What is active?

[slim j 10+ year member]

I am looking into one of these DIY setups and I am thinking about active. I hear about it frequently but I am unsure what all is involved? Is it it just running a mid and a tweet off a 4 channel amp? ie a tweet to the front 2 and mids to the rear?

Does impendance matter very much becuase I see many of the DIY setups have 6 or 8 ohms.

I am going with the Kenwood X889 so I have many tuning features in my HU. I have a 4 channel amp that does 4x50@4ohms.

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[alphakenny1 10+ year member]

yea pretty much with what you said but also you get to choose your crossover pts and slopes as well. much more flexbility in tuning than a passive setup where the crossover pts and slopes are already determined for you.

 

[slim j 10+ year member]

So you need an crossover?

 

[alphakenny1 10+ year member]

i just did a quick search on your HU and it seems (don't for know sure) that it doesn't have a crossover that will support a 2 way frontstage, so then yes you probably need a external crossover.

 

[slim j 10+ year member]

So the tuning is done by the headunit and not the amp?

 

[squeak9798 5,000+ posts]

So the tuning is done by the headunit and not the amp?

For an active setup, the "tuning" is done anywhere prior to amplification of the signal. This can be done in the headunit, with an external active crossover or with the amplifier's crossovers, or any combination thereof......whatever allows you to get the crossover frequencies and slopes you need.

Also, impedance does not matter as long as your amplifier can supply ample power at that impedance.

 

[slim j 10+ year member]

So basically...If I purchased Seas L18RNX and 27TDFC, I just tune each one with combination of HU and amp until it sounds good....this seems easy enough, but time consuming.

Is the 27TDFC okay for IB setups in doors?

 

[squeak9798 5,000+ posts]

So basically...If I purchased Seas L18RNX and 27TDFC, I just tune each one with combination of HU and amp until it sounds good....this seems easy enough, but time consuming.

It's not *that* easy.

You will need the ability to bandpass the mid and highpass the tweeter. Not only that, but you will need to be able to select appropriate crossover points and having variable slopes never hurts.

It all depends on the crossover frequencies your crossovers will allow and if you have enough crossovers to be able to properly bandpass the mid.

Is the 27TDFC okay for IB setups in doors?

That's a tweeter. You can't IB a tweeter.

But yes, the L18 should be fine in your doors.

 

[slim j 10+ year member]

It's not *that* easy.
You will need the ability to bandpass the mid and highpass the tweeter. Not only that, but you will need to be able to select appropriate crossover points and having variable slopes never hurts.

It all depends on the crossover frequencies your crossovers will allow and if you have enough crossovers to be able to properly bandpass the mid.

What should I search for in look for a tutorial on how to do this? What is bandpass? I am only familiar with high pass and low pass. My amp doesn't have that option.

That's a tweeter. You can't IB a tweeter.

But yes, the L18 should be fine in your doors.

Sorry, I got them backwards...//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[alphakenny1 10+ year member]

bandpass is basically a HP and LP to a certain speaker. As of right now i have my mids HP at 63hz with 12db/slope and LP at 1.25kz with 12db/slope. So basically its bandpassed at 63hz and 1.25kz.

 

[3.5Max6spd 10+ year member]

Your Hu doesnt support an active fronstage...so no, it doesnt have much for tuning....

You need to Highpass your tweeters above the 200hz the Kenwood xovers limit/permit you...more like generally ~2Khz +/- area

You need to band pass your midbass. Between the HP of the HU say 80hz for example, you then need to Lowpass the other end up to where your tweeters pick up....hopefully you have an amplifier with decent adjustable xovers that'll let you set them that high

 

[squeak9798 5,000+ posts]

Get one of these and you'll be good to go: http://search.ebay.com/search/search.dll?cgiurl=http%3A%2F%2Fcgi.ebay.com%2Fws%2F&fkr=1&from=R8&satitle=Coustic+XM6&category0=

 

[slim j 10+ year member]

so bandpass is roughly equivalent to a interest rate collar (all I do is study derivatives). Ie has upper and lower bounds/frequencies...which makes sense.

What type of head units support a front active stage?

 

[alphakenny1 10+ year member]

Yes. as for HUs that support an active front stage off the top of my head the Eclipse 8455, Pioneer 860, Alpine 9835 and 9855, Clarion DRZ9255. I'm sure theres more though.

 

[slim j 10+ year member]

Do they say specifically supports active front stage or is there something I should look for?