abmoore

Arc audio FD 4150 bridged to 4 ohms, and how would I individually control phase on a passive set when I am not active?

I'm suprised no one brought up sensitivity. So I will haha. It also looks like when Vd increases due to Sd increasing, that sensitivity increases. So larger Vas and lower Fs both correspond with a higher sensitivity?

Yeah, eclipse sc8365, the woofers bottom out real easy, and the aluminum dome tweet is pretty harsh. Vocals almost sound nasally and echoes. That might be due to lack of the ccf and mlv I am about to install. They were pretty much stock door angled, I changed the mid and tweet, but now the TA sounds a little off. I was thinking the CDT HD 62US, morels, rainbow kickbass, ID CX64, or diamond d6s. The cdts sound good for the money and I like the idea of the free image tweeter on the anniversary edition, plus good reviews. Not sure what the strongest midbass performer is though.

No problem, keep us updated on the decisions you make or if you need anymore help with that.

Similar, except with a vertical port, although if that sounds good its probably worth a try. You have an XL though, whats the depth of the box? And I forgot SSA does designs haha.

OK.... so generally the lower the Fs, the larger the Vas? It seems the tighter the suspension, the higher the Fs, which would be a decreased Cms correct? So Vas would increase with more Sd obviously, and a higher Fs driver, that would lower Cms, decreases Vas. This all assumes that Mms is the same. As Cms decreases (suspension gets tighter), the Fs would increase and Vas decrease. And as Cms increases (suspension gets looser), Fs would decrease and Vas would increase. As you said, this assumes Mms (and Sd) remain constant. Not sure if it was simply a misstatement; But a lower Mms would increase Fs. It's mass on a spring. The more mass you have on the end of a spring, the slower it will resonant. I wouldn't go so far as to say that a lighter cone = lower Vd. Generally yes a decrease in Sd will be accompanied by a decrease in Mms assuming the same cone material and thickness is used. And a smaller Sd would yield a smaller Vd. But Mms is more than just the mass of the cone. Mms is the mass of the moving assembly (cone, coil, former, etc) including acoustic load. A driver with a long coil overhung motor could have a higher Mms than a driver of the same materials but using a short-coil motor topology like XBL^2 even though they may have the same Xmax. This is a case of not drawing too many conclusions from the "all things equal" scenario. Low Mms + Low Cms would = higher Fs (light mass on a tight spring = higher resonant frequency). Or, think of it this way...since both Mms and Cms are in the denominator, Fs will be inversely proportional to both Cms and Mms. If those go down, Fs will go up. If those go up, Fs will go down. Started off good, think you may have trailed off a little there towards the latter part Haha I tripped myself up there, trying to remember that Cms is a reciprical of tightness of the suspension. I see where I messed up. The mass on the spring analogy helps too. Just remembered back to my physics classes, I think I remember Fs being used, never connected the dots for some reason. When I said the lighter cone, I meant as well as a lower vd, would that equate to a lower Mms. Which would generally be less spl at a lower Fs because there is less force behind the air? That sounds like where Bl^2/Re becomes relevant right? The higher the Telsa*?* on a driver with a low Fs, has a lot of low end output, because that is when Re is the highest, so basically more force moving that large mass on the end of a loose spring, while being able to do this under a heavy resistance. But I guess that all depends on where Bl^2/Re is measured, which I have no idea.

Saw that, I am not sure how to incorporate a center flared port by using that. I want this to be a challenge where I can work on my woodworking skills, probably with some help from my uncle, woodworking is his hobby. I have built boxes before, just not this size or difficulty level.

I have a couple full pass amps I am going to keep just for that. And I have the pxa h100 so I could always start active (practice) by adding a midbass to the doors after a while, and trying to incorporate that with the passive set. Not sure how that would work, just a thought, or I guess just get rid of the crossover from the passive set (duh). Just need to decide on a passive set now....

So I don't have the programs required to design a superb box, so I was hoping for some help, even if it requires some sort of payment, because it seems like an intense build to me. I am going with 2 18 inch XCONs and will use a SAZ-3500d. It will be the toughest build I have done due to the size and I want it to turn out great because I have decided to use a theme. I have been deciding on subs and amps forever it seems, so I said why not just represent the forum that has helped me through all of my indecisiveness and taught me so much (tears lol). I want to paint it in a color scheme to match my school colors, so red and white, probably with the emblem on one side, and the SSA logo on the other (already matches). I want the subs to fire up and a center rounded, flared port in the back. For tuning around 30 Hz should do the trick. My goal is to reach 150 dB, but if I come up short that will be fine, I am sure it will be up around there. I don't care about weight, and want it braced sufficiently. There needs to be room for my batteries (probably 2 XS Power 3100s or 2700s, or I will just stick with Deka 2 g31s) behind the back seat, as well as the amps, I may even do an amp rack above them or floating above the box to the sides (hope to use all sundown amps). I have a 2004 Chevrolet Tahoe, and my dimensions are H 22.5" x W 49.5" x D1 (from bottom of seat) 46" x D2 (top of seat) 41.5". There seems to be enough room to do optiomal enclosure sizes for the subs. And I guess the subs will be D2s so I can get .5 ohm from the 3500d, unless 1 ohm seems better. So if anyone has any free designs or charges for in depth designs, just let me know. Hope I can get a few people to join after seeing and hearing this creation! Thanks.

I was just wondering what are some of the best ways to keep impedence rise down. I have read that it doesn't matter much in daily but I don't see why that is true, unless it is only a db or so difference. Are there box designs that make a difference or cooling methods?

Back at you ::

I am not recommending that the OP spend 5-600 bucks on an HO, BUT do think anyone contemplating adding a second battery should also concider a HO alternator as a better solution for a Daily Driver. Agreed. ::

OK.... so generally the lower the Fs, the larger the Vas? It seems the tighter the suspension, the higher the Fs, which would be a decreased Cms correct? So Vas would increase with more Sd obviously, and a higher Fs driver, that would lower Cms, decreases Vas. This all assumes that Mms is the same. Speaking of which, the lighter the cone of the driver, and the lower the Vd, the lower the Mms. The lower the Mms, the lower the Fs. So there is generally** some correspondance between Fs and the amount of air a driver can move, therefore less spl? That is assuming a low Mms, low Cms, which would lead to the low Fs. Although high Mms, to a certain point, will create more spl? Am I catching on at all? This does show some relationship between xmax and Fs and spl, but proves it is not always important, especially with low Mms (but with high Mms, high Vd, high xmax, low Fs, high power handling, comes a true low end beast). Sorry for all of that lol.

An HO alternator supplys the current continuously NOT instantaneously. SO NOTHING is straining, not the battery, not the amplifier, not the HO alternator. A larger or dual battery is only helpful for a short instataneously burst and then is useless until charged again. THIS IS the "claim to fame" of the AGM gel batterys is they recover quick. What is going to make them recover quick????? one of two things either you will turn down the volume until your factory alternator recharges them OR YOU INSTALL a HO alternator and DON'T have to turn the volume down to recover, you just keep enjoying your music. Reread my post, I said it doesn't supply current instantaneously. Most alternators DO NOT continuously supply max current. With more reserve power, those short burst don't affect the voltage as much. And most likely his alt will not be putting out full power, unless he is reving his engine... Batteries also don't recharge immediately, it's a logarithmic recharge. And what about long drives when the alt heats up? Then it really is not putting out full current. Like I said the combo is the only sure way of maintaining voltage constantly, I was trying to save him money because with that little amount of current draw, he will be fine with batts. Even cheap ones like Dekas. With less than 200 amps of current, ESPECIALLY with music, there is no need to spend $5-600. I have seen many cars be fine with just larger batteries pulling that same amount of current. And he WOULD be discharging the stock battery every time a large note hits.... The alternator can't immediately charge that. Maybe we can agree on a battcap or something like that. Recharges quickly and discharges fast, it's not like he is competing.

I do, but I am not quite sure how to match drivers based on where break up and distortion starts. I really am starting to consider passive components, and focus on finding the best mounting locations, a solid install (learning some better techniques), and properly deadening the truck. I'm sure I could find some better components without spending too much that have a more natural sound, little better power handling, higher efficiency, and better midbass. I might tone down the sub stage as well. I want to make sure I have plenty of time to research about active so I can know more about it when I go forth with it. I feel that is my best option right now on my budget, unless anyone else thinks other wise I guess.

First of all, that is not necessarily true. I recommend the opposite. For the amount of current you are pulling, a decent agm battery under the hood and a small secondary in the back should be fine. An alternator cannot discharge current instantaneously, although it does make a difference in larger set ups where the alternator is straining to charge the system. It is also not good for the life of a battery to be discharged everytime a large note hits. So the combo of the two is obviously the best, but with only one hundred some odd amps, the battery route will be cheaper and sufficient. If you do look at alts, there are other proven brands like powermaster, ohio generators and iraggi.

I think the question came down to how high will the full ranges play. I mean I would rather sacrifice some output and midbass for a cleaner and fuller response.

Or Yen times Pesos... however that would work

Xsus = suspension limited linear excursion Xmag = motor limited linear excursion Xmax = lesser of Xsus and Xmag Xmech = mechanically limited excursion (without regard to linearity). Generally if you exceed Xmech, shit starts breaking It doesn't, really. Vas is the volume of air that when compressed to 1m^3 exhibits the same compliance as the suspension of the driver. Otherwise described as "equivalent air compliance". It's basically just another way of expressing the compliance of the driver's suspension. Larger Vas = looser suspension, smaller Vas = tighter suspension. It's most useful in determining enclosure volumes. For example, the formula for determining the enclosure size for a given sealed enclosure alignment is; Vb = Vas/([Qtc/Qts]^2-1) Basic mathematics.....since Vas is the numerator, as Vas increases the required enclosure volume (Vb) for a given alignment (Qtc) will also increase (assuming Qts stays the same). The Vas explaination makes everything fit together now. Thanks, was like one of those lightbulbs going off in my head. Seeing the correspondance in a lot of different subs and the higher Vas numbers they have. Generally speaking, will larger drivers with low Fs have a higher Vas?

Checked out some Etons, Seas prestiges, those crazy motor tangbands W7s I think, and the Morel CAW 938s for mids. Any experience with these?

He already has a BL, why sell that and take Qs? They are different types of drivers and his goal is output. And why do you say just in a truck? How is that relevant?

I meant more of a luck of the draw due to the tolerance of the voltage in the batteries. And sometimes when sitting for a while on a cool day I see mine sitting at 14.7, that's all I meant. Some people on here use the XS Power regulator, hopefully one of them chimes in about that, I myself am interested in it since you can set your voltage to 15.2 or something like that.

I can't wait to see "my" tens in there! Lol just kidding, that looks so insane drool..... Sweet work

There are 12V batteries and 16V batteries that are most commonly used. To upgrade to 16V, you need a different alt, regulator, and a few extras since your electrical system is designed to work at 14.4V, not 19V. So no, just by adding a HO alt, you cannot run 16V. There would be no point in getting that extra .5 V anyway, it would be less than 100 watt difference, which you will never be close to hearing. A better box would make a bigger difference. And for that amp, a secondary battery would be enough, or a larger starting batt. A HO alt could help some but it might not be worth the money for you, but I could be wrong.

A secondary battery or beefier main battery will make a difference, yes. As for your warranty, I am not sure if they will realize that you are just protecting your truck, but who knows, they try and void everything now it seems. That's a question for your dealer. I think the jist of that arguement is that a BTL will work for you, just be prepared for the extent of the upgrades needed. If you don't want to go that route, get another BL and a little bit bigger of an amp, and a few electrical precautions like a secondary battery, big 3, and 0 gauge. Should be fine as long as you don't go too crazy. Whenever you want to take the next step up, everyone on here will chime in and help with that. Apologies for thread jacking.