| zolthoff |
I'm fairly new to this forum, as a member at least. I've been reading the posts on here for quite some time. Over the years I've gotten pretty keen on my electronics and speaker(subwoofer) knowledge. It even helped me on my ACT. :D I'm young, like bass-y music and all that. I know there's a lot of kids out there who go to best buy and buy some stuff and stick it in their cars.. and they don't really know whats going on.
Anyways, I recently decided to buy a Mach 5 MJ-18 driver, and it came today. First off, I'm used to dealing with 12's and 15's, and this thing is Huge! Right now I have 3 12's in my car running off of 2 300 watt class AB amplifiers. As of right now, this sounds like a car audio topic, but my question is...
With the following subs
(2)Pioneer TS-W306C
(1)Audiobahn Alum12n
(1)Mach 5 Audio MJ-18
What would be the best setup?
I was thinking of using the Audiobahn and the MJ in two separate ported boxes in the trunk of my car, and possibly making some sort of low quality home woofer system with the pioneers, I'm not really looking for quality.
I was thinking for the car, a 5.5 cu ft box for the 18 at around 30 hertz and whatever's left for the audiobahn.
Any suggestions on any new ideas?
Thanks.
P.S. I'm also kinda looking for anyone else who has the MJ and what they've done with it... maybe some Xmech knowledge and how much it can really handle. It seems to have quite the tight suspension. |
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| pjpoes |
| I was actually just playing around with this specific driver. It's a heck of a bargain, and I think your box dimensions and setup will work well for you. What exactly are you looking for though here. If your looking for max output, to win some competitions, then your box design isn't ideal. However, if SQ is important, well rather, if you will be using it to listen to normal music as well, then its a great box design, but probably won't win you any competitions. That 18 will work great with a 300 watt amp, as long as we are talking RMS, however the Audiobahn is going to want a bit more power for max output. I agree with your idea to place them in seperate boxes, it will be too hard for you to design a single ported box that will optimize both speakers. As much as I want to tell you to use the 18" for really low bass and the 12" for higher bass, you actually can get greater low end extension from that 12 then from the 18, the 18 will give you a lot more output though. I know your probably trying to just use what you have, but I think a better setup would be two of those 18" woofers in a 7-8 cubic foot enclosure tuned to a similar frequency. |
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| zolthoff |
| I know that the 2 18's would give more output, but as I'm not trying to win any competitions and just want some fairly low extension for daily driver type situations, I was thinking the 30 hz tuning would be nice. |
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| zolthoff |
Today in industrial tech, I bought some scrap wood from the set crew for the musical and built a box. Its about two feet by two feet by one foot tall. It was a quick job... probably about an hour and some with me and a friend working on it. Its not the final box, just used for testing. I did some quick models in WinISD and figured out that modifying one of the sides to incorporate a 37 hz tuned port at about 11.5 x 2.5 by about 14 deep would help low end (about mid 30's) by quite a bit. Also, as I'm not hammering that much power into the thing, air velocity won't be much of a problem. As of right now its sitting in my room, with about 60 watts to it and barely moving. Even still, everything shakes. Basically, I'm looking to see if anyone has any better plans. Also, this box is still just a test box. I might run some higher tuning into the box just to see what kind of SPL I can pull. The final box is still planned to be a ~30 hz tuned ported box at 5.9 cu ft in a car, with a lot more power. I'm just playing right now until I get some more money.
Suggestions Please :D
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| zolthoff |
| Haha. You're funny. You'll probably be seeing it in action tomorrow, as well as helping me port the thing. We should use your plate amp and test it out. |
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| hooha |
Personally, I'd do the single MJ-18 in your car and forget adding the Audiobahn - you won't need it.
Not sure how much car audio experience you have, so I'll make a few general suggestions here. If you have the height to mount the driver vertically, do it and face the driver towards the rear. You won't need that big a box to get very good output. I've seen MJ-18's in boxes as small as 2 cubes sealed and they slammed.
Tuning at 30Hz *might* make things sound heavy and bloated. Tune it higher - say ~33Hz and let the car environment pick up the rest.
Best,
Mark |
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| zolthoff |
I guess you could say I'm quite above the average car audio enthusiast..not trying to be insulting. Right now my setup consists of the 3 12's as I've said. The audiobahn is at 37~38 hz tuned in a 3.5 cubes box and it is by far louder than the two sealed pioneers. Modeled, the audiobahn as it is, does better than the Mach 5 would even do at 40hz in the big box. My current setup is doing fairly well for a daily driver situation with well over 130 db from about 80 hz down to about 35 hz off of about only 500 watts rms total. I've got the bass volume pretty good, I just want to try for some lower extension and lower distortion. I've modeled my trunk out pretty nice, and as my trunk isn't tall enough for the 18 to upright, its slanted a bit. Tell me what you think:D
Thanks for the input.
zolthoff |
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| LightwaveDude |
| quote: | Originally posted by hooha
Personally, I'd do the single MJ-18 in your car and forget adding the Audiobahn - you won't need it.
Not sure how much car audio experience you have, so I'll make a few general suggestions here. If you have the height to mount the driver vertically, do it and face the driver towards the rear. You won't need that big a box to get very good output. I've seen MJ-18's in boxes as small as 2 cubes sealed and they slammed.
Tuning at 30Hz *might* make things sound heavy and bloated. Tune it higher - say ~33Hz and let the car environment pick up the rest.
Best,
Mark |
Well, I'm glad I'm not the only one who's saying the MJ-18 would hold its own, and that the Audiobahn really isn't needed. I'm not only saying this because of what it sounds like... but he's expecting me to help him fit it all in his truck and do the install :cannotbe: :D :smash: |
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| hooha |
Interesting design, but I still think you would be doing your ears a disservice by keeping the Audiobahn in there. Unless you were planning to cross the two drivers over separately and using the 12" more as a mid-bass, there is little, if no advantage. Even then, the 12" probably wouldn't fulfill that requirement as other more dedicated units can.
I recall reading a rather long thread on ca.com about this exact thing, and the consensus from the more experienced folk was that it would do more harm than good.
Best,
Mark |
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| djQUAN |
I also vote for simply use the 18 and take everything else out.
unless you use exactly the same drivers, phase shift from different drivers might cause cancellations and leave you a nasty frequency response. I'm not sure about 5.9cu ft since it seems a little small for an 18 (although I may be wrong) and 30Hz is a little low.
I'm using 5cu ft tuned at 35Hz and I get massive amounts of low end bass for a single 15. my sub is not the best one available out there either.
also, what car is all this going into anyway? |
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| zolthoff |
I have a 1999 Oldsmobile Alero. Right now I'm doing some engine work. As soon as that's finished I'm going to be deadening the trunk. If everyone thinks the best concensus is just to use the single 18 then I'll probably do that. The only problem is then I have an extra amp and 3 extra subs. Also, I modeled some new boxes and 3.5 to 4 cubic feet models pretty good. 5.9 cubes does seem a little small for an 18, and the MJ does model pretty well at 10 cubes, but it would be pretty hard to get that big of a box into the trunk. Also, as this isn't a home theater setup, the extremely low tuning wouldn't be needed. If I do go with just the single 18, which is very possible, what would be the disadvantage of tuning so low? Also, what would all of your recommendations be?
Thanks,
zolthoff |
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| hooha |
As mentioned, going with a lower tuning may result in a more bloated and lumpy sounding bass. It makes sense to have your bass authority where it counts most, since the lower in frequency you go the less information there is. That, and you'll want to crank it anyway, so you you will get teh increased volumne.
YMMV. Try it at 30Hz. If you don't like it you can always shorten your port length anyway. |
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| pjpoes |
| I'm sorry I disagree, lower tuning does not cause a more bloated sound. Just the opposite infact. Think about it, if you tune higher the peak at the tuning frequency increases in magnitude. If the speaker tunes flat with a tuning frequency at 30hz, and you tune it to 40hz, it will about 3 decibles higher at 40hz than it was when it was tuned to 30hz. Then take into account cabin gain, which at that frequency in a car is normally at least 10 decibles. You end up with what, bloated bass. However, if you tune down lower, say 20hz, you end up an extended bass shelf, and when you include cabin gain, it will flatten out. However without cabin gain you actually have less output in the bass region where music lies, and simply have a bit deeper extension. It doesn't bloat anything. This would be one of the exact myths I was talking about being perpetuated in the media. This isn't an attack on you Hooha, or anyone else that says it, its a really common myth, but I do think its time to set the record straight. |
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| zolthoff |
This is what I was wondering about. I didn't know for sure what the low tuning would do. I like all of the input, however. Without needing to build two separate enclosures(because I won't need one for the audiobahn), I can easily build a box that would fit in, and be about 10 cubic feet. If you all haven't figured out, I'm 16, and I'm in high school. I'm in industrial tech(shop) and I've already built several sub boxes in the class. Building a big box to fit inside isn't too much of a concern for me. The 10 cubic feet comes in nice because although it is a large box, it would allow easy upgrading if I purchased another 18. I'm thinking now that 35 hz doesn't sound too bad for a tuning because cabin gain will help out a lot, but I'm also not going for pure SPL. The ability to crank it and have some serious output is definitely a desire. I play bass, and I'm fairly certain that the low B string is about 32 hz, and some songs are even in drop A which would be even lower. I think 35 is a fair compromise between volume and low extension.
All I've done with the 18 so far is build a quick ~3.5 cube box sealed and send a couple hundred watts through it in some larger rooms. I definitely like the idea of porting it because I just don't have the amplifier power, yet. On a quick sidenote, what would you all recommend for RMS power in one of the box designs we've stated so far?
Thanks again, its been really insightful.
zolthoff |
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| hooha |
| quote: | Originally posted by pjpoes
I'm sorry I disagree, lower tuning does not cause a more bloated sound. Just the opposite infact. Think about it, if you tune higher the peak at the tuning frequency increases in magnitude. If the speaker tunes flat with a tuning frequency at 30hz, and you tune it to 40hz, it will about 3 decibles higher at 40hz than it was when it was tuned to 30hz. Then take into account cabin gain, which at that frequency in a car is normally at least 10 decibles. You end up with what, bloated bass. However, if you tune down lower, say 20hz, you end up an extended bass shelf, and when you include cabin gain, it will flatten out. However without cabin gain you actually have less output in the bass region where music lies, and simply have a bit deeper extension. It doesn't bloat anything. This would be one of the exact myths I was talking about being perpetuated in the media. This isn't an attack on you Hooha, or anyone else that says it, its a really common myth, but I do think its time to set the record straight. |
That's it! I'm reporting you to the mods! ;)
That's cool. Perhaps 'bloated' is a bit too harsh. Let me call it "heavy". I for one have noticed this heaviness. Why? Because you don't need to go 'low' in a car to achieve low frequencies.
You can do a nice sealed design that rolls off at 45Hz in a car and still get authority a full octave down while still maintaing the taunt bass quality a sealed box delivers. If you want truely deep, clean low end, there's only one way - IB.
Best,
Mark |
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| zolthoff |
Thanks for all the advice guys. I would definetly go sealed if I had the amplifier power, but right now I don't. Also, even with an efficient Class D amplifier, to run full power I'd probably need to upgrade the electrical on my car. From what you guys have said I'm fairly certain that I'm going to build a box as big as a I possibly can fit in my trunk for the 18. Then, I'll put a small box or something that takes up area equal to the displacement of a second 18 as my friend suggested. I'll probably tune to 35-40 hertz because I've used 37~38 hz tunings before and I liked the sound. The box should be big enough to accomidate two drivers as it'll probably end around 10 cubic feet. This way I'll have a fairly efficent box, as well as room for expansion. Does this plan sound like it would work to all of you?
Thanks again. |
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| LightwaveDude |
While I could easily talk to zolthoff myself and tell him this, I'll tell him online so that everybody else can see this example. While my buddy here has already decided to only use the MJ-18... here's a good example on why the MJ is enough by itself. Mach 5 Forum Posting.
Viperoni has 2 MJ-18's in sealed enclosures with 600 watts to the pair. Now, if I think I'm working this all correctly... that means 300 watts to each driver. Now if we take his SPL measurement of 146.38 dB, take away 3 dB for the fact that zolthoff will only be using one (half the Sd), we now have ~143. Now, since zolthoff's amp might not run a full 300 watts to the driver, we'll knock of 2 dB even though the amp is capable of doing at least 200-250 watts. Now lastly, let's assume that Viperoni on the Mach 5 forum has a much better car for car gain, so lets take 4-5 dB off for lost car gain. That now leaves us with 138-139 dB.
Now this is if we were comparing similar sized sealed enclosures in a theoretical environment. However, zolthoff will be using a ported enclosure which simulates a good 4 dB more efficient in the 40 Hz region than a sealed box, so we're kind of comparing apples to oranges.
I know that this is all theoretical and subject to a lot of variables, but it seemed like a good way to rationalize for some people why the MJ alone will be plenty for any car enthusiast who isn't focusing on SPL only. I think upper 130 dB's should be plenty for anybody in a daily driver. |
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| hooha |
Certainly much louder than a concert. I personally can't take that volume for any length of time.
I laughed at the videos Viperoni posted - his vehicle was flexing pretty good. :cool: |
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| TwisterZ |
"If you want truely deep, clean low end, there's only one way - IB.
Best,
Mark"
This might seem to easy & it sounds like you are more into building a box than getting a lot of good sounding bass. If it will fit try this, take out the back seat, make a baffle board that will seal the opening between the passenger compartment and the trunk (you can put the seat back over the Woofer), fill the wheel wells on both sides with expanding close cell foam also seal the package tray (the better you can isolate the passenger compartmant the better) then mount the Mach5 18 in the baffle board. I did this with a pair of 15" and had 16Hz pipe organ music playing load and clear and old school rap like Too Short & Public Enemy would hit hard enough to mess up your hair. :smash: :smash: :smash:
Good Luck |
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| zolthoff |
This certainly sounds like something that I would be willing to try. I'm just not sure of my ability to get everything sealed that well. I know for a fact that the panel that the rear 6x9's mount into would be very hard to seal. I would probably have to put a baffle board under it. I'll have to look at my car more in the trunk. Also, what about all the leaks of air to the outside world in the trunk?
Thanks,
Zack |
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| TwisterZ |
Hi Zack
I took the top off of the package tray and used a roof vent sealing product that looks like very thick tin foil with thick & sticky goop on the other side, You can also use the products from DynaMat or like you were saying making a board that would fit underneth the tray & use a thick rubber sheet or silicone to seal the tray.
All and all its not a hard job but I will tell you this, when working with the expanding foam wear clothes you can throw away. That stuff is very sticky and won't come off of what ever it touches.:dead:
The Mach5 MJ18 has been used alot in home theater IB installations with great success. |
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| zolthoff |
I like this idea, and I have a couple questions. My trunk is technically 14 cubic feet. Would it model like a 14 cubes sealed box? Also, in comparison with a 7 cubes ported box, which would be louder for music? Seems to me that the ported would be, by quite a bit even. My current sub is quite loud by itself, and I'm looking to at least beat it in volume, and hopefully have more range too.
Zack |
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| TwisterZ |
Your trunk won't contain the rear wave like a box, this is why it is called Infinite Baffle. You can model your woofer response by setting your sealed box size as large as your software will allow. You should find that the MJ18 will reach XMax with very little power.
As far as how loud you are right that a ported box will play louder but by sacrificing accuracy and depth. The port reinforcement will cause a hump at the tuning frequency & cause the low end to roll off rapidly.
I would suggest trying this, if your not happy all you need to do is remove the baffle and build a box. The other mods will help either way you find to your liking. |
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| zolthoff |
Yea... I know how basic boxes work. And I've modeled the ported boxes and know that it rolls off sharper. My main concern I guess, is the ability to crank it and have some ear pain. My current setup is able to do this....at least when my cab was warmer than 50 degrees. My friend and I were wondering that since the car gain area was reduced since none would occur from the truck. Would the smaller area being pressurized help with car gain (as in more volume?)
Zack |
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| TwisterZ |
It's been my experence that ear pain or when someone says its to loud is all about distortation. I have been to concerts, car stereo compititions & in many homes where everyone was saying thats loud but when I pulled out a Sound Pressure meter we found that it was still under 120dB. If your hair is blowing around or your pant legs are moving you will find that the SPL is very high even if it doesn't hurt your ears.
Now days I am persuing great sound at low volume like when I want to watch a movie and someone else is trying to sleep in the other room. When nobody else is home watch out here comes the loud.:smash: :smash: :smash: |
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| zolthoff |
Yea. I deffinetly know about how the loudness stuff works. I have a friend whose car feels really loud, but can't pull 126 on the SPL meter. My car doesn't sound as loud, but on any note, it will read 126, which is the max value of this particular meter. I would like to accomplish this same thing, but in a more efficient, better looking, professional-type setup.
Zack |
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| TwisterZ |
| Keep us posted with what you deside. I would love to here what you and your friends think of the IB setup.:hot: |
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| LightwaveDude |
I'm a friend that is really pushing Zack to install the IB setup. I'm a quality over quantity guy, Zack's a good quality high output, and my other friends are basically SPL guys compared to me. (then again, the only way to get clean bass is to have lots of headroom and spl capability, so I guess I'm not too far from the SPL guys :rolleyes: )
However, I'm really trying to push Zack for the IB install, but since neither of us has heard an IB setup in a home or car, I can see why he's hesitant.
Mark's input convinced Zack that just the MJ-18 alone would provide more than enough SPL and that the Audiobahn wouldn't be needed, so are there any guys out there who have experience with sealed and ported boxes that have also run IB installs?
For somebody like Zack who wants a good quality, but high SPL, how would one of you with more experience compare ported subs to IB subs in the areas of quality and output?
Lastly, what have most people thought of the installation of IB's in cars? Is it difficult to find all the leaks into the cabin? Any general comments would be appreciated.
Logan
[edited for spelling] |
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| TwisterZ |
Hi Logan
My current home sub is a pair of 18" drivers in a face to face Push-Pull arraingment mounted 1/4 way into a 12 foot pipe. This is known as an acoustic wave cannon and the output from the 2 ends of the pipe are in phase giving me not only lots of bass but the most defined articulate bass I've ever heard, I Love It, But I don"t think it will fit in your car.
I have done IB in both cars and home. Owned sealed and ported boxes, built ported subs and installed many a passive radiator sub in both cars and homes. For SQ sealed is always the best sounding. An IB is just like a sealed box without the box. Without a box behind the woofer it doesn't have to fight box pressure and no internal standing wave concerns. This is why the woofer will reach Xmax with much less power. If you want greater SPL a driver with greater Xmax (FIcaraudio Q18) or more drivers are your choices but for clean, efficient and very low bass you won't hear any sub that sounds better unless you can incorporate a servo control circuit. All that would do is protect the extreme output by throttling back the amp when the speaker movement doesn't match the incoming signal. |
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| hooha |
| Yup, Twister basically nailed it. It all comes down to excursion with IB. If you watch your output you will have bass quality that is unmatched by any other design. |
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| LightwaveDude |
| Well once you post some prices for the IXL-18.4, maybe I can start drooling over one (or more) of those for an IB. |
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| zolthoff |
thread stealer logan :P just kidding. that sub does look pretty sweet.. but it seems like the MJ models almost better for car.. until you get up in the really high power applications...cuz that thing just moves more air.
Zack |
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