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Nomogram ratings
Hey guys,
It's been a while since I last posted here but was wondering if anyone knows what the nomogram rating is for a RE XXX version 4 dual 2 hom subwoofer?
I have tried to contact RE on a number of occasions but have not had much luck...
Thanks in advance.
Nas :)
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nomogram? what the hell are you talking about.
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Quote:
Originally Posted by CVStroker
nomogram? what the hell are you talking about.
Lol, it's to do with box design. I don't know too much about it myself but my dealer asked me to get it from RE but they are not replying.
It is a proper term by the way and not just something that's made up.
Eric may know???
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After looking it up, a nomogram is a term that can be applied to audio, but it more or less sounds like some over-schooled wannabe trying to show off. It technically doesn't have anything to do with car audio.
You're just looking for the transfer function magnitude graph.
Really, the only things he needs to properly design you a box are the fs, Qes, Qms, and Vas numbers, other than that, the dealer is just blowing smoke up your ass
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Quote:
Originally Posted by CVStroker
After looking it up, a nomogram is a term that can be applied to audio, but it more or less sounds like some over-schooled wannabe trying to show off. It technically doesn't have anything to do with car audio.
You're just looking for the transfer function magnitude graph.
Really, the only things he needs to properly design you a box are the fs, Qes, Qms, and Vas numbers, other than that, the dealer is just blowing smoke up your ass
The dealer (who is dealing less with car audio now) said it's been a while and he can't find his ''LEAP'' and ''LMS'' box design programme and asked if I could get the nomogram rating then he can make me a box using ''bars and graphs''. He told me the nomogram ratings include,
Box Volume
Lenght of port
Daimeter of port
Frequency
Displacement
If the transfer function graph is the same as the nomogram rating, do you know where I can get the ''transfer function magnitude graph'' from?
Thanks for your replies CV.
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Give me the model number of the subs, and I'll design you a box and he can build it. If he doesn't deal with car audio that much, then I highly doubt he's familiar with the motor the XXX uses. I'll run it through my program, and give you the numbers to give to him.
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Quote:
Originally Posted by CVStroker
Give me the model number of the subs, and I'll design you a box and he can build it. If he doesn't deal with car audio that much, then I highly doubt he's familiar with the motor the XXX uses. I'll run it through my program, and give you the numbers to give to him.
Hey CV, thanks for offering to design me a box...
The sub I have is the Re XXX Version 4 Dual 2ohm.
It had a recone less then a year ago using some uprated spider things, here is a link of it incase it may be useful to you?
http://www.talkaudio.co.uk/vbb/showt...ght=xxx+recone
I believe the other specs are...
12"
Mounting Depth - 12.75"
Mounting Hole Diameter - 11.5"
Overall Diameter - 13"
Bolt Hole Circle - 12.25"
Motor Width - 10.5"
Motor Depth - 5"
Basket Depth - 7.75"
Displacement - 0.24 cu. ft.
Weight - 72 lbs.
12"
Electrical Q Value -Qes: 0.46
Mechanical Q Value -Qms: 3.29
Total Speaker Q Value -Qts: 0.404
Free Air Resonance -Fs: 21.00 Hz
Equivalent Compliance -Vas: 74.0 liters
One-Way, Linear Excursion -Xmax: 54 mm
Efficiency -SPL 1W/1m: 83.76 dB SPL
Effective Piston Area -Sd: 480 cm^2
DC Resistance -Re: 4.2 ohm
Nominal Impedance -Znom: Dual 2 ohm
Thermal Power Handling -Pe: 2000 W
Force Factor -Bl: 18.16
Appologies if this isn't what you're looking for but if there is anything else you need then please ask.
It is going into a Mk3 Vw Golf.
Many Many thanks,
Nas :)
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Oh, do you want a strictly high sound quality box? Or a high output/semi-good sounding box.
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Quote:
Originally Posted by CVStroker
Oh, do you want a strictly high sound quality box? Or a high output/semi-good sounding box.
High SQ but I want it to drop low too (if that makes any sense)? Not really interested in loads of output to be honest. I also listen to many many different types of music so allsorts of frequencies.
Do you have a rough idea of a Golf Mk3 boot or shall I get you some measurements?
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Getting really low fits in my definition of good sound quality. More than likely, the sub will be able to dip down to about 25 hz, which is lower than about everything you'll ever listen to, which is a good thing. I'll model it up and give you internal volume needed and port dimentions needed, from there, your boy can make it fit in your car (assuming he can handle simple geometry)
But right now, I'm about to head to bed, I'll model it up when I get up tomorrow afternoon (oh the joys of working 2nd and 3rd shift)
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Quote:
Originally Posted by CVStroker
Getting really low fits in my definition of good sound quality. More than likely, the sub will be able to dip down to about 25 hz, which is lower than about everything you'll ever listen to, which is a good thing. I'll model it up and give you internal volume needed and port dimentions needed, from there, your boy can make it fit in your car (assuming he can handle simple geometry)
But right now, I'm about to head to bed, I'll model it up when I get up tomorrow afternoon (oh the joys of working 2nd and 3rd shift)
Thanks CV :)
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I come up with a 85L box with a 30.5cm x 6.4 cm (387sq cm) port that is 106cm long.
If you want emperical measurements, it 3 cubic feet with a 12" x 2.5" (30 sq in) port that is 42 inches long.
This will give you a 24 hz tuning with a nice 2dB hump from 25-40 hz. Your builder should be able to figure it out from there. Just make sure he rounds over the edges of the port to prevent any noise.
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Quote:
Originally Posted by CVStroker
I come up with a 85L box with a 30.5cm x 6.4 cm (387sq cm) port that is 106cm long.
If you want emperical measurements, it 3 cubic feet with a 12" x 2.5" (30 sq in) port that is 42 inches long.
This will give you a 24 hz tuning with a nice 2dB hump from 25-40 hz. Your builder should be able to figure it out from there. Just make sure he rounds over the edges of the port to prevent any noise.
Thanks CV, could you tell me how many cubes the box is including displacement, ports etc?
Once again thanks for the info :)
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4 cubic feet gross, so just make sure the inside of the box equals 4 cubic feet, and the volume of the driver and the port will make it equal out to 3 cubic feet net.
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Quote:
Originally Posted by CVStroker
4 cubic feet gross, so just make sure the inside of the box equals 4 cubic feet, and the volume of the driver and the port will make it equal out to 3 cubic feet net.
Thanks CV I will keep you updated I just wonder what it would look like.
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Quote:
Originally Posted by CVStroker
It will be big
Lol :D......
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Quote:
Originally Posted by CVStroker
It will be big
Hey CV, I have sent the dimensions to my dealer and he told me that whoever designed your box (you) really seems to know what he's doing.
He also said modifying it to fit into my car should be very simple.
Looking good so far I will let you know the outcome.
P.s Where has Eric gone???
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1 Attachment(s)
Quote:
Originally Posted by nastynas
Hey CV, I have sent the dimensions to my dealer and he told me that whoever designed your box (you) really seems to know what he's doing.
He also said modifying it to fit into my car should be very simple.
Looking good so far I will let you know the outcome.
P.s Where has Eric gone???
It's not particularly hard. It's just a balance of keeping the driver in check and giving it what it wants to perform well. In case you're curious, this is what your speaker's response will look like in an anechoic chamber vs your car. The green shows the response you're likely to get if you just mount the woofer outside playing into infinite space. The red shows the response you're likely to hear in your car. While the gigantic hump seems a bit obnoxious, consider than once you hit about 60 hz, your hearing sensitivity is drastically reduced as the frequencies go lower. So while the sub plays louder the lower it goes, it will sound like it's keeping the same output level. It's a real trick way to shake someone's bowels loose.
Once you design and build enough boxes, you just know what to look for.
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Quote:
Originally Posted by CVStroker
It's not particularly hard. It's just a balance of keeping the driver in check and giving it what it wants to perform well. In case you're curious, this is what your speaker's response will look like in an anechoic chamber vs your car. The green shows the response you're likely to get if you just mount the woofer outside playing into infinite space. The red shows the response you're likely to hear in your car. While the gigantic hump seems a bit obnoxious, consider than once you hit about 60 hz, your hearing sensitivity is drastically reduced as the frequencies go lower. So while the sub plays louder the lower it goes, it will sound like it's keeping the same output level. It's a real trick way to shake someone's bowels loose.
Once you design and build enough boxes, you just know what to look for.
CV, you are awesome dude! thanks :cool:
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5 Attachment(s)
Quote:
Originally Posted by CVStroker
It will be big
It certainly is big! Anyway here are the pics as promised :)
Let me know what you think...
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Quote:
Originally Posted by nastynas
It certainly is big! Anyway here are the pics as promised :)
Let me know what you think...
BIG barely begins to describe the subwoofer enclosure. Feeding trough for horses comes to mind, though.
I didn't read through the entire thread. This box is going to be installed into what type of vehicle?
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That's a good looking box. My only complaint would be the port shooting out the side of the box instead of on the front baffle. There may be no problem, but I have notices some funky harmonics pop up from time to time with that arrangement.
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Quote:
Originally Posted by bustamove
BIG barely begins to describe the subwoofer enclosure. Feeding trough for horses comes to mind, though.
I didn't read through the entire thread. This box is going to be installed into what type of vehicle?
It is going into a VW Golf Mk3 Tdi (1997). I will post more pics of the full install once it's all in, Just waiting for some ID Ultra horns and some 8's now :D
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Quote:
Originally Posted by CVStroker
That's a good looking box. My only complaint would be the port shooting out the side of the box instead of on the front baffle. There may be no problem, but I have notices some funky harmonics pop up from time to time with that arrangement.
Thanks CV, I found that a bit strange too as all the other boxes have the ports upfront and that is their prefered method. It is a little bit fidgety trying to keep the port clear in the car.
Maybe the joiner did it his own way, the port is also not radded as far as I can tell and I asked him to make it a slanting box. None of that has been done but I will wait to see how it sounds and if there is any port noise before deciding what to do.
Hopefuly it should be fine :)
On another note, taken from the RE website the cutout hole size was 11 and a half inches but that seems to be to big :mad2:
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