The Advantages of Floor Coupled Up-Firing Speakers

[graaf]

Originally posted by Pan

Without this ability our ancestors would have been tigerfood and we would not exist.

/Peter

that is correct
I am glad to see that the matter of "pinpoint imaging" in live music perfomances seems to be explained. At least all positions are explained

and what about loudspeaker-room interface? what about reflections, loudspeaker perception as distinct sound source due to crosstalk and reflections from side walls etc.

any more thoughts, experiences?

[Pan]

Yes!

Obviously the more diffuse and the more reflective the conditions are the harder it is to hear the location of a source with precision. This is true for live performances as well as reproduction.

Also the time and direction of the reflections is very important. Much work has been done on this of course.


Early reflections (around 5ms or so) has a strong influence on focus. Therefore if you are interested of hearing the true size and character of the recording venue, and also a realistic 3d soundstage with localisation of the recorded sources, these early reflections most be controled somehow in the listening room.

Search for ITD (initial time delay) and RFZ (reflection free zone).

I believe what drives many to a more diffuse reproduction is becasue a lack of understanding of how to extract the information form the recording. But sure.. it's much a question of preference.

I have tried various types of speakers and room treatment and even though I sometimes can apreciate a sound that consists of many reflections from the room surfaces IMO it gets tiring in the end becasue of the same signature is coloring every recording... "sameness".

I used the German Physics 360 degree driver for some time but later moved back to boxed speakers and then to dynamic dipoles for higher directivity.

If early reflections are controled and room resonances are dealt with.. and the "RT-60" is short enough than a two channel set up can open up a big hole into the recording venue which can be very realistic and impressive IMO.

I am looking into a surround set up right now though so I can have ambience all around me for more realism. 6-8 surrounds speakers.


/Peter

[graaf]

Originally posted by Pan


Early reflections (around 5ms or so) has a strong influence on focus. Therefore if you are interested of hearing the true size and character of the recording venue, and also a realistic 3d soundstage with localisation of the recorded sources, these early reflections most be controled somehow in the listening room.

/Peter

yes I am interested and this is why I try what I decribed above

Originally posted by Pan


I believe what drives many to a more diffuse reproduction is becasue a lack of understanding of how to extract the information form the recording. But sure.. it's much a question of preference.

/Peter

to make myself clear once again - I am not into "more diffuse reproduction"
quite te contrary - I am into precise and realistic imaging and soundstaging

Originally posted by Pan


I have tried various types of speakers and room treatment and even though I sometimes can apreciate a sound that consists of many reflections from the room surfaces IMO it gets tiring in the end becasue of the same signature is coloring every recording... "sameness".

/Peter

I have never observed "sameness" using the devices I desrcibed above. Rather I have observed "sameness" in standard stereo triangle set up in comparison

Originally posted by Pan


If early reflections are controled and room resonances are dealt with.. and the "RT-60" is short enough than a two channel set up can open up a big hole into the recording venue which can be very realistic and impressive IMO.

/Peter

this is what I have experienced with pseudoambiopole and what I aim to achieve in my new room with omnidorectional speakers

please take a look at my first post

- significant reflections off the adjacent wall would not reach the listener
- floor reflection would not reach the listener
- first reflections off the front wall and off the back wall would reach the listener 9.3 ms after the first wavefront
- first reflections off opposite walls would reach the listener 8.3 ms after the first wavefront
- first reflections off the ceiling would reach the listener 8.8 ms after the first wavefront (ear at height of 90 cm, ceiling at height of 300 cm)
It seems that apart from those earliest reflections <1 ms all other reflections are delayed more than 8 ms and caught by precedence(Hass) effect.
And all this in a relatively small listening room. The bigger the better.
Also I am considering using some wide band absorbers to reduce the reverb after first 50 ms as Moulton recommends.

this is how I try to "control somehow early reflections in the listening room"

what do You think?

best,
graaf

[gainphile]

Funny thing is since I got my OB running, I no longer care or look for a "pinpoint imaging". Sound is simply "there" and it's all that important

[graaf]

Originally posted by gainphile
Funny thing is since I got my OB running, I no longer care or look for a "pinpoint imaging". Sound is simply "there" and it's all that important

perhaps I shall start a new thread on "pinpoint"?

[Pan]

Graaf,

sorry for not paying enough attention to what you have written earlier in this thread. I was talking in general terms and did not adress you or your set up specifically.


/Peter

[graaf]

Originally posted by Pan
Graaf,

sorry for not paying enough attention to what you have written earlier in this thread. I was talking in general terms and did not adress you or your set up specifically.


/Peter

absolutely no offence taken at all

I asked You to take a look at my first post just because I would like to know Your opinion.
This is sort of alternative method of dealing with early reflections.
Alternative to moving the loudspeakers as far from the walls as possible and of treating the walls with absorbers/diffusors

best,
graaf

[el`Ol]

Hello Graaf!

I have been listening this way for a while, just with the drivers on ear-height. I am using the Ciare HX201, also not ideal and originally bought for an other kind of use. The problem is a 2kHz shout. There was a large 8" fullrange driver test in a German DIY magazine and all drivers with sufficient treble rise for compensating the ceiling loss have this shout. My recommendation is the Ciare HX160. According to an other magazine it is shout-free from 60° off-axis and has a similar rise as its bigger brother. The frequency response is very rugged in the treble, but the CSD is very fast without irregularities. The measured TSPs differ from those at the Ciare site:
Fs 59.56
Re 5.53
Rms 0.48
Qms 6.44
Qes 0.34
Qts 0.33
Cms 0.87
Mms 8.23
Bl 7.05
Vas 22.68
Le 0.05 (!)
Sd 137
In my simulations it works very well in horns, so hm´s Lure, which was designed for the DDD, could be an option if a BR happens to work not properly. I haven´t bought a pair of them or notched out the shout because I intend to get an EQ/ room correction system anyway for the OB-bass. In my former listening room the ceiling reflection had a delay of 4ms, which is the border between perceiving it as part of the source vs. early reflection. This worked VERY well. In my currrent listening room the delay is higher, which results in a desintegration of the spacial image. I will have to fix this with reflectors or wheels on the speakers to get it off the door while not listening (in case the room correction or multi-band delay can´t fix it).

regards,
Oliver

[graaf]

Originally posted by el`Ol
Hello Graaf!

The problem is a 2kHz shout. There was a large 8" fullrange driver test in a German DIY magazine and all drivers with sufficient treble rise for compensating the ceiling loss have this shout. My recommendation is the Ciare HX160. According to an other magazine it is shout-free from 60° off-axis and has a similar rise as its bigger brother. The frequency response is very rugged in the treble, but the CSD is very fast without irregularities.

thank You for that information, the Ciare driver looks very interesting

as to the "shout" - in my Fostex FE206e the main problem was sharp resonance at about 2.8 kHz
I treated the cone and it has moved up in frequency to about 4 kHz and is now also reduced in level. Definitely less offensive to the ear now

Originally posted by el`Ol

In my former listening room the ceiling reflection had a delay of 4ms, which is the border between perceiving it as part of the source vs. early reflection. This worked VERY well. In my currrent listening room the delay is higher, which results in a desintegration of the spacial image.

very interesting remarks as to beneficial effect of this earlier ceiling reflection - I have to try this

thank You very much!

best,
graaf

[Graham Maynard]

Hi Graaf, and others.

Is it not the case that as you walk closer to either LS, its centre beam plus the ceiling reflection of that beam seriously interfere, thus making an optimised listening area very small and narrow ?

Also what is actually being listened to, the front of cone radiation at possibly 50 degrees plus baffle edge radiation, for much more must go into room reflections than radiates directly ?

I'm not trying to pick holes or be funny, it is just that I had already tried a loudspeaker (B200 - also shouty) on the floor as suggested and it was so much inferior, especially with regard to the noted ceiling beam interferences.

Cheers ........ Graham.