Hmmm.
I've lived with Jordans (4"), Mangers (8"), Eton (4") and now GPA/Altec.
I'm leaning towards large format mids and the efficiency as well as surface area afforded by such. There is obviously more than one way to skin the cat, but overall I like what I'm hearing.
I don't think of "Bass" as the new midrange.
They are simply larger format drivers than are commonly used in hifi speakers.
Chris
I've lived with Jordans (4"), Mangers (8"), Eton (4") and now GPA/Altec.
I'm leaning towards large format mids and the efficiency as well as surface area afforded by such. There is obviously more than one way to skin the cat, but overall I like what I'm hearing.
I don't think of "Bass" as the new midrange.
They are simply larger format drivers than are commonly used in hifi speakers. Chris
Lynn Olson said:
I already felt absolutely sure about that.
Why I stick with class A/B is a simple calculation. Assume a silicon 40 W class A - somewhere in the range of your Karna – these will have about 200W idle heat dissipation. Multiply this by 12 and you arrive at 2.4kW
In summer I would need air condition and noise would raise at levels music listening no longer would be fun.
On the other hand the amps I have already I'm very happy with – at least from a cerebral point of view - with some room left for improvement in the emotional department which is in the pipe already.
Lynn Olson said:
The whole digital stuff isn't that much annoying – it can degrade sound – yes, of course – like everything else (parts quality, layout, ...) - but also not necessarily. The advantages outweigh the risk by far (for me).
Lynn Olson said:
Very much interested to hear about your findings.
The main idea behind the concept of flying speakers in our context is that whatever structure you use to hold your speaker in place – it kicks back !
Basically every structure is a resonant part by itself.
An analogy to the issue with back EMF from the speaker to the amp.
It would be a pretty hard job to determine HOW EXACTLY the structure kicks back. – quite in contrary to flying where the HOW is of little interest as attenuation of movement is very high.
The solution isn't to try to improve stability of the structure to keep the speaker from moving – its just the other way around: allow the speaker move as free as possible to let the impulse balance locally and then isolate the structure from the speakers forces / movements with a suitable suspension or like a pendulum.
Its really easy to keep pendulum resonance way below the audio band, even for deep bass.
If flying your speakers its best to use a 3 or 4 point technique to avoid stimulating totter movements.
Currently I am flying only the mid's – pretty happy with the results.
Double 15" bass' ( at 90 degree angle with "split excursion" to compensate for power response ) had to wait and are still "conventional" sitting on the floor, as doubling our roof's isolation was at first priority driven by peak oil prices and the first snow in the upper mountains.
By the way AMT's are the only speakers I'm aware of that have impulse compensation built in (plasma's left aside).
The diaphragm folds are moving to both sides impulse-compensating each other completely - leaving only the acceleration of the very low air mass as an axial impulse.
Greetings
Michael
I'm looking at the Rane or similar pro-quality analog parametric equalizer. That's what Wally Malewicz was using for his bi-amplified speaker (on the bass channel), and I thought they sounded wonderful.
The issue of mechanical reaction forces coming from the driver certainly needs more investigation - I guess I'll be buying an accelerometer in addition to the Aco Pacific 1/2" 7012 microphone I already have.
People usually think of the mass ratio between the diaphragm and the much larger mass of the cabinet or open baffle, but there's more to it than that. At frequencies where the cabinet or open baffle goes into resonance, this mass ratio is overshadowed by the sharp change in mechanical impedance of the resonating body, and the acoustical output of the cabinet or open baffle goes up hundreds of times (compared to the emission at non-resonant frequencies). Almost all of the acoustical output of the cabinet or open baffle is at the mechanical resonance frequencies, and very little at other frequencies. In effect, the trouble frequencies fall in the 200 to 800 Hz range, with little to no emission elsewhere.
Freely suspending the driver from rubber bands or bungee cords (at 3 or 4 points, as mentioned previously) acts as a lowpass filter, preferably set well below the bandpass of the driver. This is not too different than a turntable suspension tuned to a frequency well below the 7~9 Hz tonearm/cartridge resonance, typically 3~4 Hz. It is desirable to keep the resonance above the rhythms of the music, so 3 Hz is a realistic minimum for the suspension.
I'm looking closely at 2 or 3 of the AESpeakers Dipole 15's per side in a close-fitting array, with the Selenium 15PW3's as an alternative. If anyone from AESpeakers is reading this, what are the Xmax, Qts, Fs, normalized efficiency, and pricing of the Dipole15's again? Can't find it on the AESpeakers website right now.
Regarding the Feastrex, you can think of them as super Lowthers, and priced accordingly. They have several dB more headroom than a Lowther, and don't hit the wall quite as hard - but it's not fair to reflex or rear-horn-loaded Lowther, AER or Feastrex to compare them to front-horn loudspeakers, which have 10 to 15 dB more headroom. I've never heard a front-horn Feastrex, and don't know if anyone has built one.
Any full-range loudspeaker, particularly with whizzer-cone HF, is so idiosyncratic I would never buy them without an extensive audition with CD's and LP's that you know well - these speakers are not for everyone, and you have to decide for yourself if the compromises are acceptable to you. The big plus of full-rangers is exceptional midrange coherence, and the downside is whizzer coloration and early HF breakup - and this is an area where the Feastrex is decisively better than any other whizzer-cone driver.
The issue of mechanical reaction forces coming from the driver certainly needs more investigation - I guess I'll be buying an accelerometer in addition to the Aco Pacific 1/2" 7012 microphone I already have.
People usually think of the mass ratio between the diaphragm and the much larger mass of the cabinet or open baffle, but there's more to it than that. At frequencies where the cabinet or open baffle goes into resonance, this mass ratio is overshadowed by the sharp change in mechanical impedance of the resonating body, and the acoustical output of the cabinet or open baffle goes up hundreds of times (compared to the emission at non-resonant frequencies). Almost all of the acoustical output of the cabinet or open baffle is at the mechanical resonance frequencies, and very little at other frequencies. In effect, the trouble frequencies fall in the 200 to 800 Hz range, with little to no emission elsewhere.
Freely suspending the driver from rubber bands or bungee cords (at 3 or 4 points, as mentioned previously) acts as a lowpass filter, preferably set well below the bandpass of the driver. This is not too different than a turntable suspension tuned to a frequency well below the 7~9 Hz tonearm/cartridge resonance, typically 3~4 Hz. It is desirable to keep the resonance above the rhythms of the music, so 3 Hz is a realistic minimum for the suspension.
I'm looking closely at 2 or 3 of the AESpeakers Dipole 15's per side in a close-fitting array, with the Selenium 15PW3's as an alternative. If anyone from AESpeakers is reading this, what are the Xmax, Qts, Fs, normalized efficiency, and pricing of the Dipole15's again? Can't find it on the AESpeakers website right now.
Regarding the Feastrex, you can think of them as super Lowthers, and priced accordingly. They have several dB more headroom than a Lowther, and don't hit the wall quite as hard - but it's not fair to reflex or rear-horn-loaded Lowther, AER or Feastrex to compare them to front-horn loudspeakers, which have 10 to 15 dB more headroom. I've never heard a front-horn Feastrex, and don't know if anyone has built one.
Any full-range loudspeaker, particularly with whizzer-cone HF, is so idiosyncratic I would never buy them without an extensive audition with CD's and LP's that you know well - these speakers are not for everyone, and you have to decide for yourself if the compromises are acceptable to you. The big plus of full-rangers is exceptional midrange coherence, and the downside is whizzer coloration and early HF breakup - and this is an area where the Feastrex is decisively better than any other whizzer-cone driver.
Just for reference, the IB15 isn't the same as the Lambda dipole 15. JohnJ suggested the parameters for the dipole 15 would be the same as the old and the price equal to what the other lambda drivers are.
http://web.archive.org/web/20040307231755/lambdacoustics.com/drivers/DIPOLE15.html
the thread in question...
http://www.aespeakers.com/phpbb2/viewtopic.php?f=3&t=892
http://web.archive.org/web/20040307231755/lambdacoustics.com/drivers/DIPOLE15.html
the thread in question...
http://www.aespeakers.com/phpbb2/viewtopic.php?f=3&t=892
oh, my mistake. Sorry .
Its like:
buy pair and You have 50$ discount on the total price.
http://www.aespeakers.com/phpbb2/viewtopic.php?f=1&t=1639
Its like:
buy pair and You have 50$ discount on the total price.
http://www.aespeakers.com/phpbb2/viewtopic.php?f=1&t=1639
Lynn Olson
I may be talking about something somewhat off-topic, but it is pretty much the only active thread with your presence (excuse my English). I am interested in your thoughts about the "stored energy" of a loudspeaker, and its deretoriating effect on sound.
I am interested in your opinion on Heil AMT's regarding stored energy. To me, it seems that they have more of it than normal ribbons/esl units, as air is stored inbetween layers, and pushed in/out upon appliance of signal.
I may be talking about something somewhat off-topic, but it is pretty much the only active thread with your presence (excuse my English). I am interested in your thoughts about the "stored energy" of a loudspeaker, and its deretoriating effect on sound.
I am interested in your opinion on Heil AMT's regarding stored energy. To me, it seems that they have more of it than normal ribbons/esl units, as air is stored inbetween layers, and pushed in/out upon appliance of signal.
local impulse compensation
Just for the record:
The RUBBER string was introduced by Klaus.
I wouldn't go with rubber neither with any other kind of springs as they introduce an additional set of compromises.
Having used and done quite some investigation on a Sondeck turntable you learn the hard way about the fragility of setups with spring suspended sub-chassis turntabels.
Same case with speakers here as you already mentiond.
The more elegant way is to hook the speaker up by a string.
I use 1-2mm stainless steel "ropes" for that. They have the advantage to already have a usefull degree of dampening due to friction between the litz wires so you wouldn't end up building harps.
The resonant / pendulum frequency is a very simple calculation only depending solely on the free pendulum length and is deep enough for anything you want from a 10cm free length upwards.
If you use more than on string you can better control axis of movement. Keep strings simply at same length
With a baffle or a complete box attached to the speaker, flying is a different animal. Not so much for a horn if it were of solid wood for example.
If you fly the loudspeaker alone there is only the magnet's and basket's mass that's counting. More locally you cant get to balance the impulse forces.
Radiating area to the front is very low whereas radiating area to the back is roughly the same or less as Sd for most speakers - but movement is greatly attenuated as already outlined anyway.
Also the baskets resonant pattern is counting in much less as there is way less force transmission through it.
Gretings
Michael
Lynn Olson said:
Just for the record:
The RUBBER string was introduced by Klaus.
I wouldn't go with rubber neither with any other kind of springs as they introduce an additional set of compromises.
Having used and done quite some investigation on a Sondeck turntable you learn the hard way about the fragility of setups with spring suspended sub-chassis turntabels.
Same case with speakers here as you already mentiond.
The more elegant way is to hook the speaker up by a string.
I use 1-2mm stainless steel "ropes" for that. They have the advantage to already have a usefull degree of dampening due to friction between the litz wires so you wouldn't end up building harps.
The resonant / pendulum frequency is a very simple calculation only depending solely on the free pendulum length and is deep enough for anything you want from a 10cm free length upwards.
If you use more than on string you can better control axis of movement. Keep strings simply at same length
Lynn Olson said:
With a baffle or a complete box attached to the speaker, flying is a different animal. Not so much for a horn if it were of solid wood for example.
If you fly the loudspeaker alone there is only the magnet's and basket's mass that's counting. More locally you cant get to balance the impulse forces.
Radiating area to the front is very low whereas radiating area to the back is roughly the same or less as Sd for most speakers - but movement is greatly attenuated as already outlined anyway.
Also the baskets resonant pattern is counting in much less as there is way less force transmission through it.
Gretings
Michael
Re: local impulse compensation
- Klaus
The rubber suspension was a purely experimental thing. For an "industrial solution" of a speaker or driver suspension I think I would use a set of wire rope isolators (frictious nonlinear springs) to get controlled isolation, damping and long term stability in all directions of movement. Those wire rope isolators would certainly need to be custom developped, but DIY is possible, as their basic construction is very simple and low cost.mige0 said:
- Klaus
Re: Re: local impulse compensation
Klaus, interesting idea, haven't come across this sort of isolation springs yet.
I'll always try to keep it simple – as close to the underlying physics / kinematics / statics as possible.
Any complex spring system introduces additional problems.
Wound springs for example "bend" the initial axis of movement into something rotating – nothing I would like to have - not even for the apparent micro movements we are talking of here.
Dedicated dampening of the speakers movement is not necessary – in fact its contradictory to the concept of impulse cancellation.
The dampening I was talking of for my 1-2mm steel "ropes" setup was to keep the resonant behaviour of the steel "ropes" itself low. Low mass, low radiating area, low resonances – best one can do IMO.
And – it works - as simple as it is.
Greetings
Michael
KSTR said:
Klaus, interesting idea, haven't come across this sort of isolation springs yet.
I'll always try to keep it simple – as close to the underlying physics / kinematics / statics as possible.
Any complex spring system introduces additional problems.
Wound springs for example "bend" the initial axis of movement into something rotating – nothing I would like to have - not even for the apparent micro movements we are talking of here.
Dedicated dampening of the speakers movement is not necessary – in fact its contradictory to the concept of impulse cancellation.
The dampening I was talking of for my 1-2mm steel "ropes" setup was to keep the resonant behaviour of the steel "ropes" itself low. Low mass, low radiating area, low resonances – best one can do IMO.
And – it works - as simple as it is.
Greetings
Michael