mas

I agree with MrMcGoos assessment and recommendation to hold off as long as you can Additionally, he presents some very valid points to consider; and indeed he is right, there is no reason to panic! But there is a very good reason to be aware of the issues that may play a significant factor in the future orientation and compatibility of your investment.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> The only area in which I would 'disagree' is with regards to what one might call a technicality. And this is precisely why I refrained from mentioning hard data in the initial article. Ithas been stated that <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Hollywood (the owners of the copyrighted material) have agreed to hold off implementing ICT until a stated time. But it should be understood that this general statement is NOT a binding commitment on the part of the entire industry nor to a 'hard' date! There has quite intentionally been neither a formally binding commitment nor obligatory promise of the delay. And there is no universal agreement among all studios. So, while there is a delay based upon practical concerns ( it would be very bad PR to immediately break the currently installed base of products from inception!), there is also pressure that will mount quickly within the industry to implement the standard as soon as possible! This date is not fixed, and may be modified based upon (supply side) market demand. It is this very lack of a binding agreement that makes this 'technicality' significant. Sony and Universal have publicly promised to turn off ICT for the first few years while consumers make the switch to compatible hardware. A move that makes sense for Sony as they have an exorbitantly priced and delayed PS3 that is poised to potentially be incompatible out of the box, especially as many HD DVD and BluRay units are currently being marketed as future proof, but do not currently support HDCP. In May it was reported in the German press that a behind the scenes agreement was reached between several of the major players (including Microsoft) to delay the full implementation of AACS and HDCP by delaying the use of the ICT which effectively down converts the HD signal to standard 480i resolution to sometime between 2010 to 2012. But, there has been no formal public statement of commitment to this effect. And there is no binding obligation on any parties part. And this delay will undoubtedly result in the wholesale duplication of HD recorded content, thus creating increased industry demand for its implementation, both from distributors of recorded product as well as pressure from associated market segments such as theaters who are already experiencing large declines in attendence. Thus the market is in flux! And with the average lifespan of a traditional CRT TV being 18 years, and the average lifespan of an expensive HDTV hopefully lasting more than 3 years, it is wise to consider the future orientation of your plans and thus, when you do decide to jump into the market, to have done your due diligence regarding making sure that your purchase will be as compliant with evolving standards as it can be. Currently, there are far too many being encouraged to buy $3-5K+ HDTVs without AACS compatibility. If that lack of future orientation does not bother youfine. But I suspect that for many, they would not relish the thought of such a major purchase potentially being rendered incompatible within 3-5 years. Thus, there is a very good reason to be aware of the evolving standards and the continuing flux within the industry and to be an informed consumer.

"HDMI technology has been designed to accommodate long copper cables at lengths up to 15 meters (50 feet) without the use of HDMI amplifiers or repeaters. Actual performance constraints vis-à-vis cable length, are similar to DVI in view that HDMI uses the same encoding protocol over the same twisted copper pair. ... the use of twisted copper pair to carry high bit-rate digital data without error correction can lead to severe problems with signal degradation over distance. It is for this reason that the HDMI specifications standard does not state a maximum cable length - but rather indicates the expected supported cable length using affordable high quality HDMI cables." http://www.practical-home-theater-guide.com/hdmi-cables.html If an HDMI repeater that also passes the HDCP signal is needed, the Steren 516-011 Python Digital HDMI Repeater is a workable answer... http://www.audio-discounters.com/516-011.html

Use RTV Silicone grease and air cure silicone shrink tubing designed expressly for weather exposed RF connections. The shrink tubing comes in an individually lubricated sealed pack. I don't know of a more elegant way to state this, but it is sort of like a rectangular condom package. You MAY be able to get some from your local cable technician.

Preface, or 'what this thread is and what it 'ain't'[] What this thread 'ain't'!!!: This is not a forum to debate the pros and cons of DRM! You are certainly entitled to your opinion. But whatever it is, it has NO bearing on this topic! There are a myriad forums to debate that topic - Please avail yourself to them! This topic pertains to hardware compatibility - making your 'stuff' work with the standard. I am posting the links to these articles simply because they present a pretty good intro synopsis to something many of you are already aware of, and yet some of you may not be. And while some have a pretty good understanding of the topic, many more have probably only heard rumor and inuendo featuring plenty of angst and emotion but lacking much real fact. And the purpose is pretty simple. Many of you have or are planning to make the investment in a new fancy TV or computer monitor. So in that spirit, this thread is simply an attempt to make you aware of the various factors that you need to know to make a SMART purchase in order to get a product that will suit your intended use! For some, the advent of HD recorded material will matter little! For instance, those whose interest is primarily in legacy/classic material. For others it may be more significant. But this will help you to ask the right questions when shopping (and expect to get ALLOT of blank looks & incorrect responses in the stores!) The topic is AACS/HDCP...the hardware component for both TVs and computers regarding the eDRM standard that was formally approved last June, 2005. If you don't know what these acronyms stand for, you NEED to become aware! I will let the article do the summarizing, but please be aware that MOST of the currently available computer monitors AND HDTVs are NOT AACS/HDCP compliant! And it is NOT a retrofitable feature! For example, even video cards such as the nVidia GeForce 7900GTX, or the 'best buy' Gateway FPD2185W 21" monitor , or Apple monitors are NOT HDCP compliant. I don't know for sure about the Dells, but I am assuming they are not because no one at Dell even knew what we were talking about when we checked - including tech support! Oh, and one more IMPORTANT point! For TVs. the standard requires the use of an HDMI port! DVI, component, S-Video, etc. will NOT support AACS! And simply having a TV with an HDMI port does NOT imply compliance! Does this make sense? HDMI is a pre-requisite, but it is not sufficient by itself! It will ALSO have to have the client side AACS circuitry and firmware! And it is NOT retrofitable onto an exisiting HDMI TV. My point isn't to push or denounce any brand or format, but simply to illustrate that MANY/MOST current top rated products are STILL NOT complaint! So...if you have ANY intention of being able to watch the forthcoming HD encoded pre-recorded materials, you NEED to buy ''smart and to MAKE sure that your gear is AACS/HDCP compliant! Otherwise you are going to have the opportunity to repeat your buying experience and repeat the excitement of unpacking another unit!! And unfortunately, the retail vendors are not doing an adequate job to inform consumers! There are many sources for this info, but the link for the posted article is: http://www.pcworld.com/article/122738-1/article.html And additional article also deals with this topic:http://news.com.com/2100-1025_3-6040261.html (Edit: Sorry for not including this link initially.) Here you will find the additional info and the specifications for AACS as well: http://www.aacsla.com/home Also...I do have updated infor regarding the delay of the full blown implimentation of the encoded HD program material! And yes, they have chosen to not only delay the release of almost all of the forthcoming material due to the unavailablity of hardware on which to play them, but they ARE definately going to phase the full implimentation of AACS in during the next 2-3 years! So, please be aware that any reprieve from fully encoded pre-recorded material is ONLY a TEMPORARY reprieve! If you care, PM me and I will try give you what I get as I receive it - as we are being kept up with AACS/HDCP for information assurance network and data security compliance for use with NSA, SOX, HIPAA, FISMA, ISO17799 , etc. implementations. Also, in a totally separate topic regarding security, if any are interested in IEEE802.11i-AES - sometimes referred to as WPA2 - the new unbroken successor to the terribly flawed WEP and WPA/WiFi for wireless connectivity, PM me as well! Hope this is of some benefit....

AMEN![<)]

I too examined the idea... But if I may humbly offer another perspective... offered with a mixture of wry humor and a bit of practicality... ~3500 CDs, figuring ~10minutes apiece to 'losslessly' rip each CD -> 35,000 minutes which is: 25 - 24hour days 72 - 8hour days 145 - 4hour evenings Or... Figuring a real time transfer as I actually listened to each one, and assuming a conservative average play time of 40 minutes (single, extended and multiple disk sets), the figures would be around: ~3,500 CDs, figuring ~40minutes apiece to rip each CD -> 140,000 minutes which is: 97+ - 24hour days 292 - 8hour days 584 - 4hour evenings ...yeah, right! And I haven't even figured time to take bathroom breaks! And that is JUST for ripping! :-S This doesn't include admin time, organizing playlists, etc. etc. etc. (And what are the missed opportunity costs of throwing away 145-584 dedicated 4hour evenings when I ALREADY have all of the resources close at hand?) (And this assumes that there is not an automated TIVO-like method of automatically archiving only the untransferred titles over a period of say 3-4 years where I would actually listen to most of the titles!!!) Regardless of the storage required, the conversion time renders any subsequent savings in time a moot point! After all, with several ganged carousels, or just the sneaker net selector (me), ANY title is just a few seconds away, as they are all organized and alphabetized. So, regardless of any perceived value, & not to mention the expense and squirreliness of the Media Center, my time is MUCH more valuable than that![] It's indeed a laudable idea, but the realities involved relegate it to the pile with my other 'worthwhile but impractical' ideas.[] But I hope that you can devise a better system than I was able, and I sincerely wish you folks well![] P.S. But if there exists some intrepid soul who would like to do this FOR me, they are welcome to a copy of the material when complete![][] Oh, and then you you can start digitizing the ~2500 pristine records!

While it may not directly address your particular need and/or desired aesthetic result, may I suggest the use of a particular technology that is elegant in both design and results. Russ Berger has designed a spatial diffraction grating that has several useful applications. As marketed in conjunction with Aurelex, the SpaceArray diffusor is based on a quasi-random series that provides superior performance without visual patterning. It is a very effective for its intended purpose. And an even more useful design is the Space Coupler - essentially a SpaceArray minus the filler in each cubicle. These frames (the Space Coupler diffraction grating) could be easily made for home use and the Arrays could be easily constructed using the grating filled with pieces of styrofoam cut to snugly fit into the individual cubicles at their corresponding heights to create the appropriate well depths. The usefulness and effectiveness of the grating as a diffraction grating was discussed by Russ and measured this past February in Dallas at the TEF seminar. And they work amazingly well! This grating, which is simply panels of empty squares ~2in x 2in x 2indeep are not filled with any absorbtive or reflective material. You might think of this as being similar to a larger scale grating used for overhead flourescent lights. It allows 90 degree waves to pass unimpeded, but waves with incident angles greater or less than 90 degrees are reflected in the well and are either diffused into the coupled space (creating a very diffuse 'manufactured reverberant field' for a small acoustical space), or diffused back into the environment. This presents myriad uses as either a surface treatment (as most of the incident waves would be >< 90 degrees) or as a simple diffraction grating that is excellent for use as a suspended ceiling that allows for the use of the coupled space above while minimizing beaming and uncontrolled reflected sound. It is a treatment that can be used without allot of discrimination, UNLIKE other absorptive materials whose use is very specific in order to achieve a desired result. Meaning, that it has allot of beneficial uses without many potential negative affects! Additionally, the pass-through characterisitics of a suspended grating present MANY potential uses, and if the asthetics of your application allow it, it would easily tame many mid-high frequency problem areas. This concept is a welcome and very practical tool that has many applications. And it is also rather easily reproduced in a home shop. Of course, LF treatment modes still require the use of traps and more fundamental techniques not addressed by simple absorption and/or diffusion techniques. More details regardiing the concept and the commercial product are available at http://www.auralex.com/partscience/spacecoupler.asp SpaceArray&SpaceCoupler.pdf

Please pardon me if I am simply being a bit obtuse this morning before a cup of coffee, but what does a Karlson have to do with the Keele lit and ported W box configurations? This is not a thread about basic comparative LF horn topologies. Have I missed something?

DBKeele - LF Horn design Using Thiele-Small Parameters AES paperLF_Horn_Design_Using_TS - Keele.pdf

Bump... I have updated the posts and also posted Don's plan+notes again in each. Heck, I just may post it again here![] The file names for the 2 diagrams are different, but the contents are the same, so please don't let that become an issue! And one other observation...these plans are from right after Don published his LF Horn design Using Thiele-Small Parameters AES paper. It might be useful to give him a call and see if there is any direct relationship, as Don has a propensity for generating several proof of concept designs whenever he brainstorms like that! I assume most have that fundamentally significant paper, but I will also post it again as well for anyone who might have missed it in the past. Keele K151 2240H W Horn Plans.pdf

Thanks for the explanation Doc...FWIW, I agree! In the meantime I will attempt to refrain from being my own best enemy![] This version is the same as the other posted. The difference is the inclusion of the application notes, response measurements, and the exploded construction drawing. Note that Don did this circa 1977, just after moving to JBL from his stint with Klipsch in 1976. Keele K151 2240H W Horn Plans.pdf

If I might inquire... Why would that be?

...Not sure if this has been posted before, but it may be of interest to both the LaScala and Jubilee camps. The design is for a W Box that, except for its scale, most closely resembles a ported LaScala bass bin format, but the concept easily carries over to the variants including the Jubilee. Just thought there might be some who might find it interesting... Keele_W_BoxPlansPDF.pdf

...Can't disagree with the overall suggestion, but if I may, I will take issue with a small technical point just for the sake of 'clarification'.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> One of the strengths of steel studs used for acoustical isolation is the fact that they are more compliant ('more springy' - pardon the techno speak! ;-) then wood studs, and hence they do not acoustically couple spaces and transmit the acoustic energy as well as the wood. "Since wood transmits sound well, a standard wood stud wall doesn't do well for soundproofing. A steel stud with a "C" shape cross-section does a better job. The "C" is a bit springy and absorbs sound, improving the STC rating by about 5 points over wood." "About Soundproofing" But, as correctly mentioned, many factors contribute to the selection of the materials for use in the home. I simply mention this in order to allay the fears that many have expressed about steel studs. Nice job!

Addressing the issue of the use of steel studs, there is absolutely no problem using them! In fact, in some cases they make the job of acoustically isolating an environment alittle easier. The primary difference is that steel studs are more commonly used in commercial buildings. The building industry, generally, is reluctant to adopt alternative building methods and materials. And we are seeing that tendency here!! ;-) And the techniques that facilitate fire-resistance often compliment acoustical isolation as well. Hard data regarding soundproofing techniques for wood &/or steel supports is available! Acoustical isolation techniques and ratings are exhaustively detailed in: Residential Steel Framing: Fire and Acoustic Details (HUD) http://www.huduser.org/Publications/pdf/residential_steel_framing.pdf An additional excellent to the point resource is also found at: http://www.sdsc.edu/~nadeau/Rebuilding/About/AboutSoundproofingWalls.htm Table 3.1 - STC of Various Construction Materials Building Component STC ¼-inch plate glass 26 ¾-inch plywood 28 ½-inch gypsum board, both sides of 2x4 studs 33 ¼-inch steel plate 36 Concrete block: Autoclaved aerated 45 3-inch concrete wall 47 6-inc Reinforced concrete slab (4-1/8 thick) 44 6-inch concrete block wall 42 8-inch reinforced concrete wall 51 12-inch concrete block wall 53 12-inch Brick 56 2x4 wood studs (16 o.c.) with 1/2 GWB both sides 33-39 1-5/8 inch steel studs (24 o.c.) with 1/2 GWB both sides 39 3-5/8 inch steel studs (24 o.c.) with 5/8 GWB both sides 40-44 3-5/8 inch steel studs (24 o.c.) with 1/2 GWB both sides 39 Be aware single dual sided studs are NOT the most effective for minimizing acoustical sound transmission in wood or steel stud walls! 2.) Construction for an STC 55-60 wall (omitting < STC 57, sorted by total wall thickness) Wall Stud type Stud width Air gap Drywall layers Insulation STC Total wall thickness Staggered Steel 2" 2.5" 3" 1.5" 1" 0.5" Two layers, 5/8" each side thermal 58 6" Double Steel 2" 2.5" 1.5" 0.5" Two layers, 5/8" each side thermal 58 8" Staggered Steel 2" 2.5" 3" 3.5" 4" 3.5" 3" 2.5" Two layers, 5/8" each side thermal 59 8.5" Double Steel 2" 2.5" 3" 3.5" 3.5" 3" 2.5" 2" Two layers, 5/8" each side thermal 60 10" Double Wood 3.5" 1" Two layers, 5/8" each side thermal 58 10.5" Double Steel 2" 2.5" 3" 3.5" 5" 4" 3" 2" Two layers, 5/8" each side thermal 63 11.5" 1.) Construction for an STC 55-60 wall (Standard and double walls) Wall Stud type Stud width Air gap Drywall layers Insulation STC Standard Steel 2" Three layers, 5/8" each side thermal 54 Standard Steel 2.5" Three layers, 5/8" each side thermal 55 Standard Steel 3" Three layers, 5/8" each side thermal 56 Standard Steel 3.5" Three layers, 5/8" each side thermal 57 Staggered Wood 3.5" 1.25" Two layers, 5/8" each side thermal 54 Staggered Steel 2" 2.5" 3" 1.5" 1" 0.5" Two layers, 5/8" each side thermal 58 Staggered Steel 2" 2.5" 3" 3.5" 4" 3.5" 3" 2.5" Two layers, 5/8" each side thermal 59 Double Wood 3.5" 1" Two layers, 5/8" each side thermal 58 Double Steel 2" 2.5" 3" 3.5" 4.5" 3.5" 2.5" 1.5" 5/8" each side thermal 57 Double Steel 2" 2.5" 1.5" 0.5" Two layers, 5/8" each side thermal 58 Double Steel 2" 2.5" 3" 3.5" 3.5" 3" 2.5" 2" Two layers, 5/8" each side thermal 60 Double Steel 2" 2.5" 3" 3.5" 5" 4" 3" 2" Two layers, 5/8" each side thermal 63 Well, you don't want my opinion of the editing tools here, but the last 2 charts above should be 'reversed' in their order[] Table 1.) shows a larger selection of potential configurations, while Table 2.) features a subset of configurations, omitting from consideration standard walls and anything less than STC 57, showing effective measures and sorted by total wall thickness. Also, please be aware as well that the most critical source of noise transmission is not the wall and floor surfaces, although they are certainly the most apparent! I have more documents, if needed, but I have yet to figure out how to attach them. ...Hope this helps alittle...

Just a suggestion for taking measurements... Set the enclosure outside on the ground (away from any vertical surfaces ) in a Large drive or area such as a parking lot. Lay your measurement microphone flat on the ground. In this way you will effectively 'eliminate' (minimize) the ground plane reflections that result in the comb filtering that is evident in the measurements. Don Keele developed that technique and it sure saves allot of additional effort that would ordinarily be required to accomplish the same results any other way! An interesting thread...

Hi! ...thought I would give my 2 cents as I have been lurking for quite awhile and have a 'little ' experience with this. Regarding the Baltic Plywood vs. MDF issue: With all due respects to both the high quality Baltic plywood camp (which I must profess to prefer in most cases simply due to its being more resilient to handling and moisture ) and to the high quality MDF camp (which does have superior density - and thus it is heavier - and lower resonant qualities and the ability to be tooled to very high tolerances), you would do fine with the MDF. If you aren't planning on using them for SR use and carrying them around and banging them up, and you don't have to worry about the wear and tear (not to mention shooting Polane!!), the MDF will actually present you with some superior qualities compared to plywood as you have already mentioned. And it accepts veneer very well. Also, I am sure from previous discussions that you are intimate with the differences in joinery required by the different materials. One additional note, MDF is hard on bits and blades! Whether it is the binder, the density, or a combination of all that, it results in greater heating of the bits and blades, not to mention the nasty dust (please wear a respirator! - although regular hard/softwood dust is not safe either!). Bottomline, for internal stationary use and if you are prepared for the dust and tool wear and heed the required joinery techniques appropriate for MDF, you would do well to use MDF. Good Luck!!

Quote: DrWho wrote the following post at 02-25-2006 3:11 PM: The articles I read about LF ear damage were in direct response to some of the research that tried to show no damage occurs...I really should just find the articles and post them instead of asking ppl to take my word for it...the articles were talking about sustained levels as low as 100dB that cause permanent damage. And just because the wavelengths are big and wrap around the body, doesn't mean that the sound doesn't travel down the ear (aka, just as much LF energy makes it down the ear as HF energy...if anything, high frequencies have a harder time turning the corner). Lower frequencies also have better bone conduction (which is the real issue). There is a point though where the frequency gets low enough that the behavior of the ear moves into a different "mode" for lack of a better description...(if you think about it, normal daily movement could be modelled as sound waves - which would correspond to like 5 and 8Hz, but such movements don't damage our ears....in fancy terms, I suppose we could talk about the impedance of our ear and how it acts like a high pass filter...) FYI: Low frequency signals can indeed cause damage, but the damage does not manifest itself in the usual manner associated with mid/high frequency hearing loss. Much of low frequency signal is not experienced via the traditional paths of the ear, but rather via conduction. Large pressure amplitude low frequency (LPALF) noise (defined as >= 90 dB & <= 500Hz) can result in respiratory problems. It is commonly refered to as vibroacoustic disease (VAD). This is most often encountered in construction environments, although exposure to loud music can easily induce the effects as well. This effect is confirmed by the folks at the House Ear Institute. When asked why more information is not available, they pointed out that the OSHA office on hearing damage was shut down in the very early 1990's once the basic hearing protection levels were established, so that only individuals doing research are publishing data. Additionally, they observed that most of the studies were performed by the military and NASA - not surprising when you consider the exposure of artillery personnel, etc. (Think 'sitting inside of a tank'! :-S ), as well as exposure to extra low frequency noise in space. So beware, while there is little likelihood of developing tinnatus from LPALF signals, you are NOT out of the woods. One of the clinical studies is documented in Pub Med 10189161, The Effect of Chronic Exposure to Low Frequency Noise on Rat tracheal Epithelia, published in Aviant Space Environment Med. I have posted the article summary below - hope it helps alittle: Aviat Space Environ Med. 1999 Mar;70(3 Pt 2):A86-90 The effect of chronic exposure to low frequency noise on rat tracheal epithelia. De Sousa Pereira A, Aguas AP, Grande NR, Mirones J, Monteiro E, Castelo Branca NA Abel Salazar Institute for Biomedical Sciences, University of Porto, Portugal. INTRODUCTION: Vibroacoustic Disease (VAD) is a multi-systemic entity caused by occupational or chronic exposure to large pressure amplitude and low frequency (LPALF) noise (> or = 90 dB SPL, < or = 500 Hz). The clinical picture involves extra-auditory pathology, such as neurological disturbances, respiratory disorders and cardiovascular problems. Among the first complaints of VAD patients are coughing, bronchitis, and inflammation or infection of the oral cavity and the upper respiratory pathways. The goal of ths study was to investigate the effects of occupationally simulated LPALF noise exposure on rat tracheal epithelium to determine if they could explain the symptoms found in VAD patients. METHODS: We exposed 20 Wistar rats to occupationally simulated (8 h x d(-1), 5d x wk(-1)) LPALF noise for an accumulated total of 1236 h. The control group consisted of 10 age-matched rats, kept in equal conditions but in silence. Histological and ultrastructural studies were performed on the tracheal epithelia of both populations. RESULTS: The most dramatic changes were identified in the ciliated cells of the exposed rats. There were frequent images of shaggy or necrotic cilia as well as regularly to partially sheared cilia. Also, there were frequent images of different stages of cilia recovery. CONCLUSION: Occupationally simulated exposure to LPALF noise can cause important changes in ciliated cells rat tracheal epithelia. This may partially explain the clinical findings observed in VAD patients. PMID: 10189161 [PubMed - indexed for MEDLINE]