Help me design a trunk setup

[marakka]

Wow... I know my stereo shit and you guys are confusing the fuck outta me. *LOL* IDQ has some high quality stuff in their lineup. I really dig their mids. Solid drivers for just midbass. Did some setups with 6.5 drivers in Audis a few years back that really turned me on to them. Subs are nice and tight. Not much for big boom.... but a high quality good sounding speaker.

[Digitalwave]

That's what I was afraid of too. I want to compromise, but lean towards the responsiveness. I guess I will wait till I get the sub and see what the spec sheet says.

Thanks for adding in marak... sound Q and tightness is exactly what I am after. Some of the double bass is so fast on some of the music I listen to that it can just blend together on crappy systems. Not very interested in boom.

[marakka]

Well.... the benefit of going with a smaller sub and subsequently a smaller box allows for tighter response times and less "mud" in the sound. Last sQ system we helped build used .4 cu/ft boxes on 2 10" idq's. I don't remember all the specs but he threw ungodly amounts of power at them. Something like 800w rms if I remember correct.... a/d/s amps back then....

The dual coils allows you more flexibility. You can use the 2 2ohm coils to run the sub at 1 ohm if you wire them parallel and 4 ohms in series. Using the amps 2 rear channels to run a sub by bridging them is a popular setup. When you bridge an amp, you use the best of both of the channels. An amp will be rated in stereo at 4ohm. By dropping the impedance (ohms) you can produce more power. Not insulting here... just explaining... So they rate it also at 2ohm stereo. 2ohm stereo ratings are usually twice the 4ohm rating. 2ohm stereo ratings added together usually gives you your 4ohm mono rating. You use half of each rear channel to get your mono rating. By halfing each channel you drop that channels rating to 2ohm. Basically you wire the channels in parallel to each other. Its not as confusing as it sounds. You have to make sure your sub is wired up at 4ohm to get the 4ohm rating obviously. You get the high out put amps that are rated down to 1ohm mono and such..... now THATS big boy toys.....

If you aren't a real big audio buff, you'll be happy with most anything you put in your car if its not Jensen. Don't try to break your wallet on high end stuff the first time out. Work your way into it. I've had a $1200 set of highs in my car and people were convinced their 6.5 coaxs sounded better... just because they couldn't believe my shit was $1200....

As far as the template for Jordans stuff..... . thats easy mang. Get you some cardboard and do some rough sketches.... trim it... and try to fit it. If its too big.... trim it some more.... if its too small.... add cardboard to the area's that don't fit snug with some tape. It'll take a lil while, but you'll get the outline. Once you get one side... go to the other. Once you get both.... put em in place and run some cardboard between the two.... Now you've got your full template.

[Digitalwave]

Wow, that might have been the most informative post I've ever read on this forum, honestly. Your explaination of the loads completely made sense to me, and it previously didn't. I know see how bridging the amp puts it at 4 ohms, and how wiring a dual 2 ohm voice coil to 4 ohms, and bridging the amp makes the load 2ohms. This is going to be a perfect setup because the IDQ's have an RMS rating of 250 watts and my amp will put out 220 watts at 2ohm bridged (if I understand correctly) so it should be just dandy.

[marakka]

*cough* 4ohm bridged.... 2ohm stereo they are both the same. *cough* But yeah.... I see you are grasping it. The idq will be wired to itself in series. The output of one coil going to the input of the other. That way the 2 coils act as one and add to each other. You will wire that setup to the amp directly.... usually the positive of say... channel 3 and the negative of channel 4. It could be neg of 3 and pos of 4 depending.... or even pos of both channels... just depends on the amp.... But you wire the positive to whatever the amp tells you and the negative to the other. Very very simple. The more you do things like this the more you get comfortable with it and the more you learn.....

[permit]

I have the JL 10W4 sub in a relatively small enclosure (wide, but not that deep, wired for 4ohms) and it is great for the responsiveness you're looking for. Its not like those shitty subs that seem "stiff" and can't hit most frequencies; I think the JL would bode well with the music you're describing.

http://mobile.jlaudio.com/products_s...php?page_id=15

[StereoInstaller1]

Remember when you double the load (go from 4 ohm to 2 ohm) you also multiply distortion by 10...that is why you want to use most all car audio amps at 2 ohms per channel (4 ohm mono on 2 channels) in low frequencies, but on the highs, you can go 4 or even 8 ohms.

Luke
oh...BTW, I prefer the sound of a low "Q" woofer with a really low resonant frequency in a VERY large ported box...the next home sub I will build will be the ultimate in SQ, but will require about 18 cu.ft. in a transmission line enclosure. I expect less than 5% THD at 18HZ, while playing 125 DB in my living room...in terms of clarity, ask anyone who has heard my work.

LF

[KenC]

in terms of clarity, ask anyone who has heard my work.

LF

:bow:


TJ,
If you need a cap, I have a 1/2 Farad Rockford Fosgate one I'll sell you. Just hit me up with a PM or AIM if you're interested.
Ken

[StereoInstaller1]

OK, so I did a bit of reading on the IDQ10. I personally would not recommend this woofer for a small sealed box, no matter what the marketing department at Image Dynamics says.

As a general rule, any woofer with a Qts of less than .4 is not a candidate for sealed box. That woof is .34. I also would not recommend a woof with such a low Fs for sealed box application, especially if you plan on using it in a tiny box...they recommend 1.1 cu.ft sealed.

May I suggest Diamond? I really liked the D610D2, in a sealed .65 cu.ft. box. I had about 450RMS going to it, though. Kind of low SPL output, but very clean. http://www.diamondaudio.com/products...h%20Sheet2.pdf

Luke

[KenC]

Thumbs up for Diamond stuff. A friend of mine had a car full of the Hex line from about 5-6 years ago running off of Xtant amps. I loved them.

[Digitalwave]

Its about $180 for the sub and will 220 watts be enough to power it? It's not that I WANT to run a small box, I just want tight response. The ID sub is more of an SPL sub I take it?

If I use the IDQ with a larger box sealed box would it still be good? Say 1.1 or whatever ID suggests?

[StereoInstaller1]

No, the ID is actually suited best for fairly large ported box, according to theory. The rules aren't always true, though. Alumapro is an example of a low Q woofer that works very well in a small sealed box.

Check out this reveiw of the MX10. http://www.alumapro.com/rvn5.html

Luke

[Digitalwave]

Well looks like my first choice is the Diamond now. Got any more suggestions a little cheaper than that? Will 220 watts be enough for that Diamond?

[DrMcDave]

hey luke pm me i wanna talk to you about that box some more.

[StereoInstaller1]

In the world of sealed box subs, I really like the Infinity Reference series. They go for about $65. They work well in .75 FT3, sound terrific. They play plenty loud, considering.The "Perfect" is very nice too, but the higher moving mass slows it down a bit. I had a Perfect 12 in my car, but the Q is too high for a vented box. Either will play louder than the Diamond, but with less power handling.

My big bitch with subs is it seems no one builds one with great efficiency AND great power handling. It takes a ton of power to move some of these, and I don't want huge amps. I wanna see "Sensitivity" of 95db@1W/1M at least.

A quick aside...

Anyone who says "that sub would sound better with a bigger amp" is full of shit...meaning, 10 watts is 10 watts no matter if there is a hundred more watts or a thousand more watts available. Swimming is swimming no matter if the pool is 10 or 100 feet deep.

Better amp, yes. Louder, still yes. But equal quality and equal volume, 10 watts is 10 watts. Remember that it is very diffucult to hear any difference in amplifier quality on bass.

Back to your regularly scheduled broadcast...

Basically, look for a "Qts" of about .5, a "Fs" about 30Hz and power handling over 300WRMS, usually gonna have a 2" or bigger voice coil.

Hope for moving mass under 200 Grams. Moving mass basically determines accleleration...accleleration is mass VS. thrust. A bigger motor makes more thrust, but that is expensive and heavy. Accleleration is clarity, assuming the cone is moving in a pistonic fashion, not flapping like a flag in a hurricane. How the voice coil attaches to the cone can help fix that issue quite a bit, but any additional bracing is heavy.

I have some Morel 12" subs, serious exotics. 3" voice coil, Hexagonal wire, 1200W peak, 600W RMS, magnesium frame, internal magnet beauties that were $400 each wholesale 15 years ago, they have a moving mass of 32 grams...but require about 10 cu.ft. each. That is the drawback of a light moving mass. Higher moving mass makes muddier bass, but work better in smaller boxes.

There are a ton of great woofers out there these days, really cheap. Even the Jensen XS series (WalMart stuff) is a good sounding woofer, in the right box. I use a POS Sony 12" in a 2.2 cu.ft. box in my Astro, running on a Sherwood amp that makes about 250RMS watts. That woofer was sold in WalMart for like $63.00.

You would not believe the quality and quantity of bass I get from this combo....Technology is my friend!

/ramble

Luke