ohseven

I'm gonna install 300/4 and 500/1 do i grab my signal pre-amp or post amp no processor yet?

Trunk Monkey

iTrader: (1)

Pre-amp. JL slash and HD's can handle our balanced/differential signals in their inputs

ohseven

Thanks for the reply Trunk Monkey

Trunk Monkey

iTrader: (1)

Per your question on DIYMA...

You asked " So the sounds are 4 ID8V3's, 500/1, 300/4 and ID comps(on the way). Is a processor needed or would it make a big difference in this setup."

It depends on you. Those amps will accept a balanced signal and will integrate just fine into the factory system. You will be able to run them perfectly and all will be fine. If you wanted to get a processor, you'd gain Time Alignment for better stage height/width/separation, EQ, & the ability to run active with your components. When a processor like the 360.2 can be had for $200+ish shipped...it's a no-brainer. If you can spend more, the MS-8 works wonders with its auto-tune, but can be a little tricky. There's plenty of info over at DIYMA on this though so you'll never be out of the loop or without help. The audison bit.1 is another great processor, but pricey. A few other options out there also, but a little less common (alpine, audiocontrol, etc).

I hate cars

Post amp will have much less chance of ignition and alternator noise. It's easier to do and I would recommend it if doing just the sub. However, you will always have a hiss due to the high noise floor of the stock amp. If you keep the gains down on your aftermarket amps, it's not bad at all but you are limited at how loud you can run the fronts without noise. There's nothing you can do about the hiss, you're amplifying a dirty signal.

Pre-amp has the potential to give you a very clean signal but also increases the chance of ignition interference if your install is not right. I had a couple small problems with noise when I first went pre-amp but right now my noise floor is almost non existent. I have a ton of power on tap and you can only hear noise if you have the engine off and your ear by the speakers with no music playing.

If you're considering 4 8" subs, I highly suggest you reconsider and do something like a single 12 or 15.

ohseven

Thanks for the reply. IHC why would you run a single sub verses multiple subs. Its my first IB try so chime in

I hate cars

I didn't realize you were going IB, nice choice.

More cone area is always better no matter what enclosure you use. More cone area= less excursion = less power compression = more linear = less distortion, and you also get higher efficiency. In short, the less the cone has to move, the better. IB is so much more efficient than sealed, you will be able to test the mechanical limits of your subs with much less power.

Think of it this way. A box is a mechanical highpass filter. The lower in frequency you go, the more the air spring resists movement and the more power is required to produce the really low bass. The box cuts the lower bass by lowering efficiency....not the way you want to do it if you can help it. IB removes this filter so they become super efficient in the lower octaves compared to sealed. You can use the subsonic filter on your amp to simulate the box which is just an electrical highpass filter and enjoy a super efficient system with all of the advantages of running less power and still have more low end than sealed could give but with a little protection from over excursion.

I run a 20hz@6db filter on mine just to protect the subs from some unwanted subsonics. It still plays organ music down to 15hz where you can see the car moving and sense the energy but can barely hear anything. It RTA'd +-1db from 18hz to over 150hz with no eq which IMO is pretty amazing for a sub setup. You're still going to have a very tight, snappy bass, probably even more so than with a sealed box but the really low stuff is going to come through and it's going to sound very good, not muddy. There might be a few songs where you hear notes that you did not know were there.

If you want to simulate a sealed box with your IB setup or go for SPL, just throw a 50hz@12db filter on it and it will sound like a sealed setup but more efficient. Above 50hz, IB and sealed are pretty close in output since excursion is very low and the air spring of the box is not resisting it as much.

The reason some people say IB is not as loud as sealed and the reason we tend to run more cone area....

First, loudness in a sealed or IB setup is determined by displacement, nothing else. Put a sub with the same cone area and excursion and it's going to have the same SPL in sealed or IB assuming it can hit full excursion in a sealed box before hitting it's thermal power limits which happens most of the time. Back to the difference.... Since IB does not have that mechanical highpass filter we call a box, the subs will play the lower notes with greater authority with less power. If you set your gains so that the subs won't hurt themselves from over excursion in the low bass, it will also lower the volume in the upper bass where excursion is not an issue. The cure is a subsonic filter at a reasonable frequency or as most of us do, tons of cone area and decent excursion capability so we can take advantage of IB's low end extension by keeping the gains up and keeping it plenty loud in the 50-80hz range as well.

Some will point to the additional 1db or so in a sealed box over IB but what everything points to is some frequencies inside the box coming back through the cone. This is called distortion lol.

What setup are you using?

I hate cars

I just woke up, I forgot you were going to run a bunch of 8" subs IB.....

One of the important specs when going IB is Fs. Usually the larger the sub, the lower this will be and lower is what you want for a flat response. What a bunch of 8s will likely give you is a lot of output around 50hz. It will annoy you, trust me. You can eq the response flat but you're going to make it very inefficient because you may have to run anywhere from 2x-10x the power down low to make the response flat.

4 8" subs will have about the same cone area as a single 15 so overall output should be about the same but usually the larger subs have a little more excursion as well.

I'm not saying it won't work but chances are they're going to buzz you out of the car unless you have a ton of eq.

shawn_vs

Ihatecars whats the best way to hook up a aftermarketamp my installer is saying i mght get signal noise with my rf360 ?

jokerman826

I am running the same two amps and for the 300/4 i am going from the radio output and NOT from the amp out put. On the 500/1 I am grabbing the signal from after the amp in the back where the wires connected to the sub. Dont use a LOC, splice some RCA connectors right to the sub wires coming from the amp and then set the amp to a High Level Input