somebody better tell Mark Eldridge to remove his rear fill, cause he has it all wrong
LOL.
I've heard Mark's car with and without the rearfill.
The difference is HUGE.
Way better with the rearfill, just to make it clear.
Even with it on you cant hear (localize) it and it doesnt pull you to the back.
It gives you an incredible sense of envelopment.
It "erases" the physical booundaries of the car and takes the stage way outside the car.
Jorge, dont do it man. all the top sq cars have no rear fill what I think is funny is that I have rear fill in my truck. My scores are higher with it on. NOBODY has ever asked me if I had rear fill Top secret stuff mang!!
Team Zapco
"once you go floor, you'll never go door"
"I can easily make the most expensive car stereo system sound like junk in less than 30 seconds"
Rear fill done properly with T/A can sound good to some...
It seems to be that very few people with rear fill do it properly though.
I've run 0 rear fill in my last 4 vehicles, and have yet to tell me that it sounded like something was missing.
Stereo recordings through a well done front stage should not need the band-aid of rear fill. IMO of course...
"Tact is the knack of making a point without making an enemy." - Sir Isaac Newton
“The wise understand by themselves; fools follow the reports of others”
Tibetan Proverb quotes
I don't use it as a a bandaid, and I agree that a proper front stage set up properly works just fine, BUT, if done correctly, rear fill can enhance the entire listening experience. again, my .02 on the matter
Team Zapco
"once you go floor, you'll never go door"
"I can easily make the most expensive car stereo system sound like junk in less than 30 seconds"
werewolf[/B];101449]"rear fill" encompasses many possibilities :
- simple, attenuated L and R
- delayed (beyond Precedence, or Haas, Effect), attenuated, bandlimited L and R
- delayed, attenuated, bandlimited difference signal, L-R
there's a world of difference between these options. Some will confuse the front stage, others will enhance the front stage.
Quote:
Originally Posted by [B
werewolf[/B];101475]Your friend isn't the only one who thinks you can get surround from a 2-channel signal
Dolby Pro Logic II, DTS neo:6, Harman Logic7 come to mind ...
Sure, they have more sophisticated steering algorithms ... but have you heard a well-tuned system using a delayed, bandlimited L-R difference signal sent to the rears?
Quote:
Originally Posted by werewolf
Big difference between a concert hall and car: size of the acoustic space!
And it's NOT just a relative difference ... there's a real, tangible threshold involved, as defined by the Haas Effect. In a car, there's a real good chance that the natural reflections will not exceed the precedence effect (about 20msec, if memory serves) ... meaning that natural reflections will only tend to smear and confuse the front stage. In a concert hall, there's a real good chance that the natural reflections will exceed the precedence threshold.
So if you delay the rear fill by ~20msec or slightly more, you can create an apparent acoustic space that is much larger ... without confusing or ruining the front stage. This is a good thing Yes, we face the orchestra in a concert hall ... a classic argument against dumb rear fill ... but we also sense that the concert hall is bigger than about 25 cubic feet ... a very good argument in favor of smart rear fill
How to best accomplish it, is perhaps a discussion for another thread. You need a processor with time alignment, and the ability to bandlimit the rears. The difference signal can be formed either actively before the amp (trivial with balanced signals, not even hard with transformers and single-ended signals), or speaker-level after the amp (the classic Hafler matrix was the old, dumb example ... with no time delay, and even only crude attenuation and bandlimiting). But here's an interesting link for further reading:
Of course, you may want to consider the options mentioned above ... Dolby Pro Logic II (invented by Fosgate with an automotive acoustic space in mind), DTS Neo:6, and the new Harman Logic7 processor for the car (which, by the way, is starting to get some very encouraging reviews). All of these options create a multi-channel signal from a 2-channel source, and make very intelligent use of speakers behind your head
I guess my main point is this : all "rear-fill" is not created equal It's important to distinguish what type, before we summarily embrace or dismiss the entire category.
Quote:
Originally Posted by [B
werewolf[/B];101740]The "L-R difference" signal is really just that : the algebraic difference between the left and right signals. Sometimes it's called the "ambience" or "surround" component of the original 2-channel source.
Consider a largely mono signal, like voice (in most recordings, certainly not all). A mono signal will have about the same level in the left and right channels ... and will therefore disappear in the difference So immediately we recognize a HUGE difference bewteen standard, L and R rear-fill and a rear-fill signal constructed from the L-R difference : one will have the main vocal in the rear, the other will not Perhaps that alone is a big incentive to resist lumping all rear-fill possibilities together?
Anyway, check the link i posted earlier for more about L-R difference signals, and how to construct and manipulate them without using PL II, Neo:6 or Logic7.
[SIZE5"]Power kills speakers ... not waveform shape. ~ werewolf[/SIZE]
LOL.
I've heard Mark's car with and without the rearfill.
The difference is HUGE.
Way better with the rearfill, just to make it clear.
Even with it on you cant hear (localize) it and it doesnt pull you to the back.
It gives you an incredible sense of envelopment.
It "erases" the physical booundaries of the car and takes the stage way outside the car.
J.
YES!!!
Ge0
Alpine, Zapco, Scanspeak, Image Dynamics, Critical Mass
Life lesson #1) En boca cerradas no entra moscas! (loose translation: sometimes it is best to keep your fuggin mouth shut and listen)
No way rear fill helps the sound in no way. A real SQ setup will have no rear fill.
Just plain ignorant. Listen to a vehicle with this set up PROPERLY before rendering judgement. If one does it half assed, one will get half assed results. Therefore, one will think rear fill sucks. But in reality... enough said.
Ge0
Alpine, Zapco, Scanspeak, Image Dynamics, Critical Mass
Life lesson #1) En boca cerradas no entra moscas! (loose translation: sometimes it is best to keep your fuggin mouth shut and listen)
Ok, this is not as technical or in-depth of an answer as many others but here it goes.
Yes, when I get my system installed, I will use rear fill. However, unlike my fronts which are amped, the rears get the privilege of running off HU power
I'll play with the TA and volume for the back, but at the end of the day it will come down to what sounds good to me.
I'm sure this has been said, but would it not be most beneficial to run rear-fill from a single mono channel?
I think this would depend on the location of your rear speakers (doors vs. rear deck) and the signal summing capability of your amp/processor.
"Tact is the knack of making a point without making an enemy." - Sir Isaac Newton
“The wise understand by themselves; fools follow the reports of others”
Tibetan Proverb quotes
Jorge, dont do it man. all the top sq cars have no rear fill what I think is funny is that I have rear fill in my truck. My scores are higher with it on. NOBODY has ever asked me if I had rear fill Top secret stuff mang!!
Are you funnin' with us? If so you should be careful because some of us little people really look up to guys like you.
If you really do use rear fill maybe you could tell us how it's done without the techno-babble.
Seriously though. Lately I feel that something is missing between the height and depth of the frontstage and the localization of the subs(at volume) in the rear. Maybe it is time to experiment with rear fill.
- simple, attenuated L and R
- delayed (beyond Precedence, or Haas, Effect), attenuated, bandlimited L and R - delayed, attenuated, bandlimited difference signal, L-R
there's a world of difference between these options. Some will confuse the front stage, others will enhance the front stage.
....
[SIZE5"]Power kills speakers ... not waveform shape. ~ werewolf[/SIZE]
I have overkill on my rear deck dynaudio 340. Front stage is 340, soon to be 360 with the mw 170in place of the mw 160.when driving I like about 20% on the rear deck, seems to be a very good cure to outside noise and road hum. For more critical listening its just the front stage. I do use the head unit in the acura tl type s and its does have all the multi-channel features with the right dvd-a's and dts multi-track disc,s.
Using rear-fill depends greatly on the front set-up or the car itself. I personally don't use rear-fill because I was able to get the front speaker positioned properly to fill the car. I done many installs before and some cars just need rear-fill to sound full. Best thing to do is to try it yourself and see what sounds better in your own set-up. Just a thought.
Wow, I think I am going to do a rear-fill. If you were to do rear fill, do you recommend to have 2 ways back there or just 1 way? I was thinking about just doing 1 way in the back and make it have the mid-bass or something.
Coaxials are fine for the rear. Do not use components for rear-fill. You are not even suppose to notice its there, so having seperate tweeters will ruin your front stage.
Coaxials are fine for the rear. Do not use components for rear-fill. You are not even suppose to notice its there, so having seperate tweeters will ruin your front stage.
How is the tweeter being built into the speaker better or worse for rear fill?
What is suggested is that if you bandwidth limit your rear fill to midrange/midbass, it will be easier to blend into your front stage, and will be unnoticeable that it's coming from the rear. You would also use time alignment to integrate it into the front stage. The whole idea is that you never even notice the fill is there... which kind of proves that you really don't need anything in the rear.
For those stating "I heard a car with properly done rear fill, and then it was shut off, and it sounded much better with it"
Of course it did. If you set the car up to have rear fill to have proper tonality, and you suddenly take that "band-aid" away, of course it would sound better with it turned back on.
I also saw some arguments regarding direct vs. indirect sound. Basically stating that rear fill should simulate reflections from the back wall at a concert. I don't follow this. Your front speakers would still have reflections off your rear windsheild. If anything, you should have mirrored drivers in the front reflecting off the front windsheild ala Dipolar or Omnipolar speakers. Natural sound radiates 360 degrees, speakers do not. If you used a dipole/omnipole design, that would be closer to 360 degree dispersion.
These IMO are the reflections that would matter, the ones in front of you. You naturally hear things better when they come from in front of you, your ears are somewhat directional. This is why you naturally turn to face someone speaking to you (other than politeness).
Maybe this is why one of my favorite car's had dash mounted off axis 6.5" drivers and on axis tweeters. The midbass both provided direct off axis sound, and indirect (reflected) on axis sound. Soundstage was high, and everything sounded real. Voices had depth, and an impressive staging presence.
This same car BTW had no rear fill.
"Tact is the knack of making a point without making an enemy." - Sir Isaac Newton
“The wise understand by themselves; fools follow the reports of others”
Tibetan Proverb quotes
Re: Rear Fill: do you use it?
Re: Rear Fill: do you use it?
[SIZE5"]Power kills speakers ... not waveform shape. ~ werewolf[/SIZE]
Re: Rear Fill: do you use it?
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