Forte II positioning

[lionheart-uk]

I talk to a lot of people who have gone back to vinyl with mixed results, usually it's the limited availability of affordable decent record decks/Cartridges and setting them up correctly that is the problem. Unless buying 2nd hand most returnees choose new Low to Mid-Fi budget decks and wonder why they don't sound anywhere near as good as digital.  I can understand both analogue & digital camps but being a bit of a 'flat-earther' I find vinyl to be the medium of choice. 

 

 

[lionheart-uk]

I've been listening to the Fortes at 45 degree for a few days now and the soundstage has shrunk dramatically and I get that listening in a corridor effect, I guess this is 100% due to the width of the room, toeing them in a few degree but keeping them close to the walls I think is the best way for me to go in this restricted room, they certainly sound at their best in this position. 

[Chris A]

On 11/6/2016 at 2:51 AM, lionheart-uk said:

Is there any sane reason why my Fortes sound better when placed tight in corners?...

 

I have tried them in numerous positions but always go back to having them 6" off the rear wall and 4" from the side walls, firing straight down the room with no toe in because they sound so much better.

 

I know this flies in the face of what most people think about positioning of these speakers and if I had not done an A-B comparison I would have agreed and expected to hear boomy muddled bass from the 15" passive being so close to the rear wall, to my ears the sound is just right and pulling them out from the walls makes them bass shy and bright.

See:

If you can remove any electronics, racks and other acoustically reflective objects from between the loudspeakers (or place acoustic absorption on their sides), I think that you'll find that toe-in suddenly works.  A little absorption here and there just around the loudspeaker midrange horn mouths will improve that corridor effect--rather effectively.

 

Chris

[mkane]

Nothing like it when done well. A deck and a nice phono pre=

 

 

[WMcD]

I have a theory on aiming.  

 

There is a lot of traffic on aiming the horns so "on axis" is in front of, or at, or behind the listener.  My thought is that there are such differences in experiences because everyone's room set-up is different.  Hard to argue to the contrary about different experiences in different rooms.  In view of this, any favorable experience is valid.

 

But . . . my theory further to those.  We have to consider what you're aiming away from.  Granted, it may be that at 45 degrees we're not beaming toward the adjacent walls if the pattern is narrow enough.  We are beaming to the opposite wall though, and maybe this is not so good.  Generally,  we might get radiation which is harmful to the listening experience by following the common practice of 45 degree toe-in as dogma.  It  all depends on the room.

 

I'm thinking that if you are getting good results by aiming straight down a narrow room you are aiming away from the front wall behind the speakers (which if there is an echo would cause harmful short delay echos) and away from the opposite wall (which would mix with the sound from the speaker on that side).

 

If it works for you, it is good.

 

WMcD

 

 

 

 

[WMcD]

FWIW:

 

There was an article in Audio about what Klipsch called the tractix mid of their design when Klipsch adopted it in the Forte II.  The Forte had an exponential mid.

 

I had posted the article along with my annotations.  Unfortunately I'm seeing a 500 server error when looking for it. I was able to find a graph with my annotations.  (Hint, you can find your attachments in your profile.)

 

It is not entirely clear that the graphs in the article are actually a comparison of the Forte versus Forte II.  It sure seems to be, though.

 

My major point, there, was that the graphs of horizontal and vertical polar coverage showed something which should be expected in theory.  It borrows from design of radio frequency antennas which says that if you want an antenna which is directional with a narrow beam, it must be large compared to the wavelength.  Therefore, the Klipsch tractix horn is larger than the exponential in the vertical dimension and can be expected to get more directional (lower angle) in the vertical before the exponential does as frequency goes up (wavelength goes down).  Don Keele used this in his seminal paper on "What's so Sacred . . ."

 

This is a bit counter intuitive.  You'd think this is like having a flashlight (torch in the UK) at the position of the driver and shining into the rectangular mouth.  So if the mouth is narrow in the vertical, the light coming out is narrow in the vertical plane though the mouth.  But it doesn't work that way.

 

That is not really the point here.  I want to talk about horizontal polars which are expressed as beam width in degrees.  We read about 90 degree exit angles and even 90 degree patterns.  But those numbers are just not true. 

 

The graph supplied by Klipsch shows that the tractrix and exponential have very similar horizontal beam widths as shown on the left graph.  At lower freqs (long wavelengths) the pattern is much greater than 90 degrees and at higher freqs it is more narrow going to 60 degrees. 

 

How does this fit into my theory of "aiming away"?  It just shows that at higher freqs the horizontal pattern is narrow at 60 degrees.  Therefore we can aim it away from walls.  At lower freqs the pattern is 120 degrees and so aiming doesn't do much good.

 

I know that doesn't give easy answers or applications.  Nonetheless, it is getting closer to the truth.