Xmax is the maximum cone displacement allowed for the speaker. Vas is the equivalent air volume of the speaker and this value relates to the air volume of the particular enclosure. Qes is from memory, the sharpness of the resonance curve of the cone at the resonant frequency of 100 Hz measured in the open air. The data sheet says that the accoustic efficiency is 91 dB per watt. They relate to the accoustic efficiency of the loud speaker in a box. Qts and Qes are damping parameters related to the electromagnetic damping of the loudspeaker. thats where the 8 ohm comes from.įs is the cone resonant frequency, and is 100 Hz, and is below your cut off frequency of 300 Hz. Re and Le is the voice coil resistance and inductance and because the resistance dominates the impedance, it can be taken as 8 ohm. The data values they give are the Thiele/Small parameters. Your 0.77 litre is very small and will most likely lead to too much accoustic damping on the cone, which will lead to a higher electrical power input. But I would be using a larger box rather than a smaller box and to me 0.7 cubic feet sounds adequate. So if you go for a wide range loudspeaker, then you will not be bothered by such design parameters. At the time,Neville worked at EMI Australia this company being part of EMI of the UK. Thiele and was presented at the IRE Convention (australian IRE) in March 1961. The reference is essentially considering the low frequency response only. The paper is a hallmark work on loudspeakers and considers the box, loud speaker parameters including cone equivalent compliance and damping due to the magnet system and the amplifier output impedance and low frequency response and accoustic efficiency. This stuff comes from a paper by Neville Thiele who was the Technical director of the Australian Broadcasting Commision in the 1960's/70's. The paper you refer to is based on the Thiele/Small parameters. Some of the posts are canvassing this aspect. This requirement suggests a larger diameter cone than 3 or 4 inch more like 12 inch. The figure of 50 watt worries me a little. However, in your case the low frequency range is probably above the cone resonant frequency, or at least, you choose a cone resonant frequency of less than 300 Hz. The general problem of loudspeaker box design is due to the frequency range required at the bass end.įor bass speakers, the audio frequency range required generally extends down to below the normal cone resonant frequency. The waste pipe can be made malleable with a heat gun to 'suit' the speaker fit. = 4.5" ) could be made into a housing by endcapping one end and mounting the spkr in the other.
If that's a decent ballpark I can work with that.Īlso, I am wondering if 4" PVC waste pipe (true dia.
Interestingly there is a sample for a 4" spkr on this page: Needs data I don't understand, if someone can explain those parameters (and where to find em) I would appreciate it.
#Speaker enclosure design box vs cylinder how to
Not sure how to size the box volume though.as I am NOT trying for bass here. Thought I could reuse the woofer and midrange in a smaller sealed box enclosure as I don't need the low end of the bass. Scrapped an Aiwa mini stereo today, but got a 6.5" woofer and a 2" Mid and a tiny tweeter out of a reflex enclosure.
#Speaker enclosure design box vs cylinder driver
I guess the driver might be around 4 - 5" but I am open to suggestions. I am looking for a guide to design such a box. The spkr 'box' can be a cylinder as well. I am hoping for perhaps something in the 8 x8 x8" range as the max dimensions.
The flat diagonal of the box rear panel should not exceed 12" as it must fit inside a 12" cylinder. I have a requirement for a midrange, 300 - 4000Hz drive at around 50W RMS max.
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