Simon's new model.
- deadbeat
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16 years 1 month ago #3076
by deadbeat
Beranek\'s law
\'bits of ply round a driver\'
Replied by deadbeat on topic Simon's new model.
Sorry simon, long plane trips, crap business, I'm going to read this in bits - I only have my Powerbook on me so I can't run any sims or anything...
I've skimmed bits of your first post, and agree on the most part, haven't read your bit on multiple horns through yet, though; it looks like the meat on your posst, though.
My summer project is learning Akabak. Does anybody know any good guides to this?
Also, your statement on air in a horn made me remember this:
I learned about horns starting off with one statement - the air in a horn acts like a slug moving back and forth - that's helped me visualize quite a bit (though that got all screwed up when I delved into waveguide theory [img]smileys/smiley11.gif[/img], which was recently. You learn something new everyday...)
And nah simon, it's not a 2-way discussion - we've got Rog's ghost in here too!
I've skimmed bits of your first post, and agree on the most part, haven't read your bit on multiple horns through yet, though; it looks like the meat on your posst, though.
My summer project is learning Akabak. Does anybody know any good guides to this?
Also, your statement on air in a horn made me remember this:
I learned about horns starting off with one statement - the air in a horn acts like a slug moving back and forth - that's helped me visualize quite a bit (though that got all screwed up when I delved into waveguide theory [img]smileys/smiley11.gif[/img], which was recently. You learn something new everyday...)
And nah simon, it's not a 2-way discussion - we've got Rog's ghost in here too!
Beranek\'s law
\'bits of ply round a driver\'
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16 years 1 month ago #3077
by simonr
Replied by simonr on topic Simon's new model.
@ Deadbeat, I love your tame slug!.Good to hear a few echoes in the cavern. @Mykey, At least someone else read it, or was the laugh directed at the content, not me ranting on to myself like an imbecile?. (I'm having a good chucklemyself at the moment)The comments you made regarding some other cabinets and spls, any more information to go with this, or your views to explain your conclusionswould be helpful.
I'm lining up all my ducks in a row on a target shoot, andasking people to take a shot or two, any more sharpshooters out there?
I'm lining up all my ducks in a row on a target shoot, andasking people to take a shot or two, any more sharpshooters out there?
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16 years 1 month ago #3078
by simonr
Replied by simonr on topic Simon's new model.
OOOOOO! I'm a groupie!!.
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16 years 1 month ago #3101
by simonr
Replied by simonr on topic Simon's new model.
Hi guys, here's what I've made of the WSX horn.
Drawing of WSX to extract horn dimensions.
Drawing of 1850 to extract horn dimensions:
Single WSX Horn plotted using following model:
Single 1850 horn plotted using following model:
Multiple WSX horn model for 4 horns:
Multiple 1850 horn model for 4 horns:
Please note that the drivers that may appear in the above models were NOT the drivers used to derive the following plots. They are the first relavent model that came to hand.
Plot of single / 4 horns at 1w / 1mtr V18-1000 in both horns with
plot of 4 horns (series parallel) above.
WSX red, 1850 blue.
Same but at 3200 watts into 8 series parallel.
A comparison of horns. Red is WSX.
A few notes on the above just to put things in perspective.
Whenever I plot the PD1850, or the V18-1000, I seem to get an exagerated hump at 60 hz. The trough that is seen between 70 and 100 hz does not exist as such. I have measured a drop of 3db on the void at
80 hz on the 1850 horn. However this is a more pronounced notch, and the response is back up much quicker at 90 hz, and is at a much higher level than 70hz. About 1.5 db. Also, the peak seen at around 120 to 160 hz is not so pronounced. As far as the lower frequency roll-off is concerned, I would agree that in the 1850 horn it is pretty steep. As predicted and shown here, it is at around 54 hz that it falls pretty sharply.
As far as the WSX is concerned I have not been able to measure one, and I rely on figures only. Please take into account that everything is done in half space. There is no reference to the measuring conditions that were used to derive the +/- 3db figures. If you look at the horn lengths that I have asigned to the WSX, then you will see that the length is within 3% of the stated figure for the multiples. If the length figure was the total from diaphragm to mouth, then because the compression chamber has been entered as a separate figure, the length has been exceeded. RM's figure of 1590mm for the 1850 horn was, after much playing with positions for different things, bang on. I must say that if I didn't agree with that length, then I knew it was MY calculations that were wrong, not the other way around!. I'll let everyone digest this lot for a while and wait for the fall-out. I think I'll go out to try and find a flack jacket at the army surplus.The final picture is a representation of both horns, with the WSX translated into a 600mm wide horn!.Draw your own conclusions
from this. AsI stated, there isn't a lot of difference in the response, except at the top end. I have probably madea mistake somewhere along the line, so please let me know if you find anything. I've had to goet through a lot of info.I need some proof checking done to verify what I've produced so far.Has anyone got a response plot of a WSX taken under proper conditions toshow otherwise?. More of the same will appear in the 1x18 horn thread over in sub-base section.
Happy building!.
Drawing of WSX to extract horn dimensions.
Drawing of 1850 to extract horn dimensions:
Single WSX Horn plotted using following model:
Single 1850 horn plotted using following model:
Multiple WSX horn model for 4 horns:
Multiple 1850 horn model for 4 horns:
Please note that the drivers that may appear in the above models were NOT the drivers used to derive the following plots. They are the first relavent model that came to hand.
Plot of single / 4 horns at 1w / 1mtr V18-1000 in both horns with
plot of 4 horns (series parallel) above.
WSX red, 1850 blue.
Same but at 3200 watts into 8 series parallel.
A comparison of horns. Red is WSX.
A few notes on the above just to put things in perspective.
Whenever I plot the PD1850, or the V18-1000, I seem to get an exagerated hump at 60 hz. The trough that is seen between 70 and 100 hz does not exist as such. I have measured a drop of 3db on the void at
80 hz on the 1850 horn. However this is a more pronounced notch, and the response is back up much quicker at 90 hz, and is at a much higher level than 70hz. About 1.5 db. Also, the peak seen at around 120 to 160 hz is not so pronounced. As far as the lower frequency roll-off is concerned, I would agree that in the 1850 horn it is pretty steep. As predicted and shown here, it is at around 54 hz that it falls pretty sharply.
As far as the WSX is concerned I have not been able to measure one, and I rely on figures only. Please take into account that everything is done in half space. There is no reference to the measuring conditions that were used to derive the +/- 3db figures. If you look at the horn lengths that I have asigned to the WSX, then you will see that the length is within 3% of the stated figure for the multiples. If the length figure was the total from diaphragm to mouth, then because the compression chamber has been entered as a separate figure, the length has been exceeded. RM's figure of 1590mm for the 1850 horn was, after much playing with positions for different things, bang on. I must say that if I didn't agree with that length, then I knew it was MY calculations that were wrong, not the other way around!. I'll let everyone digest this lot for a while and wait for the fall-out. I think I'll go out to try and find a flack jacket at the army surplus.The final picture is a representation of both horns, with the WSX translated into a 600mm wide horn!.Draw your own conclusions
from this. AsI stated, there isn't a lot of difference in the response, except at the top end. I have probably madea mistake somewhere along the line, so please let me know if you find anything. I've had to goet through a lot of info.I need some proof checking done to verify what I've produced so far.Has anyone got a response plot of a WSX taken under proper conditions toshow otherwise?. More of the same will appear in the 1x18 horn thread over in sub-base section.
Happy building!.
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- tommysb
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16 years 1 month ago #3265
by tommysb
Replied by tommysb on topic Simon's new model.
Hi please don't think this is a monologue, (it is mostly a dialogue
) but you raise some very good, interesting points. I will contribute when I have a bit more time!
Tom
![:P :P](/media/kunena/emoticons/15.png)
Tom
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16 years 1 month ago #3284
by mykey
took this and loaded it against the brute 45
brute 45 black and WSX grey
<A id=the ="return fitsIn;"> </A>
Anyone got any ply?
Replied by mykey on topic Simon's new model.
took this and loaded it against the brute 45
brute 45 black and WSX grey
<A id=the ="return fitsIn;"> </A>
Anyone got any ply?
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16 years 1 month ago #3285
by mykey
Anyone got any ply?
Replied by mykey on topic Simon's new model.
I'll see ifI can go over the Dims for the WSX, see if yours are correct Simon
Anyone got any ply?
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- deadbeat
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16 years 1 month ago #3296
by deadbeat
Beranek\'s law
\'bits of ply round a driver\'
Replied by deadbeat on topic Simon's new model.
Yay! Mykey's beaten me to a model, I've just gotten back.
simon if you could, would you mind annotating on the diagram what you took as the mouth and throat of the horn (WSX) for everyone to see? Not everybody has the dxfs...
Thanks,
Edited by: Deadbeat
simon if you could, would you mind annotating on the diagram what you took as the mouth and throat of the horn (WSX) for everyone to see? Not everybody has the dxfs...
Thanks,
Edited by: Deadbeat
Beranek\'s law
\'bits of ply round a driver\'
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16 years 1 month ago #3309
by simonr
Replied by simonr on topic Simon's new model.
Hi there, good to see a bit more input!. Sorry to say that I've had to go mobile for a time, due to work,so haven't got access tomy drawings at the moment. So to answer your question, Deadbeat, the throat chamber in my model includes the volume of, what some would say is, the firstsection of horn. This is the area directly in front of, and in line with thedriver. The whole of this area is at 544?(no figures to hand). The horn starts at the leading edge of theslot or letterbox. I think this is a better representation of the physical reality. If this sectionwas to be considered as horn it would give a false raised compression figure at the throat if it was considered to be (404?) at the back wall, which is then completely open to the larger area of the chamber anyway. This will also give an exagerated figure to the length of the horn. The way I have put things more accurately represents the length ofthe path, from diaphragm to throat, as this is figured in when converting the volume of the chamber into a length in front of the diaphragmequivalent to the cross-sectional area of 544. Is this clear enough?, I'll tackle it when I get back to base otherwise.
@Mykey, that plot looks pretty damn good for the brute!, got some more info on this to put it in perspective?. What is the driver?. Is it the void?. Somr parameters from your sim would be appreciated to give the plot more meaning. If anything else occurs to me I'll post up some more questions.
TTFN Chaps!
@Mykey, that plot looks pretty damn good for the brute!, got some more info on this to put it in perspective?. What is the driver?. Is it the void?. Somr parameters from your sim would be appreciated to give the plot more meaning. If anything else occurs to me I'll post up some more questions.
TTFN Chaps!
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16 years 1 month ago #3310
by simonr
Replied by simonr on topic Simon's new model.
Just noticed that I put this bit of horn in as a cyan line on the drawing posted. This is part of the chamber, not horn in my model. The throat is represented as the line that crosses the path line at right angles drawn from the leading edge of the letterbox. Clear as mud?.
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