18" speakers
- Dave the bass
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#227
Unless you happen to be Bobba Fett. <pushes glasses up nose and blinks awkwardly>
DTB
DTB
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- pre65
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#228
After extensive listening since the full range speaker was replaced, and with the aid of Andrew I's ears, I'd like to experiment with the sound balance between the two drivers.
Ideally I'd like to reduce the full range output just a tad, or increase the woofer volume.
Thing is, with a series crossover, I'm not sure how to do it.
Here is the crossover diagram. Any hints or tips from crossover experts ?
Ideally I'd like to reduce the full range output just a tad, or increase the woofer volume.
Thing is, with a series crossover, I'm not sure how to do it.
Here is the crossover diagram. Any hints or tips from crossover experts ?
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
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#229
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
- pre65
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#230
Thanks Paul.
I clip leaded in a 1R resistor, and that has made a positive difference.
Will try other values later on.
Somewhere I have a few 0-2.5R pots, could try those if I can find them.
I clip leaded in a 1R resistor, and that has made a positive difference.
Will try other values later on.
Somewhere I have a few 0-2.5R pots, could try those if I can find them.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
- pre65
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#231
Now trying a 2R resistor.
Slightly better on first listen.
Slightly better on first listen.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
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#232
many years ago it was discovered on the forums that Lowthers benefited from thin wire. But all that was happening was a series resistance was applied. Just as you are doing here with your fostex. Maybe the fostex benefits like the lowther from a little series resistance. All of which is asside from the fact that you need to attenuate the fostex. you could have done it with an L Pad attenuator but this way tends to work well in the circumstances, at least that has always worked well for me on listening tests.
Although what I know in this scenario could fit on a postage stamp.
Although what I know in this scenario could fit on a postage stamp.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
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#233
They can do: depends on the driver Q, the output impedance of the amp, box / baffle / whatever alignment, what you like & what you're trying to do. Many of the large motor Fostex units have similar basic Q & general characteristics to Lowther drivers. You're just adding distributed series R so a slightly different effect to an L-pad where impedance is held constant. In the rising response (acceleration) BW, that has the effects you'd expect. Can also be beneficial higher up in the mass controlled BW, providing system efficiency is high enough.
Leaving aside the increase in system Q I suspect one of the reasons for the brief flurry of interest back around the turn of this century was that the really thin gauges can't properly handle low-frequency current demands, so for want of a better phrase, LF dynamic peaks were 'clipped' relative to the rest of the range, which can have the effect of seeming to enhance detail in the 'unclipped' mid - high range. Either way, it's a valid enough approach & resistive wire is not something to be ignored, providing it's employed with care.
Leaving aside the increase in system Q I suspect one of the reasons for the brief flurry of interest back around the turn of this century was that the really thin gauges can't properly handle low-frequency current demands, so for want of a better phrase, LF dynamic peaks were 'clipped' relative to the rest of the range, which can have the effect of seeming to enhance detail in the 'unclipped' mid - high range. Either way, it's a valid enough approach & resistive wire is not something to be ignored, providing it's employed with care.
- pre65
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#234 Re: 18" speakers
I've bought a couple of Mark Audio tweeters from Colin, and they are destined for my baffles.
I have ordered a 43mm hole saw today, so perhaps by next week something might have happened.
I have ordered a 43mm hole saw today, so perhaps by next week something might have happened.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
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#235 Re: 18" speakers
I had a lull in the mosfet amp proceedings, so using the 43mm hole saw I've cut out the tweeter apertures.
They are now in situ, but I'll leave wiring up and cap selection testing till another day, I've got too much on at the moment.
They are now in situ, but I'll leave wiring up and cap selection testing till another day, I've got too much on at the moment.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
#236 Re: 18" speakers
I would have thought after 7 years of this thread it would be time for some measurements
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
- pre65
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#237 Re: 18" speakers
Quite possibly Nick.
Although some would say that measurements are totally unnecessary.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
- Dr Bunsen Honeydew
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#238 Re: 18" speakers
If you are going to design the drive unit you need to measure, if you are just going to use those designs you only need to listen
- pre65
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#239 Re: 18" speakers
I sorted through my capacitor box a while ago and thought I had got some polyprops to try with the MA tweeters I got from Colin, but I can't find them now.
I might have put them somewhere "safe".
Anyway, I've found a pair of MKT 3.3uf so I'm trying those as a first step. Just listening to Solid Air, and the treble is more prominent.I'll try some contrasting tunes later.
Just ordered two 2.2uf MKP for the next trial.
I might have put them somewhere "safe".
Anyway, I've found a pair of MKT 3.3uf so I'm trying those as a first step. Just listening to Solid Air, and the treble is more prominent.I'll try some contrasting tunes later.
Just ordered two 2.2uf MKP for the next trial.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
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#240 Re: 18" speakers
Pad it down with a 0.5r resistor, it may be that the efficiency means a little padding is necessary. Mine have a 1r in series to do this as they are a little more efficient than the 6" drivers