Measured monopole and dipole room responses

[seanny]

Hi John,

would you high pass the monopole to be comparable to the other 2 then run the test for it again?

[markus76]

Originally Posted by john k...

This is a dedicated listening room build in the basement of my home.

Such a room probably doesn't generate the data we're looking for. The typical North American stud wall construction works as a good low frequency absorber. In Europe, one is more likely to find rooms with rigid walls and severe modal ringing.

[mondogenerator]

in the UK, most pre-1960s homes are brick, post 1960 are breeze block, and for at least 20years they became stud wall. In my 5yr old home they are twin layer plasterboard with green glue, and cement loaded MDF floorboards.

Generally.

[markus76]

I once have seen data from a converted attic which had unbelieveable low modal ringing. The neighbors probably could hear the bass very well too

In any case the solution has to be tailored to the room. It's not as simple as "multiple subs is best" or "dipoles is best".

[john k...]

Guys, you are not paying attention. In my first post I showed that all three sources have the same anechoic far field response. Differences in the in room results are due only to how the different sources behave in that room. Everything is fixed but source type.

See the top two plots in post 376

[markus76]

Yes sure but the damping of your room probably dominates the results too much. We should look at the behavior in a room with rigid walls. This would make any differences caused by source type more obvious.

[Elias]

John,

What are the perceptual differences between the three source types in your room in the same configurations as the measurements were taken ?

Have you tried to listen modulated tone bursts ?


- Elias

[markus76]

Originally Posted by Elias

John,

What are the perceptual differences between the three source types in your room in the same configurations as the measurements were taken ?

Have you tried to listen modulated tone bursts ?


- Elias

Look at the burst decay. The only perceptual difference is probably caused by magnitude differences.

[john k...]

Originally Posted by markus76

Yes sure but the damping of your room probably dominates the results too much. We should look at the behavior in a room with rigid walls. This would make any differences caused by source type more obvious.

I'll post the impulse responses. I don't think you would say it's all that damped. My room is probably more rigid than a typical listen room here in the USA, particularly for the axial modes in the front to back direction where there are concrete walls directly behind, or within a couple of feet of the studded walls. What to you guys live in, concrete boxes?

Originally Posted by Elias

John,

What are the perceptual differences between the three source types in your room in the same configurations as the measurements were taken ?

Have you tried to listen modulated tone bursts ?
- Elias

I don't listen to test signals. I have no idea what they are supposed to sound like. As far as music goes, you may recall that the original NaO II had a woofer system which could be mechanically and electrically converted between U-frame quasi-cardioid and sealed box, with identical free field response. The NaO II RS has only the U-frame cardioid. That should tell you something. The only advantage I found with monopole subs was their greater efficiency so they could play louder. I haven't listened to dipole woofers for several years. They are just too inefficient for a small foot print full range speaker like the NaO II RS.

Also, in this test I am not trying to find optimum position for the placement of the woofers. I'm interested in how they perform in a typical stereo speaker setup.

[markus76]

Originally Posted by john k...

I'll post the impulse responses.

Yes please - thank you.

Originally Posted by john k...

What to you guys live in, concrete boxes?

Yes and there are steel bars in front of the windows
The walls at my current place are about 70cm (2.3ft) thick.