[Nils]

Update:

I've kept the RealTraps MiniTraps HF on my rear wall for the time being.  I feel like my room is pretty darn well-treated.  I am also enjoying the MicroTraps treating the side wall reflections.

I recently biamped my Magnepans with modified Quicksilver V4 tube monoblocks driving the mid and hi and my trusty Bryston 7B-SSTs handling the bass panels with firm authority ..  Removing the (crappy) stock large-value components made such a difference in dynamics that it'd be scary to have a less absorptive real wall!!



Of course, when GIK comes out with their stand-mounted diffusors, I'm gonna want to try out some of those

-- Nils

[GregN]

What are the four grey vertically positioned, semi-rounded treatments doing for your system (behind your cd player, in between your speakers, etc.)? Is there any general rule of thumb which might provide the necessary guidance for whether something like this would be more applicable than, say, multiple 2' x 4' front wall treatments?

[youngho]

Greg, those look rather like TubeTraps (my guess is StudioTrap, which you can read about at http://www.asc-hifi.com/studio-trap.htm). Nils has Magnepans, and many users of dipolar speakers argue for the diffusion, rather than absorption, of the back wave. Technically, the StudioTraps will act more as diffractors than diffusors. For a little more about this topic, please look at this thread: http://www.audiocircle.com/index.php?topic=50695.0

Nils, I'm glad to hear that your panels (or ears) have "broken in". For other readers, my earlier post was meant as a joke. That's why I made the quip about the principle. At the time, I thought of the analogy of the calibrated television or display, since viewers will initially feel that the picture looks dimmer and less vivid than it did out of the box, but over time, as they get used to it, they should appreciate the more realistic reproduction of colors and black levels. Or the Coke/Pepsi challenge, where many drinkers will initially favor the sweetness of the Pepsi but eventually miss the balance of Coke (I said many, not all). It would be interesting to hear your impression of diffusors, rather than Studio Traps, behind the speakers, so please let us know.

Young-Ho

[GregN]

Great response, youngho. I couldn't remember where I had seen those (what I now know to be) fractional Studio Traps before. Thanks for the usage clarifications.

I was a little worried about your break-in comments earlier, but the subsequent responses reassured me that you were probably just being a wise guy.   

[Nils]

They're indeed 4 9" StudioTraps, with the reflective side oriented into the room (note that the corner ones are not oriented directly towards the listener).

I bought 4 StudioTraps and 8 SoundPanels on Audiogon from a local seller at a STEAL of a price.  I'd be hard-pressed to ever justify paying full price for ASC products.

Note that I'm also using 8 dampened GIK D1 panels and 4 GIK tri-traps behind my speakers.  I started with a 4' x ~8' array of D1s on the front wall, which led to a really cool, holographic sound, but the imaging was too diffuse, detail was lacking, and there was QUITE a bit of treble energy.  55" line source ribbons are quite good at dispersing energy

I tried more abosption, but I found that using absorption robbed the dipoles of their open, natural sound.  I also noticed that the canvas covering of the tri-traps was reflecting high frequencies back into the middle of the room.  I tried two of my StudioTraps there with great success.

A picture is worth a thousand words... I'll have some up soon!

-- Nils

[satfrat]

Nils, I'm glad to hear that your panels (or ears) have "broken in". For other readers, my earlier post was meant as a joke. That's why I made the quip about the principle. At the time, I thought of the analogy of the calibrated television or display, since viewers will initially feel that the picture looks dimmer and less vivid than it did out of the box, but over time, as they get used to it, they should appreciate the more realistic reproduction of colors and black levels. Or the Coke/Pepsi challenge, where many drinkers will initially favor the sweetness of the Pepsi but eventually miss the balance of Coke (I said many, not all). It would be interesting to hear your impression of diffusors, rather than Studio Traps, behind the speakers, so please let us know.

Young-Ho

Personally i took it as being a smarta** remark, guess I was wrong and adjusted my response accordingly. Thanks for setting me straight. In fact I totally agree with you. This is one of the main "breaking in" princples of your eyes after having an ISF calibtation done on a display device which usually involves lowering the light output while educating the user about viewing in a room using ambient lighting. It took me a week to accustom myself to this process and I actually emailed the ISF dealer and likened this calibration to my paying someone to come into my house and raping my wife! A few days later, I totally regretted my outburst.  I think it's the same with audio sometimes when we accustom ourselves to something and have a hard time accepting a more accurate improvement. But there is also a personal preference that everyone has and sometimes a "break in" period only ends with change. If that's the case by all means change, a pefectly calibrated video or audio isn't for everyone. It's all about what personal preference and any good ISF calibrator will tell you give it a week and if you're not happy, they'll be back until you are. 

Cheers,
Robin

[youngho]

Greg, I'm pretty sure these are regular StudioTraps. I don't think that ASC offers fractional ones in this particular model, which is 9" diameter. I think you're just seeing the flattening of perspective that occurs with photographs.

Nils, I saw that ad on Audiogon. Nice pickup for you. I did see the D1s in the picture but missed the Tri-Trap until you mentioned it.

Robin, I was trying to make an understated joke. I do think that break-in probably has to do with listener adjustment to change, rather than physical changes happening in the actual equipment itself over time (electrons aligning or settling, dielectrics relaxing, etc), which may be why these changes can be difficult to measure in a reproducible fashion, as well as why changes due to break-in are virtually always positive. Certainly, anyone with a background in medicine or wine will acknowledge the potential impact of expectation on perception. However, just as you note, individual preferences favors euphony (or the visual equivalent) over "accuracy" in certain instances. Another example would be the "beer goggles" phenomena versus the cold light of morning.

Happy listening (and drinking),

Young-Ho

[satfrat]

Another example would be the "beer goggles" phenomena versus the cold light of morning.

Happy listening (and drinking),

Young-Ho

  Just memories Young-Ho, I've been substance abuse free for 6.5 years now but alas at 56, the damage has already been done.  But I'm real high on the "Happy Listening". 

Cheers,
Robin

[Ethan Winer]

I think it's the same with audio sometimes when we accustom ourselves to something and have a hard time accepting a more accurate improvement.

I agree Robin, and I've often said that a well-treated room can be an acquired taste for some people. Sometimes after adding treatment the initial perception is that too much ambience has been removed, making the sound seem sterile and lifeless. But once you get used to the change it becomes apparent that what's been removed is bad ambience that previously clouded the sound. In fact, once the room's own small sound has been removed, you can then "hear into" the music much better, and appreciate the larger sounding reverb and ambience that's embedded in the recording.

--Ethan

[GregN]

Greg, I'm pretty sure these are regular StudioTraps. I don't think that ASC offers fractional ones in this particular model, which is 9" diameter. I think you're just seeing the flattening of perspective that occurs with photographs.

Oh, you are right. I checked their website. Still hard to believe that they are round though, given the perspective provided by the picture above.. they still look half round to me!

[Nils]

Full rounds, as shown here:



Yeah yeah, I'm a shameless showoff..

-- Nils

[MaxCast]

Hi Nils,
What kind of racks are those?
Thanks

[darrenyeats]

Clearly there are people here with more experience of acoustic treatments than I. However I would like to share some thoughts and see if someone sees it similarly.

I have certainly tried acoustic damping and probably too much of it. This resulted in the "dead" sound which someone mentioned earlier in the thread. One comment was that it takes some time to get used to this, but in the end cleans up the sound and makes it more neutral.

However, I have had more success recently with removing some of the acoustic damping and returning the room to a more natural acoustic. (One problem I have is that my stair well is on the other side of the left wall in my listening room, and this stairwell has a terrible mid/hi echo/zing. So I need to damp the whole of the left wall - it is a double plasterboard wall - and therefore all of the right wall.)

The point is, all these room treatments are great but the pyscho-acoustic theory I've come across (and IME works) is based on getting your listening room to be as normal as possible. According to this approach, ANYTHING that is different to normal is bad. Hence having an overly damped room is bad, not really because it is too dead-sounding with rolled-off HF per-se, but because normal rooms are not that dead-sounding. And again, an overly echoey room is not bad because the HF is too bright, but because normal rooms are not that bright-sounding. It's all about presenting a situation which the brain is used to processing. (Accordingly, my stair well is bad because it's not normal. Everything I've done is to try to move it back toward a normal situation.)

The idea is that - assuming the speakers are set in enough space - the brain is well capable of filtering out room reflections from the sound. BUT the room acoustic has to be as normal and usual as possible for this to occur.

The same theory says that omni-directional and dipole speakers ought to do better because they have a "normal" dispersion characteristic. Real sounds tend to disperse in all directions, and are not beamed at the listener, so the brain has an easier time dealing with reflections from transducers that do the same.

Anyway, I have had some success with making the acoustic more normal. You might tell from my footer that I use Inguz digital EQ but (since my speakers are set in space) only for 200Hz downwards. Below 200Hz, I can see the sense in using bass traps and other treatments. Above that, are specialised treatments always necessary, considering that normal rooms don't contain them?

Any comments would be welcome; I believe this is firmly on topic?
Darren

[rajacat]

What is a "normal" room . I thought that the purpose of acoustical treatment was to eliminate, as much possible, the influence of your particular room so that you can hear what is actually on the recording. As an earlier poster stated, the goal should be to hear the unique acoustical characteristics of the venue or what the sound engineer intended in the recording studio.

-Roy

[youngho]

It's definitely possible to have too much absorption, particularly if certain parts of the mid- and high-frequency audio spectrum are absorbed more than others. Basically, bass trapping is generally beneficial, and first reflections usually should be treated, but further absorption is not typically necessary. If Darren Yeats placed significant amounts of absorption on both sidewalls (the entire walls?), then it's not surprising that he found this undesirable.

Normal rooms typically contain things like furniture, rugs, and bookshelves. Siegfried Linkwitz and Floyd Toole argue that these sorts of things may be sufficient for typical listening rooms. Others disagree.

Omni-directional and dipole speakers require more careful placement in order to reduce early reflections, i.e. those occuring under 6-10 milliseconds.

[Ethan Winer]

bass trapping is generally beneficial, and first reflections usually should be treated, but further absorption is not typically necessary.

I agree with this. I have a huge amount of treatment in my living room, but it's all bass traps except for the side wall and ceiling high-frequency absorption at reflection points, plus four diffusors on the back wall. My room is absolutely not too dead, and sounds very much like a normal room.

--Ethan

[Nils]

...

Omni-directional and dipole speakers require more careful placement in order to reduce early reflections, i.e. those occuring under 6-10 milliseconds.

Yes and no.  With dipole speakers, you don't need to worry about reflections on the null axes, which may end up being where your first reflection points on the sidewall are.  Also, with line-source Magnepans, the ceiling is less of a worry than with standard cone dynamic drivers.

However, you do have to worry especially about the first reflection points on the front wall (i.e. the one behind the speakers).  I ended up using 2 of my ASC StudioTraps to treat those spots.

-- Nils

[youngho]

Sorry, I was both simplifying and generalizing a bit, and I consider toe-in to be a part of speaker placement. You're right that with a little toe-in that the side walls are less of an issue for bipoles, although you probably still wouldn't want to put your speakers <1' away from the side walls (but, of course, excellent results have been reported with the smaller wall-hanging Magnepan panels when placed very far apart from each other and toed-in severely, i.e. mounted at something like a 75 degree angle with respect to the wall). I wonder whether you might notice a difference with true diffusion behind your panels, and I look forward to reading about your experiences with the upcoming GiK panels, if you get them and place them behind your panels.

I never quite understood the argument "Real sounds tend to disperse in all directions." For example, unless the head is tilted far back so that the mouth points at the ceiling, a singing or speaking human doesn't quite have either a omnidirectional or bipolar radiation pattern. This is true for many most brass and woodwind instruments over large parts of the audible frequency spectrum, as well.

[bpape]

Actually, it has less to do with what is making the sound as it does the frequency.  Stand outside and turn your back to someone and speak.  Can they hear you?  Sure they can - but mostly the lower frequencies.  There's no reflections there but the lower frequencies are more spherical in their dispersion pattern.

Bryan

[youngho]

I'm sorry about my writing. I try to write carefully and simply, but clearly it's not working. I wrote "a singing or speaking human doesn't QUITE have either a omnidirectional or bipolar radiation pattern" (emphasis mine). This does not mean that the human voice does not have ANY omnidirectional radiation, and I wrote bipolar, rather than dipolar, for a reason.

As you know, the head itself casts a shadow, so the radiation pattern will be rather cardioid, with differences from front to back ranging from <5 dB to as much as 12 dB depending on the frequency. Many wind and brass instruments the frequency range of the human voice. In these cases, the player will act to cast the shadow. Hence, these don't have quite an omnidirectional radiation pattern. String instruments, however, will have a radiation pattern more akin to a bipole.

Also, if you take a conventional non-omni, non-bipole, non-dipole loudspeaker and play it outside, of course you can hear it even if you're standing behind it. So, even with reproduced sounds, they tend to disperse in all directions, but the dispersion will vary at different frequencies, and with real sounds, with different patterns for different instruments.