt instrument on music genres requiring more delicacy.
Liquid Links Martini (USD $349)
Another hefty 8 wire cable, of gold plated copper & palladium plated silver, the Martini boasts the same superb dynamics, soundstage & resolution improvements of the Ares S.
However the Martini emphasises the upper midrange rather than the lower frequencies of the Ares S, leading to slightly improved articulation coupled with a more polite overall signature, tastefully smoothing out the treble in the process.
Liquid Links Venom (USD $1089)
Despite possessing only 2 ‘quinary alloy’ wires, Venom emulates the improvements to soundstage & dynamics of the 8 wire cables previously mentioned, and adds even better resolution, separation and a blacker background.
Though unquestionably the first choice in this cable shootout for improving the EST50s technical performance, Venom’s natural V-shaped inclination towards boosting sub bass & treble emphasises the EST50s existing strengths in a way that doesn’t feel as satisfying as expected – instead inflecting a somewhat clinical tonality.
Conclusion
Returning to the earlier question of how much bass is enough, ISN have provided an answer your ears deserve to hear.
There is ample weight and power to be savoured here without suffocating the rest of the frequency spectrum. Even the midrange, so often an afterthought in V-shaped signatures is instead rendered with commendable weight and presence.
Make no mistake however, the EST50s want you to have a good time. Delivering a fun, bouncy sound is their priority at the expense of refinement, though you’ll still get most of the resolution & technical performance of far more expensive IEMs.
Could ISN have delivered more effortless detail, an even larger soundstage and more pinpoint imaging whilst maintaining the same bass-driven flavour? Perhaps by adding more BA & EST drivers, but then the EST50s would be physically larger as would the price.
Instead they struck an excellent balance – but is that why since arriving simultaneously the EST50s have enjoyed far more of my ear time than Penon’s 10th Anniversary?
I’m not sure being smaller & slightly more coherent explains it – no, there’s something compellingly satisfying about the way the EST50s deliver those glorious bass drops which you’ll understand when you hear them.
