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What Exactly Does Running Active Mean..??

23K views 32 replies 10 participants last post by  07azhhr  
#1 ·
As im shopping for a new head unit, the Pioneer DEH-80PRS seems to be a popular & smart choice, but im on the fence for getting this head unit only cause i have no idea what it means to run an "active" system. Someone posted up a thread asking if getting this unit was too much if ur not gonna go active, so with that in mind, can someone explain to me in laymans terms what running a fully active system means etc etc??

Equipment:
Front: 6.5 Image Dynamics CTX components
Rear: 6.5 Image Dynamics CTX coaxials
Pioneer Premier 12" W3004SPL Sub
Two Lanzar MXA422 amps
 
#3 · (Edited)
An active system basically means you can apply and adjust the speaker crossover points in the head unit rather than using a passive crossover unit that comes with a set of component speakers( the little box that the speaker wires run into before it goes to the amp).

In this pic you can see the woofer, tweeter and the passive crossover box. The passive crossover is already set to certain cutoff frequencies and slopes, which can't be changed unless you add or remove parts from the box itself. Passive crossovers are usually specifically made for the set of speakers they come together with. In an active system, you can set and change the frequencies for different drivers or tweeters. Example- say the crossover below is made to cut the woofer off at 2.5k @12db, but in your car it would sound better if it was at 3k and 24db slope. With the active system you can go right into the 80prs menu and adjust it where as with the passive, you'd be stuck with 2.5k 12db, unless you want to change parts in the crossover, which requires knowledge of crossover design.

The system I am running now, is my first active system, and while it took some work and experimenting to get it set correctly (for my ears anyway) I do not regret it at all.

JL Audio C2650 2 Way 6 5" Component Speaker System 368298559434 | eBay

BTW, active systems in musical/pro audio usually means it has an amplifier built in already, this is a different meaning than car audio, just an FYI.

Hope this helps.
 
#4 ·
In laymen terms, active is altering the signal before amplification, passive is after amplification.
 
#6 ·
This is the short answer of it in true laymens terms when related to car audio. So any form of electronic only adjusting of the x-overs is considered active. This could be done in the HU, it can be done in the amp itself, or it can be done via an inline electronic x-over or processor. Any form of electronic adjustment.
 
#5 ·
running active is a term used for components that are hooked to a power supply and usually have settings that can be changed. remember, crossovers are not only used for audio, but for video, rf propagation, radar, and all sorts of other applications. active and passive systems are used throughout many types of electronics.

for example, passive crossovers in an audio system do not require external power, and they have fixed attenuation of frequency. they are put inline to a speaker (or speakers) and may have jumpers on them to change some settings - they way that works is by having multiple crossovers on one board, with a physical connector the installer moves to select the proper crossover. a benefit of the passive crossover, is that it enables the user to disect the bandwidth on the input side to several smaller portions on the output side. so one channel of amplification can drive multiple speakers.

an active system has to be powered, weather by a battery, or a power supply. there are usually digital or analog dials, knobs, or settings to adjust what the unit is made for. example, the active crossover in an audio system will allow you to adjust a low pass filter for chanel 1 between 1000hz and 5000hz. the drawback, is that each speaker or group of speakers need its own channel of amplification after the active processing. the settings are dependant on the unit and its engineers.

other examples of active versus passive are inline GPS amplifiers, antennas, etc. the main point is that active requires outboard power, and passive utilizes the power already present in the signal path.

i hope that helps :p
 
#9 ·
Basically, instead of controlling your front and rear speakers, each using its own passive crossover box, you by pass the supplied crossover box and let the head unit output directly (often by the means of external amplifiers) the front tweeters and woofers. Since the head unit has only three sets out outs, the rear speakers are not used. This results in a very good sound with the right tuning, that's worth giving up rear speakers.
 
#10 ·
remember, thinking on a larger picture than just "audio system" makes it easier to understand.

passive - no use of external power or internal power supply
active - uses external power\has power supply\battery powered

these principals are in use in a much wider realm than just audio crossovers. you can even have active or passive equalizers too.

but most commonly, when referring to "active" in the car audio industry - people are referring to active crossovers, where the user can set the frequency cutoff for a particular audio channel, for one speaker, or for many - that is dependent on the setup.
 
#12 ·
Techinally, you wouldn't use the crossovers in the amp or passives for the front speaker components. However, can you even go active front stage if you are running rear speakers with that HU? The old Alpine 9886 required you to choose- you only had 3 pair of RCAs coming out Front/Rear/Sub. When you went for an active setup the outputs corresponded to Woofer/Tweeter/Sub.....
 
#13 · (Edited)
Theres no way for me to do that since the amps have built in crossovers with 5 adjusters & a frequency switch that have to be set at something. Im also using 2 amps so i only need 2 RCA's.. (but im guessing that to go active, id need a set of RCAs per set of speakers to make adjustments rather then the crossovers on the amps..)

All this new way of doing things is a bit confusing as im old school where everything was plug & play, where the only goal was to see how far away people can hear you coming, & the only numbers that mattered were watts!
 
#14 · (Edited)
Not familiar with your specific amps, but if an amp has a built in crossover network, it usually has a defeat button switch. If not, you would just raise or lower it to a point that wouldn't interfere with the intended passband.

We're all happy to break that down for you if needed.

By saying you need only two RCAs, I assume your amps are two channel (again, not familiar with them). How were you intending on running your fronts, rears, and sub? By my math, that would require 5 channels......

EDIT: Checked out of boredom.

If these are the amps you are using:
Image


They are four channel amps, so you can run the front stage active off one amp and the subs bridged off the second. You would need to provide another pair of inputs, but you should do that anyway so you can use the built in fader on any head unit to balance the front and rear. Anyway, that switch that says HPF/LPF/Full is your active crossover network. If it is on FULL, it has been defeated and the crossovers are taken OUT of the loop.
 
#15 · (Edited)
Yes those are the amps & setting the HPF/LPF/Full switch was the answer i was looking for.

As for the RCAs, on amp 1, i would use a set for the fronts, & a set for the rears using all 4 channels. As for the sub, it would be bridged to 2 channels, one for each voice coil & the RCAs would get those splitters since theres no need for adjustment from one channel to the other on the single sub setup.

Note that im well aware that the 2nd amp is grossly underpowering the sub & if i had the money id buy an amp that can send that Pioneer W3004SPL the true 1000RMS that it needs! Maybe in the future i will try to spring for newer & cleaner amps but for now they will have to suffice.

So how am i doing so far??
 
#16 ·
Are you saying you WANT to go active? If so, why?

To add a level of complication- you need to understand the real benefit of going active in the auto environment and it isn't simply the crossover functions. Passive crossovers work just fine for that- the real benefit is to help control the phase relationship of each driver being a different distance from the listener. This is often regarded as time alignment (T/A) and effectively "delays" the signals to closer drivers in the "system" to represent equal distance from the listener- as in a true studio monitor environment where you are in the center of the speaker setup.

If so, you will have some issues with the current setup and adding the 80PRS. It can only process 5 channels actively, two for the front tweeters and two for the front midrange with the last to the subwoofer. The use of this unit desiring active playback will not account for the rear speakers. If you wish to use them for rear fill and additional sound, they must also be active in order to achieve the benefits. If they are simply run off HU power, you will not have T/A control to get the phase response corrected. The act of going active for just the crossover points is kinda a waste.... IMHO. Passives and/or the amps can achieve the same results- the T/A and EQ are the reasons to move that direction; and to achieve that you would need control of EACH point source.

You could still benefit from "going active", but it would be to use T/A for the current drivers using the current passive crossover networks. That would work well for the coax drivers as they are point source, but the components up front probably don't have the same distance for the woofers and tweeters, thus will throw off an ideal result.
 
#17 · (Edited)
Well heres the deal, as i was researching & reading threads on getting a new head unit, the 80PRS by Pioneer seems like a good choice. As i was reading thru a few threads, alot of people kept mentioning this being a good choice if u wanna go full active & thats where i asked this question on what that exactly means.

Now since people claim that this setup sounds so much better & are getting better sound out of the same speakers is whats making me think about doing the same, especially since i have not purchased the in-car speakers yet. The things that are still rattling my brain is that this is the first time ive ever heard of people only running front speakers calling it there front sound stage & reffering to the rear speakers as rear fill. See for me & my old school thinking, that rear fill acts like suround sound just like i have in my living room, & when i turn that on, movies sound so much better & makes them better to watch!

BUT to be totaly honest, ive never been totaly happy with my in-car sound & this brings me back to confusion & makes me wanna give this a go since this would change what speakers i buy. I think ill probably buy the 80PRS reguardless of my decision so ill have the option of going active later on as im still leaning towards the basic setup that im used to.
 
#19 ·
....I think ill probably buy the 80PRS reguardless of my decision so ill have the option of going active later on as im still leaning towards the basic setup that im used to.
I guess my first reply summed it up well then. ;)
Maybe this will help some as this is how i was picturing setting up my system before i read about this active stuff:

-Newer head unit.
-2 sets of RCAs to one of the Lanzar amps powering the front components & rear coaxials.
-The crossovers will be set to making the rears slightly louder so there tuned to sound like surround sound would.
-3rd set of RCAs to the Sub amp bridged to 2 channels powering each voice coil on the sub.
-Last, i may run a set of tweeters & possibly midranges off of the head units unused speaker wires.

It also may help to mention that im half deaf as my right ear cannot distinguish words but i can hear sound out of it.
Bottom line- do what works for you. I have all my hearing, so I can't relate nor give great advice as to what will work FOR YOU. When you bring up surround sound in the home theater and try to relate it to car audio it does make me cringe a bit. Home theater- movies specifically- are using a decoding algorithm to give each channel specific information. The rear channels aren't playing the same complete information as the front channels to give you the feeling of action happening behind you in a movie or sound from reflections in a live venue with music..... so the audio system you describe won't technically give you the same results feeding the same info to front and rears. Will you tell the difference? I don't know. It bugs the **** out of me- personal preference.

You are on the right track... other than using the crossovers for volume control. You should set the amps with identical gains running full range. If hooked up like you indicate, you can use the fader and sub control from the HU to put the sound levels where you want them. (You can use the HP filter to limit low frequency on the components/coax and limit distortion risk- but not necessary)

Keep in mind there are two key elements to "essque" in a car- tonality and sound staging. By selecting solid components you can get the tonality part right (considered more important). To get the staging right you will need active processing of some sort. Again, with your particular hearing loss- what may be "right" may not work for your full enjoyment.

Do yourself a favor as you read around on this forum- become a critical thinker. That doesn't mean be critical of everything said and go all internet commando- it means think about what is said and why and try to relate it to your experience/situation. All scenarios are different and perspectives vary. Ask good questions while providing crucial information as to YOUR situation and YOUR goals. Not everyone is looking to score 90 in the competition lanes.... ;)
 
#18 ·
Maybe this will help some as this is how i was picturing setting up my system before i read about this active stuff:

-Newer head unit.
-2 sets of RCAs to one of the Lanzar amps powering the front components & rear coaxials.
-The crossovers will be set to making the rears slightly louder so there tuned to sound like surround sound would.
-3rd set of RCAs to the Sub amp bridged to 2 channels powering each voice coil on the sub.
-Last, i may run a set of tweeters & possibly midranges off of the head units unused speaker wires.

It also may help to mention that im half deaf as my right ear cannot distinguish words but i can hear sound out of it.
 
#22 ·
I dont wanna debate surround sound VS car audio sound cause like i said, it was just an analogy reguardless if it was a good analogy or not.

A better debate is one that alot of Jeep Cherokee XJ owners do when they mod the doors to be removable for rock crawling such as how my jeep is built, & thats moving the rear sound bar foward to just above there heads since your now loosing ur door speakers. The Jeep Cherokee XJ, (not to be confused with the grand cherokee), has a bar going across the rear of the roof & that is where the rear speakers are mounted slightly aimed towards the front. So lets say if i were to move it foward to, lets say just behind my head, what would u guys say about this setup??
 
#24 ·
I currently own the 80 prs, memphis big belle and m3 12" subs, just purchased 4 polk mm571's. I am thinking about returning the coax, and purchasing components for front only? Any suggestions on seperates would be greatly appreciated(I am considering polkmm6501) as I like their sound. Sorry if this is in the wrong thread, this forum is a little overwhelming to me. Oh yeah, my stock speaker size is 5x7, but I believe I could fit a 6 3/4 with slight modification(2001 ford explorer) thanks again.
 
#29 ·
We are not saying DON't run rear at all just that if you want an accurate sounding stage then the rears need to be kept down in volumn and used soley as rearfill. But with all things that have been suggested you say NO WAY and this is what I am trying to do. We have heard you but you do not seem to be listening with open ears to us.

Believe me I understand your background story as I am older then you and have also had some type of system in every single car I have owned since I was 16 as well. I used to think you had to run as many speakers and as much wattage as possible but after listening to people on this site my eyes were opened up quite a bit.

When I joined here last year I had never been without speakers in the rear. Never would I have imagined how good a system could sound without them. Infact my first thread on here was asking what components to get to run for both front and rear. The responses were much the same but were stated as "you DON'T want that, what you want is this" blah blah blah. I wanted to reach thru the computer and sock that guy lol. But you know what? He was correct.

It took me a while to try no rears but once I did I never missed them. I even then disconnected my GF's rear speakers and never told her just to see if she would mention anthing. She never did. About 6 months went by before I mentioned having disconnected them and she had never noticed ever.

I would highly suggest trying it. But seriously if you want our advice then be willing to listen to it since it seems that most every time someone suggests something you come back with a different REASON why you NEED them. That is what is called arguing.
 
#30 · (Edited)
After re-reading thru the thread, i agree as ive been a bit thick headed & im sorry for coming across that way & am also thankfull that u took the time to tell me this in a polite way! Its not that im not listening with an open mind, its just that its hard to picture this & since i havent bought my in-car speakers yet, im now in a delema to either spend $300 on front components & rear coaxials, OR spend the whole $300 on components for the front.

I think my biggest quagmire here is that i would want to run a frontstage system active, but id wanna get more then just a component set & run 3-way components adding in a mid-range or even run a set of coaxials ontop of a component set. I just cant picture having a single set of components as my entire in-car setup & being loud enough!
 
#31 · (Edited)
So would i be able to run a 3-way component system fully active using the 80PRS deck & my 4-channel Lanzar amps??

A 3-way component system within my budget:
WoofersEtc.com - 165A3 - Focal 6.5" + 4" Access 3-Way Component Speakers

-Edit: just did a bunch of reading on this & it appears to be a bit more complicated to run 3-way components active as they require added tuning, BUT, those that have successfully done so have said it is well worth the troubles!!
-Warning, another question is coming: since this would add yet another degree of dificulty, can i run a 3-way component set in a passive system using only 2 out of the 4 channel amp??
 
#33 · (Edited)
It can be done in a hybrid passive/active setup if you can couple the 6.5's and the 4's off the mid out of the 80. Then run passives between them and use the HU to do the x-over for the 6.5's hi-pass and the 4's low-pass. Then the tweeters could be run off the other 2 channels of your amp and the hi outs on the 80. The concern here is time alignment since these two speakers are playing in the ranges that t/a matters. So you would want to get the physical distances from both the 6.5 and the 4 to be the same distance to your head.

I forgot to mention that I would suggest starting bith the front stage. Focus the $300 on that. 2- way or 3-way, pre made sets or pick and match drivers doesn't matter, you can be successful with any combo and can equally fail just the same. But focus on a good install with whatever you get. If amp channels/wattge needs are are not met then try to give some to that as well. Or atleast plan for it.

If in the end you still feel like you need more you can try various options. But a good install and good level and phase matching can go along way to making you happy with the sound even with few speakers. For example I am running 3 way in my car but 2 way in my girls car, both running the 80prs hu. Hers is even still having to use passives for the front speakers so no seperate t/a for the front. BUT since I mounted the tweeters in the pillars at the same distance to the drivers ears as the mids in the doors I actually do not really need the t/a between the mids and tweets. The install here allows for this. In many cars this is not physically posible between these two spots but for this car it was. In the end I am very satisfied with the sound quality and volumn of both vehicles. They both can get plenty loud and neither is running over 700 watts for the whole system. Not to mention but with all the level matching of channels I would doubt that I even can reach to 500w for mine or 300w for hers.