You are also able to calculate a Closed-Box if you make the value of the vent diameter very small (i.e 0.01).Īttention: You can put in your own Thiele/Small-parameter only if the speaker-select "parameterinput" is selected. Red: any construction of your enclosure using the same Thiele/Small-parameter.Blue: Closed-Box (without filling material) aligned with Thiele/Small-parameter and a desired Qtc.Black: Vented-Box with Thiele/Small-Parameter (Bullock alignment).The colors of the curves in the diagrams for frequency response, step response, group delay and voice-coil impedance have the following meaning: (Side question that is certainly more off topic - what effect does implementing more than one port have on a woofer's response? Ex: Equator Q10 - two ports for a single woofer.On this page you are able to calculate a speaker enclosure with Thiele/Small parameter. Much love/Many thank yous in advance everyone. If you guys could help me figure the phenomenon I described above would greatly appreciated.) However, I'm a little confused as to how someone would go about figuring when to implement that idea - as they say small woofers are best sealed, while larger woofers are best ported (so as to reduce overall distortions) - I'm curious how one would be able to figure out when and at what frequency to implement the port depending on the woofer size. This idea of tuning a port lower than usual (than audible, perhaps?) is certainly interesting and perhaps therein lies a trick to achieving something that's like a combo of the two? 2), I've learned that part of their success is due to the fact that they use their ports quite low, for the sake of tuning the woofer to the cabinet/to increase efficiency of the woofer, not so much to increase bass response. (As something of an off topic mention - in my original posting, I had brought up ATC monitors and the fact that "they sound the least ported" - upon some research (thanks to a stereophile article - The Fifth Element #85 pg. Thank you, everyone, for the responses so far - they've been interesting and thoughtful. SOS speaker expert Phil Ward replies: Id absolutely agree ported.
Snyder P.J., "Simple formulas and graphs for design of vented loudspeaker systems", 58th Convention of the Audio Eng. The fact still remains that, for same-size bass speakers (enclosure, driver). In other words, "the best of both worlds".Įven longer answer: take the time to read and study the fundamental articles on Closed Box and Bass-Reflex speakers by R. In this way, one obtains a very low Group Delay at all frequncies that matter, and a lower peak-to-peak excursion between 20 and 40 Hz vs. See: Project | Homebuilt Hi-Fi - A user submitted image showcase of high quality home built hi-fi components. This allows to set the box resonant frequency at a very low Fs = 0.39*(Fs/Qt) = 23 Hz, and the box volume at Vb = 2.0 * VAS * Qt^2, while still achieving a -3dB cut-off frequency of 40Hz (anechoic). In general terms, the lower the (Fs/Qt), the lower the -3dB cut-off frequency you can get away with while ensuring a shallow initial roll-off below cut-off, and hence a low and inoffensive group delay.įor example, my Woofer of choice is a 15" unit with a low (Fs/Qt) = 60. In particular, on the Woofer's (Fs/Qt) ratio, and on the desired -3dB 'cut-off' frequency. Longer answer: it depends on the Woofer's parameters. Short answer: yes, it is possible (sort of). (Part of the reason I ask is because of the ATC studio monitors, where people describe them as sounding "the least ported" of a ported design - where they have it sealed for most of the band, and then ported for the basses.then again, I recall hearing that they use their ports more for efficiency than for bass extension, so that may have something to do with it.)īut I digress, if you guys could help me figure out this idea, it would be greatly appreciated Or is mixing these two phenomenon a strange idea, and that I should simply stick with a sealed box if I want the transient response I desire. I've been curious about this - Is it possible to somehow achieve the benefits of both a sealed cabinet and a ported one? (With some careful placement of where/when you wish to use the port.)įor example, would one be able to achieve the tight transient goodness of a sealed cabinet from say something like 100hz and up, and then use a port for the woofer below that frequency to extend it bass response? (Or is the group delay still too much of an issue at the these bottom frequencies, seeing as how there aren't all that much in terms of transient energy going on down there)
0 kommentar(er)
