Cardioid Bass.... yes, very good!!

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Hi Roflynn

Thanks for the story, interesting, I have made also H frames and U frames, (leaking box version and normal version) the H frames did sound the best from all except the leanking box has more spl watt, (6dB) so it is worth to test further later on but try to make it cardioid is not easy below 40 hz you need a delay line and extra speaker then, oke what you sy about localise the bass always keep crossover below 100 Hz say 90 Hz will do because every ob can easely do 90 Hz without to much loss, and so you can put the subs on other places but fase can go troubling.

H frame

second test of H frame dipole speaker. - YouTube

and low tone with a dipole cardioid who has very small openings on the cones to lift up the qts, it did give serieus output but needs power and heavy cones so this one has not
much power need before going out of xmax..

20Hz bas tone trough dipole box - YouTube

it came from here.

http://www.kirchner-elektronik.de/~kirchner/DIPOL-CARDIOID.pdf
 
I did some measurement on the linkwitz w dipole, here are the results of a shelf filter in the amp and 120 hz low pass, on 260 Hz you see a rest of the dipole peak plus 4 dB so we need a notch here, I think make the box bigger, or longer bigger baffle when not folded we get a peak lower then the 260 Hz, I think the notch technic can alowed for a bigger folded open baffle W frame, even one with a slot two woofers and folding with notch give a higher efficienty what is oke. Even we go to 50 Hz or lower but it get a pipe and need maybe even more notch, I don,t now or notching wil have effect on the sound, never tryed.
 

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I will . . Thus will be a littler different because I will be using digital eq and delays to make things absolutely identical.

If we get a couple of rainy days I may be able to throw the old CRAW together and see if it still works. I don't have the drivers it is supposed to be used but some that are pretty similar.

When you get to it, I'm Very interested, I'll keep my eye out - what might you call the thread

In theory I like cardioids too. They have the potential of allowing them placed very close to the room front wall

Elias/ JohnK

Do you have a link or reference, re allowing them to be placed very close to the room's front wall?

Thanks
 
We must remember the room and it's modes and nodes, if we consider bass output and reflections. They always create a resonant system (It is practically impossible to kill those) As we know music contains many frequencies and harmonics of them. It is a very heavy task to manage all this.

I think that a multisub approach is the most practical solution, it gives remarkable results even without dsp.

This is valid for bass region 20-90 (150)Hz. Above this early and late reflections are important. How do you control all this - I don't believe in making a well behaving (in a room) single speaker that goes 20-25000Hz.

The AV amplifiers have a subwoofer xo around 80Hz for a reason. This always gives me better bass than full range speakers (at home). And using this feature makes it easier to choose good main speakers and good sub(s) And I can place mains and subs to their optimal positions. (which are never same)

I have also a "pure 2ch" set. It is very hard to get bass right with it. The practical solution is to use it when playing vinyl records, speakers are 9 liter closed box that fail to go very low! They can however exite my room mode at 45Hz
 
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I have been very much appealed to the discussions around Cardioid Bass. More complex to design than dipoles, yet they seem to promise good things when compared to monopoles or dipoles: <snip>

Some of the dubstep folks are starting to run these types of setups. The difference in the venue is jaw dropping. It's the aural equivalent of going on a big rollercoaster. Just mind bending.

Off the top of my head, some shows I've been to that used cardioid bass:

1) Bassnectar (Rat Sound)
2) Skrillex (PK Sound)
3) Excision (PK Sound)

At the Bassnectar show the sound behind the speakers seemed to be about 20 decibels lower than in front of the subs. If I'm not mistaken, they used identical speakers placed behind the mains and delayed to form a cardioid.
 
I've managed cardioid like response out of an AE TD15M in an enclosure stuffed with denim insulation. The enclosure has 12 2" holes on each side, but it is only usable from 150hz to 450hz due to excursion on the bottom end and odd off axis response on the top end. It then passes onto a large horn that takes me to 20k. I would love to have cardioid response from 20 to 20k without separate delayed speakers, etc...
 
What is the best QTS for a cardioid? maybe a 15 inch car woofer (2x) will work but are sometimes qts=0,60 to 0,90/1,00.

I think a higher qts means a lower electronic correction.

This kind of woofer I have not yet try, now i have a T-TQWT who do very wel down to 15 Hz, but is big you have smaller ones.

my T-TQWT dow work together with two open baffles with phillips 1973 speakers, very nice sound.

regards

kees
 

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I think that a multisub approach is the most practical solution, it gives remarkable results even without dsp. This is valid for bass region 20-90 (150)Hz. Above this early and late reflections are important. How do you control all this - I don't believe in making a well behaving (in a room) single speaker that goes 20-25000Hz.

I caught myself -saying that above in Feb '12 and right after that I started the AINOgradient project! My lowest bass is omnipole crossed LR2 to dipole at 130Hz (about, varies). I have just done a seris of measurement with convntional monopoles to see the effect of different radiation patterns, and they are dramatic! I will post them later in my own thread.

There are many ways to create cardioid response and shifting it to dipole or monopole. Kimmosto is an expert o cardioid bass, see his projects eg. KS-1804 DIY archive of Kimmo Saunisto
 

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I busy with horns.

Seems like a lot of people end up there.

Bass is important and cardio bass may be a good option, but its the midrange where horns excel that makes the most perceptual difference. Get that right and then the bass becomes important. But good bass and poor mid range will always be a poor sounding system.

I've looked at cardio many times, but the complexity is hard to get past. To me, multiple subs is the most effective solution to the bass problem in small rooms. Whether cardioid bass is better or worse is unclear as there is so little data.
 
What I did have that with the dipoles I had, these have good bass without much room infloences, most what I did like was the air arround it.

But the system you mentioned, is there some documents about it?.

I did see these, I think digital filter is needed, this is a resistance box, some types.

Cardioid bass

regards
 
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I don't know if double bass arrays (DBA) are analogous to cardioid bass but Todd Welti used software to compare DBA against multi-sub sound field management (SFM.) DBA was a possible solution -- in rectangular rooms -- but SFM did not choose it as a solution. I don't know if one can run cardioid bass through the SFM algorithm or if DBA is essentially the same thing.

Welti did this comparison back in 2011. Today, we have access to inexpensive DSP which might tip the scales even further in favor of multi-subs.

Comparison of Double Bass Array to Sound Field Management: THE MEATY PART!!! | What's Best Audio and Video Forum. The Best High End Audio Forum on the planet!
 
I have read this on linkwitz, I have some big woofers I do like to test that, what I need is a closed box radiate on the floor all around and a dipole like on pc? connected on a special way in polarity. I had the dipole one day, these are for mine ears better then the horn, but mucho less efficienty, so for stage not to possible, but I read a hardrockband has used such a combination, so maybe I am wrong, for shure so big it will not fit in mine room, I have quite a smaa room of 27 square meter incl kitchen.

H-U frame woofers

For as I ready later with the amps, I need for shure a good loudspeaker system.
 

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