Need help on designing a car subwoofer enclosure
Hey guys,
I hope I am posting in the right category. So I've been trying to design an enclosure in VituixCAD and WinISD. I've got some difficulties making it meet my desired specs. The cab + subwoofer are designed to be in a car trunk.
From what I understand it would be best fit into a rather small enclosure (max 40l), I've tried many things and past 45l f-3 keeps getting higher.
I just achieved something pretty good. My biggest problem is the cone excursion though.
The speaker I have is this one :
Sica 10 SR 2,5 CP 4Ω. Specs are attached.
I would like to get a solid 40Hz @ f-3. Here are the specs of my actual simulated enclosure :
Actually pretty good IMO. But then, as you can see, here is the problem : the cone excursion.
This @200W (which is the maximum power I can get from my amplifier)
i get roughly the same result in WinISD.
Is that a problem ? Is there another problem I don"t see ? Do you see a better alternative ? I'm a total beginner so I would be happy to get as much info as I can.
Thank you !
Hey guys,
I hope I am posting in the right category. So I've been trying to design an enclosure in VituixCAD and WinISD. I've got some difficulties making it meet my desired specs. The cab + subwoofer are designed to be in a car trunk.
From what I understand it would be best fit into a rather small enclosure (max 40l), I've tried many things and past 45l f-3 keeps getting higher.
I just achieved something pretty good. My biggest problem is the cone excursion though.
The speaker I have is this one :
Sica 10 SR 2,5 CP 4Ω. Specs are attached.
I would like to get a solid 40Hz @ f-3. Here are the specs of my actual simulated enclosure :
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Actually pretty good IMO. But then, as you can see, here is the problem : the cone excursion.
An externally hosted image should be here but it was not working when we last tested it.
This @200W (which is the maximum power I can get from my amplifier)
i get roughly the same result in WinISD.
Is that a problem ? Is there another problem I don"t see ? Do you see a better alternative ? I'm a total beginner so I would be happy to get as much info as I can.
Thank you !
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This driver gives a clean 40Hz at 111dB before running out of xmax at about 100w. You will never go that loud in a hifi setting except when you want to be deaf. And you don't want to push the amp to maximum neighter as it start to distort (even if the driver can handle it).
And even if your amp would be more powerfull, the driver will not break, the bass will only be more distorted as xmax is the limit of linear excursion, mostly the driver can handle way more before hitting xmech and go in physical overexcursion.
So i would not worry.
Btw, i come to a 50L ported cabinet with 2 10cm diameter ports of 51.4cm long for your tuning.
And even if your amp would be more powerfull, the driver will not break, the bass will only be more distorted as xmax is the limit of linear excursion, mostly the driver can handle way more before hitting xmech and go in physical overexcursion.
So i would not worry.
Btw, i come to a 50L ported cabinet with 2 10cm diameter ports of 51.4cm long for your tuning.
Thank you for the answers, lets put it another way :
Whats the best possible response I can get from this speaker, getting as low as possible, SPL doesn't matter as much as getting close to the lowest the speaker itself can go.
And, would my design work or are there evident flaws to it that I can't see ?
Last, does the tuning frequency matter that much ? thank you again, sorry I have a lot of questions
Also @waxx, how do you tell xmax is running out at 100W, is that from my graphics ? I cannot see how you did that, its interesting and I'm curious
Whats the best possible response I can get from this speaker, getting as low as possible, SPL doesn't matter as much as getting close to the lowest the speaker itself can go.
And, would my design work or are there evident flaws to it that I can't see ?
Last, does the tuning frequency matter that much ? thank you again, sorry I have a lot of questions
Also @waxx, how do you tell xmax is running out at 100W, is that from my graphics ? I cannot see how you did that, its interesting and I'm curious
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Ah ok, well you can just open them in another tab, but I will also reup them as attached files if I can.
You should defo check out my images cause everything is in there and that would help me a lot
Edit : I cannot attach images anymore, so just open the links in a new tab.
So you mean you put in WinISD the woofers info and then you did what you said, and thats it ? So the woofer is basically limited by itself at more than 100W ? it can't go lower than 35Hz anyway. How do (or, can) I SPL limit so I can keep the excursion ok ?
You should defo check out my images cause everything is in there and that would help me a lot
Edit : I cannot attach images anymore, so just open the links in a new tab.
So you mean you put in WinISD the woofers info and then you did what you said, and thats it ? So the woofer is basically limited by itself at more than 100W ? it can't go lower than 35Hz anyway. How do (or, can) I SPL limit so I can keep the excursion ok ?
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Greets!
As already noted, normally will just distort more till eventually the VC will hit the back plate if no high pass filter is used to protect it, which may/may not damage it enough to need re-coning, but if you look at the 54 m/s vent velocity that ideally should be at < 17 m/s, the vent will be 'choking'/'chuffing' so bad it will be limiting its excursion, which in turn is making it heat up [thermal power distortion] to the point where the amp will be overload clipping, so if this distortion 'sounds' good to you [and IME way too many 'boomers' do], eventually the amp's protection ckt. will shut it down, assuming it has one.
In short, just protect it down low and use the largest/longest vent you can tolerate and 'it is what it is'.
Hey thank your for the answer, that's helping me. I didn't know anything about the velocity, though I 've heard of it multiple times in several topics.
Thanks a lot for pointing that out. What do you mean about way too many boomers do sound good at clipping ? I'm not sure I get that right ahah
So, what best could I do with that speaker ? Would someone mind making me a setup if I gave him my actual settings in VituixCAD/WinISD ? I'm really not sure where Im going at right now...
My amplifier either have is an HPF or a LPF, and I was planning to use it as a LPF so I can crossover with the speakers in front of the car.
Thanks a lot for pointing that out. What do you mean about way too many boomers do sound good at clipping ? I'm not sure I get that right ahah
So, what best could I do with that speaker ? Would someone mind making me a setup if I gave him my actual settings in VituixCAD/WinISD ? I'm really not sure where Im going at right now...
My amplifier either have is an HPF or a LPF, and I was planning to use it as a LPF so I can crossover with the speakers in front of the car.
So I've come to this now, @160W which would be the max power I'll give from the amp to the driver, to prevent clipping of the amp:
See attch1
As you can see, no more cone over excursion, velocity is better, but, f3 is sooo damn high... (attch 2).
If I make vb bigger, I then again go to over excursion and all that stuff.
It is a 10" speaker, that can take 300Wrms, is there nothing better I can do with it ??? I believe I am making a big mistake in my simulation, because I can't believe I can only have that kind of result from the specs that speaker has. Or it is not made to be a subwoofer at all.
Please, please someone help me understand this !!! Thanksss
See attch1
As you can see, no more cone over excursion, velocity is better, but, f3 is sooo damn high... (attch 2).
If I make vb bigger, I then again go to over excursion and all that stuff.
It is a 10" speaker, that can take 300Wrms, is there nothing better I can do with it ??? I believe I am making a big mistake in my simulation, because I can't believe I can only have that kind of result from the specs that speaker has. Or it is not made to be a subwoofer at all.
Please, please someone help me understand this !!! Thanksss
Attachments
1: putting a speaker in a car gives you a degree of free bass boost known as "cabin gain", which means you probably can live with a response that's not flat in the model because if should reach a bit deeper in the car. Exactly how much gain you get is variable though, you may want to do some research on it before committing to a particular design.
2: The difference between 160W and 300W is less than 3dB, which in the grand scheme of things isn't an awful lot - I wouldn't worry about that. Like waxx said in the very 1st reply, 111dB @ 40Hz (before accounting for cabin gain) should be more than enough for normal enjoyment IMO.
3: It's quite normal for drivers to only be able to handle full power under certain conditions in real life - the power rating is only what it can take before damage, not what it can take while still sounding good - that's where the modelling comes in to assess excursion, vent airspeed etc.
2: The difference between 160W and 300W is less than 3dB, which in the grand scheme of things isn't an awful lot - I wouldn't worry about that. Like waxx said in the very 1st reply, 111dB @ 40Hz (before accounting for cabin gain) should be more than enough for normal enjoyment IMO.
3: It's quite normal for drivers to only be able to handle full power under certain conditions in real life - the power rating is only what it can take before damage, not what it can take while still sounding good - that's where the modelling comes in to assess excursion, vent airspeed etc.
Ok thank you, I think I am taking this way too seriously, not that this is a bad thing, but I am overthinking a lot, as usual, and I'm a newbie so I don't want to make a big mistake.
But, still, no chance to get a lower f3 from what I have now ? I'm mostly listening to bass music and metal and while I would definitely enjoy my metal "sub high", my drum n bass, not so much...
Any tip ? Maybe changing the woofer ? I'm looking at the Dayton RSS210HF-4 8" and it goes down pretty good despite being it only 8" (I got the tip from another thread here on diyaudio)
But, still, no chance to get a lower f3 from what I have now ? I'm mostly listening to bass music and metal and while I would definitely enjoy my metal "sub high", my drum n bass, not so much...
Any tip ? Maybe changing the woofer ? I'm looking at the Dayton RSS210HF-4 8" and it goes down pretty good despite being it only 8" (I got the tip from another thread here on diyaudio)
Yes, you can still get a lower f3 than at present, but the trade-off is that you will have a lower maximum volume before running out of excursion, and probably a box that uses up slightly more of the space inside your car.
(In loudspeaker design, just about everything is some kind of trade-off, FWIW.)
Cabin gain may well mean that you can still get loud enough however, so I'd start by looking into that if I were you.
(In loudspeaker design, just about everything is some kind of trade-off, FWIW.)
Cabin gain may well mean that you can still get loud enough however, so I'd start by looking into that if I were you.
Ok thanks, but for cabin gain, I would need to have the sub in the car already and built, right ? Or can I do some sort of simulation here too ?
In order to have a lower f3 here, I would need, in the software, to mainly limit the voltage fed to the woofer, and then adjust the volume of the box/port ? Just to confirm that I got it right
In order to have a lower f3 here, I would need, in the software, to mainly limit the voltage fed to the woofer, and then adjust the volume of the box/port ? Just to confirm that I got it right
You're welcome!
'Boomers' [AKA 'boombox' vehicles] as in folks that enjoy driving around 'experiencing' a loud, massively distorted bass output. In my locale there's so many they're a 'dime a dozen' with most in upscale late model vehicles, so presumably they can afford much better.
Only have Hornresp nowadays.
Normally a low pass filter [LPF] [AKA 'TT rumble filter' from the vinyl era]; a high pass filter [HPF] is for tweeters, so would roll off all below it.
'Boomers' [AKA 'boombox' vehicles] as in folks that enjoy driving around 'experiencing' a loud, massively distorted bass output. In my locale there's so many they're a 'dime a dozen' with most in upscale late model vehicles, so presumably they can afford much better.
Only have Hornresp nowadays.
Normally a low pass filter [LPF] [AKA 'TT rumble filter' from the vinyl era]; a high pass filter [HPF] is for tweeters, so would roll off all below it.
Cabin gain ideally needs to be measured, but here's some info that may at least give you an idea:
https://integralaudio.com/blog/wp-c...d-Advice-issue-53-Proper-Subwoofer-Design.pdf
Car Audio Cabin Gain Transfer Function
https://farm4.static.flickr.com/3194/2516534482_b0d155d5ac_o.jpg
motor vehicle room gain - Google Search
https://integralaudio.com/blog/wp-c...d-Advice-issue-53-Proper-Subwoofer-Design.pdf
Car Audio Cabin Gain Transfer Function
https://farm4.static.flickr.com/3194/2516534482_b0d155d5ac_o.jpg
motor vehicle room gain - Google Search
Ahah, ok, well tbh I did understood it well then. So to clarify, I like clear sound (not speaking of the brand lol), clean, crisp, proper good sound. I like my music to be heavy and clean, as much as possible, I like quality to its finest, at least to whats possible for me and my wallet. I am running some clean and crisp yet powerfull monitoring system in my house and I'm very good with it, if I wish I had the same system in my car lol but I cannot, really. Just trying to get close to it.
Anyway, no distortion for me except when its meant to.
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