Hi guys
I am trying to design a small Sub, nothing big and am still learning how to use and interpret WinISD.
I have an existing MDF cube I would like to use, 27cmx27x27cm inner measurements (~19.6 liter) and played with a couple of drivers . I do understand the meaning of F3 but the curves (see attached) look quite a bit different between vented and closed and I don't exactly know how to interpret them. To me the orange one seems to be the best, but I might be wrong.
Any help is appreciated.
Kind regards
Phil
I am trying to design a small Sub, nothing big and am still learning how to use and interpret WinISD.
I have an existing MDF cube I would like to use, 27cmx27x27cm inner measurements (~19.6 liter) and played with a couple of drivers . I do understand the meaning of F3 but the curves (see attached) look quite a bit different between vented and closed and I don't exactly know how to interpret them. To me the orange one seems to be the best, but I might be wrong.
Any help is appreciated.
Kind regards
Phil
Attachments
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Greets!
Vented yields up to a 1/2 octave of usable gain bandwidth [BW] over comparable sealed alignments as the orange trace shows with the trade-off of higher distortion and this particular one may not blend as well in room as one of the others [or different sealed/vented alignment] depending on where it's located, so no right choice per se, just which one [or another] best meets the needs of the app.
PS: need to subtract the driver's, vent [if used] and any bracing volume from the ~19.68 L volume [Vb], though sealed is so forgiving I don't bother except when making them really small [high tuned] for horn loading.
GM
Vented yields up to a 1/2 octave of usable gain bandwidth [BW] over comparable sealed alignments as the orange trace shows with the trade-off of higher distortion and this particular one may not blend as well in room as one of the others [or different sealed/vented alignment] depending on where it's located, so no right choice per se, just which one [or another] best meets the needs of the app.
PS: need to subtract the driver's, vent [if used] and any bracing volume from the ~19.68 L volume [Vb], though sealed is so forgiving I don't bother except when making them really small [high tuned] for horn loading.
GM
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Hi GM
thanks for your reply. Just to clarify, are you saying that the W6 (orange line) is not a particularly good driver for this application? Further, are you recommending sealed designs when they are used for music only? Are there any particular drivers you could recommend in the 4 Ohm/8"-10"/<$100 range?
We played again with a few drivers with closed designs and the Dayton RS225-4 and DCS205-4 produced good results with our desired and existing MDF box (see attached graph).
Thanks again for your help.
Phil
thanks for your reply. Just to clarify, are you saying that the W6 (orange line) is not a particularly good driver for this application? Further, are you recommending sealed designs when they are used for music only? Are there any particular drivers you could recommend in the 4 Ohm/8"-10"/<$100 range?
We played again with a few drivers with closed designs and the Dayton RS225-4 and DCS205-4 produced good results with our desired and existing MDF box (see attached graph).
Thanks again for your help.
Phil
Attachments
Greets!
??? I'm saying nothing about the driver, only the differences of the box alignments.
Technically, the blue curve has the lowest distortion, hence the best sound quality [SQ], but as you can see the trade-off is it has the least bass until down really low where there's only the low B pipe organ [16 Hz] and LFE special effects, so not much of a woofer unless in a solid/massive room corner plus a bit of EQ to just get a minor bit 'rumble' since it's a tiny sub and so many dBs down.
The green curve has second best SQ, more [mid] bass, but more distortion.
Obviously then, the orange curve has the most distortion, gain bandwidth [BW].
That said, vented alignments are the most used in most apps, so its distortion is considered acceptable by most and at a relatively minor loss of deep [rolled off] bass, its distortion can be lowered down almost to the green curve's by critically damping the vent or just adding some minor internal stuffing between the driver/vent, so by far the most common variant.
But the room's acoustics dominates how it will perform in room, hence my first response. Best overall is to go with damped 'orange' and use DSP to time delay [TD] and frequency shape [EQ] it in room where it and you sit.
To 'critically' damp the vent: Click Test | GM210 | Flickr
Re driver selection, for various reasons I make no attempt to stay up-to-date, but I built my 'tiny' sealed computer 'sub' in '96 using a very early TB woofer, so combined with many others since then, do know they are a good value and widely used in small subs, both DIY and mass market [or at least use to].
Before you ask ;), I used sealed since the sound card in the Win95 computer only went down to around 120 Hz, so no need for any real bass extension.
GM
??? I'm saying nothing about the driver
Technically, the blue curve has the lowest distortion, hence the best sound quality [SQ], but as you can see the trade-off is it has the least bass until down really low where there's only the low B pipe organ [16 Hz] and LFE special effects, so not much of a woofer unless in a solid/massive room corner plus a bit of EQ to just get a minor bit 'rumble' since it's a tiny sub and so many dBs down.
The green curve has second best SQ, more [mid] bass, but more distortion.
Obviously then, the orange curve has the most distortion, gain bandwidth [BW].
That said, vented alignments are the most used in most apps, so its distortion is considered acceptable by most and at a relatively minor loss of deep [rolled off] bass, its distortion can be lowered down almost to the green curve's by critically damping the vent or just adding some minor internal stuffing between the driver/vent, so by far the most common variant.
But the room's acoustics dominates how it will perform in room, hence my first response. Best overall is to go with damped 'orange' and use DSP to time delay [TD] and frequency shape [EQ] it in room where it and you sit.
To 'critically' damp the vent: Click Test | GM210 | Flickr
Re driver selection, for various reasons I make no attempt to stay up-to-date, but I built my 'tiny' sealed computer 'sub' in '96 using a very early TB woofer, so combined with many others since then, do know they are a good value and widely used in small subs, both DIY and mass market [or at least use to].
Before you ask ;), I used sealed since the sound card in the Win95 computer only went down to around 120 Hz, so no need for any real bass extension.
GM
You're welcome!
I hear ya, I got started at age 8 when I noticed the Kleenex box had an oval opening that was just about the right size for the oval speaker Dad had removed from the car dash to fix some wiring, so out went the nose wipes and in went the speaker, held in with a couple of screw in spring clamps and here I am 66+ yrs later.
GM
I hear ya, I got started at age 8 when I noticed the Kleenex box had an oval opening that was just about the right size for the oval speaker Dad had removed from the car dash to fix some wiring, so out went the nose wipes and in went the speaker, held in with a couple of screw in spring clamps and here I am 66+ yrs later.
GM
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