edwinr Posted March 29, 2005 Share Posted March 29, 2005 ---------------- On 3/28/2005 2:40:29 AM dragonfyr wrote: Why not find out exactly what is occurring and deal specifically with the issues at hand? You may find yourself rather surprised at the diagnosis and remedy! ---------------- Good point you make, dragonfyr. It's like having a car with a flat tire. You can tune the engine, fit new seat covers, even polish out a few dents in the bodywork. But until you change the tire... Quote Link to comment Share on other sites More sharing options...
dragonfyr Posted March 29, 2005 Share Posted March 29, 2005 A couple of comments as there are many tangents running here... May I be so bold as to 'ignore' the issue of specific technologies, especially DSP, that claim to operate in the time domain! I am NOT endorsing, in fact I tend to disagree with many if not most of the products tending to market themselves as operating in the time domain. Making claims and being based upon analysis in the time domain are two different things!!!!! And I tend to resist any of the 'processed' sound claims.... (After all, a simple but valid criticism here is the 30 year old issue with the Bose 901, a HEAVILY processed system! I defy anyone to obtain meaningful 30-40Hz output from a 3 inch driver! And synthesized harmonic output simply doesn't cut it! Much like the heavily touted (upper frequency) aural exciters of the early 90's)...but I so easily digress! I guess what I mean is that I am not here to sell anyone on some product that labels itself as some time aligned salvation! I speak more of the fundamental analysis techniques and their ramifications within the audio/acoustics realm. For now, I would prefer to focus on the fundamental of signal interaction within the time domain, and from which so many of the 'stuff' that we focus on in the frequency domain is a direct result of time domain interaction. And while we may observe them from the point of view of the frequency domain, you cannot resolve them in this domain! You must go back to the time domain and deal with the time based signal interaction, from which, when this is resolved, the frequency response anomalies, as if by magic, disappear! Once behavior is understood in this domain, all sorts of heretofore issues are solved, and all sorts of new causal relationships exposed and challenges & opportunities present themselves! The problem we face right now is in jumping too far into the middle of specific effects &/or products without understanding the basic foundation! (And I am perhaps more prone to this than others!!!) If you will pardon my analogy, it is as if I were to suddenly explain & illustrate how Laplace transforms provide a shortcut to solving differential equations. While valid, it begs the point if one does not understand the basic concepts of differential calculus. Even with such insight, most of the resulting questions and confusion result not from issues with the Laplace transforms, but from a basic misunderstanding of 'simple' calculus. It would be prudent to step back and examine the fundamental concepts of sound within the time domain. And it is indeed a major paradigm shift! The rules and perspectives change, and the questions asked are altered as well (said Alice, as she entered into a world where the rules (logic) changed!;-) So, in this case, I think it is a mistake to jump too soon into trying to examine individual claims of products that have seen it prudent to attach a "time domain" label to them for the sake of trendy marketing. Does this make sense? But once the precepts are well understood, i think that you will see why it becomes so easy to avoid many of the debates that rage so commonly! As it is not at step 27 that the problem occurs, but in the initial question and the assumptions which condemn the approach! (Oh, and I am not trying to disparage any particular product either! But, I don't see the real benefit of a valid design needing to attach any label to itself such as frequency or time domain based! It seems redundant to me (and begs the question!) to say that a speaker is accurate in the acoustical spectrum or that it utilizes acoustical principals! Duh! ;-) So.....where does one begin? As far as classes, the best sip from the fire hose that I can suggest are the Synergetic Audio Concepts (SynAudCon) seminars. If you take the two most comprehensive components they last a week. You will be taken on a theoretical and very practical applied tour of sound in the time domain, along with its corollaries in the frequency domain. It is comprehensive and you will emerge, like in the Calvin & Hobbes reference, seeing all sorts of possibilities and with having so many old nagging issues simply dissolving as if Wittgenstein was your tour guide! (sorry for that obscure reference!) SynAudCon was begun by Don & Carolyn Davis and has been assumed by Pat Brown. The amazing thing about this collection of associated audio luminaries is their willingness to share insight, research and it extends even to social functions. And while unknown to many, their seminars are frequented by folks whom moist of you would be amazed at meeting, let alone being able to individually discuss issues with. Heyser(deceased),DB Keele,J Prohs,E Patronis, B Howse, Anhert, R Berger, Berkow... (and yes, Paul Klipsch was a CLOSE associate of these folks, especially DBKeele and the Davises!) You name it and MANY more! - And all the principles from the major design firms, etc. routinely associate. And the benefit is that you become introduced in a very practical way with the cutting edge research and concepts that are being actively developed and shared. And not only that, the entire organization is oriented toward networking and sharing their knowledge! They feature a list serve where any question can be posed and you will be amazed at whom may respond! The entire organization is simply one designed to develop and share the research that is being conducted even as we speak. It is an enlightening and a humbling experience rolled into one. But I apologize if I sound as if I over-hype this association! But I know of no better way to become introduced to the concepts that define the current audio/acoustics landscape - and your perspective will never be the same! Oh, and by the way, it has been a remarkable experience to have attended the Loudspeaker Design Seminars from the late 80's to the present and to have watched it grow from a handful of luminaries, to the monstrous affair it has become! And yes, the Klipsch engineering principles were also there from the early days! (Now, if we could ONLY get Klipsch to address the alignment of the acoustical centers of the heritage and pro lines!!!! And why not a co-axial alignment of component horns to eliminate the off axis cosine error inherent in the current designs!?!?! Sorry!!!!) Even Bose has FINALLY come over! (Despite the fact that you can't see any real impact on their designs! But at least they aren't adding any new direct/reflected systems to their product line! Perhaps they are simply curious as to what all the fuss is about!?;-) Sorry, even I cant resist! ) What is also amazing is to watch the individuals & companies that have begun attending and to see the lag between their awareness of the concepts and the implementation and incorporation of said concepts into their products! - some faster then others! (I can only imagine Dick Heyser and Richard Feynman (and others!) sharing a beer as we speak, smiling and shaking their heads as they observe us trying to understand that which was so clear to them!) Also, membership in SynAudCon also provides a technical topics newsletter which is full of practical information each month. But I guess I sound like a salesperson for SynAudCon. I wish I qualified for a commission ;-) But they have been the spearhead of the new technological breakthroughs in the industry, and while you may not be aware of the organization, merely stop by their suite at any NSCA event and marvel at who stops by! It will be a who's who of the principle movers and shakers in the industry! And they all like to share their insights! Now, regarding products... Alot of folks have become interested and introduced to concepts and have attempted to bring said principals to bear on problems. Does this mean that every solution, regardless of the concepts employed is valid and mature? I wish!! And it doesn't stop folks from simply attaching labels to products regardless of their appropriateness or validity! After all, a prime case of this is Monster with their time aligned and frequency balanced cables! Believe me, long before you folks became aware of these issues, others were taking them to task for the physics principals they bastardized! After all, isn't a cable/circuit that results in different frequency signals going down different conductors more properly called a crossover? And I guess that for all these years we have simply been using all those extra components simply to stimulate the economy and keep other folks employed! (On the other hand to be fair Monster cables are not bad per se! Over priced and marketed with spurious claims, yes! But they are not bad connectors!) So, may I suggest that you remain a bit skeptical whenever you see the "time aligned" label attached to anything! (Besides, as Don Davis so often pointed out, you don't align time! You align signals within the time domain! ;-) But several primary tools for quantifying and qualifying phenomena in the time domain, and subsequently the frequency domain (and via Hilbert and associated transforms other domains...). These allow an examination of phenomena within the various domains, and allow fro a mapping of one domain to another so that the effects in one domain can be seen and understood more easily in the associated domain. The holy grail of these techniques is TEF. Other mechanisms, with various strengths and weaknesses exist as well. MLS (Maximum Length Sequence)/MLSSA, SMAART, SysID, and others. There also exist several quasi-tools that I will refrain from commenting on, as I am (and many others are) NOT convinced as to their validity. A far as any signal processors that claim to operate in the time domain other then precision digital delays; well....I will reserve judgment on an individual basis! But suffice it to say that I would not spend my time looking for a magic box! As far as an all in one introduction in book form, aside from Dick Heyser's AES Anthology mentioned above(and no!, don't expect to breeze through it!) I would suggest the comprehensive Sound System Engineering by Don & Carolyn Davis. But nothing will supplant attending the SynAudCon seminars for a comprehensive introduction to the principles. Now - as if I haven't rambled enough!!!! As far as room analysis goes, a TEF will quickly identify the factors, reflected signal paths, etc. and quickly allow you to isolate the components that when addressed properly, will result is a correction or moderation of the complex interactive system. Once the arrival times of the various direct and reflected signals are 'well behaved', then all sorts of classical problems will 'resolve themselves' and also allow may heretofore desired options to be performed. Just remember, the issues we face are multifaceted and multilayered! We face these issues not only in the electrical domains, but in the transducer-transducer relationships, the speaker-speaker relationships, and in the room-speaker relationships. We haven't solved them all! And as such there are tradeoffs that must be made in each. Establishing a reasonable risk-benefit analysis is still a real issue! But there are some easy priorities that may be generalized. Wow, not that I have opened this can of worms I am not sure where to go ;-) For the radical skeptics, or those who are simply desirous to see a few seemingly magical demonstrations of the profundity of some of these concepts I can suggest a couple of very simple yet powerful demonstrations. I guess I will find out by any replies to this post here or in private. I am glad to try to address any questions folks may have, as well as I can (as I do not claim to know all!) I just know that the questions I ask have been forever altered with my perspective! But one thing I would be very open to doing is to generate complete TEF response plots for the various heritage and pro units. Even the various couplings of units, as the results are often radically different than anything that you might have expected. These plots are already available for many array types ranging from all of the various line arrays to the Bessel array (an UTTERLY FASCINATING configuration possessing such benefits that I am amazed it does not consume many members attention!) But armed with this information, modifications are much more easily targeted to REAL problems, and their real effects quantified in a correlative manner with actual subjective experience, and room anomalies are identified and appropriate treatments (and their affects) easily determined. And no, for all of you who still desire to actually listen to a system rather then to simply live in front of a computer, these do NOT replace the actual experience of listening! At least not in my world! But the proper tools sure do make it easier to identify and focus in on specific factors that exhibit real correlative factors to enhance that experience... So... I will shut up for now... I thank you for your indulgence, and I hope that I have stirred the pot in a constructive manner - hoping that I have encouraged some to ask good questions while ALWAYS retaining a healthy skepticism! ;-) Quote Link to comment Share on other sites More sharing options...
dragonfyr Posted March 29, 2005 Share Posted March 29, 2005 D@mn I hate posting something and them going back and seeing all of the bone head typos and grammatical errors! Quote Link to comment Share on other sites More sharing options...
DAX616 Posted March 30, 2005 Author Share Posted March 30, 2005 I put aurelex mega lenrds in the corners above the Khorns. It sounds good cleaned up the base. Quote Link to comment Share on other sites More sharing options...
formica Posted March 30, 2005 Share Posted March 30, 2005 Dragonfyr... Ok, i'll bite since no one else posted a follow up. With only 56 posts, you obviously have quite a bit more knowledge that you are offering to share. ---------------- On 3/29/2005 8:42:12 AM dragonfyr wrote: But several primary tools for quantifying and qualifying phenomena in the time domain, and subsequently the frequency domain (and via Hilbert and associated transforms other domains...). .... The holy grail of these techniques is TEF. Other mechanisms, with various strengths and weaknesses exist as well. MLS (Maximum Length Sequence)/MLSSA, SMAART, SysID, and others. There also exist several quasi-tools that I will refrain from commenting on, as I am (and many others are) NOT convinced as to their validity. ---------------- I have heard of SMAART and EASE and experimented a little with MLS... but I'm unfamiliar with TEF and it's science and advantages. Since we are already off on a tangent here, I think it would be appropriate and appreciated to continue in a new thread in "Technical Quesstions" to discuss some of these principals. I'll even start the thread... TEF analysis versus using the more typical MLS Rob Quote Link to comment Share on other sites More sharing options...
dragonfyr Posted March 31, 2005 Share Posted March 31, 2005 Just a quick statement that might help clarify things just a little ... TEF is a platform (whcih is an acronym for Time Energy Frequency) that arose directly as a result out of Heyser's research and Techron-Crown's assistance. Goldline subsequently 'acquired' the TEF division from Crown. TEF runs TDS - time delay spectrometry as well as MLS and provides significant post processing for a great many functions. The primary distinction between the two is that the TEF running TDS is immune to ambient noise (you can run a sweep during a championship ball game or auto race!) while MLS and others are extremely sensitive to ambient noise. Thus with the TEF, you have a plethora of great tools at your disposal! Quote Link to comment Share on other sites More sharing options...
dragonfyr Posted March 31, 2005 Share Posted March 31, 2005 I tend to (erroneously) use TEF and TDS as synonyms! I fear it is a common practice with many! Quote Link to comment Share on other sites More sharing options...
phatbass Posted April 17, 2005 Share Posted April 17, 2005 To answer the original question. I think your bass in the kitchen problem will still be there regardless of bass traps in the room. You would want some mass loaded vinyl on the ceiling, then maybe two layers of drywall with a resilient channel. This would be the first start towards stopping the bass. Mass loaded vinyl could also be put under the flooring in the kitchen. After you do this you would also want to seal any air gaps in the listening room (ex: weatherstrip the door). Now if you would like to make the bass in your room sound better, get good bass traps. Something like a membrane absorber or Mondo traps from Real Traps (see link below). Put a few of those in your rooms corners and the bass will sound amazing. Just take a look at the absorbtion coeffiecients. Also if you email the guys at real traps they will always give some good advice. Or you could build a membrane absorber, which is slightly more difficult but also fun. Just measure the modes and nulls before you build one, because certian sizes work better at certian frequencies. Real Traps Quote Link to comment Share on other sites More sharing options...
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