What is my box tuned to?
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Bronze Member Username: Dpaw20FL USA Post Number: 95 Registered: Mar-05 | I got 2 Alpine Type-R's in a ported Obcon box I ordered. Its 1.56cuft per chamber, but I dont know what it's tuned to. Heres where I got it http://www.cardomain.com/item/OBCGZ32812 Does anyone have any idea? |
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Bronze Member Username: Dpaw20FL USA Post Number: 96 Registered: Mar-05 | anyone? |
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Gold Member Username: InvainMichigan United States Post Number: 2012 Registered: Aug-04 | Not sure, (got rid of Winsid, should get it again), but because of the volume and the fact that it's prefab I'm guessing it's gonna be moderately high. Mid 30's - 40's. |
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Gold Member Username: James1115Wilton, Ct Post Number: 2341 Registered: Dec-04 | I would say around 40-45htz |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 917 Registered: Sep-04 | Assuming that 1.56 figure is net displacement after port volume subtract .06 ft^3(?) for an estimate of the net volume after driver displacement(~1.5 ft^3). Next mesure the port depth and port opening dimensions and take those figures here: http://www.carstereo.com/help/Articles.cfm?id=31 Select "square port" and "slot port" and enter the net volume(1.5 ft^3) and vent opening dimensions. Keep trying different tuning frequencies until you get close to your measured port length. -Fishy |
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Bronze Member Username: Dpaw20FL USA Post Number: 97 Registered: Mar-05 | hmmm, dont know what you said. And if it were 40-45...is that ok or is that very bad? Im hoping its more like 35, cuz I know above 50 is for SPL competition and I dont want that. If it is, I dont get why Obcon, which makes average boxes for average systems, would tune a box so high? |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 922 Registered: Sep-04 | Ok just give me your port dimensions and I'll do it. I need: 1) slot opening width (in) 2) slot opening length (in) 3) actual port length (in) If it has an "L" shaped port just give me a good guesstimate of the total length. The tuning frequency won't be that far off. -Fishy |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 923 Registered: Sep-04 | Lol, sorry, if you haven't got the box yet you need to call up Obcon and ask em.  -Fishy |
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Bronze Member Username: Dpaw20FL USA Post Number: 98 Registered: Mar-05 | omg...I did what you said, and it with all my calculations almost exact (to the hundreths), it said its tuned to 55 hertz... is that average for premades or what? Is this really terrible? Am I screwed? This is my first system...I only got 2 Alpine Type-R's so would this be considired below average? Or am I overeacting? I thought it sounded pretty good except for really low sounds which aren't really that common in my music (Even though most of it is for loud bass). |
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Gold Member Username: InvainMichigan United States Post Number: 2025 Registered: Aug-04 | If you did everything correctly, then I guess your stuck with 55 hz. I guess that goes along with your statement about the low sounds not being that good. 55 hz is really high for a daily driver. I would consider finding something else, or you could always take the port out and seal the box up or something? |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 924 Registered: Sep-04 | Yeah that wouldn't surprise me. From the looks of that picture that port seems mighty short. Thats pretty darn high. With that kind of tuning frequency you probably need to be using a subsonic filter as well. Those subs will unload fairly quicky below tuning frequency. You could try sealing up the port openings. You'd lose some output but might get a lot better low end extension. Run those dimensions by me and I'll double check them and maybe run your subs/enclosure through WinISD. Make sure they're the internal measurements. -Fishy |
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Bronze Member Username: Dpaw20FL USA Post Number: 99 Registered: Mar-05 | man s*hit. Now im pissed again. Why the hell would somone sell a ported box tuned to 55 hertz to everyday people who aren't into competition? That pisses me off. Stupid box was $150 shipped. All I wanted was somthing to hold my subs and make it sound better than free air...and I got a box tuned to 55 hertz. Am I really that screwed? Maybe ill just get used to it. Getting another box is out of the question. At least within 6 months. Anybody know anything that'll make me feel better? lol |
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Bronze Member Username: Dpaw20FL USA Post Number: 100 Registered: Mar-05 | port height is 11.4375, port width is 3.0625, port depth is around 14.4, per chamber is 1.5ft^3...says 55 on the thing dammit. |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 925 Registered: Sep-04 | Errr.. wait. Is there only ONE port common to both chambers? That's a whole other ball of wax. You'd get a lot lower tuning frequency that way. Thats not really a "slot" enclosure if thats the case. Just run your same numbers with 3.0 Ft^3 with a regular square port(not slotted). You should get a tuning frequency more around 30 Hz then. -Fishy |
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Silver Member Username: Dpaw20FL USA Post Number: 101 Registered: Mar-05 | now its says its about 39 |
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Gold Member Username: InvainMichigan United States Post Number: 2029 Registered: Aug-04 | Right around 38, 39 hz works out. But Fishy, look at the box. I think the port splits and goes into each chamber seperate. Wouldn't that make the tuning higher again, the ports gonna be longer since it wraps back up twice, once for each chamber. |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 926 Registered: Sep-04 | If there's just one common port your box is tuned to around 40 Hz. It might be a lil less as you should get some mass loading with that configuration. You'll still want to utilize a subsonic(high pass) filter around 30 Hz or so. -Fishy |
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Silver Member Username: Dpaw20FL USA Post Number: 102 Registered: Mar-05 | wew, thanks fishy. So I guess im not screwed. I know 40 isn't ideal, but I deffinatly shouldnt be stressin over it right? |
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Silver Member Username: Dpaw20FL USA Post Number: 103 Registered: Mar-05 | but yah, it raps around about half the size of the port for each chamber...would that make it tuned high again? |
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Gold Member Username: InvainMichigan United States Post Number: 2031 Registered: Aug-04 | If it is 40 then your not screwed. That is a ton better than 55. Your still gonna notice a big drop off when you play notes below the tune frequency though, but it's not gonna be horrible or anything. Just not as loud in the low end. |
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Gold Member Username: InvainMichigan United States Post Number: 2032 Registered: Aug-04 | If it does wrap around, then your gonna have to measure it all again. And when you do the width, make sure you get the width of just one side, so only go half way on the front, you know what I meen? Since is splits in two. |
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Silver Member Username: Dpaw20FL USA Post Number: 104 Registered: Mar-05 | so is the port length going to end up being longer or shorter? |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 927 Registered: Sep-04 | Ah man, I just saw that hole up front. *sigh* Ok, use half the port opening width and 1.5 ft^3 and guesstimate how long that "snake" is(use a string through the center). :P Use the "slot" port calculator again. It won't be perfect, but should give you a ball park figure.... a lil bit lower than the single non-slot calculation we all just did. Maybe we should just trust these Obcon guys know what they're doing. If it sounds good....... -Fishy |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 928 Registered: Sep-04 | Man, this could be more complicated. Is the port width where the port ends in each enclosure half that of the external opening? Gawd I hope so. Man my monitor suxxorz. Didn't see the opening in front and just assumed it was in the back. -Fishy |
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Silver Member Username: Dpaw20FL USA Post Number: 105 Registered: Mar-05 | lol, back in the 50's...I did what you said and guessed around 53 and that was around half of the original port length...god, I hope it aint in the 50's. I mean, wouldnt you think an average box made by Obcon would be tuned to 40 hertz? |
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Silver Member Username: Dpaw20FL USA Post Number: 106 Registered: Mar-05 | To what you just said, from what I remember (which I could be wrong) I dont think it was, ifnot the same width. |
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Silver Member Username: Dpaw20FL USA Post Number: 107 Registered: Mar-05 | and if the lengths of the different ports arent half that of the end...it says 70 hertz...no way it would be that high though, right? People say Obcon is way better than Q-Logic and Ive heard people with ported Q-logic boxes sayin they were awsome (even though they suck). |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 929 Registered: Sep-04 | You get an estimate of the port length? Should be 14.4 plus however far that piece of MDF we can see in the pic comes out. I'm guessin about 8 more inches which would give you about 34 Hz tuning given a 1.5" internal termination width. Thats a nice tuning frequency. I've got a JL designed "purist" enclosure tuned right at my 10w3s' fs(28 Hz). -Fishy |
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Gold Member Username: InvainMichigan United States Post Number: 2036 Registered: Aug-04 | I highly doubt it's 70 hertz. Ok, first, how deep is just one of the ports. Remember, you gotta add how far back it goes and then the part that comes forward together, because it doesn't just go straight back, it's a u shape. Second, how wide is just one port? And then find the height. |
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Silver Member Username: Dpaw20FL USA Post Number: 108 Registered: Mar-05 | OHHH. I thought you said not to add it...thanks a lot fishy. I can sleep now Im going to the audio store near by tommarow to get an inspection on my installation and to troubleshoot any problems (I think my subs are out of phase), plus anything else since I did it all myself. Also ganna see what I can do about the rattling because my 2000 Jeep Cherokee sounds like its falling apart. So if its around 34 hertz at all Ill be happy. SOOOOO glad its not ganna be 55. Thanks man. |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 930 Registered: Sep-04 | Measure the length from the big port opening thru the center to its end in one chamber, a "J" on one side....... or call up Obcon tomorrow and ask the bastidges. Btw, I like the way that thing is designed. Simple yet elegant. -Fishy |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 931 Registered: Sep-04 | Oh if you want to check for phase just connect a flashlight battery(pos to pos and neg to neg) to your box's speaker terminal(s). If both subs move out they're wired correctly in phase. If they move in they're in phase with each other but may be out of phase with your mids and highs. If thats the case hook pos to neg and see if they sound better. Whew! is right. hehe -Fishy |
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Silver Member Username: Dpaw20FL USA Post Number: 109 Registered: Mar-05 | like an energizer battery? |
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Gold Member Username: InvainMichigan United States Post Number: 2037 Registered: Aug-04 | Just take a D battery and put pieces of wire in your terminals once the subs are mounted in the box. Then just touch the wires to the terminals on the D battery. |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 932 Registered: Sep-04 | http://www.carstereo.com/forum/showthread.cfm?tid=15008&fid=4 That link might save you good chunk of change on some sound deadening(20% off coupon codes). I just ordered 60 ft^2 of eDead v1se(70 mil thick) for $94 shipped. I think you made a good choice going with that box. Now just get them rattles out. -Fishy |
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Silver Member Username: Dpaw20FL USA Post Number: 110 Registered: Mar-05 | and what do I look for when I touch the wires to the battery? Do I hook up all 4 wires to the battery at once? And about sound deadening, is it as simple as ordering 50ft^2 of eDead v.1 (for back doors and trunk lid for a Jeep Grand Cherokee) and installing it? Will that get rid of the terrible rattling? Do I need to get a professional to install it? |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 933 Registered: Sep-04 | You can do one sub at a time(pos to pos, neg to neg). Just watch which way the cone moves. Sound deadening helps with the rattles and can clean up and improve your bass output as well. You could probably do it yourself. Just be careful pulling the plastic panels and doorskins off and keep all the screws and stuff in a container so you don't lose em. I'd do your front doors as well if you've got mids mounted there. It'll help your midbass a bunch. 60 sq feet should be enough to do your doors, your rear trunk lid, rear quarter panels and possibly your rear floor and/or ceiling. You might want to go with the v1se. That way one layer might be sufficient. -Fishy |
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Gold Member Username: Jonathan_fGA USA Post Number: 3683 Registered: May-04 | Since you're already fooling with the measurements on calculators, I'll let yall have that , but most prefab ported boxes are tuned in the 45hz region, just so you know. Anything a little higher or a little lower wouldn't surprise me. Most prefabs aren't there for quality, they're there to boom nice in a showroom. |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 936 Registered: Sep-04 | I'd call em up. Thats a fairly complicated port design. Unless we got the measurements all wrong it should be less than 45 Hz tho. -Fishy |
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Silver Member Username: Dpaw20FL USA Post Number: 111 Registered: Mar-05 | Yah, I hope its less than 40...but I guess as long as its not 55 lol. And about v1se, would I really need it? Because around $60 is about as much as I can spend right now. I know there would be a difference, but I cant look to spend $100. For my situation, do you think id be at least satisfied with v1? |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 944 Registered: Sep-04 | Try the the regular v1. It may get the job done and would definitely be better than nothing. If need be you can always add more layers later. Just out of curiosity, you said the the vent opening height was ~11.4 inches. Is the actual external box height really 15" as described in the specs? Do the other given dimensions match up as well? If not that 1.56 ft^2 figure may be a not be the net volume after port displacement and the actual tuning frequency could be a lot higher than what we're guessing at here. Jonathan's right. Most prefab box are built for output, not SQ. Call Obcon. -Fishy |
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Silver Member Username: Dpaw20FL USA Post Number: 113 Registered: Mar-05 | I measured it, and its like 13 3/4" tall, around 34" wide, and 15" depth. Why are the measurements so far off? |
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Silver Member Username: Dpaw20FL USA Post Number: 114 Registered: Mar-05 | Called them, kind confused on who to contact but they didnt pickup anyway. |
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Silver Member Username: FishyTamarac Ft.Laud, FL USA Post Number: 945 Registered: Sep-04 | I dunno why the dimensions are different, but if those are external dimensions they yield about 1.55 ft^3 a side BEFORE port and sub displacement(3/4" mdf). I think Jonathan may be right. My guess is you actually have around 1.25 ft^3 net a side after port and sub displacement which would give you about a 37-39 Hz tune. If it sounds good then go with it. You could always try covering up the port and see how those subs play sealed. You'll get less output, but possibly more low end extension. Wow, this got to be one long@$$ thread didn't it. -Fishy |
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Silver Member Username: Dpaw20FL USA Post Number: 118 Registered: Mar-05 | I emailed them, hopfeully they'll respond (doubt it). As long as it's below 40 id be happy. But about the demensions, somthings wrong. No way they would be that off. I mean, isnt that illegal or somthing for false information? What if you only had 30" of width room in your car, and it turned out to be 34" long. Could you send it back and get the money?(which im not ganna do) Just seems kinda wierd. |
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