Positioning

Doc B. · 4002

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Offline Doc B.

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on: November 12, 2019, 08:30:37 AM
Spending some time this week running tests in the new listening room with my new Jager cabinets. On the drive into work this morning I figured out this is the fifth room that I have set Jagers up in. A few consistencies in the method of setting them up are beginning to appear.

Some of you may recall my surprise in finding that the modeling of our old listening room suggested putting the prototype speakers up very close to the front wall, and that I found that setup to work very well. That has also worked well in my home theater, PB's listening room and now it seems to work quite well in the new room. Note that these rooms vary quite a bit in size from 12' x 13' thru 15' x 25' to the current 23' x 24'. This close placement to the front wall seems to give the best bass balance in any room, a nice feature that keeps the good sized towers from intruding in the room as much as a speaker that needs to sit farther out into the room. My hand waving theory is that it has to do with the position of the ports on the back, one being near the floor and one being about halfway up the wall. I suspect the reinforcement given by the front floor/wall and ceiling wall corners might be spread out a little more over the bass spectrum with this configuration than the bass from a single port would. Or maybe I am totally wrong about this.

Part of the reason this positioning close to the front wall works seems to be due to the horn tweeters with their felt diffraction treatments. The tweeters image extremely well and I find in most room setups that I can put the speakers as far apart as I wish without any loss of the center image. The current setup has them about 14' apart on centers with a couple listening positions at about 15' and 20' from the speakers. But it also works in our little home theater at a listening position of about 10' from the speakers with them spread about 9' or 10' apart. All that said, some acoustic treatment on the front wall to reduce early reflections will help here as it does in virtually any speaker setup.

Speaker polarity matters. In setting up the system this week I am using a single Kaiju 300B amp and the stock passive crossovers. I tried swapping polarity of the speaker cables right at the amp (in other words I was switching the polarity of the entire speaker not just the tweeter), searching for the best sounding bass. Interestingly I found that the most profound effect was actually in the lower to mid treble, with vocals smoothing out nicely in one polarity and gaining a bit of harshness when that polarity was reversed. There will be no correct answer on which way this polarity should be in your system vs. mine. You will just have to experiment. It is very much worth the slight effort it takes to swap cables and listen for differences. Yes, this could possibly take you down a rabbit hole if you decide to check the polarity of every recording you have. But I found that one polarity was pretty consistently better than the other with the majority of songs I tried.

Toe-in is not absolutely necessary, but I find I prefer toeing the speakers in so they are firing directly at the listening position or slightly farther in. But they sound pretty good facing straight out into the room too.

The cabinets themselves feel pretty dead when you play music through them, and I think the efforts we took with driver isolation and cabinet bracing have paid off. However there is a significant improvement in the clarity and dynamics when the cabinets are lifted off of wood floors with spikes or other methods.

None of this bypasses the basics of good common sense room treatment. I have a 12' x 16' rug on the floor in front of the speakers to kill the floor reflection and to add some absorption to the plywood floor in this fairly hard and live room. The left wall has three large windows and those have been treated with acoustical blackout curtains. Below these windows are older Ikea Expedit shelves filled with various media (CDs and tapes). The right side wall has two of the large Expedit cabinets, filled with more media (LPs and tapes). The ceiling is somewhat unusual in that it has exposed plastic backed insulation which is up against the roof of our second floor warehouse room, creating a sort of soft dropped ceiling. For the moment there are a couple of 16" diameter 6' tall DIY tube traps on the front wall between the speakers, to add a little treatment for front reflections. This was all relatively inexpensive to install and IMO worth way more than the equivalent amount spent on some whiz bang piece of gear to try to get similar sonic improvements.

That's what I have so far regarding this latest installation. I'll post any other enlightenment I may experience, and please offer up your own findings as well in this thread.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Deluk

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Reply #1 on: November 13, 2019, 04:11:53 AM
Photos would be good if that is possible. Good advertising and PR too.



Offline Doc B.

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Reply #2 on: November 13, 2019, 07:03:28 AM
When I feel the room is ready to be shown I will post some images. Right now it is still a mess as it is being put together.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline robertod

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Reply #3 on: November 15, 2019, 05:13:39 AM
Thanks Doc for the info.

Rega P6
George Wright Sound WPL20 preamp with phono
George Wright Sound 2A3 Mono Blocks 3.5 watts
Audio Note M-1 Phono Pre-Amplifier
Jager Speakers


Offline Doc B.

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Reply #4 on: November 15, 2019, 05:32:25 AM
I should add that you can see a couple pics of the early process of putting the new room together on our FB @bottlehead and IG @bottleheadaudio feeds.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Hank Murrow

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Reply #5 on: November 16, 2019, 07:45:55 AM
I read your story of Jaeger positioning with interest(though mine are far from finished). I noted that you strongly advise coupling the Jaeger base-plates to the floor with some arrangement of spikes. Do you have a suggestion among the many iterations of these devices that yield the best bang for the buck? I find that there are sets from $15 to $200+ per set of 8. Also, I find the weight per speaker nowhere listed, what do yours weigh/side?

I am stoked to see how much improvement in soundstage and headroom that will likely accrue with the introduction of the Jaegers into my all-BH system, and the eventual addition of the electronic X-over remains a possibility to explore later. BTW, check out the Rudolf Barshai reading of the Mahler Tenth for a thrill-ride with your setup.

Cheers, Hank in Eugene



Offline Paul Birkeland

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Reply #6 on: November 16, 2019, 11:26:48 AM
I bought a McMaster Carr 60015K42 Vibration-damping pad and cut it up so there was one square on each speaker corner, then pressed the speaker down into these pads to suction cup them down to my floor.  For me, this worked better than the metal PartsExpress spikes that I tried, but I have an engineered floor over concrete. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Hank Murrow

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Reply #7 on: November 18, 2019, 02:43:50 PM
Thanks, Paul;

My floors are varnished wood, but I imagine your technique would work if the suction holds. I will order some of that pad and try it with the speakers I am now using to see how well it holds. I had hoped to get North this fall, but that seems remote at present. Perhaps in Spring.

Cheers, Hank