Jubilee, 402, digital, CD....comments

[Rudy81]

Of course, all this violates the rule of thumb..."don't use absorption in the room - use diffusion, especially on the front wall". Heresy...I know.

Chris

Chris, I have never heard of this rule of thumb. I have heard and read that judicious use of absorption in first reflection points is essential to preventing the main sound and closely spaced first reflection from muddying up the sound. I have HF and LF absorption at all first reflection points, including the ceiling. All corners have as heavy a bass trap as I have been able to construct as well. My large diffusers are in the back wall, 27 feet from the front wall.

I have been very pleased with the treatments thus far and get outstanding imaging and a really good soundstage. The soundstage has varied depending on my choice of horns. My previous P. Audio CD horns did a very respectable job, but have found the DIY tractrix horns to really produce a very nice sound field.

My understanding is that it is precisely these first reflections that cause problems depending on your listening position.

In my case, there is nothing between the main speakers. They are about 5' in front of the wall and 3' from the side wall. Toe-in is just very slight, about 10 degrees. Spacing between my mains is about 14' and I sit 14' from the speakers.

[Rudy81]

I've had that happen with my La Scalas. My LS are only slightly modified, and I will attribute the great imaging to the room layout. It has since been changed, to make the room more useful for other things, but it was really magical. They were basically five feet from the back wall with nothing in between them left to right.

Bruce

Bruce, I agree it is a magical experience to get the mains to disappear and to have sounds 'outside' the physical limits of the speaker. I have found that I only have a few songs that achieve this large envelope magic. I have a list of demo songs at home that include a couple of songs that can place instruments outside the speaker. I don't recall off hand which ones they are and am away on business so can't look them up right now.

On my limited experience with speakers, I am certain that you must have your speakers away from the walls to achieve this kind of soundstage.

[mark1101]

I'm always fascinated and frustrated when I read comments about room treatments. In everything I've ever done in audio, room treatments are without a doubt the most difficult for me to grasp. I have a bunch of expensive treatments I purchased for specific frequency ranges, and they basically lead me to a "dead" room. I tried most of things people are posting here. No magic for me at all. I removed them all completely and went to diffusion which worked OK, I guess. I really don't know. You can't see what the treatments do, and it is difficult to measure as well. How do you know what you really did? How do you know when the measurements are correct?

I've seen the waterfall plots, and other room measurements. All they tell me is that some frequencies and durations have been reduced. But how do you actually KNOW that you made an improvement? What is the right amount of duration and decay for specific frequency ranges? I think it is very tricky business to REALLY properly treat a room.

I believe that moving the speakers around as some posters are describing...........now that does something for me. I agree that can be a good move.

The whole idea of using treatments is just really confusing to me. One thing I know is that I really didn't like my room when it was heavily treated. It was literally dead. The diffusion was simple and much more pleasing, because I simply don't really know what I'm doing when it comes to properly treating a room.

[Rudy81]

mark1101, I agree that the whole room treatment thing can be frustrating and it does take a lot of time and work. Everett's book Master Handbook of Acoustics discusses all the items you mention although it is math intensive and sometimes difficult to understand if you are not an audio engineer, which is why I have tried to read that book a few times. I found that Ethan Winer's site is a wealth of easily understood information on how to treat rooms. The effect of treatments is easily measureable by using several available pieces of software, a computer and a microphone. In this page, http://www.realtraps.com/art_measuring.htm , he discusses using REW to 'see' the effects of treatment efforts.

I agree that using too much or the wrong treatments are just as bad as no treatments. I still can fine tune some stuff in my room, but mostly feel I have done what I can to balance the room problems. Based on my experience, treating a room is well worth the effort.

JWC, do you have any room treatments in your main listening room? Curious as to your experience in that area.

[jwc]

I own none......I've tried none.

[Chris A]

But how do you actually KNOW that you made an improvement?

I've had the same thoughts about treatments as you, Mark. This time--I used my ears, and it worked (for me). But I was only trying to kill early reflections...

Chris

[Rudy81]

I own none......I've tried none.

JC, Sounds like time for a new venture into DIY absorbers, bass traps and diffusers.....[]

[DrWho]

For example, when presenting a center stage singer, the K402 left me with the impression that I was in a concert hall with the voice coming from all directions. Whereas I look for a clearly defined image that makes it feel like the singer is right in front of me in a much smaller venue. To me, the K402 always made it seem like the sound was coming from all directions and that is what I call lack of imaging.....much like a sound reinforcement system in a very large concert

I only bring this up because I've had this happen to me dozens of times, but are you sure one of your tweeters wasn't out of polarity? If I intentionally wanted to create that effect, then inverting a single tweeter is a great way to accomplish it.

One down side to these forums is it is so hard to experience what others are experiencing....I'd love to hear what some of you guys are calling good imaging and whatnot. Sometimes I wonder if I'm missing out on something better too.

[DrWho]

Btw JC, how far back from your 3-way do you sit?

[Rudy81]

DrWho, I experienced the issue with the 402 on two systems. One of them was Roy's setup. Yes, we checked the HF drivers for polarity, because that is exactly what that sounds like. It sounds as if one of the drivers is out of phase.

[jwc]

10-12 feet

[Chris A]

That's a fairly typical distance to sit from the fronts. For critical listening and HT mode, I sit ~9 feet (~2.7 m) from the Jubs and ~7 feet (~2.1 m) from the Belle center--which is triamped/time corrected.

Tri-amping made a very large difference in timbre and the Belle's ability to integrate with the Jubs. I can now walk up to the Belle to within ~2 feet (~60 cm) and it stills sounds integrated. But my room is 40 feet (12 meters) long and we listen from the back of the room, too. It sounds very good there.

Otherwise I'd've had to switch to something other than the stock Belle: for instance a JuBelle (K-510/K-69A/Belle bass bin). I may still do this, but it now isn't on my priority list (settings that I use on the Belle with EV Dx38).

Chris

[mark1101]

I'm sure you all will think I am nuts............but there is NO SITTING in my listening room. In fact, I removed all the furniture except equipment racks on one wall, and a similar sized table with all my PC equipment and peripherals on the opposite wall. These racks, tabel, and all the equipment are my "diffusion" room treatments.

There are only 2 places to sit really, on my office chair that I use at my PC (which rolls), or on the floor. But I stand up and walk around. Never sit. Sound weird? I'm listening to live music and reenacting concerts right down to standing there in front of the sound system and drinking beer.

JC, that table you gave me is in the room and where I keep the currently played music CDs and DVDs.

You can stand 3 ft. from the MCM system or up to 24 ft. from it, or anywhere in between.........your choice.

If you want to sit down you go upstairs in the livingroom and do something else.

[whatever55]

10-12 feet

OK 10-12 feet from the Jubs...

How far apart are the Jubs ?

[Chris A]

I'm sure you all will think I am nuts..but there is NO SITTING in my listening room.

Mark - that's kind of unusual, but not necessarily nuts...just..."unique"...

What do you do for short people? -Hand them a riser or have them stand on one of your racks? [8-)]

Chris []

[dtel]

I'm sure you all will think I am nuts..but there is NO SITTING in my listening room.

Mark - that's kind of unusual, but not necessarily nuts...just..."unique"...

What do you do for short people? -Hand them a riser or have them stand on one of your racks?

Chris

Short people just get more bass than tall people. []

I can't see how there would be a bad spot in Mark's room, except behind the speakers, which is where at one time was a very special, specially tuned GIANT blue animal who clamed that spot.

[mark1101]

I really need to update my avatar and post a good picture of my speakers.

If you are short you can stand on the table in the avatar. Actually, you dance on it. I do sometimes when I shouldn't. It's only about 18 inches high, so a short fall. I also tilted the 402 horns down a little.

It really doesn't matter how tall or short you are, you can't escape the sound in that room. I know, because my wife is REALLY short, and tells me all the time that she hears it perfectly.

[jwc]

12-15 w/o jubes

[Chris A]

I really need to update my avatar and post a good picture of my speakers.

Is this it?

[mark1101]

Yes, that's the speakers. I have a cleaner looking setup with a flatscreen now. Notice the carefully placed room treatments on the ceiling and floor..........and the ceiling mounted chrome bass traps.