GM said:
Hi GM,
Since when?
Just use Exp instead of Con
.Help File page 1:
"A cylindrical horn segment can be generated by specifying an exponential segment with zero flare (mouth area = throat area)."
Help File page 15:
"To model a tapped horn specify three conical and/or exponential flare segments connected in series and set Vrc and/or Lrc and Vtc and/or Atc = 0."
Hope this helps.
Kind regards,
David
Greets!
Huh! Apparently yesterday's fever did me in more than I thought as I don't remember posting on this thread. I admit though that when I started to learn Hornresp enough to do these simple TP, TH designs all I did was browse the definitions/input HELP pages and try what I considered was a couple of obvious ways to input it and when I got an error message with conic and the wrong calc with hyperbolic, I accepted the program's 0.01 minimum conic expansion since it was close enough. It never occurred to me to try expo since by definition it has a M (T) = 1.0, though I see now after playing a bit more with hyperbolic that it works when 'Fxx' = 0 and 'T' = 1.0.
FWIW, though my doctor says my vision is average for my age I can barely read the HELP files since the script isn't either a higher contrast or larger type and I had to get a younger neighbor to read the green sections to me as they have too little contrast.
Anyway, thanks for the correction.
GM
Huh! Apparently yesterday's fever did me in more than I thought as I don't remember posting on this thread. I admit though that when I started to learn Hornresp enough to do these simple TP, TH designs all I did was browse the definitions/input HELP pages and try what I considered was a couple of obvious ways to input it and when I got an error message with conic and the wrong calc with hyperbolic, I accepted the program's 0.01 minimum conic expansion since it was close enough. It never occurred to me to try expo since by definition it has a M (T) = 1.0, though I see now after playing a bit more with hyperbolic that it works when 'Fxx' = 0 and 'T' = 1.0.
FWIW, though my doctor says my vision is average for my age I can barely read the HELP files since the script isn't either a higher contrast or larger type and I had to get a younger neighbor to read the green sections to me as they have too little contrast.
Anyway, thanks for the correction.
GM
Hi GM,
Thanks for the info. One small snag is the basket and magnet of the driver will not fit in that pipe - if its wide enough to fit the 12" in (31cm) then it would need to be 8.5cm high. The driver is 16.5cm high.
What I'm thinking though is that the pipe would be constricted by the driver so I could calculate the area of the driver side on, and then add that much area to the pipe where the basket sits.
I'm going to bed soon, but will have a play with some small tapers that could give a bit more room for the driver.
Cheers,
Rob.
Will try and get an idea of the cabin gain in the car this weekend, weather permitting (have a sealed test box ready to go)
Thanks for the info. One small snag is the basket and magnet of the driver will not fit in that pipe - if its wide enough to fit the 12" in (31cm) then it would need to be 8.5cm high. The driver is 16.5cm high.
What I'm thinking though is that the pipe would be constricted by the driver so I could calculate the area of the driver side on, and then add that much area to the pipe where the basket sits.
I'm going to bed soon, but will have a play with some small tapers that could give a bit more room for the driver.
Cheers,
Rob.
Will try and get an idea of the cabin gain in the car this weekend, weather permitting (have a sealed test box ready to go)
Hi GM,
Sounds like you must have been really "done-in", then.
Have you tried experimenting with a lower resolution on your display? The Help File should be a bit easier to read at say, 800 x 600 pixels. Hornresp will actually work down to 640 x 480 pixels. The setting I normally use myself is 1024 x 768 pixels.
You're welcome.
Kind regards,
David
GM said:
Sounds like you must have been really "done-in", then
.GM said:
Have you tried experimenting with a lower resolution on your display? The Help File should be a bit easier to read at say, 800 x 600 pixels. Hornresp will actually work down to 640 x 480 pixels. The setting I normally use myself is 1024 x 768 pixels.
GM said:
You're welcome
.Kind regards,
David
Ok I tested the in car response of the infinity 12.1 in 1 cubic foot enclosure (probably .8 once driver vol removed)
Also tested with my wifes old car sub, a cheapy 10" in a small sealed box.
I couldn't measure them outside as it's been raining all day so the winISD plots will have to suffice for comparison.
There's some interesting modes there, and it seems a need for a flat response from ~40Hz down. The 10" used to measure flat from 80Hz down in my wifes small hatchback.
Rob.
Also tested with my wifes old car sub, a cheapy 10" in a small sealed box.
I couldn't measure them outside as it's been raining all day so the winISD plots will have to suffice for comparison.
There's some interesting modes there, and it seems a need for a flat response from ~40Hz down. The 10" used to measure flat from 80Hz down in my wifes small hatchback.
Rob.
Attachments
So.....
looking at the cabin gain, I'd need a speaker that is flat from 45Hz down, and from 45Hz rises up to 80Hz or higher by about 18dB, depending on how I interpret the graph.
I've had a go and can muster a rise of around 10dB which should help a lot.
I've had a go at modelling a tapped pipe of similar size with my JBL 2020h driver. It seems to resemble the BP curve. Is there anything wrong with having such a sharp peak on the TP ?
Cheers,
Rob
looking at the cabin gain, I'd need a speaker that is flat from 45Hz down, and from 45Hz rises up to 80Hz or higher by about 18dB, depending on how I interpret the graph.
I've had a go and can muster a rise of around 10dB which should help a lot.
I've had a go at modelling a tapped pipe of similar size with my JBL 2020h driver. It seems to resemble the BP curve. Is there anything wrong with having such a sharp peak on the TP ?
Cheers,
Rob
Attachments
RobWells said:
You hit the nail on the head there Eva
Rob.
Now you understand why I design my bandpass enclosures in such a strange way
Most people think that I'm crazy when they simulate one of my designs and see the tilted SPL plot. The dip around 50Hz due to the distant tuning frequencies is actually quite useful when you get it.The roll-off below 40Hz happens because the cabin of most cars is not that rigid and leaks the lowest LF to the outer world resulting in not enough gain. You can easily compensate this with a parametric EQ or by applying some treatment to the large frame sheets and panels, but be aware that cabin gain interacts with such a low tuned rear-chamber resulting in more 30Hz port gain than predicted by software. I don't usually aim for much output below 40Hz, it is around 100Hz where most car systems suffer a (depressing) lack of SPL.
Thanks Eva,
I've treated the roof, rear doors, and tailgate so far. Have to order more to do the rear quarters and the front doors. Done the floor too.
It's a shame my comps aren't fitted yet as I'd love to see what horrors await me there.
I also own a pair of peerless 6" 850518 drivers which look good in the BP, but I'm not sure if they'd be loud enough? They hit xmax at around 98dB @ 30Hz - if the 10mm xmax is to be believed.
Cheers,
Rob
I've treated the roof, rear doors, and tailgate so far. Have to order more to do the rear quarters and the front doors. Done the floor too.
It's a shame my comps aren't fitted yet as I'd love to see what horrors await me there.
I also own a pair of peerless 6" 850518 drivers which look good in the BP, but I'm not sure if they'd be loud enough? They hit xmax at around 98dB @ 30Hz - if the 10mm xmax is to be believed.
Cheers,
Rob
Attachments
Thinking out loud here....
What if you make the sealed box so small that it has a sloping response from ~90Hz down. Then add a bit of bass boost at 35 - 40Hz to flatten the response below 45Hz. ??
Takes up less room than all other options, even if it means buying 2 more subs....
plot done with 4 perfect 12.1's (should have enough displacement for a bit of eq)
What if you make the sealed box so small that it has a sloping response from ~90Hz down. Then add a bit of bass boost at 35 - 40Hz to flatten the response below 45Hz. ??
Takes up less room than all other options, even if it means buying 2 more subs....
plot done with 4 perfect 12.1's (should have enough displacement for a bit of eq)
Attachments
Hi GM,
Here's the thing...
I want to use my suv for the reasons it was built for, hence huge enclosures impact on the cargo space I| need for a fridge, camping gear, spare parts / wheel etc....
That doesn't mean I don't want great sounds when I'm out 'on the trail'
I can dedicate more volume if it is no more than 6" high as I'm making a set of storage enclosures to hold tools etc and the back half of the enclosure is spare.
I have an amplifier that can do :
425 @ 4ohms
800@ 2 ohms
1100@ 1 ohm
RMS
I already have 2 infinity perfect 12.1's
I have 1 JBL 2020H
I have 2 peerless 6" 830518 drivers.
I don't mind an enclosure approx 3' x 1' x1' , and external ports can be accomodated.
What did you think of the TP I posted with the big gain at 80Hz ?
Edit: Should have said that the small box was not due to space concerns but due to trying to counteract the cabin gain.
Also doing 'selective eq' in car audio means buying more stuff. Right now I have various amps with xo's, plus an 'ok' alpine with adjustable freq's
Rob
Here's the thing...
I want to use my suv for the reasons it was built for, hence huge enclosures impact on the cargo space I| need for a fridge, camping gear, spare parts / wheel etc....
That doesn't mean I don't want great sounds when I'm out 'on the trail'
I can dedicate more volume if it is no more than 6" high as I'm making a set of storage enclosures to hold tools etc and the back half of the enclosure is spare.
I have an amplifier that can do :
425 @ 4ohms
800@ 2 ohms
1100@ 1 ohm
RMS
I already have 2 infinity perfect 12.1's
I have 1 JBL 2020H
I have 2 peerless 6" 830518 drivers.
I don't mind an enclosure approx 3' x 1' x1' , and external ports can be accomodated.
What did you think of the TP I posted with the big gain at 80Hz ?
Edit: Should have said that the small box was not due to space concerns but due to trying to counteract the cabin gain.
Also doing 'selective eq' in car audio means buying more stuff. Right now I have various amps with xo's, plus an 'ok' alpine with adjustable freq's
Rob
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