nice
what's interesting it perhaps can work also the other way round like in case of Samadhi Cube
Its a bipole also.
Has another Tangband on its back. So no wall proximity effect any good for it. That cube is applying Roy Allison.I guess that Joachim is using a guided planar wave because it matches the extended ranger's -45deg lateral at some point around fXo so it must behave better than needing another plane of launch.
Wahab, the Group Delay measurements have been taken in doors so there is a lot of reflexion. As soon as the weather allowes i will take that masurements again outdoors.
I just whanted to show that the crossover to the tweeter is phase linear.
Graaf, thanks for the contribution. I use the ribbon tweeters because i like resolution of micro detail. Crossover is very importand though so i tried a constant groupdelay design.
Soundwise it blends quite well and i even did no finetuning yet.
Salas, yes i choose the Horn Ribbon because of adiation pattern but also because the acoustic center is set back a bit making a phase linear crossover easier to implement.
In the horizontal plane everything is fine. Vertically i get some lobing but i put the tweeter over ear height ( the wideband is on ear height) and the panels are much further from my seat then my nearfeld monitors so unless i stand lobing is not audible.
Setting the panels back had no negative effect on 3 dimensional imaging to my surprise and the sound is more seemless.
The reason for the good phantom image despite the panels being around 2.5m from my ears seams to be the radiation pattern that bundles more then my monitors. The acoustic plane is much bigger so to say.
P.S. : nice little cubes you are building !
I just whanted to show that the crossover to the tweeter is phase linear.
Graaf, thanks for the contribution. I use the ribbon tweeters because i like resolution of micro detail. Crossover is very importand though so i tried a constant groupdelay design.
Soundwise it blends quite well and i even did no finetuning yet.
Salas, yes i choose the Horn Ribbon because of adiation pattern but also because the acoustic center is set back a bit making a phase linear crossover easier to implement.
In the horizontal plane everything is fine. Vertically i get some lobing but i put the tweeter over ear height ( the wideband is on ear height) and the panels are much further from my seat then my nearfeld monitors so unless i stand lobing is not audible.
Setting the panels back had no negative effect on 3 dimensional imaging to my surprise and the sound is more seemless.
The reason for the good phantom image despite the panels being around 2.5m from my ears seams to be the radiation pattern that bundles more then my monitors. The acoustic plane is much bigger so to say.
P.S. : nice little cubes you are building !
Ok , Joachim..
The global perfs seems very good, though..
Now, for the weather , i think we ll have to wait
some time...
I live 20km from Germany s Black Forest , and i feel
that spring will be a bit late, but we never knows...
ANyway, keep the good work.
We had fine weather recently but now it got unstable and cold again. There was even some
watery snow today.
I build a fitting dipole subwoofer for the MPL. It has 2 LAT modules, horizontally arranged to avoid assymetric gravitation load.
I call it an X - Baffle and it looks a bit like a truncated pyramide.
Textile cloth could be put over it and a lamp inside.
It will be actively steered with two amps. one each for one LAT.
The LAT is well suited for this aproach but sadly seems to be discontinued.
I found only some white papers on the Tymphany site and no other information.
That is a pitty because the push-pull operation makes them low in second harmonic distortion and as far as i remember the Q was quite high, also good for dipole operation.
I had successfully made an H - Dipole with one Lat some time ago so i know it will work well. Sound was fast and clean amd this X - Baffle design should do even better.
watery snow today.
I build a fitting dipole subwoofer for the MPL. It has 2 LAT modules, horizontally arranged to avoid assymetric gravitation load.
I call it an X - Baffle and it looks a bit like a truncated pyramide.
Textile cloth could be put over it and a lamp inside.
It will be actively steered with two amps. one each for one LAT.
The LAT is well suited for this aproach but sadly seems to be discontinued.
I found only some white papers on the Tymphany site and no other information.
That is a pitty because the push-pull operation makes them low in second harmonic distortion and as far as i remember the Q was quite high, also good for dipole operation.
I had successfully made an H - Dipole with one Lat some time ago so i know it will work well. Sound was fast and clean amd this X - Baffle design should do even better.
Attachments
Today we had exeptionally nice weather after two weeks of cold and rain so i could build something outside. My son likes my MPL very much so i build him a pair of MPL light. I took the ScanSpeak 10F/4424G00 in 4 Ohm and build it in an open baffle of 60cm x 125cm. It has 15cm wings on each side so in total it amounts to 90cm. I had experimented with 90° wings that where much longer but the sound gets very hollow, so this is a compromise between size and sound. When i measured the completed speaker is was pleasantly surprised. No crossover is necessary this time exept the line level cap i use that roles off my tube amps under 100Hz. The result is a classical difuse field response with some lift over 10kHz. 15% off axis the response is very flat so i setup the MLP Light in the nearfield, speakers crossed around 30cms before my ears. I used my X-Baffle dipole bass and set the crossover around 150Hz. The sound is exeptional considering the very small driver and playes loud too. The midrange and soundstage is something to behold. Treble resolution is fine too. I had build a similar system with the Jordan 13cm driver in a wide and narrow transmission line some years ago but as good as the sound was, the treble was a bit metallic and not very detailed.
Not so this time. It does not have the estreme micro detail of the horn ribbon in the big MPL but this is the best treble i heard from a wideband except the amasing Manger Wandler. The advantage this system has even over the MPL is a totally seamless sound. The step response showed a time coherent result so this works a a bending wave transducer. The higher the frequency goes, the smaller is the aerea that radiates so off axis extention is very good. Here are some pictures and then come some measurements.
Not so this time. It does not have the estreme micro detail of the horn ribbon in the big MPL but this is the best treble i heard from a wideband except the amasing Manger Wandler. The advantage this system has even over the MPL is a totally seamless sound. The step response showed a time coherent result so this works a a bending wave transducer. The higher the frequency goes, the smaller is the aerea that radiates so off axis extention is very good. Here are some pictures and then come some measurements.
Attachments
I saw your Dipass design and I like it a lot. For me it has only one drawback - Mundorf tweeter price. It cost arm and leg...
In your MPL you use much cheaper horn loaded ribbon, so maybe you can redesign the crossover to use it in Dipass too?
By the way, I have b200 with phase plugs and i think they do not neet a tweeter.
Regards
The standart B200 has a lot of problems higher in the frequency range that are not visible in the frequency response. It is a very noisy intermodulation product. That is the reason i use a relatively low crossover frequency in the Dipass. The Mundorf was handy because it is also a dipole. The MPL does not use a dipole tweeter and the sound is fine. I will experiment with a second tweeter to the back in antiphase soon. I do not know how the phaseplug in your version changes the situation. Anyway, even a modified B200 will never have the micro detail that a ribbon is capable of. That is simply a physical fact because of much lower moving mass. The horn ribbon tweeter i use works extremely well but i use it only over 8kHz. Mundorf has new tweeters you can see in Hobby HiFi that are less expensive. One model has very good extention in the treble but it is not a dipole. Sure, it´s not easy to find a tweeter that complements a high sensitivity wideband AND is affordable.
I agree that fullrange top end will never be as airy and detailed as ribbon tweeter. When I wrote that b200 don't need a tweeter I ment that there is no feeling that something is missed and sound is totally seemless and coherent. I think you know what I'm talking about?
I do not made measurements B200 with phase plugs, but improvement was audible. I think that Charles Altmann was right.
What do you think about Bohlender Graebener Neo3 PDR?
Zaph|Audio
It can be dipole too.
P.S. I'm not saying that you did something wrong with Dipass design. I'm just looking for cheaper alternative.
Yes, i know what you mean with seemless. It´s a very atractive feature of wideband drivers. The Neo3 came out best in the test at Zaph but it may not have high enough sensitivity. Maybe you could use two for 6dB more output. I can recommend the Fountec Horn Ribbon. You can buy it under the Dynavox brand really cheap.
More and more people listen to the MPL Mini with Scan Speak widerange in an open baffle.
Recently i got a visit from a friend. Actually she is a she and plays the Flugelhorn and also conducts a little orchestra. As small and affordable the Mini MPL is, for her it was even too big and expensive. So i made a sugestion to build an even smaller MPL. I call it the Baby MPL. It is a 28cm x 105cm baffle and this time the driver is in a glass pot, so this is a closed box system in a baffle. I used the Fountek, Dynavox FR88EX this time.
This system can be build for less then 60,-€ a pair. I am still using my X.Baffle woofer but it is now time to construct something smaller. The FR88EX does not play as loud and clean as the Scan Speak but for my friend it is more then loud enough. I am often surprised at how soft levels "normal" people listen. This time i present the measurements first and will post some photos tomorrow. The treble of this unit is a little ragged but i found that under 15° it´s ok, I also did a nearfield measurement where you can see the behaviour of the membrane. Up to quite high frequencies this driver works as a piston, then you see the usual edge resonance that is well controlled this time and then the driver breaks up in bending waves. Again, sound is surprisingly 3 dimesional and open, in a way more natural then many expensive a speaker provided the volume is moderate. Again i use no crossover, only a 10nF cap in front of my driving amp with 330kOhm input impedance.
Recently i got a visit from a friend. Actually she is a she and plays the Flugelhorn and also conducts a little orchestra. As small and affordable the Mini MPL is, for her it was even too big and expensive. So i made a sugestion to build an even smaller MPL. I call it the Baby MPL. It is a 28cm x 105cm baffle and this time the driver is in a glass pot, so this is a closed box system in a baffle. I used the Fountek, Dynavox FR88EX this time.
This system can be build for less then 60,-€ a pair. I am still using my X.Baffle woofer but it is now time to construct something smaller. The FR88EX does not play as loud and clean as the Scan Speak but for my friend it is more then loud enough. I am often surprised at how soft levels "normal" people listen. This time i present the measurements first and will post some photos tomorrow. The treble of this unit is a little ragged but i found that under 15° it´s ok, I also did a nearfield measurement where you can see the behaviour of the membrane. Up to quite high frequencies this driver works as a piston, then you see the usual edge resonance that is well controlled this time and then the driver breaks up in bending waves. Again, sound is surprisingly 3 dimesional and open, in a way more natural then many expensive a speaker provided the volume is moderate. Again i use no crossover, only a 10nF cap in front of my driving amp with 330kOhm input impedance.
for me it is surprising that most loudspeaker designers tend to ignore "normal" people needs in their work and even to disregard them quite arrogantly
here is my lenghty discussion with Dr Earl Geddes on the subject of normal listening levels:
http://www.diyaudio.com/forums/multi-way/121893-spl-targets-speaker-design.html
I think that this tendency - focusing of the loudspeaker industry on the needs of "abnormal" audiophile listeners - is partly responsible for the HiFi market decline into a freak niche
best,
graaf
Well, graaf, this is why I design my speakers for 80dB @ 2.5m. This is, to me, a normal listening level. But, then, I listen to classical, jazz and girl-and-a-guitar. Those who listen to mainly rock want higher levels, and this has been progressive as time passes until current rock is not much more that 100dB+ white noise.....I think that this tendency - focusing of the loudspeaker industry on the needs of "abnormal" audiophile listeners - is partly responsible for the HiFi market decline into a freak niche
best,
graaf
Note that with most people, the desire for loud music decreases with age. Older people are keeping jazz and classical alive. One wonders if the current generation of head bangers will listen to as they age, since they have never been exposed to "good" music. "Good" music just doesn't work as 256K MP3 through ear buds.
Bob