Dear Get Better Sound readers,
Welcome to the fifth issue of Quarter Notes!
Quarter Notes is a quarterly newsletter for Get Better Sound readers, expanding on the Get Better Sound manual, as well as introducing new and timely subjects. From time-to-time, we may have a guest writer on a special topic.
For this issue, I’ve asked David Aiken, an Aussie who is known and respected for his helpful replies on Audio Asylum, to write an article about room treatments. He did, and I’ve posted it below. Thanks, David!
Also in this issue, I spend some time answering various reader inquires, as well as offering an article about ACK.
In addition to addressing some basic issues, I’m introducing a “What if” concept that I call Stacking the Decks with DEQX.
Don’t forget, you are invited to e-mail me with your questions and comments. If appropriate, and with your approval, I may include your note – or a reply to it – in an upcoming newsletter.
Best e-mail address
Since you’re reading this, the e-mail address that I used to notify you must have worked. However, the only e-mail address I have is the one associated with your initial Get Better Sound order.
If you have an e-mail address that you’d prefer to use to receive Quarter Notes notifications, send it to firstname.lastname@example.org. Be sure to list the month of purchase (if possible), and definitely include the address I used originally along with the one that you want to use to replace it.
The ACK Attack and Un-common Knowledge
In English-speaking circles, the term “common knowledge” refers to a thing that everyone knows, or at least, should have known when searching for the cause of some wretched decision. As in, “I cannot imagine why she ran away with that poor excuse for a man. It’s common knowledge that he is a drunken lout!”
In audiophile-speaking circles, it’s a different thing altogether. I’ve always called the phenomenon “Audiophile Common Knowledge.” It’s the same stuff we’ve heard for years and years.
Although they may be without any basis, or the basis for their truth requires a number of unlikely concepts to line-up, these myths have become almost legendary. For the purposes of this discussion, instead of Audiophile Common Knowledge, let’s use the acronym ACK.
The Problem The problem with ACK is that it prevents many audiophiles from attaining what is rightfully theirs. That’s because ACK keeps audiophiles from taking the basic steps that can dramatically improve their systems.
Some of the biggest sources of ACK are the various Internet audio forums/message boards. OK, maybe not the forums, but the inhabitants thereof.
By the way, it’s not those who ask legitimate questions that concern me. Although I’m still not sure why anyone would take the advice of a complete stranger on the Internet. Especially when said advice is – all too often – completely wrong, or at least, improperly presented as the first avenue of action.
Surely, ACK that is delivered with such self-assured righteousness must be true! But is it the ACKtual truth?
Self-styled experts It’s the self-styled experts that are worrisome. They indiscriminately dispense a load of ACK, as if they actually know something. It must be said that sometimes there are pearls of wisdom to be found. But all too often, the pearls are hidden in a pile of ACK.
In their defense, they’ve heard these ACK myths for so long that they (1) believe them to be fact, and (2) they actually believe they are dispensing good advice.
Honestly speaking, I didn’t realize how pervasive – or damaging – ACK really was until I spoke to an audiophile group/society last year. I had prepared an interesting presentation. But I never got to make it, because ACK comments kept coming up.
The time flew by as cherished audiophile “facts” were challenged. Much to my surprise, debunking these myths produced a lively interactive meeting. The debate was fun! Most importantly, a few days later, I received numerous positive comments from various club members, as they tried out my Uncommon Knowledge suggestions.
A similar thing happened at a Seminar on System Optimization that I conducted recently. Veteran audiophiles just didn’t want the discussion to end, once they found out that many of their cherished beliefs had been hindering their sound. And they heard a few simple Tips to improve their systems that they hadn’t previously considered, because they didn’t line up with ACK.
ACK responsible In my experience, ACK may be responsible for doing more harm than good. Here – in no particular order – are some ACK favorites – myths that have developed into Audiophile Common Knowledge:
Rooms with non-parallel walls sound better.
The “rule of thirds” is a great set-up guide.
Cathedral ceilings provide great sound.
A wide sweet spot is best for great sound.
Bass is non-directional, so exact woofer placement and orientation isn’t critical.Bass is non-directional, so only one sub is required.
The best speaker drivers must be low-mass.
A “fast” bass driver is superior to others.
The best sounding systems are dead quiet.Granite makes a great isolation material.
Cones & spikes provide isolation.
Wide dispersion is desirable for consumer audio loudspeakers.
An equilateral triangle (speakers and listening seat) set-up yields great sound.
The best bi-amplification is done with transistors on bass, tubes on top.Achieving the tightest bass should be your goal.
Speaker set-up diagrams/guides from various manufacturers will provide the best sound.
There are several known “good” listening room sizes/dimensions.
Building a new listening room with a good spread-sheet program will provide great sound.
If you’re past 50, you can no longer hear well enough to really care about your sound quality.
And others, equally as revered, and equally as questionable (once you know the facts).
Of course, as a GBS reader, you already know the real insights on most of these ACKisms….
Basics re-visited - a little more info
I continue to be amazed at how often these questions come up from readers. So I thought I’d give a bit more insight into them, but briefly, as we are out of space for this issue. If it appears necessary, I can expand more on them later.
Why do I need subs if I have full-range – or near full-range – loudspeakers? You don’t necessarily need subs. But more often than not, where you end up placing your loudspeakers, no matter how large and costly they may be, may not be the best location for bass and for soundstaging. It’s usually a compromise and we all make them every day. Having subwoofers can allow you to have the best of both worlds. For me, it’s not so much about better bass, but about the uncanny realism that arrives from a palpable space produced from enhanced low frequency cues.
Sub polarity vs. mains – how do I know which is the best phase? First – and most important - You should ALWAYS listen to the phase options on your subs. Of course, if you run one at 180 degrees, then you have to run the other at 180 degrees also. The best position will yield a more solid (upfront) sound for instruments and even voices that are near the crossover region. The least correct setting will yield a hollow and recessed sound on these same instruments and voices.
Speaker separation and staging – speakers set up equal to or wider than an equilateral triangle in relation to your listening seat…
I covered this in the GBS manual, but here is another way to consider it. I’ve said that wider spacing gives even more precise imaging, at the expense of tone.
Also, there is an issue with depth of field. Wider spacing can yield tremendous depth, with the front instruments or voices beginning at or slightly behind the plane of the speakers.
Something less than an equilateral triangle (such as my arbitrary 83%) can produce the same apparent distance to the back of the sound field. The difference is, as you bring your speakers closer together, the instruments and voices in the front start to appear even with - or more likely, a little forward of - the plane of the speakers. The sound – IMO – is more intimate and involving, not to mention more realistically portrayed as a believable soundstage. The tonal quality is icing on the cake. But this one is a matter of taste – yours, not mine.
Long wall or short wall? The long and short of it is that I usually prefer short wall placement, assuming that the short wall is wide enough.
Long wall placement can work extremely well, and some rooms – due to their geometry – work better that way. But I think there is more flexibility in short wall listening seat placement. As you know, this is of utmost importance – it’s foundational in being able to achieve an ultimately satisfying and compelling sound.
Affordable RTA Wow, this might be one of the most often asked questions, even though I classified the RTA as a semi-pro tool!
While I always say that I have to have personally used anything that I recommend, there is one that, from what I can read – should be a useful device. It was recently reviewed on 6moons.com. If you’re interested in a less expensive RTA (when compared to the semi-pro units that start at $1,000), check this one out:
Absolute phase/polarity – Here’s another one I get asked about.
Try to say “phase” or “polarity” as you exhale. Then try to say it as you inhale. That indistinct sound when you inhale is an exaggerated demonstration of reversed absolute phase.
The best polarity will have a more pronounced leading edge. A little more dynamic. Voices sound a little more present.
However, MANY speakers are designed with drivers in reversed absolute polarity – say, the mid is in reversed polarity to the bass and treble. These speakers obscure the effects of absolute polarity. And some systems don’t have a simple polarity switch. I am referring to the entire system, not a sub-woofer.
If you can hear it and you have a switch, by all means, make use of it.
If you can hear it but you don’t have a switch, just forget about it. That’s what I’m doing right now as I listen to some prototype products for a manufacturer. The recordings are too variable in absolute polarity for me to get up and swap speaker cable connections every time I put on a new source with a different recorded polarity.
If you can’t hear it and you don’t have a switch, just relax and enjoy your music!
Sliding base for spiked speakers Spiked loudspeakers are a major pain to get placed in just the right spot, whether on carpet, wood, or other surfaces.
With heavy spiked speakers, get a board or granite slab to enable sliding them around on your carpet. Consider countersinking the holes.
Also - on hardwood or other hard floors, use a carpet with spikes that sit into metal pieces on a small area rug that you can slide around. Or get small hard plates that can slide. With a slab, board, or plate, put felt spacers on the side that meets the floor. They help sliding and they prevent scratches.
Also, check out the accessories from Herbie’s Audio Lab: http://herbiesaudiolab.net/stud.htm
Rack in the middle – AGAIN! Sheesh!!!
This is such an improvement for so little money.
I tell people that I’d prefer the sound with the rack on the side with Home Depot hardware department 16-gauge lamp cord to the rack between the speakers with ANY exotic cables! It’s not even close. So do it already!
Unless of course, you can’t…
Spikes – AGAIN! Spikes are NOT isolation devices. They are tuning devices. They will always “lean out” the sound. True isolation devices will yield a fuller, more realistic sound with better dynamics (critical for maximum musical involvement).
That’s not to say that you can never use spikes. In fact, they are on a prototype pair of speakers that I’ve been evaluating. Although, if they were mine to keep, I’d replace the spikes…
No really bad products – only bad optimization of them We see comments on message boards about real clunkers. But I never see them.
As I’ve voiced various readers’ systems, I’ve come across a huge variety of components. Never had a problem making their systems “play the room” and provide deep musical enjoyment. Never replaced – or recommended replacing – one single component.
So does that mean that all components are created equal?
Nope. It means that given half of a chance, a lot of so-called “clunkers” aren’t.
Stacking the Decks with DEQX
When I wrote my question about the validity of room equalization in GBS, I was referring to the classic full eq programs that we’ve all heard – or heard about.
Frankly speaking, they didn’t hold much interest for me, for a number of reasons.
However, there is a new product that addresses much of what has been ignored to date. Although it’s been around for a few years, the latest iteration has captured my attention.
It’s the DEQX HPD-3. This latest DEQX (pronounced as “decks”) technology not only addresses some issues in the digital domain that can profoundly affect the sound of our systems, but it’s actually been improved in the analog stages as well.
The first way that I always want to test a device is to compare it with no device (bypass), or if it exists, the device I’m thinking of replacing. In the past, the earlier DEQX analog stage was pretty good, but you could hear the device in the circuit, even when it was set for flat response and no correction of any kind. Even then, the question was, is the potential outcome good enough to overcome the downside of having it in the circuit?
For purposes of full disclosure, I had the privilege of working with a review sample of a speaker manufacturer’s system in 2006 that employed the earlier DEQX system. I have to say that it was one of the top systems I’ve ever heard. Certainly in the top two or three - at any price. Yet it was much lower in price than the usual speakers we think of that are in the top echelons. The sound was uncannily alive and realistic. However, the company ultimately failed for typical business reasons, in spite of the promise of the product.
In my opinion, the principal sonic performance advantage of DEQX is gained basically from working with fundamental loudspeaker issues. Yes, there are some things that you can do with rooms, many of which we are already doing, but I want to address the biggest offender in any system of components – the speakers. The typical errors in speakers (time, phase, distortion, frequency response, etc.) are on the order of at least 10 TIMES greater than the magnitude of errors in any other components!
And some of the biggest offenders in speakerdom are some of the most expensive and well-known brands. And for the first time, the problems that these manufacturers don’t even want to discuss can be solved, transforming a very good speaker unto an entirely more dynamic, more alive, and a tonally more correct reproducer.
Tonally more correct, not due to any speaker eq adjustments, but because for the first time, harmonics arrive in proper relation to their fundamentals. Instruments and voices sound amazingly more lifelike.
So, although it has sophisticated room eq, and I might have some interest in it below 300 Hz, it’s the loudspeaker correction tools that can make a significant difference. Since I have been associated with several brands, but one in particular, for purposes of this discussion, I’ll discuss it.
One of the issues that always bothered me was the complete lack of time alignment of the Avantgarde speakers. I fooled around on my own, trying to come up with a way to mechanically adjust the distance of driver cylinder setback to correct for it. But (1) it was ugly, and (2) moving the cylinders around in the their front-to-back relationships allowed nasty reflections to occur as a driver’s wave-front would be interfered with by the lower frequency horn.
Don’t get me wrong. I loved those speakers. And apparently the press and audiophiles did as well, since we won Best Sound of Show Commmnerts 5 out of 7 times.
But what if there was an elegant solution to their problems? A solution that didn’t require a klutzy re-alignment and placing of the various drivers? A solution that could remove certain residual colorations and other effects as the entire harmonic envelope is delivered intact for the very first time.
Here’s a quick analogy. Could you hear it if the bass and treble arrived at roughly the same time, but the mids arrived an hour later? OK, that’s a silly comparison, but it proves the point. Improper alignment, no matter what the phase may be, is audible. It’s not IF we can hear it. It’s WHEN we can hear it. Put another way, at what point in time does uncorrected time delay become audible as a smearing of the sound?
To quote DEQX, “using DEQX Calibrated™ correction, measured errors caused by loudspeaker drivers, loudspeaker cabinets, signal electronics and even DEQX’s own analogue electronics, as well as room acoustic problems are significantly removed. DEQX correction results in a more natural and ‘realistic’ performance because the sound arriving at the listening position more accurately represents the originally recorded audio than has previously been possible, even in expensive audiophile systems.
A DEQX corrected system typically demonstrates improved three-dimensional resolution and an accurate harmonic balance when the full suite of DEQX processes are implemented with suitable loudspeakers. DEQX can provide the elusive audiophile ‘being there’ experience for a fraction of the cost of high-end systems. Even so, DEQX provides further performance gains when using audiophile grade source media and electronics.”
There is much more I could say, particularly about the applications of active multi-amplification, bypassing compromised passive crossovers altogether. This technique yields another level of dynamic and instrumental realism, but it’s not inexpensive.
I’ve said all this for two reasons:
As a test, I’m going to be working with one of these units on an Avantgarde TRIO system that I’ve personally designed, voiced, and maintained for several years – a no compromise system that includes three BASSHORNS per channel. The system – as it currently is configured – sounds fabulous. If the DEQX is any good (and if I can become good at running its exceptionally complex program), it should be able to address the inherent design problems of the Avantgardes and take them to even higher levels. I’m also skeptical enough that I want to see if the promise can actually be fulfilled in such a system. If it can, then there are thousands of systems that could benefit from a proper DEQX installation. For this test, I am purposely NOT going to multi-amp and bypass the TRIOs’ crossovers. After all, most folks couldn’t go the full active amplification route. Furthermore, as I envision a DEQX voiced system, it will have to have been previously voiced to its ultimate performance before introducing the DEQX. I see the DEQX as a potential major enhancement of a properly voiced system, not as some band-aid that can never really overcome unnecessary obstacles. I think the story of what happens could be of interest to many of you, not necessarily because you should do it right away, but because you probably love this stuff as much as I do!
I’m interested in your thoughts about this concept as I enter into it. E-mail me with what you think.
Demystifying Room Acoustic Treatment
By David Aiken
If you hang around any of the audio bulletin boards, you’ll see a lot of talk about room acoustic treatment. All sorts of questions are asked and - unfortunately – all too often there are several different answers given for any one question.
So how do you decide? In this document, we’ll demystify the subject and hopefully reduce the natural confusion and frustration that can arise when you’re faced with differing opinions from so many self-styled experts.
What we hear when we listen to music, whether in a concert hall or at home, is a combination of direct and reflected sound. Direct sound travels in a straight line from the source of the sound (whether it’s a performer or a loudspeaker) to your ears. It arrives first. Then, the reflected sound arrives, having traveled further around the hall or room. It takes longer to arrive because it has been reflected one or more times before it reaches your ears.
Some aspects of the nature of the sound we hear depend primarily on the direct sound while others also take into account the nature of the reflected sound. A primary reason that different rooms sound different is often mostly related to differences in the characteristics of the reflected sound. After all, there may be only small changes in the nature of the direct sound because of the differences in the length of it's travel path.
There are, however, much greater differences in the character of the reflected sound from one room to another since various surfaces reflect sound differently. Plus, varying room dimensions alter the frequencies of the natural resonances which occur in an enclosed space.
In Get Better Sound, Jim places a very strong emphasis on setup, on locating the speakers and listening position for best effect. The reason changing the location of the speakers and listening position makes such a huge difference is because changing the proximity of speakers and/or the listening position to the walls changes the relative level and tonal character of the reflected sound. On the other hand, changing the listening distance primarily has an effect on the direct sound.
These setup changes alter the mix (the ratio) of direct and reflected sound that the listener hears. However, there are limitations to how much that mix can be changed simply by setup.
Acoustic treatments allow us to make bigger changes in that ratio, and especially to change some things that setup alone can’t always change as much. This would include making the tonal character of the reflected sound closer to the tonal character of the direct sound, so that the reflected sound doesn't change tonal balance by making things sound too bright or too dull. Although you may not need to acoustically treat your room in order to make it suitable for listening to music, it can certainly help you to achieve a sound quality that you will find more pleasing.
There is also no one single way in which to treat a room. Rooms can be treated in different ways with quite different results, which is why quite different advice is often given on room treatment. Not everyone wants the same results and it’s easy for people giving advice to forget that not everyone agrees on how things should sound.
So what is involved with acoustically treating a room? The chances are that you may have already been doing some level of room treatment, perhaps without even realizing it…
It’s simply a matter of placing various objects that either absorb sound or diffuse sound (spread the sound over a wider angle than it would otherwise spread) at certain locations in order to get closer to the sort of sound you want. If you’ve noticed the sound in your room change when you open or close curtains, or when you change window coverings or furniture, and you find yourself opening or closing the curtains or moving the furniture around a bit when you listen, then you’ve already started acoustically treating your room!
You might start by reducing the amount of hard reflective surfaces in the room or covering them, perhaps by increasing the amount of absorption in the room by adding curtains and/or floor coverings or a bookcase full of books. These are all forms of room treatment - even though they may be simple steps - that you can adopt in any room.
You don’t need to race out and buy bass traps, acoustic panels, and quadratic residue diffusers in order to treat a room. It’s often possible to make significant improvements in the sound you’re getting simply by redecorating or refurnishing your room and still have it look like a normal living room. In fact it will still be a normal living room, but now it’s one that is more acoustically satisfying to you.
What the best commercial products and their DIY equivalents do is let you get a more powerful effect and/or a better tonally balanced sound from the same area of treatment than you will get from curtains and the like. Of course, some things can't be achieved simply by changing room furnishings.
The biggest problem with acoustic treatment products is that they usually don't fit into a living room all that well; they’re big, they’re obvious, and they tend not to match the furnishings. Let’s face it - aesthetically, they’re often extremely unwelcome in the living room!
However, with careful colour matching as well as choosing or building products that aren’t too large, it can be possible to place some commercial products or their DIY equivalents in a room without having them stand out as an eyesore. Of course, this sort of product usually isn’t a problem in a dedicated listening room where you may even want to make a visual feature of them, something you would never consider in a listening room.
If you decide to do something about acoustic treatment, it’s your choice whether you want to simply rely on how you furnish your room or if you want to go further and use specific treatment products. And you’ll need to decide just how far to go with whatever approach you decide on.
Whatever you choose to do, paying attention to what you hear and what you would like to hear plus giving a little attention to the fine details of what you do will always help you achieve better sound. (Note from Jim – When making these decisions, my first consideration is whether or not the human voice sounds natural in the room).
Just remember that before you start treating a room, you do need to spend some time thinking about why you want to treat the room and what kind of result you want to achieve. What you need to do in order to achieve different sorts of results is outside the scope of this brief overview. However, just as the right changes in system setup can make your sound better and the wrong changes can make it worse, there are ways to treat a room which will get you closer to the type of sound you want to achieve and other ways which will take you further away from that sound.
The bottom line? Room treatment is not an automatic improvement, but done right, it can create a more musically compelling experience in your home.
[Note: Although I fully agree with David, I still caution folks to be careful that you don’t over-treat your room. However, I must admit that I have often over-treated my own rooms, and then realized that I had gone too far. In that respect, it can be comparable to focusing a lens.]
That’s about all I can fit in this Quarter Notes. Hope you found it helpful, or at least interesting.
Please write with any questions, comments, or suggestions. See you next time!