new front stage

[Intruder]

Well, I thought that those diodes "clamp" the voltage to 1.8V and won't let anything more than that go to your sound card even if it is much higher than the 25:1 ratio.

edit: but then clipping will occur and you won't see anytihng that is higher than 1.8V. so basically this setup will work for anything that fits in the 25:1 ratio. If you want to use it for anything that won't fit, just use a 50K resistor in place of the 24K and then your ratio will be 50:1 You could put all this in a small plastic box and have a common ground but several inputs with different ratios. Don't worry about the wattage because your input impedance is so high that those resistors will get very little current. Just pick a couple of resistors that you think will fit the voltage ranges for your different amps and just connect them to the point between R1 and R2. Then use the other ends for your input.

[asylum24]

Originally posted by Intruder
Well, I thought that those diodes "clamp" the voltage to 1.8V and won't let anything more than that go to your sound card even if it is much higher than the 25:1 ratio.

edit: but then clipping will occur and you won't see anytihng that is higher than 1.8V. so basically this setup will work for anything that fits in the 25:1 ratio. If you want to use it for anything that won't fit, just use a 50K resistor in place of the 24K and then your ratio will be 50:1 You could put all this in a small plastic box and have a common ground but several inputs with different ratios. Don't worry about the wattage because your input impedance is so high that those resistors will get very little current. Just pick a couple of resistors that you think will fit the voltage ranges for your different amps and just connect them to the point between R1 and R2. Then use the other ends for your input.

of course that makes since and all gee blue why didnt you figure that one out gosh you dumbass....


(wtf did he just say)

[blue LEDz]

Intruder, i was thinking about making a bit more complicated and have a rotary switch to select the different resistor values the diodes will be the same, and i'm making it with 2 inputs, one for RCA's and one with alligator clamps for amp outputs

[Intruder]

Originally posted by blue LEDz
Intruder, i was thinking about making a bit more complicated and have a rotary switch to select the different resistor values the diodes will be the same, and i'm making it with 2 inputs, one for RCA's and one with alligator clamps for amp outputs

mmm... nice!

[Intruder]

hey blue, I guess you've done plenty of experiments with your sub's position, so I'm gonna ask you this -- is there a difference in SPL when your sub is facing you as opposed to facing the other way?

[asylum24]

yes there is. louder if it points the rear

[blue LEDz]

if you are going to have the sub face you, you need to isolate it from everything behind it. i'm planning on doing that for my next SPL box. it'll be at the front of the trunk, and the trunk will be sealed off from the rest of the car. otherwise it sounds better and can be better for SPL facing the rear i usually always face mine to the rear, but for pure SPL purposes it's generally better having them face forward, so they are closer to the mic for a general daily driving box, you lose 3 dB when you face your box forward to face a box forward, it has to be either a sealed box, for SQ, or a ported box, designed for SPL in mind either way it can be a gamble, if not done properly.

[Intruder]

Originally posted by blue LEDz
it has to be either a sealed box, for SQ, or a ported box, designed for SPL in mind either way it can be a gamble, if not done properly.

hold on, I thought that ported boxes are for SQ and sealed boxes are for SPL.

[blue LEDz]

Originally posted by Intruder
hold on, I thought that ported boxes are for SQ and sealed boxes are for SPL.

huh? not in the least. sealed boxes are actually the worst for SPL typically SQ guys like the roll off of a sealed box, but i personally hate it. i think a low tuned ported box has better over all response, and more even output, therefore making them a better choice for SQ course then you have to factor in transient response, delay, and port velocity (ie port noise). i'm fairly certain that every major SPL winner is using a ported box. course we're talking a HUGE ported box, with a port area around the size of the sub, and high tuning, say around 55 hz or greater.

[Intruder]

that's what I thought... I remember you telling me that I want a ported box because it would sound nicer, and at that time I also checked out a few pre-made designs and didn't like their sound. the general observation was that ported boxes (not the plexiglass window type) sounded better to me than the sealed ones... so I've always thought that ported is for SQ and my design was a mix between SQ and SPL.

I generated some sine waves with a various frequencies and the ones that sound more like the bass I want are around the 50-60Hz range. Let's say I want to tune my eD box to 55Hz. I'd have to build a new box but how does that fit with the driver I already have (e12K.44)? Is this something unusual (tuning the sub to 55Hz)? I feel like 30Hz is too low.

[blue LEDz]

if you tune your box higher, it will sound like ass in the lower freq's, not to mention the sub will bottom out at a higher freq. try turning the bass boost on your amp up. it should be a boost at 45 hz, but it'll increase around it also tuning it high to 55 hz would only be for SPL purposes, and not for daily driving. what HU do you have? some HU's come with a built in 7 band EQ, like mine, and it has adjustment at 60 hz. or you could look into getting an EQ. they usually have adjustment at 60 hz. an audio control EQX would be a nice thing to have, from their new lineup, but good luck finding one for under $150. from their older stuff, i found this on e-bay:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3061406534&category=3290

the reserve has been met, so i don't think the price will go much over $60. you can run the front channels to the USP200 for your components, and the rear to your sub amp

[Intruder]

The TSUNAMI 1100d amp I have doesn't have bass boost. My HU right now is an Alpine 9807, but I got a 9815 which I have not received yet. My current HU doesn't have an EQ but has a bass boost which I can adjust (center frequency - 60, 80, 100 or 200Hz). I think the 9815 has a better EQ plus a HP/LP crossover, so I'll check it out when it gets here and I install it. The EQ on eBay is really nice, but I might not need it if my new HU has a good EQ. Do you think so?

[blue LEDz]

i was looking at alpines website for info on the HU you have coming. it should be able to do exactly what you need it to do. it says it has parametric EQ adjustment from 20 hz to 20 Khz, at 1/3 octave steps. if it works like a normal 1/3 octave EQ, you'll be set. otherwise it does have a plus or minus 14 dB at 60 hz boost

[Intruder]

what do you think about my new HU? would you buy one?

[blue LEDz]

Originally posted by Intruder
what do you think about my new HU? would you buy one?

HELL YEAH!!!
i wanted to try the JVC i got, and while i love it, i'm still keeping my eye out for a good deal on a top of the line alpine