well then dont take into account cabin gain or your in house response will suffer.
youl get more bass if you put the box facing the back of the car,less cancelation in most cars.(probably)
the cabin gain curve that ive seen somewhere,but now cannot find.it started at 50hz not 70hz. Ofcourse it varies alot.
measure the response of the woofer in the car.measure the response of the woofer when sitting outside on the ground.
the difference is the cabin gain. winisd models 2pi response.
An spl meter doing this is abit rough,use speaker workshop(if u can figure it out and get it working right)
or some other program.
If u design your box without cabin gain youl have to EQ out some low end.This in my opinion,is better than Boosting with EQ while in the house (because of your cabin gain optimised sub doing crap low freqs in your house) bear in mind, that 40hz is fine for most normal music!
Re: Sealed or ported... the dilemma continues
Most hatches have insane cabin gain, I doubt that yours will be much different
Another option for a dual venue box is to make the enclosure a slightly large sealed, but calculate a port length that will work "ok" in that volume (it'll sound a bit boomy vented but that is fine for party use) then you simply plug up the port for use in the car , there are a few pvc fittings (screw on ends ect) that you can use for this.
the subs sound fine at 30hz their quite linear, have no nasty suspension noises ect, but the car and sub location and how well made and securely fitted the sub box is will make a bigger impact. You're starting to fell the bass more at 30hz than hearing it, so having solid enclosure that it's self is solidly mounted is important.
if you are sticking to having the sub firing through the hatch cover then mount the sub as far back as possible to maximize cabin gain, it's free, may as well take the best advantage of it.
that hi pass on the 6x9's will be fine.
MikeHunt79 said:
I doubt my car has 18db/octave of gain tho, but it would be nice to know how much cabin there really is. Maybe I should try some of that room analysing software in my car?
But in the otherhand, I'm really tempted to build a box with a flat freq response (or close to it), and use EQ to cancel out the cabin gain. I currently favour this option since I occasionally bring the sub in the house for house parties, and such like, where there is no cabin gain at all (I guess I should've mentioned this earler).
Having the sub in the parcel shelf sounds like a good idea (if I decide go the sealed route) since I need to keep my 6x9's and there's no where else to mount them. I could make the box so that it touches the floor of the boot, and supports the weight of the parcel shelf (which is already starting to sag).
Since you've used these drivers before in a sealed enclosure, can you tell me what they sound at the lower frequencies... Would 30Hz sound good, for example?
Yep, I was going to use a 3 or hopefully a 6db/octave filter at around 80Hz to do this. Does this sound ok? I chose 80Hz since my amps LPF for the sub is 12dB/Octave butterworth at 80Hz.
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Most hatches have insane cabin gain, I doubt that yours will be much different
Another option for a dual venue box is to make the enclosure a slightly large sealed, but calculate a port length that will work "ok" in that volume (it'll sound a bit boomy vented but that is fine for party use) then you simply plug up the port for use in the car , there are a few pvc fittings (screw on ends ect) that you can use for this.
the subs sound fine at 30hz their quite linear, have no nasty suspension noises ect, but the car and sub location and how well made and securely fitted the sub box is will make a bigger impact. You're starting to fell the bass more at 30hz than hearing it, so having solid enclosure that it's self is solidly mounted is important.
if you are sticking to having the sub firing through the hatch cover then mount the sub as far back as possible to maximize cabin gain, it's free, may as well take the best advantage of it.
that hi pass on the 6x9's will be fine.
mikee12345 said:
the exact orientation of the sub doesn't matter, only the physical location in the car, sometimes you can squeeze an extra db or 2 out of a sub by aggressively (quazi horn) loading it against the rear wall or window in a hatch but this can lead to rattle based distortion and changes in the frequency response (which may be good, bad or indifferent).
Circlotron said:
by eye they have around 5-6mm (one way) linear xmax (though the suspension isn't all that "linear" to begin with) and ooh 8-9mm x-max with compression and some distortion.
[note] to me a linear suspension is one that has a more or less constant resistance to motion within x-max.
Thanx again for the replys guys, I'm slowly understanding this whole thing. Sorry I havent replied sooner, I've been having computer problems hence my different IP addy).
Those PVC attachment things sound exellent... Having the ability to have a box that can go from ported to sealed sounds good, even just to be able the difference between the two so I can see which I prefer.
I'm now certainly more knowledgeable about the whole speakerbox thing now. Unfortunately, time has really been up against me recently, so I'm gonna have to postpone this for a week or two, on order to get all my assignments finished. I'm glad I checked with you guys before building tho, since I was about to rush to get it done, without considering all the consequences. I'll have it done by 2004, and so I should have something to show for it by then. (I should also have pics of my computer running in the car... 10" LCD and all)
Still, my existing box is ok for the meantime, even if it does sound quite boomy. (I've been playing with my EQ both in the car and house and I've got a nice sound out of it tho). I'm still full of questions tho, so I might aswell for it:
I also now have a couple of MegaVox 8" woofers to play around with, but I havent been able to find any specs on them, but that site cadmaniac mentioned (DIYsubwoofers.ORG) had info on how to find this out with a sig gen and multimeter. Yet another thing to get done over christmas. I was toying with the idea of of having the Pioneer 12" and the two MegaVox 8's in the same box, but the 8's are being powered from the crossover from the front components, so theres going to be a lot of complexity with gain balancing... Maybe this isn't such a good idea?
Im also gonna get round to giving speaker workshop a go in the car, but my USB soundcard isnt full duplex, so I'm gonna have to borrow a laptop. I take it even tho laptop soundcards aren't the best quality, it'll produce correct results if it's full-duplex wont it?(I'm sure someone heer mustv'e used speaker workshop).
I've just seen the horn thread (the one where skinnyboy has built something the size of my car)
and I'm interested to see the results, especially mikee12345's since he's using a 10" or 12" inch... This might be another option, having a hatch and all, but I guess I'm gonna let the experts have a go first, since I've only just grasped the principles of basic ported enclosures, let alone the whole horn thing.
Those PVC attachment things sound exellent... Having the ability to have a box that can go from ported to sealed sounds good, even just to be able the difference between the two so I can see which I prefer.
I'm now certainly more knowledgeable about the whole speakerbox thing now. Unfortunately, time has really been up against me recently, so I'm gonna have to postpone this for a week or two, on order to get all my assignments finished. I'm glad I checked with you guys before building tho, since I was about to rush to get it done, without considering all the consequences. I'll have it done by 2004, and so I should have something to show for it by then. (I should also have pics of my computer running in the car... 10" LCD and all)
Still, my existing box is ok for the meantime, even if it does sound quite boomy. (I've been playing with my EQ both in the car and house and I've got a nice sound out of it tho). I'm still full of questions tho, so I might aswell for it:
I also now have a couple of MegaVox 8" woofers to play around with, but I havent been able to find any specs on them, but that site cadmaniac mentioned (DIYsubwoofers.ORG) had info on how to find this out with a sig gen and multimeter. Yet another thing to get done over christmas. I was toying with the idea of of having the Pioneer 12" and the two MegaVox 8's in the same box, but the 8's are being powered from the crossover from the front components, so theres going to be a lot of complexity with gain balancing... Maybe this isn't such a good idea?
Im also gonna get round to giving speaker workshop a go in the car, but my USB soundcard isnt full duplex, so I'm gonna have to borrow a laptop. I take it even tho laptop soundcards aren't the best quality, it'll produce correct results if it's full-duplex wont it?(I'm sure someone heer mustv'e used speaker workshop).
I've just seen the horn thread (the one where skinnyboy has built something the size of my car)
and I'm interested to see the results, especially mikee12345's since he's using a 10" or 12" inch... This might be another option, having a hatch and all, but I guess I'm gonna let the experts have a go first, since I've only just grasped the principles of basic ported enclosures, let alone the whole horn thing.
MikeHunt79 said:I've just seen the horn thread (the one where skinnyboy has built something the size of my car)
Actually... I think what Mike is working on at the moment is also only an 8inch woofer horn... and his woofer is even lower powered than mine...
Mine is so big cos it doesn't have any folds..
its just an experiment..
its an 8" speaker on horn(34cm wide horn flare,so the lab12 can fit on it),
-its maximising the woofers potential
the results are not meant to be 135db @ 40hz
the fact that i have a basshorn ,hornresp'ed, CADed (folded) and now constructing,shows that ive learnt a little..
and now i can apply those ideas to the lab12 woofer when i buy it which can take high compression ratios if need be.
-its maximising the woofers potential
the results are not meant to be 135db @ 40hz
the fact that i have a basshorn ,hornresp'ed, CADed (folded) and now constructing,shows that ive learnt a little..
and now i can apply those ideas to the lab12 woofer when i buy it which can take high compression ratios if need be.
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