Chris A

Bill W.,One of the most important pieces of information that I would like to know is, "what room/venue are you using--I assume it is outside(?) If so, is there a roof and side walls?" I haven't owned my K-402/K-69 two-way Jubilees for 100 days yet but I don't think that I need 100 to concur with everything you said relative to the Jubilee's sound. I haven't been around the suite of Klipsch Heritage products in a long time to have an opinion about those comments you made. Now for more granular discussion based on your writeup above. The comments about not being able to hear them before you buy them - I was in the same situation and fortunately through this forum I bet and won on other Jubilee hearers' experiences. This was a big risk but I believe in the "Wisdom of Crowds" for this sort of thing. I have to say that the K402/K69 two-way Jubilees are one of the best kept secrets I've seen. I understand Klipsch's problem of not being able to have retail listening rooms for these. My contribution to this issue--I offer my listening room on a reasonable basis for those that want to hear them. You can get in touch via this forum (via email or PM). I live in the Dallas/Fort Worth area about 25 minutes drive from DFW International. I cannot remember a home listening experience that matches the one in my den now. I might have heard theater or movie installations that match or better it, but it's really hard to remember and somewhat unfair to compare because of the differential size of the rooms. The two-way Jubilee is the best speaker system for small/medium size room that I can remember that I've experienced. Bass perf: I find that the Jubilee bass response is much better in my small-to-intermediate-sized listening room (i.e., ~5500 cubic feet) than the Khorn clones I had in their place. I won't try to infer why but I will tell you that this is the first thing that grabs everyone's attention. The ease, accuracy and depth of the Jubilee bass response (without subs, which IMHO are not needed for my venue) is an experience that needs to be first hand. Put on any really well-recorded jazz combo with string bass and you will immediately hear but it will take you a moment the believe what you are hearing. Everyone I've seen falls silent in mid-sentence as they turn their full attention to listening. Treble perf: I will try to infer something here--not having two crossover regions is a really big deal. The 500 Hz crossover point I'm currently using leaves the K402/K69 uncompromised in its operating region to have outstanding imaging, depth, frequency/loudness stability and focus. Ultra-low distortion is probably another factor here. The bass traps in the corners help to clarify the bass region so that the 500+ Hz performance is tonally balanced with the bass for a realistic performance--"real" is the key word here. This is the second thing that usually grabs everyone's attention. These units don't sound "loud" like other speakers - turn up the gain and they sound more and more like "...you are there...". No other explanation can suffice until you hear them. Overall perf: Everyone that hears these speakers in this venue says the same thing--that they are hearing things in their favorite recordings that they've never heard before. This includes folks in their 60s and 80s (mostly males) with significant natural hearing loss due to age. My 80-year-old father even mentioned that he was hearing things that he had not heard in many years. Females have an advantage in auditory capability with advancing age, and the females that have come through here have mentioned that they sound natural and alive - like the performers are in the room. Comments from listeners: I fear that the worst part of this discourse is that many people simply will not allow themselves to believe that these words could be true. If they have a lot of bucks sown into things other than Jubilees (like other speakers and expensive electronics), I fear that they will be more inclined to discount and nit-pick these words. My only comment is "bring your own music sources and listen for yourselves". Thanks for your attention and kindest regards, Chris A.

Are you saying you've used RTA's that use those techniques? If so, I would be interested in some specific models. Unfortunately, it was 25 years ago in the geophysical industry doing seismic source/receiver array design and development (both impulsive and "chirp" systems). I'm sure those specialized systems are no longer used or available. I assume that laptop applications with calibrated mikes are the order of the day in audio. Chris

The definition of "RTA" (real-time analyzer) now used is narrower than prior experience--which also includes time domain impulse, chirp, or pseudo-random cross correlation techniques. Analyzers not having these capabilities are of limited value for understanding acoustics in almost any venue. All acoustic installations have either reflection, standing wave "modes" (including feedback) issues, or need analyzer capability for setting driver array delays. Thanks for your responses. Regards, Chris

What is your suggestion for room acoustics measurements? Chris A.

Probably couldn't hurt, yea? Unless of course one forgets to use ears, too. If you've got the money, we've got the time to read your review(s). That'd be a good subject for a not-for-profit web site, wouldn't it? Regards, Chris

I was very surprised at the effectiveness of two Ready Acoustics "Ultra Bass Traps" in the front corners above the speakers for my room. Rigma - I understand this won't really work for your pitched ceiling - there isn't really a good corner at the speakers but any corner is probably much better than a floor/wall line or a flat-wall-mounted trap. In looking at the pix of your room I see your listening position fairly close to the back wall. I don't know if traps or diffusers are going to strongly affect the balance for this position. If the path length from your speakers to the pitched ceiling behind your head then down to your listening position is less than about 50 feet, then that reflective pitched ceiling area behind your head probably isn't your friend. If you experience loss of bass in any position then I think you are probably sitting in some sort of mode null--and this is almost inconceivable for extreme low-bass frequencies but check those ceiling reflection modes and consider trial bass traps hung up high with diffusers/reflectors hung below that. I really can't find much in the way of a deep bass null point in my listening area but I don't have a pitched ceiling. That in itself is probably a clue--arranging reflective panels to approximate a flat ceiling could be one thread of pursuit. [update: I see from the pix that your ceiling has a horizontal peak section. I'm sure you've thought about it but suspending traps from that center section would be a prime location. Some pretty aggressive wall-mount diffusers along the ceiling (both surfaces) might also help to break up those strong reflections. Try shining a flashlight from each speaker location upwards from horizontal to 30 degrees up angle at night with lights out in different directions. Look at the reflection bounce areas of max brightness - those are candidate areas for diffusers (higher frequencies). From Geddes, et al: "It appears then that the best rooms for serious listening would have a great deal of low frequency absorption accompanied by very low amounts of high frequency absorption (i.e., the exact opposite of what is usually done). Also consider the fact that absorbing material placed in a small room is orders of magnitude more effective than this same material placed in a larger room. That’s because virtually all sound absorption takes place at the enclosure boundaries and a sound wave in a small room strikes these boundaries many more times in a given time period than it does in a large room. Thus, even small amounts of sound absorption in a small room can lead to an over-damped condition - especially at the higher frequencies. The earlier and the greater in level the first reflections are, the worse they are. This is true up to a point - about 20 ms - after which the perception of a refection is usually positive and perceived as early reverberation and spaciousness. In small rooms, the first reflections can never occur later than 10-20 ms (basically the definition of a small room), so the first reflections in small rooms must be thought of as problems that cause coloration and image blurring. These reflections must be considered in the design. Reflections become less of a problem as coloration and image shift at lower frequencies. Below about 500 Hz. early reflections are not as much of an issue. The ear has a longer integration time at lower frequencies and it has a poorer ability to localize resulting in a lower sensitivity to early reflections. Image location is strongly weighted towards higher frequencies.] Regards, Chris

All of that sounds like alot of work ! For the best room treatments just use the one wife with 3 girlfriends, even 1 or 2 girlfriends is also an improvement to a room ! Or in your case just add 1 or 2 additional girlfriends to improve any room ! I think you will like and notice a huge difference ! Yea, but they get tired of sitting in the corners...Regards, Chris

WYSIWYG on the "cum Laude" speakers - I didn't find anything else at the author's site. I suppose Google on "Audio Intelligence (Ai) of Bangkok, Thailand" might get you closer to the answers. Note that his company has done work on psychoacoustic effects of what we call "IMD". The paper and presentation can be found at this site - http://www.gedlee.com/distortion_perception.htm (sorry about the link- "bad HTML day"). One of the surprises: IMD effects are more discernable at low signal levels than at high...interesting, if true. He also introduces a new parameter (Gm) that tracks the nonlinear psychoacoustic effects of hearing using experimental trials, basically replacing IMD and TMD as primary engineering parameters. Also interesting, if true. This forum is almost a bottomless pit - serendipitous in this case. Chris A.

Well,The above referenced web site (Geddes, et al.) has a jewel of a white paper embedded in it. I've taken the liberty of cleaning up a couple of typos that were slowing my reading. This paper is hawking his speakers, the IP of which he subsequently sold to an Asian firm which promptly stopped manufacturing them and started to apply his other IP to smaller speakers. I hope that Klipsch Corporation doesn't mind the repost here because the principles found in this paper just hit the mark on the Jubilee design for home use and the use of bass traps in smaller rooms--two for one. It's like deja vu all over again.... Read carefully, re-read if necessary. I hope that if there is anything here that is hard to understand, you'll come back to this thread and post a question or two. I'm sure someone will gently answer. There are another couple of white papers/presentations on non-linear distortion and the human ear. These are a bit more difficult to digest, but if your math and physics are up to it, really say some things about low-distortion speakers. Regards, Chris A. Cum laude.pdf

Mike,The temporary floor coverings I used were old comforters that we use when watching DVDs. They work very well as movable absorbers. I also find that room furnishings work to diffuse sound - there is never a lack of things to be placed on level surfaces in this household, including the mantle, wall-mounted shelves, and bookcases. The behind-the-sofa location on the right is now hosting a bass trap at a 45 degree angle along the baseboard. The front of the sofas can be bare or covered with soft comforters to adjust reflectance/absorption. It only takes a moment to rearrange these to devices to achieve many different combinations. However, the only remaining issue is ceiling bounce. In that respect, your ceiling rack looks very good indeed. I'll need some time, however, to convince the boss that this is "the next thing to address." However, the Jubs do pretty well without any real effort there. I had a lot more ceiling and floor bounce issues with the Khorns, however. Thanks again, Chris A.

Cool, very cool...

My friend Dtel is quite correct. Remember guys - they aren't 'jubs', 'Jubes', or even 'Jubilees'. The proper name is the Klipschorn Jubilee. Roy finished the job but Paul started these behemoths. It's carried through on our part number- KPT KHJ stands for Klipsch Professional Theater KlipscHorn Jubilee. A rose by any other name... Roy's been a huge help in getting these set up for home use, whatever the (K402+K-69) and KPT-KHJ-LF two-ways are called. I don't think I could ask more from the guy. Bravo, Roy. Chris A.

At it's very minimum, an RTA is just running a continuous FFT while it generates the pink noise. I believe the reason it looks like it updates certain bands at a time is because the pink noise doesn't always contain every frequency. Usually averaging filters are used in RTA's so that the results of multiple FFT's are averaged together (so that there is more frequency content showing up). Sometimes there are peak holds that just record the loudest amplitude at each frequency and then of course there are the smoothing filters that make the frequency response less jagged and a continuous line. One of the interesting things about the FFT is that the low frequency limit is set by the length of the sample...however, the longer the sample length, the less often the frequency response updates. In other words, it's not going to give you very useful time domain information... Mike, Do you have documentation on the Behringer UltraCurve Pro 2496 RTA algorithms, by chance? Chris A.

Mike TN: I tried 2' x 4' x 6" bass traps ( http://www.readyacoustics.com/index.php?go=products.proddetails∏=RT426B --- plus 3 Owens Corning 703 2" fiberglass panels per bag) in the corner above each speaker, each angled at 45 degrees toward the center of the room. This didn't affect the liveness or width/depth of the soundstage but it made the listening sweet spot much wider, slightly taller and much less sensitive to changes in listening position. Since my ceiling is 9' high I didn't have to rearrange the Jubs to set the bass traps directly on top of the horns toward the driver end; the traps are lightweight enough to do this. Subsequent to the above results, I laid out floor covering--my floor is tile--which slightly damped the soundstage liveness but increased the vertical dimension of the image. I haven't had a chance to try many other locations for the other two traps I've got but it seems like they do well down low on the left to balance the couch's damping on the right. My wife could really hear a difference. Deneen: Have you thought about wooden shutters for your windows, like plantation style? Regards, Chris A.

So by complementary logic, should we assume that younger folks don't pay for any entertainment? http://pogue.blogs.nytimes.com/2007/12/20/the-generational-divide-in-copyright-morality/

Double post...

Thanks Mike, I'll take a look. I've used golden oldies like Harris' Handbook of Noise Control and Olson's Acoustical Engineering or even Beranek's Acoustics for reference in the past. However, these books are not up to date with respect to current acoustic treatment products, etc. Your URLs will help. Thanks again, Chris

Nice looking black speakers with ficus tree. Kind of tall, though, don't you think?

Roy, Commercialization of music can be a terrible thing. The whole rush toward vinyl today is sometimes justified based on commercialization of "loudness compression" in CDs. I really don't understand this but there it is. Anyone that would change the music of the artist (i.e., the musician/composer, not the guy pushing sliders) seems pretty brazen, but who am I. Chris

Well, I've had an itch for audio since - well I can't remember. We had a Khorn clone in the house growing up. I built acoustic suspension speakers in high school and college. Much more recently, I acquired a pair of Khorn clones. I then learned about Jubs on this forum. Well, you know the rest.

I think (seriously) that you & MAS would probably enjoy a conversation. I realize you might not (yet) necessarily know who he is. Coytee, I'll take that as a term of endearment. I've only seen a couple of posts from "MAS" but I can't say that I know that person. What I really want is this: practical and effective solutions to problems that I've run into listening to sound reproduction systems.

Mike B: I've just now taken the time to munch on your EQ vs. room acoustics reply. 1) I don't mind anyone being rough in their responses as long as it isn't ad hominem/childish stuff. My wife reads some of these posts, and I didn't want to turn her off after the first posting on the Jubs. Roy recommended that I go the forums, which I happily obliged. 2) Some of your reply addresses Haas effects (for others on the forum, this is the loudness-integrating effect of the human ear and the selection of the direction of the first arrival for multiple-source delays of less than 50 ms). Everything else connects the dots on my understanding of the physics of matter. Have you ever wondered if the RTA/EQs are doing some sort of cross correlation on the input pseudo-random noise generator as reference? That would change our understanding of the behavior of RTA/EQs if true. I look at how the unit sequentially adjusts the bands and wonder if the unit is doing something like this. This would preserve phase/time-of-arrival information. However, the RTA/EQ information from Behringer doesn't say enough to really understand what it is doing. RTA/EQs typically don't consider Fletcher-Munson, Haas, etc. effects because, first cut, machines don't integrate listening like humans do. 3) Both of my "stupid questions" I asked are actually connected to each other . I believe that your whole argument on room acoustics really points out that we must deal with early reflection and "mode" problems at their source. 4) Source material (i.e. CDs, SACDs, vinyl, whatever) mixing/EQ problems are horses of different colors, I think. These issues are hard-coded into our source bit streams/RIAA pathways, and I was wondering what the membership of this thead does about those problems. Generally speaking, I just don't listen to poorly mixed music for very long before I hit the eject button. This is a sad situation, really. If the problems are induced via "sound engineer signal processing" or mixing room acoustics issues then I believe we are basically out of luck.

And apparently a really nice guy. Ray Charles mentioned that the only person that could stay in the room with Art Tatum was Oscar. Ray called Tatum "God over in the corner." He wanted to count his fingers... Chris A.

Paul, Congratulations on the Jubs. You obviously have a pretty spectacular wife, too. When it comes to Jubs, hearing is believing... Happy new year to you and yours, Chris A.