In 'Explorations in Audio' I aim to share some practical insights on setting up and optimising an affordable HiFi system. Although one would think that, really, all has been said about HiFi, some surprisingly simple questions still remain, e.g.: 'Is digital superior to analogue?' 'Do cables matter?' 'Can digital cables pick up interference?' 'Should speakers be placed on spikes?' 'Has evolution in HiFi made older gear obsolete?' 'Where should I place my sub?' 'Which room correction works best?' - On the other hand: 'Are these really the right questions?' - We shall see.
While the entries in this blog are divided into the three distinct categories above, you will find a mixed listing of the most recent postings below. The most recent article is shown first. If this is not your first time visiting, the listing below is a good place to quickly check if anything is new.
Your input is more than welcome, as long as you follow the basic audiophile rule of ‘ear over mind’. This means that you do not comment based on what you think you know, but only on the basis of your own listening experience. Please feel free to suggest gear for testing as well as leave comments on the descriptions provided here.
Author: Karsten Hein
Category: Gear & Review
To be honest, my original intention was to sell off a pair of speakers and not so much to purchase a new one. But when a caller expressed interest in my pair of KEF iQ30, somehow I could not help but enquire what troubles he was hoping to solve with them. It turned out he had a small listening room, and that his current speakers were simply too large for the job. To my surprise, they were of the exact model that I had been running a web search on for some time. We consequently agreed that he would bring them along when auditioning mine. What a strange coincidence that was.
Let me explain: Ever since replacing our KEF iQ30 bookshelves with a slim and tall pair of Tannoy DC6T floor-standing speakers, I could not rid myself of the sensation that they too were lacking the muscle to fill our 70 sqm office with music. Although articulate and pleasant in their presentation, their performance mostly inhabited the space right up to the listening position, at about 1/5 of the room’s depth, rather than filling it completely. While the pair of Tannoy DC6T was better suited than the KEFs for that same location, it still seemed a little light on the bass, not terribly underperforming but not impressive either.
The trouble is, when your designated listening space is a sleek and modern office, this sets some limits to the possible speaker choices, especially in terms of colours, shapes, and sizes. And this does not even consider the WAF (wife acceptance factor) an aspect that does come into play when running a family business. Yet, since the DC6T had been chosen well and also found acceptance from the other dwellers, I tentatively set up an automated web search on the next larger (and more recent) model, the Tannoy XT8F. Hence my excitement when I heard over the telephone that there now was a pair on offer and that it was going to be brought to our house, instead of us having to take the trip.
As you might imagine, our double-interest in each other’s speakers created a strange scenario in which we both had something to gain and something to lose at the same time. I could see that it would be a challenge for both of us not to let this get in the way of enjoyment. Upon his arrival, I helped our guest by carrying up one of his Tannoy XT8F speakers which he had kindly brought along for them to be auditioned, and I immediately noticed how large and heavy they were in comparison to their smaller cousins. Although they were only wrapped in thin blankets and not bulky boxes, I had to take especially good care not to scrape them along the inner walls or banister of our stairwell.
Since the original reason for his visit had been the KEF iQ30s, we decided that they should be auditioned first. I had them hooked up to our DB Systems DB1 + B&K ST140 system in our main listening room. We had a choice of vinyl, CD, as well as the possibility of streaming via Amazon Music available, but we ended up only playing CDs, some of which he had brought along as his reference. It is always fun to listen to other people’s music, and so I simply sat and listened to new sounds or enjoyed playing some of my own. The KEFs do play well in our main listening room, and there were moments in which I forgot the original purpose of our meeting and was simply taking in the music.
Without a final decision on whether he would purchase my KEFs, we proceeded to our office upstairs. Here, our Tannoy DC6Ts were still connected to the Restek V1 + Hafler XL280 combo. With everything perfectly set up from hours of listening, I asked him to sit down and listen to these first. I know how our system sounds, so I simply stood aside and let the music play. My impression was that he enjoyed what he was hearing, however, the second purpose for his coming to Frankfurt was for me to decide whether I was interested in the larger Tannoys that he had brought for me. We therefore quickly took the protective blankets off and connected the XT8Fs to our system.
My first impression was that the sound was muddled and massive, resonating far too chaotically in the large office space. Would I be able to make them blend in with the room, and what was it worth to me to find this out? After all, where the DC6T had been articulate and refined, the larger speakers now seemed disorganised and colossal. However, since this forum is called ‘Explorations in Audio’, you can probably guess my final decision, although it was not one that resulted from a positive first impression. That they already had some bumps and bruises on the finish only contributed to this sensation. What consoled me was the fact that the whole room was energised by these new speakers. And this was the one thing the smaller Tannoys had been missing. We both made our respective purchases, content with each other’s offers, and the buyer went on his way.
I have learned not to judge new gear arrivals too quickly. Some of the best devices I have ever owned, have taken me weeks if not months to set up well. New speakers can be tricky in this way, because many factors come into play: distance to the front and side walls, width of placement and toe in angle, listening position, and system matching, to mention just a few. These factors are hardly solved within a day’s work, as even one centimetre difference will have a pronounced effect on the speaker’s ability to perform. While this is true for all speakers, larger speakers tend to be more difficult to place, especially when taking interior design considerations into account.
Given some time to experiment, I came up with a placement that allowed me to keep my accustomed listening position at about 1/5 of the room’s depth with only minor adjustments. The XT8F are positioned about 5cm further away from the front wall than the DC6T had been, and my listening position had to be moved 10cm back. This way, the toe in could remain unchanged with both speakers directed just past my ears instead of straight at them. This has a positive effect on sound stage and reigns in the highs which are a bit overly pronounced when played on axis. During the placement I listened to Bruce Springsteen’s Song ‘Tougher than the Rest’ from his live on-Broadway performance. This way I could be sure that there was a real stage to be recreated. In fact, I listened to it so many times in an endless loop, I have been humming it ever since.
The XT8F have a full and rich sound, in comparison with the DC6Ts, but also more generally speaking. At close distance, the sensation is one of bathing in music. There is plenty of good quality bass, and due to their 91dB performance at just one watt, they play loud with ease. Although they look chunky and provide plenty of depth, they play voices intimately, as if listening to a cozy living room performance. This contrast of mighty roar and delicacy is highly addictive to my ears. Due to their concentric construction, the XT8F are very exact when it comes to locating instruments. Perhaps not quite as exact as the DC6T but still industry leading at this price level. If the sixes sounded as though one was taking part in a studio session, the eights invite you to the jazz club. Both speakers are insightful enough to be entertaining at all times, but if the room is right, the eights appear just a bit more rounded, especially towards the lower end. I now understand that in a smaller room this much bass can be overwhelming.
When the music is subtle, the XT8F will play this with delicacy and insightful detail, and when the orchestra swells, their excellent dynamics generated from a 50 litre corpus with down-firing bass port will thrust forward with a vengeance. I could not detect any compression when going loud, which is new to me and wonderfully pleasing. It is quickly clear that this is a completely different beast. Those who purchase the XT8F hoping for an upgrade to their DC6T might be disappointed that their room is simply too small of a playing companion. But those who have ended up with the DC6T in error, like myself, have a real chance of being very happy.
Author: Karsten Hein
Category: Audiophile Music
Christian McBride — Live at the Village Vanguard. A must for all Jazz enthusiasts who are into live and authentic small club performances. Published by Mac Avenue Records in December 2014, the high quality double album stretches over nearly 70mins.
While the recording itself was compiled from three consecutive live sessions, listening to the full album appears natural and seamless. As is typical for performances of this nature, the music grows on you while it becomes more familiar, to the point where you can allow yourself to dissolve in the moment.
Although ‘Live at the Vintage Vanguard’ is completely instrumental, it is easy to enjoy the brief episodes of spoken English, listening to Christian introduce the band, or thank everyone for coming. The album closes with renditions of “Down by the riverside” and “Car wash” and manages never to be boring despite these familiar tunes. Great job and wonderful on vinyl. Enjoy.
Author: Karsten Hein
Category: Gear & Review
Tag: Power Amplifiers
Do you have a bucket list? I have sometimes heard and read of people who write up a personal list of experiences that they hope to have during their lifetime. I suppose, bucket lists include places to travel to and experiences to have, and—until a few days ago—I was not aware that I even had items to put on such a list. But, when I dropped by Luigi’s new apartment to listen to his current HiFi setup and he suggested that I give his B&K Sonata mono block amplifiers a try, I suddenly had a great sensation that an important item was being crossed off my list.
Ever since I first listened to an ST-140 stereo amplifier, I have been a fan of the B&K sound. Simple in their design, these relatively inexpensive amplifiers offer great musicality while being very articulate in their presentation. There is nothing careless or sloppy about their approach to music. And, if the 105 watts RMS per channel amplifier can drive even difficult speakers with ease, just imagine what the 200 watts RMS per channel M-200 mono block amplifiers can do. After all, there is something humbling in a dedicated 19.5 kg amplifier designed to power a single speaker.
Luckily, my car was not parked too far away that evening, so that carrying the equipment to it proved to be an easy enough task. Getting them up the stairs on my own later that night was another story, of course. While the amps have handles up front, the sharp cooling fins extend out the back, causing ugly marks on tables and racks. It is therefore much wiser to ignore the handles and grab the amps by the body to raise them straight up. To be honest, I actually prefer this amp design, as it supports passive cooling when the units are mounted in a rack. Since both HiFi and professional racks are usually open towards the back, having the fins in this position facilitates convection cooling.
In our living room setup, the two B&K M-200 mono blocks were to replace the ST-140 stereo amplifier by the same manufacturer and to drive our Martin Logan SL3 electrostatic speakers. This is not an easy mission at all, because of the Martin Logan’s hybrid design, featuring a conventional woofer that is matched with a Mylar foil electrostatic panel. The difficulty is the low impedance of the panel—of below 2 ohms at 20,000 Hz—but also handling woofer reactance with the panel in the signal path. The SL3s therefore need a powerful amp that will perform into low ohms and offers enough damping to steady the woofer. 105 watts are barely enough for this task, although the ST-140 does have massive reserves and with its huge caps and power supply is relatively unimpressed with the Martin Logan’s impedance curve.
As usual, I gave the ST-140 a good listen first, playing Jazz, Folk, and Gospel that I know well. The Martin Logans sounded large, relatively slow, and relaxed. As a two way system, with a low crossover frequency towards the bass, the sound is generally homogenous and smooth. The ST-140 in combination with the SL3’s closed cabinet woofer produces a full bottom end but does lack some punch in the representation of kick drums. The highs are pleasant but not too crisp. This may have to do with the felt pads that we use as spike coasters to reign in the sound for a more musical and less technical performance.
Changing over to the M-200, I first noticed improved stereo imaging. The sound was still large, but now it was more articulate and slightly more spacious. Not in the sense of wider, but here was simply more room around the instruments. The SL3s now appeared more naturally agile and more forward directed. When listening to Springsteen’s ‘London Calling’ concert, for instance, ‘Youngstown’ had that same immediacy to it that I remember so well from the live concert. Since I already know this DVD well, the ability to evoke such memories at the blink of an eye really says a lot about the quality of the amplifiers. With the M-200 mono blocks, the music found it easier to loosen itself from the speakers.
Bass performance was less boomy and more refined with slightly more punch on the kick drums. While this was still not the SL3’s strong point, I now understand that larger amps will help in blending the bass in with the panel frequencies. And there is another difference that I noticed while watching TV later that night. Namely, that cinematic effects sometimes seemed to be unnecessarily emphatic, as if the engineers had mastered the sound track for equipment that was less revealing.
I hope I will be afforded the luxury of being able to listen to these amps for a few days, before returning them to their rightful owner. Well done, B&K. The Sonatas are accurate and musical amps that manage difficult speakers with ease and have enough power to convince even the otherwise relaxed Martin Logans to step it up a notch.
Number of channels: 1
Power output (8 ohms): 200 watts RMS
Power output (4 ohms): 400 watts RMS
Total harmonic distortion: 0.09 %
Signal to noise ratio: 95 dB
Damping factor (50Hz): 600
Frequency response: 1 Hz - 100,000 Hz
Slew rate: 25 V / uSec
Power consumption: 800 watts max / 65 watts (idle)
Dimensions: (w)43.18 cm, (h)14.68 cm, (d)38.70 cm
Weight: 19.5 kg
(1987 - 1990)
Author: Karsten Hein
Category: Gear & Review
Where do I begin? Perhaps best with an apology. Because, up until this point, no other speakers had captivated my attention and imagination more than these little bookshelves. And, in my attribution of positive and negative qualities to these loudspeakers, I may not always have been fair. It actually took me quite some time to find this out, and, in the end, it took the whole journey to get to the truth of things.
We had originally bought the KEFs as unobtrusive bookshelf speakers to play background music in our home office. This was well before I began contemplating to set up a second audiophile system to use when the kids where blocking our main listening room. As usual,I had studied reviews on entry level bookshelves that punched above their weight, and KEFs were mentioned repeatedly in this context.
In our office they had to replace some ageing Denon bookshelves that were left over from my old F-07 midi system. Driving these was an entry level Rotel preamp and amplifier combo rated at 2x 60 watts. The match was actually pretty decent in retrospective, as the Japanese combo had been designed with the affiliated Bowers & Wilkins in mind and is said to be following the philosophy of ‘British sound’. This, to my understanding, is characterised by accuracy, tonal balance, and a warm midrange.
While the Denons with their soft dome tweeters had been forgiving of flaws and therefore easy to integrate, the KEFs immediately revealed the sonic weakness of our cheap glass and aluminium speaker stands. Hence, we replaced the stands with a simple DIY design (using 4 cm MDF boards) and immediately noticed a shift from a harsh and technical sound towards a more pleasing and natural performance.
Another aspect revealed by the KEFs was the lack in bass response from the listening room. Our office is situated under the roof of the building and has many acoustic disadvantages: slanted gypsum walls all around that absorb much of the lower frequencies, lots of hard furniture surfaces that reflect higher frequencies, and an extensive room depth of 13 meters with the listening position located at just 2.5 meters from the speakers.
In my attempt to make the KEFs sound well-balanced, I brought in a range of preamplifiers and amplifiers, spanning from Rotel, via Hafler, to Harman Kardon. But the KEFs, to various degrees, remained harsh and bright sounding. I looked at the Uni-Q driver’s sharply pointed wave guides and could not help but wonder whether KEF had somehow got them wrong. Just like I had found my earlier Canton Ventos to have accentuated highs, which, as I later read in a test, actually turned out to be true.
Unable to get the iQ30s balanced in our office, I gave them to my brother for listening and switched to Tannoy DC 6t tower speakers instead. With an additional dedicated bass driver, the Tannoys offered more direct bass punch and sounded more balanced at short distance. Yet, on listening to the new speakers for longer, I realised that they, too, were struggling with the size and structure of the room.
Last week, I received the KEFs back from my brother. And—as during their absence I had started wondering if there was not something I had missed in setting them up—this time I decided not to take them to the office upstairs but rather to hook them up in our main listening room. To be honest, my expectations were not too high, as their rivals downstairs are not some old Denon bookshelves but rather the formidable Martin Logan SL3 electrostatic speakers.
I started out by playing a few songs on the Martin Logans. Jazz and Folk that I know well and enjoy listening to. Then I switched to the iQ30s, half expecting to have a big laugh. Surprisingly, this is not at all what happened. The KEFs set in at similar volume and almost identical sonic characteristic, so that at first, I looked over at the Martin Logans in disbelief. With the tweeter on axis and the wave guides to cast the highs deeply into the room, the KEFs displayed a similar energy and authority when setting the stage.
The SL3s strength lies in the accuracy and subtlety of voices, the iQ30s play voices well, but do not reach that same level of subtlety and intimacy. And yet, they come very close. If the Tannoys love piano keys, the KEFs caress the guitar. Nils Lofgren’s playing was thrust into the room much like I am used to from listening to the Martin Logans. Notes linger a little shorter on the KEFs than on the SL3s, which is no wonder considering the exceptional lightness of the Martin Logan’s Mylar membrane.
The KEFs now sound balanced in our main listening room. None of the former harshness is still present, so that listening for long hours is now highly enjoyable. Bass is full and present and at times even punchier than on the SL3s. However, when it comes to playing very low notes, these are still present on the Martin Logans and simply missing on the KEFs. This should not come as much of a surprise, considering the 30 cm woofer size on the SL3s as opposed to a small 16 cm full range speaker on the iQ30.
The KEFs present a wonderful stage and—like the Martin Logans—can play loud as well, creating a wonderful live atmosphere. The Martin Logans can play louder, of course, but personally I never listen to music at volumes where this would really matter. Considering the size of the KEFs, their ability to fill the room is a respectable. Doing so with accuracy and authority to take on much lager and more expensive floor standing speakers is incredible. Hence, my apology. When the KEFs did not perform well at first, it was obviously not a design flaw of the speakers. It was the room.
Author: Karsten Hein
Category: Audiophile Music
I first came across the singer and songwriter Sandra Mac Beth listening to her song ‘8 Ball’ on the ‘Uncompressed World Vol. II - Audiophile female voices’ sampler. The song immediately stuck a cord with me, because of the high quality of its recording, its warm and insistent piano tones, and because of Sandra’s voice that startled me in its rawness, clarity, and warmth. The song did not appear to have have any of the smothering effects so common to modern recordings and, as such, was very pleasing to my ears.
I set out to find out more about the artist, because I was hoping to listen to more of her songs. Yet, for some reason, none of my usual sources of music purchasing and streaming produced the desired result. I also watched some YouTube clips of Sandra’s, but since these were lacking the desired quality and even material, I decided to write her an e-mail and ask her to send me a copy of the album that ‘8 Ball’ was originally on.
Sandra wrote back to inform me that her album ‘Conjugal Scene’ included ‘8-Ball’ and was available on Apple Music—which I have not subscribed to—and that she could send me a copy of the album and a more recent long player on CD from Scotland, to which I happily consented. The little envelope holding the CD and long player arrived just a few days later, and I was happy to find that about half of the tracks are of similar quality and attraction as the song that had led me to my search.
There is a marked difference between the earlier tracks, which are of average recording quality and the tracks around ‘8 Ball’ which sonically really open up into the room and manage to carve out that purity in the voice that is so hard to come by. This has lead me to the idea that I would ask her for an interview with me on Music & Talk. Quite audacious at this point in time. Obviously, much more needs to be done, before I am ready and able to provide the setting online, but…I have already started ‘exploring’ the possibility. And that is the motto of this page.