Mr Marv's Silverdo build

[Mr Marv]

Is rear fill even worth bothering "With"?

I used to believe in the myth that "rear speakers just mess up your front stage" until I heard a car with rear fill set up "properly" and now I won't be without it. One thing to note is "rear speakers" not processed can be "considered" rear fill however to implement rear fill that will actually "enhance" your front stage instead of taking away from it you will need specific
processing.

I used instructions from JL on how to set up the inputs of the twk88 for a left minus right signal and from what I understand there are many dsps/amps with balanced inputs that can accomplish this (my old JL slash 500/5 actually had left minus right built in on the rear channels). Per guru werewolfs instructions I band pass the rears from 100hz-7khz and if my calculations are correct they are delayed approximately 18ms from the front stage for now (ideally you want around 20-21 ms depending on who you talk to however the twk88 will only allow a max of 21 ms delay per channel so when I get time I am going to loop the remaining output so I can get additional delay).

It took just a little experimenting to find the right output level for the rears and if you go past that "sweet spot" you'll know. After getting it dialed in I set 2 other presets for quick comparison, 1 with all settings the same but no left minus right (just bandpass, delay and attenuation) and one with rear fill muted.

Switching from no rear fill to rear fill you immediately hear the stage gets wider/higher/deeper and has a sense of a larger space WITHOUT smearing the center imaging as some believe (stage is well beyond the a pillars, center is eye level right about at the windshield and stage extends well onto the hood)

A few things to note:

My left rear speaker in my regular cab pickup is only 11" from the center of my head yet you cannot "hear" it even if you turn your head towards the speaker (best I can understand from my reading is that its one of those scientific "effects" where your brain somehow disregards the delayed sound and only hears the direct sound of the same frequencies) however if you mute the front stage you definitely hear the rears playing. From what I recall werewolf stating the rear speakers ideally should be above and to the outside of your ears (the car I originally heard this in had them in the side "C" pillars between the rear window and rear door instead of on the rear shelf) however I have never done a direct comparison so I cannot say how much difference location makes.

Without the left minus right engaged the stage still gets deeper/wider/higher however the center image gets more "pronounced" for lack of a better word. Interestingly it did not totally destroy the imaging so my belief has always been the delay/attenuation are the most critical part of this.

"Well engineered" recordings do not get too affected by this however the "lesser quality" recordings are greatly enhanced (I listen to Satellite a lot and it makes a big difference).

Is it worth the time/expense to you? Can't say however I can say it is the "icing on the cake" for me AFTER getting the best front stage I can without rears.

As usual, "I can't hear what you can hear and you can't hear what I can hear so our results may differ" and if you happen to be near Monterey Ca you are welcome to come by and listen!

[BigAl205]

[Hic]

A double eagle for that post !

Tou che` ! ! !

[WhereAmEye?]

Hey Mr. Marv. I can thank you for getting me into diy car audio! I pretty much memorized your build log in the Tacoma over on tacomaworld like a decade ago and it’s still one of my favorites (hybrid Clarus, JL shallow sub, and some slashes). I still remember your list of what makes a good sound system, when you purposely miss your exit just to keep listening to music. Don’t want to derail the thread just wanted to give you a shout out

By the way, any time I build a box I compare it to one of your masterpieces as a cornerstone.


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[ajt976]

Dude, that's hilarious. After I joined up here I of course went right to this build (being another Silverado) and immediately recognized the OP. I contacted MrMarv in 2010 for some feedback and suggestions on a potential build in a Tacoma I was looking at buying, based on that same build you referenced. I was enamored with his sub box in that Taco, at the time I'd never really seen that level of install.

It was funny because last night I went back and looked up all my old emails with him, everything really does come full circle. MrMarv was gracious enough to drop some knowledge on an eager college grad with his first job looking to blow some cash. His suggestions then are still relevant and is a testament to his experience. I didn't buy that Tacoma, or putting a system in the Jeep I ended up with, but I always remembered the conversation and guidance provided (even tho I bumped into his 3 email limit). Cheers MrMarv, anxious to see what else you come up with in your truck!

[Mr Marv]

Hey Mr. Marv. I can thank you for getting me into diy car audio! I pretty much memorized your build log in the Tacoma over on tacomaworld like a decade ago and it’s still one of my favorites (hybrid Clarus, JL shallow sub, and some slashes). I still remember your list of what makes a good sound system, when you purposely miss your exit just to keep listening to music. Don’t want to derail the thread just wanted to give you a shout out

By the way, any time I build a box I compare it to one of your masterpieces as a cornerstone.


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Glad I got you interested (hope I didn't cost you too much money!) and thanks for the kind words! I remember that comment and to this day I still skip exits on the way home!

[BigAl205]

... to this day I still skip exits on the way home!

That sounds more like an old age thing, but anyway...

[Mr Marv]

Dude, that's hilarious. After I joined up here I of course went right to this build (being another Silverado) and immediately recognized the OP. I contacted MrMarv in 2010 for some feedback and suggestions on a potential build in a Tacoma I was looking at buying, based on that same build you referenced. I was enamored with his sub box in that Taco, at the time I'd never really seen that level of install.

It was funny because last night I went back and looked up all my old emails with him, everything really does come full circle. MrMarv was gracious enough to drop some knowledge on an eager college grad with his first job looking to blow some cash. His suggestions then are still relevant and is a testament to his experience. I didn't buy that Tacoma, or putting a system in the Jeep I ended up with, but I always remembered the conversation and guidance provided (even tho I bumped into his 3 email limit). Cheers MrMarv, anxious to see what else you come up with in your truck!

I found your old emails Andrew and yes you did go past my 3 email limit at the time but I'm glad our conversation was useful to you!
I still stand by my philosophy on car audio..buy the "best" speakers you can fit in your budget and play them within their limitations, install them "properly", power them properly to get the output you want within their limitations without audible distortion, get your polarity/phase/levels correct and THEN learn to use an EQ "properly" to get the best sound for you! Also, I am still a fan of the KISS principle (Keep It Simple Stupid) and I literally just today yanked the entire system out as I was thinking about trading the truck but I have a feeling I'll keep it and try something new so stay tuned!

[Mr Marv]

That sounds more like an old age thing, but anyway...

I should have said "on purpose!

[JimmyDee]

Thanks for the post Marv.
I know I am in the minority here (and on 'the other site')... but I have always done rear fill, and definitely prefer it. Personal choice.

My first few installs were rather crude... I'll admit. The rear fill wasn't setup properly, because I didn't know what I was doing.
It was only my last few vehicles, where I truly mastered rear fill. It also helps to have a decent DSP, and know how to use it...

It doesn't mess-up my front stage... at all. The front is still the priority, and I definitely know where my sound stage is.

I've mentioned this before, and I will say it again;
Rear fill costs money: Extra amplification. Extra DSP channels. Extra speakers. Extra wiring.
If you have the means to buy the equipment and do it properly, then go for it. But do it properly.
If you are adding rear fill, and taking money out of your front stage budget to do it... then forget rear fill.