Okay- I see you used the mH range of the tweeter at the intended xover frequency to find the inductance at that point of xover. That's not what I thought you were doing. Oh- an 'tt' is not a symbol for 'pi'. Just use 3.14 for a numerical reference, or 'pi'. Your inductance formula is incorrect:
L = R/(2*pi*Fc)*10^3, where L is in mH.
But- you don't at all get what the 0.75-2.0mH coil is for apparently. I said this was for the BSC, and it ues the second coil setup for this value range. You didn't understand my statements.
You think I don't understand or want to know, but I'm just trying to understand the why, and the reasoning behind it.
I've discussed this stuff with 'speakerman' in the past over on PETT. I still don't believe some of the statements he makes actually hold water, but I'm trying to understand his methods. The main reason I started into this thread is that it seemed like the same old as before, but I'm approaching it differently this time around. He kept asking why noone is answering his questions- so I answered them. I have no preference for either parallel or series xovers, and have used both on many occasions. I am not currently a believer in 2-component BW6 SXO's being enough or adequate rolloff attenuation.
I'm sorry if it looks like I intruded, but I want to know what makes this Fried stuff tick for speakerman.
Later,
Wolf
You are debating crossover plans done by the expert. . You are claiming additional inductance for baffle step which is not needed in enclosures that are narrow and routed and time aligned and phase correct..
I get what every thing is. You and most forum users are full of it.
You are incorrect , Look at the different topologies you can look at this from. values of their voice coils.. You don't know the value of the inductors in the crossovers are. Now you are telling me the crossover plans from the kits are wrong.
I was giving one value.The Hiquphon 2092 mh is .03mh and the midbass is
.33mh These value are basis. I know I didn't go into more detail but I had to start somewhere about the relation ship with both drivers mh. Woofer mh=L1
There is no additional inducatance added of about .75-1 mh. in the midbass tweeter crossover. I have the plans . I don't understand why you persist. Everyone is wrong and you and certain forum users ar right ha. How can you make these statements when you do not have the woofer specs to the the many woofers invented by the man. The Scan Speak tweeter has a .08 mh value that tells me that 32,000hz . I see i forgot one zero in prior post sorry. I f I use one tenth of this value at 3200hz and use twice the capacitor value I get 6.4 mfd for the approximate C1 usinfg this method of values. and I found I had to increase this by testing and measuring. i have used this tweeeter at 6.8 -7.2mfd with an Rc circuit with Carboneau drivers in the past you could use a 4.7- 5.0 mfdmfd as C1 and 2.2mfd with RC
Values for 12dB Crossovers by Solen
You put down his deigns in the past. I don't care what your opinion is.
I get what every thing is. You and most forum users are full of it.
You are incorrect , Look at the different topologies you can look at this from. values of their voice coils.. You don't know the value of the inductors in the crossovers are. Now you are telling me the crossover plans from the kits are wrong.
I was giving one value.The Hiquphon 2092 mh is .03mh and the midbass is
.33mh These value are basis. I know I didn't go into more detail but I had to start somewhere about the relation ship with both drivers mh. Woofer mh=L1
There is no additional inducatance added of about .75-1 mh. in the midbass tweeter crossover. I have the plans . I don't understand why you persist. Everyone is wrong and you and certain forum users ar right ha. How can you make these statements when you do not have the woofer specs to the the many woofers invented by the man. The Scan Speak tweeter has a .08 mh value that tells me that 32,000hz . I see i forgot one zero in prior post sorry. I f I use one tenth of this value at 3200hz and use twice the capacitor value I get 6.4 mfd for the approximate C1 usinfg this method of values. and I found I had to increase this by testing and measuring. i have used this tweeeter at 6.8 -7.2mfd with an Rc circuit with Carboneau drivers in the past you could use a 4.7- 5.0 mfdmfd as C1 and 2.2mfd with RC
Values for 12dB Crossovers by Solen
You put down his deigns in the past. I don't care what your opinion is.
For the last time I will talk to you and Sreten the midbass voice coli inductance is L1 .
The tweeeter voice coil incuctance by about 1/10 is a close approcximation of C1
Every thing is an approximation I test with spl and tones. I have the plans for so many of the speakers If a cabinet is pyramid shaped ther is no baffle step needed . I remember reading about it a long time ago. I looked up the formulas . It does not apply with these narrow a cabinets. How wide do you make your caniets.
If I make a spelling error sorry. I try and not use to high of a magnification of glasses because it weakens a persons vision over time then you need stronger glasses.
The tweeeter voice coil incuctance by about 1/10 is a close approcximation of C1
Every thing is an approximation I test with spl and tones. I have the plans for so many of the speakers If a cabinet is pyramid shaped ther is no baffle step needed . I remember reading about it a long time ago. I looked up the formulas . It does not apply with these narrow a cabinets. How wide do you make your caniets.
If I make a spelling error sorry. I try and not use to high of a magnification of glasses because it weakens a persons vision over time then you need stronger glasses.
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My whole point is midbass driver voice coil inductance is L1. if you dont' understand the rest? I have all 5 model C pyramid shaped crossover plans. And you are basically telling me the plans are wrong because they do not have a baffle step. Do yuo know the cabinet width. If any one knows more then certain experts on this forum they are harasssed. What plans do you have from the company. How can you tell me a certain coil has to be used. It is not neeeded . This forum is pathetic.
There is a relationship between each tweeters voice coil inductance and free air resonance. Maybe you can explain it.
Of course there is. Ask the moderator (Planet10). We're just cheerleaders 😀
Of course I know that you know like I know. You just do not have enough patience to mention it
Hi,
Seems to be speakerman illustrating he has absolutely
no idea what he is talking about and boring everybody
else rigid in the process.
rgds, sreten.
The inductance value above, is of course wrong.
Nominal 8 ohm values for 3.2KHz are 0.4mH and 6.2uF.
Small narrow boxes inevitably have baffle step, and so
does a small pyramid shaped baffle, its just physics.
To try to pretend otherwise is just boringly banal.
Speaking of banal, that pretty much sums up Fried Products.
Only those that don't know anything would get taken in
by the flowery pseudotechnical prose used to "describe"
their products. They are nothing special, never have been.
It would be unfair to criticise because I used to build pyramids too, back in the day...
Nowadays I wouldn't take the time. Diffraction ought to be eliminated, not smeared.
Hi,
I don't know how you can eliminate the baffle step of small boxes.
Its inevitable for open placement, and only possible to eliminate
with flush wall mounting, or moved down with very big baffles.
Shown is are the baffle effects for a very typical 6.5"/1" layout.
Baffle step is 6dB going from 2 pi to 1 pi loading, most people
don't realise there is always also a ~ 2dB hump to consider.
(Loads of typical box speakers will look like this, with the
driver size near baffle width, frequency changing with width.)
You can smooth box edges to reduce effects further up,
but there is no way round the physics of box baffle step.
rgds, sreten.
Hi sreten. I mainly posted to have a rant about pyramids. I agree with you about the step.
Interesting point.
I recently did some informal personal experiments with placing an ordinary box flush with a wall. The lower midrange was rife with issues as a result.
Yep- I'm in agreement with you as well. I took a guess at what he is doing, and was apparently still wrong, and then he stated he didn't state it right before. I can't understand if he doesn't, and apparently none of us on this forum should be seen as experts.
Whatever- I'm done once again. I guess if this forum is pathetic as he says, then he can still look for another one.
On to the next topic....
Wolf
from 2pi to 4pi.
The 2 dB hump i assume is a reference to a specific example of the ripple that accompanies the BS, the amount and shape of which is largely dictated by the shape of the baffle.
dave
The bump referred to is similar to the dipole peak. As the frequency increases from DC there comes a point on axis were the diffracted sound is in phase with the direct sound. This leads to an amplitude which can have a theoretical maximum of 1.5 or 20*log(1.5) in dB. Above that frequency the series of dips and peaks can occur, depending of directionality of the driver.
I went back and read over some of this thread and what I see is statements of theoretical L and C values based on purely resistive loads and some hand waving about changing L to compensate for the woofers Le. Obviously, you can not change L without changing C if the crossover point is to remain constant. Plus, it certainly is not so simple as adding the impedance magnitude of wxLe to Re to compute the crossover component values as wxLe is a reactive impedance.
This thread seems to rely heavily on the work done in the 60's and 70's which, while worth while at the time, has been surpassed by todays understanding of crossover design. This thread just seems to want to reinvent history asserting that what was done 50 years ago is superior to what is done today.
I went back and read over some of this thread and what I see is statements of theoretical L and C values based on purely resistive loads and some hand waving about changing L to compensate for the woofers Le. Obviously, you can not change L without changing C if the crossover point is to remain constant. Plus, it certainly is not so simple as adding the impedance magnitude of wxLe to Re to compute the crossover component values as wxLe is a reactive impedance.
This thread seems to rely heavily on the work done in the 60's and 70's which, while worth while at the time, has been surpassed by todays understanding of crossover design. This thread just seems to want to reinvent history asserting that what was done 50 years ago is superior to what is done today.
Hi,
Yes, from full space to halfspace, my error.
And yes again, with a driver nearly as wide as the baffle for a
rectangular box speaker the shape of the curve is the same.
The 6dB baffle step and a broad ~ 2dB single hump.
The smaller the driver the more ripple you get, you
can see that on the two plots for the tweeter.
rgds, sreten.
The crossover is 1st order Butterworth series values which are quasi 2nd order after measurements.. The drive placement has to be exactly in line The pyramids are on top of the subwoofer.
Using a Scan Speak carbon fiber driver the voice coiil mh is.4 mh that gives a crossover frequency of 3200hz. Since voice inductance is .4mh the upper limits of the driver are 2189hz. You don't add inductance to these types of crossover circuits unless you want to fry the tweeter.
ScanSpeak Classic 18W/8545 7" Mid Woofer Paper Cone: Madisound Speaker Store
If I tried this with a woofer having a voice coil inducance of 1mh the useable upper frequency limit is 955 hz. Now that would be stupid .
I am tired of the sarcasm and name calling . If some forum users did this in everyday life your life expectancy would be much shorter.
Using a Scan Speak carbon fiber driver the voice coiil mh is.4 mh that gives a crossover frequency of 3200hz. Since voice inductance is .4mh the upper limits of the driver are 2189hz. You don't add inductance to these types of crossover circuits unless you want to fry the tweeter.
ScanSpeak Classic 18W/8545 7" Mid Woofer Paper Cone: Madisound Speaker Store
If I tried this with a woofer having a voice coil inducance of 1mh the useable upper frequency limit is 955 hz. Now that would be stupid .
I am tired of the sarcasm and name calling . If some forum users did this in everyday life your life expectancy would be much shorter.
0.4 mh give a x-o frequency of 3.2k? Why, because Led x 2PI x F = 8 ohms at F=3.2k?
2.2k seems reasonable for a crossover point wth the 18W (I've used it for many years) but a quasi-2nd order series x-o at 2.2k won't address a number of issues with that driver. FWIW, I was designing speaker with series x-o's back in the '70s.
2.2k seems reasonable for a crossover point wth the 18W (I've used it for many years) but a quasi-2nd order series x-o at 2.2k won't address a number of issues with that driver. FWIW, I was designing speaker with series x-o's back in the '70s.
What are the issues John K? I know Fried tried everything on the market in late 90's before getting the composite cones made. He would sell test drivers pretty low priced. I am giving examples of the design parameters.
I stated a crossover frequency of 3200hz.
He gave up on the Focal Kevlar because they rang on high spl.
I stated a crossover frequency of 3200hz.
He gave up on the Focal Kevlar because they rang on high spl.
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