I have my MW16 Satori (white cone, 4 Ohm) and Aurum Cantus G3Si Ribbon up for sale listed on the swap shop. Asking $150 per pair US. Shipping ONLY in US, Canada and Mexico costs are way too high. I agree to pay shipping if you agree to pay my asking price...PM me for details...spread the word, getting ready for TX 13 MR mids...
I had a very knowledgeable speaker guy tell me the best sounding woofer boxes were TL or close variant or hybrid. This was a scientific study with blind A/B/X...many say closed box is next followed by bass reflex (vented) and horn loaded. I have had MANY very good sounding BR designs in the past; I do recommend anyone interested to study CAREFULLY the designs and alignments; if you have a woofer with a Qt around 0.37 to 0.39; you can get GREAT results...NOT for first timers though for SURE!!! If you are a first timer; follow a very well established and proven design...FWIW...PM if you want some hints on BR design; I have a few tricks up my sleeve...I have been doing this over 50 years now; I have a few tricks not published by anyone anywhere to my knowledge anyway...
It could be very interessting to share that on a dedicated forum like this one
In few words, wichs parameters do you play with ?
The aperiodic loudspeaker is a closed box system that contains a vent stuffed with damping material. The stuffing, usually foam or fiberglass, provides a pressure release for the system at low frequencies. The term aperiodic literally means an absence of resonances at any specific frequency or multiple thereof. Aperiodic damping is defined as “damping of such a high degree that the damped system, after disturbances, comes to rest without oscillation or hunting” (Turner 1988). In a standard acoustic suspension system, the trapped air in the box is quite reactive, or springy, at very low frequencies. The reactive nature of the air will cause excessive cone excursion at system resonance. Adding an aperiodic vent to the system releases internal pressure at resonances, resulting in better control of the cone motion at very low frequencies. The aperiodic offers some of the performance advantages of the transmission line in terms of excellent woofer control and a reduction in internal pressure at frequencies near system resonance, but with enclosures much more manageable in size. It is important to note that no sound emerges from an aperiodic vent, so this design does not resemble a vented loudspeaker in any way. The first patent on such a loudspeaker enclosure was issued in 1936 to Marvel W. Scheldorf, an engineer from RCA; he described his invention as an acoustic resistive device - Thom Holmes - The Routledge Guide to Music Technology
Audio Concepts Inc. explain their APL: “Performs Like a well-Tuned Transmission Line but with Superior transient Performance and Control” Source.
A review of an aperiodic loudspeaker:
“Luck: high. Time for another movie hero. Enter Clint Eastwood's Dirty Harry with "you gotta ask yourself one question; do I feel lucky? Well, do ya, punk?" The Codex is that lucky punk. Its bass alignment not only aims down like earlier Audio Physic models. It's not ported. The first means none of the typical rear-port issues so often mistaken for room modes whose ubiquity makes them seem innate, ergo unavoidable. The second means no port-ly behavior of bloat and ringing so endemic to traditional vents. Obviously even Audio Physic's engineered luck can't magically obliviate room modes. However, compare a rear-ported speaker of equivalent bandwidth, situated in your best spot, to the Codex in the exact same spot. Codex bass will be dramatically more linear and clean. What you thought were room modes but really were port crap, disappear. What were actual modes remain. With the usual port debris cleared out, those modes now are far smaller road bumps. Because this woofer loading is taut like a high-torque sports car not softly sprung like a lazy family sedan, remaining bumps absorb better. This superior control with lower room interactions is uncanny and easily heard. If the core difference between big and small speakers is that the former go louder and lower, spending serious money on more quantity bass (lower/louder) only to suffer lower quality bass (ringy and boomy) is plain stupid. The Codex puts an end to such nonsense. If your room can support 30Hz, you'll get it at unusually high quality, without the unfortunate byproducts of ported bass overlaying resonant dirt on the vocal range; and with better extension from a smaller enclosure than sealed bass. If that was it, the Codex would already be a winner. [http://6moons.com]
Audio Concepts Inc. explain their APL: “Performs Like a well-Tuned Transmission Line but with Superior transient Performance and Control” Source.
A review of an aperiodic loudspeaker:
“Luck: high. Time for another movie hero. Enter Clint Eastwood's Dirty Harry with "you gotta ask yourself one question; do I feel lucky? Well, do ya, punk?" The Codex is that lucky punk. Its bass alignment not only aims down like earlier Audio Physic models. It's not ported. The first means none of the typical rear-port issues so often mistaken for room modes whose ubiquity makes them seem innate, ergo unavoidable. The second means no port-ly behavior of bloat and ringing so endemic to traditional vents. Obviously even Audio Physic's engineered luck can't magically obliviate room modes. However, compare a rear-ported speaker of equivalent bandwidth, situated in your best spot, to the Codex in the exact same spot. Codex bass will be dramatically more linear and clean. What you thought were room modes but really were port crap, disappear. What were actual modes remain. With the usual port debris cleared out, those modes now are far smaller road bumps. Because this woofer loading is taut like a high-torque sports car not softly sprung like a lazy family sedan, remaining bumps absorb better. This superior control with lower room interactions is uncanny and easily heard. If the core difference between big and small speakers is that the former go louder and lower, spending serious money on more quantity bass (lower/louder) only to suffer lower quality bass (ringy and boomy) is plain stupid. The Codex puts an end to such nonsense. If your room can support 30Hz, you'll get it at unusually high quality, without the unfortunate byproducts of ported bass overlaying resonant dirt on the vocal range; and with better extension from a smaller enclosure than sealed bass. If that was it, the Codex would already be a winner. [http://6moons.com]
I'm convinced that exist some really good designs whatever the choosen alignement
I like my BR designs and at the same time I've tried some closed simulations with that speakers with no success so...
Btw, a port leaking its resonnance sound at vocal range with an audible SPL is surely a bad design...
I like my BR designs and at the same time I've tried some closed simulations with that speakers with no success so...
Btw, a port leaking its resonnance sound at vocal range with an audible SPL is surely a bad design...
Well, just go back to the very basics and physics if you will. EVERY design type can be properly implemented if you are willing to not just follow the pure science and math but also put in many very hard hours of experimenting and tweaking. A BR (vented) can be just as accurate as any other type; you just have to NOT assume ANYTHING will ever work out the first time around. The Qt is probably the MOST important parameter for a PROPER BR design; this is CRITICAL...too low is much less than ideal; too high is also less than ideal. Remember to factor in ALL sources of DCR, inductors, cables, wiring, etc...Read the V Dickason section on vented design; some people think this is out of date; I think it has enough details, math and science to point us all in the right direction; even if it is older data...THINK, what did we learn from the ancient great minds about science and math? Many theories still hold true to this day even though they were formulated hundreds of years ago!
Old is certainly not obsolete. Look at Harry F. Olson paper; Direct Radiator Loudspeaker Enclosures - which is dealing with the geometric shape vs acoustical performance (diffraction) released in 1951. That research is in use today and is the basis for most loudspeaker designs. Ofc, it can be improved upon by doing complex geometric shapes, but non the less, the research is still valid.
And it pay's off looking at older research or even material one read a long time ago, go back to it. So thanks oldspkrguy
And it pay's off looking at older research or even material one read a long time ago, go back to it. So thanks oldspkrguy
Yes, QT are importants. Simulations show that accuratly!
DCR are also game changer in all speakers
From what I understand, BR basics are the same since that they have been written down and analysed by guys like V. D. (A must read btw)
Todays simulations tools like basta or vituixcad are accurate enough to play with all the parameters.
But still global, not historical related , topics/questions. What to optimize ? Air speed ? Woofer excursion ? Group delay ? Excursion ? SPL shape ? etc etc etc...
Oh, and I'm agree, prototyping is part of the design process (like any other designing sessions) to check that simulations & assumptions are correct.
DCR are also game changer in all speakers
From what I understand, BR basics are the same since that they have been written down and analysed by guys like V. D. (A must read btw)
Todays simulations tools like basta or vituixcad are accurate enough to play with all the parameters.
But still global, not historical related , topics/questions. What to optimize ? Air speed ? Woofer excursion ? Group delay ? Excursion ? SPL shape ? etc etc etc...
Oh, and I'm agree, prototyping is part of the design process (like any other designing sessions) to check that simulations & assumptions are correct.
Copyright material removed by moderation teamI read the chapter on Bass Reflex (vented) MANY times; what is important is to understand what you want to do before you even try to do it. The discrete alignments may be a little difficult to achieve but once you hear one properly designed and implemented; all of your fears about vented boxes will disappear!
And yes, the ROOM plays the biggest factor overall; never forget the listening room!
When I was working on/with my aperiodic research I completely forgot to check a fundamental part and that is the duration of certain frequency's (duration in time) and the box/driver combo group delay.
A complete cycle (duration) at: 20Hz = 50ms - 50Hz = 20ms - 100Hz = 10ms.
It is my understanding that as long as your driver and box is bellow the duration of the frequency at any given frequency, you have a transient perfect enclosure.
Is that correct ?
A complete cycle (duration) at: 20Hz = 50ms - 50Hz = 20ms - 100Hz = 10ms.
It is my understanding that as long as your driver and box is bellow the duration of the frequency at any given frequency, you have a transient perfect enclosure.
Is that correct ?
I'm not sure of your train of reasoning, but any system or filter that results in a significant amplitude alteration also results in a phase change. The enclosure and woofer system (sealed, or bass reflex, aperiodic, etc.) functions as a high pass filter. So the declining lower frequencies will go through significant relative phase changes, related to their low end slope order and frequency difference from the flat non-attenuated response.
Also, some incorrectly post that a system Qt =0.5 yields a transient perfect response. Qt=0.5, termed critically damped, is an engineering term related to damping and response of overshoot (or no overshoot) to a step or impulse input.
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