jubilee

[Coytee]

It was a serious comment (about MAS). He can get a little detailed and for a dummy like me, get WAY over my head real fast... but he's got some experience, at least a weeks worth [], and is willing to share what he knows with those who have the interest to learn.

Might I impose to ask you to tell us a bit more about yourself and how you came to get the Jubilee? and of course, obligatory pictures?? How'd you hear about them, what are you replacing with them? How you meet your wife... oops, skip the last one! [] []

[Chris A]

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.

[Coytee]

with son David counterbalancing

I simply did the double fulcrum pittman arm cantilever over the ducted bearing trick...and they popped right out!

(ok, I just now made that up to intimidate you!!! I actually used a box knife [:$])

[Chris A]

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

[Guest BobG]

If you'd like to hear Jubilees at a dealer, just stop in at our loyal dealer Walter Novak in Eindhoven, Holland. He's a great guy!

[mikebse2a3]

Mike TN: Sounds like you have been doing the room treatment thing for a while. I'd be interested in any insights you have with moving your panels around. I'd also like to have an idea of your relative room dimensions so I can understand if your setup is applicable to mine.

Hey Chris

My setup and room dimensions are much different compared to yours but the basics(goals) needed in treating a domestic sized room would be similar.

If you aren't familiar with these sites I would encourage you to explore and read their articles/papers (especially the RPG site).

I also feel if someone is going to spend money and effort treating a room then economical software like Mike(Dr Who) mentions or ETF(RPlusD) is an absolute necessity to explore/verify what needs to be done when acoustically treating the room. To Much, To Little, or Wrongly Placed room treatments can have negative effects on sound reproduction in the room and this is where testing each room/setup is a must IMO if at all possible for someone.

Main RPG site:

http://www.rpginc.com/

Important info on application of diffusers:

http://www.rpginc.com/news/library/TechBullDiffCritList.pdf

RPG acoustic library(the RPG Book contains information from these papers so they are well worth reading.

http://www.rpginc.com/news/library.htm

Two of the best books on acoustics and acoustical treatments I've read:

http://www.rpginc.com/book/

http://www.soundsystemengineering.com/

Another excellent site with articles:

http://www.acousticsciences.com/index.htm

ETF(RPlusD) site: Very Informative

http://www.etfacoustic.com/

mike tn[]

[Chris A]

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

[Chris A]

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

[Chris A]

Double post...

[PrestonTom]

Well, the books you are citing are probably 30 and 45 years old, respectively. They are good ones (especially Beranek).

There are newer ones of course, but you can get quite a bit of good information (along with plenty of bad ...) on the internet. The stuff by RPG is worth looking at to get started.

Good Luck,

-Tom

[DrWho]

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.

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...

[ClaudeJ1]

I could take this drum kit and move it just a few feet in the room and I would have to retune the drums for their new location which just goes to show how much the room influenced the sound of the Real Drums and my point is the Loudspeaker's reproduction is influenced even more dramatically by the room's qualities. So again I would emphasize that the weakest link and most neglected to reproduction in the home is the Room and swapping or adding equipment(this assumes reasonably good equipment Tube or Solid State) will not bring about improvements to that reproduction like dealing with the room-setup issues.

mike tn

Since we are talking about 90% reverberant field at a 10-foot distance from the speakers, your point has been well made here and rarely discussed relative to amps and speakers. Based on the chasing the room anomalies, with the speakers being the data transfer, all amps sound the same, relative to the room anomalies.

[DrWho]

What do you do about windows, for example?

Board them up.

[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.

[mas]

What do you do about windows, for example?

There are several options depending upon the topology and context. Unfortunately there is not a simplistic one size fits all response for all "windows" and conditions and concerns that such a question seems to assume.

And the context is critical and certainly not defined here...Issues that immediately come to mind such as:

Are you retrofitting a space or designing a new space?

Where are the windows located?

Are you concerned about sound transmission or their impact upon the internal acoustical sound fields?

What is your budget? While not necessarily a limiting factor, it can certainly place constraints upon the viable options.

If they are on any surface other than the rear wall, windows are an easily addressed issue with regards to the internal specular reflections. (and no, angling them is not an effective solution ). Just be aware that large expanses of windows are 'perfectly' reflective surfaces, and their presence on the back wall are not ideal for a room designed primarily for listening - just as trunk space is not a big priority in a formula one race car.

If anyone has a problem with this, PM me. I will be glad to suggest a very real practical and effective applied solution based upon the real scenario.

RPG's product mix reflects their primary market which is in supplying product for room designers. They place windows as necessary where they like.

[Chris A]

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.

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.

[Marvel]

Mark,

I certainly have windows in my living room, which is my primary listening room. The room isn't very large (13x21 w/8 foot ceilings) the LS are on the long wall, with a set of double windows behind the listening position and a double set on one of the short walls. The opposite end goes around to the kitchen and hallway.

I'm certainly not worried about sound transmission, as the nearest house is a couple hundred yards away and I usually listen at about 80-85db at the listening position. I know the reflections off the windows behind me are more problematic than the end wall. I'm not averse to putting temp coverings over the windows while listening to music. Would even make the room more energy efficient...

I would want the fixes to be easily removeable, since I might move in another year or so. Partly depends on my present gf and love of my life and the housing market (current house is paid for).

Bruce

[oldtimer]

Open them up and then go work in the garden as you enjoy the bounty of sound.

[mas]

On the side and front walls a phase grating can be used over the windows. They can be moveable or left in place, as they will allow the light to pass through.

The rear wall will need diffusion (and perhaps a degree of absorption - but only if warranted).

Depending upon the rear wall window size and location, and the result of measurements (or at least an examination of an accurate drawing of the room allowing for very basic ray tracing or more complex modelling in EASE), rear windows may need to be covered with diffusive treatments either permamnently or temporarily. But witout more detailed information, it is difficult to provide much more details than that. Variations in treatment are possible, but they can vary greatly depending upon the aesthetic concerns and material costs.

All treatments can be specified so that they can be moveable in the sense that they can be removed and taken to a new residence.

If you would like more detailed suggestions, feel free to PM me.

[Islander]

I'm not averse to putting temp coverings over the windows while listening to music. Would even make the room more energy efficient...

I would want the fixes to be easily removeable, since I might move in another year or so. Partly depends on my present gf and love of my life and the housing market (current house is paid for).

Shortly after I moved into this place (before I had a sound system in the living room), I put sheets of white Cor-Plas in one of the windows to darken the room for doing photography with studio flash units. A year or two later, after I'd started building up the stereo, I got tired of the gloom and removed the Cor-Plas. The difference in increased echo was very noticeable, even though the window wasn't all that big. I've done other treatments around the room to compensate, but that plastic sure helped when I had it up. I'm using it in other spots now, leaning against the wall in some corners.

If you're not familiar with Cor-Plas, it's that plastic material that looks just like corrugated cardboard and is often used by sign shops. It comes in a number of colours and is available at Home Depot. I thought black would look odd in my window, so I used a double layer of white, which dimmed the room enough for my purposes. I cut it so it was a snug fit in the windowframe and had to flex it a little to put it in.

It's inexpensive and easily removable if you don't like it.