Dungeon Keeper
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#271 Re: Dungeon Keeper
ffs not another spelling Nazi
- andrew Ivimey
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#272 Re: Dungeon Keeper
Err.
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.
- Scottmoose
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#273 Re: Dungeon Keeper
I'll respectfully beg to differ on that one Nick, although 'disadvantage' may have been the more correct term. The potential disadvantages I mention are real though.
Well, there's no industry standard for production tolerances on moving coil drivers, but the average is about +/-10% for components with QC for samples in a batch of completed drivers usually based on a mean Fzero (Fs to us) & the same overall tolerance. That's assuming they even bother, which is not always the case with very cheap units. Some of the quality brands run a lot tighter; Scan Speak, Seas, SB, Mark Audio etc. are usually in the 3% region. For high order filters you go into it knowing that you need to minimise insertion losses (other than those that are inherent to the filter), so you'll typically be using caps & inductors with very low resistance, and very close tolerances; if you don't you're asking for trouble. Working with those kind of tolerances, the drivers themselves typically have more deviation than is caused by losses from the filter components. What other losses or additions the filter components might make, especially the caps, is another matter; I tend to treat that separately. YMMV though.And I dont TBH understand the second part as it looks to me like a conflict of units. "insertion losses" on one side, "production tolerances" on the other side.
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#274 Re: Dungeon Keeper
Thats exactly my point, insertion loss for a filter is measured in dB and would refer to the loss in the pass band area. Fs is measured in Hz, so you have a conflict of units.
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- Scottmoose
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#275 Re: Dungeon Keeper
Fs is just a quick & simple means commonly used for assessing a batch tolerance of drivers. It is not the only thing that varies, and I am not suggesting it is, or that those particular units are comparable. Sensitivity in dB for a given input and frequency is another sometimes used for instance, albeit less convenient, so less common. The point I am making is simply that the insertion losses caused by a reasonably designed high order electrical filter* are typically small compared to the inherent variation in behaviour of most drive units across a range of factors, be they frequency/amplitude response, impedance etc.
*As in, one using components made to close tolerances with low resistance where necessary to avoid undesired / unintended changes
*As in, one using components made to close tolerances with low resistance where necessary to avoid undesired / unintended changes
'"That'll do," comes the cry of the perfectionist down the ages.' (James May The Reassembler)
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- Dr Bunsen Honeydew
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#276 Re: Dungeon Keeper
Drive units do not cause leading and lagging phase. Filters do.
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#277 Re: Dungeon Keeper
And?
'"That'll do," comes the cry of the perfectionist down the ages.' (James May The Reassembler)
Website www.wodendesign.com
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#278 Re: Dungeon Keeper
I'm breaking my own rule by replying to you, but here goes.Dr Bunsen Honeydew wrote: ↑Tue Apr 18, 2017 8:16 pm Drive units do not cause leading and lagging phase. Filters do.
Fostex FE126E, with cone treatments and a phase plug. No filters, EQ or anything else here, and the phase shift is quite obviously there.
Chris
- Dr Bunsen Honeydew
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#279 Re: Dungeon Keeper
I would stand corrected if I believed anything those bloody charts tell you, but I don't.
#280 Re: Dungeon Keeper
... and I'm back to ignoring you. That was quick.
Chris
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#281 Re: Dungeon Keeper
That fostex is a full range driver nes pa ?
#282 Re: Dungeon Keeper
It is, yeah. Does that matter?
Chris
#284 Re: Dungeon Keeper
well, I would have said that between 300Hz and 5kHz its not. Outside of that range the drive is working as a mechanical filter, so I would expect to see shifts. A good example of how much a 'full range driver' is no such thing.I'm breaking my own rule by replying to you, but here goes.
Fostex FE126E, with cone treatments and a phase plug. No filters, EQ or anything else here, and the phase shift is quite obviously there.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#285 Re: Dungeon Keeper
I'm getting closer and closer to full-range out of these, but really that should be a different thread. There's nothing much I can do about the steep drop in the treble, but the bass is getting there. Getting below 40Hz now, but it's costing a lot of headroom.
I see your point about 300Hz-5kHz. It's not perfectly linear (something going on around 1.9kHz, reflected in the SPL graph too), but it's not far off. Mechanical filtering at either end is affecting the phase curve, but I'd argue that's inherent to every driver.
Chris
I see your point about 300Hz-5kHz. It's not perfectly linear (something going on around 1.9kHz, reflected in the SPL graph too), but it's not far off. Mechanical filtering at either end is affecting the phase curve, but I'd argue that's inherent to every driver.
Chris