My Focal based audio build

[P3tras]

Hey everyone,

Just wanted to log my audio build. Since I started driving my BRZ, I was planning to upgrade audio system sooner or later. Almost a year later, it's time to do so!

Key points of the build:

• I want to make everything to look as OEM as possible. All speakers in factory locations, amplifiers hidden as well as possible.
• Of course there is no factory location for subwoofer, but I am planning to build fiberglass box that will sit in a corner (something similar as OEM audio box). That will be most difficult part of the build, as I do not have prior experience.
• Building it for sound quality, not for SPL. But I also want to make it as light as possible, thus I do not plan to use a lot of sound-proofing (doors are #1 to sound proof).

I got main components for build today. They are:

• Focal PS 165 F3 - 3 way speakers.
• Focal P 20 F - 8" subwoofer
• Focal FD 2.350 - amplifier for main speakers. It is very compact, I am planning to install it in stock amplifier location.
• Focal FPP 1000 - amplifier for subwoofer. Planning to install it upside-down on top of trunk compartment.
• Ownice C200 android based head-unit - I have it installed since I got the car. Thankfully it has low-level RCA outputs.

Here's photo of all components:


Unfortunately, it is going to be a slow build. I will do basically everything by myself and right now I do not have much spare time (I am student). But by end of next month I should get started.

Any tips or tricks for the build are greatly appreciated. Right now I am thinking if I should mount crossovers in doors or somewhere else. By mounting them in doors total wires length will be longer (as there are separate wires for mids and tweeters), but I am not really sure where to mount them else.

P.S. Tuning should be not an issue. My father is a sound engineer, thus we have all required equipment for measuring frequency response.

[Cockatoo]

Look forward to seeing where this goes!

I went with a 2 way component system up front so I could have the tweeter mounted in the stock location, and then the crossover fit perfectly in the empty space where the 3.5 inch speaker was...

[TOOSTUBBORN2FAIL]

What are you going to use to tune it? For sound quality, your going to at least need time alignment and 16 bands of eq per side, minimum.

As for deadening, search for my CLD Testing thread. Objective evidence for many products, including finding out which product is the absolute best for the weight.

[P3tras]

Tuning options are not very advanced. Crossovers have adjustable mids/tweeters outputs. There are adjustable high/low pass filters in amplifiers, sonic filter, bass boost and etc. I will try to get as flat frequency response as possible using tuning on equipment. Then (as I am using Android based head-unit), I will fine-tune system using equalizer. As for time delay - there won't be any processor, thus there's nothing I can do about it. But it's a small car, there shouldn't too many issues regarding it

CLD testing thread was already in my bookmarks, but thanks for the advice!

Just noticed that CLD testing was your work!

[P3tras]

OK, I was reading all info about sound insulation, checking tests, local retailers and etc. My head is already spinning.

I will be brave enough to give my ideas.

• Sheet of Dynamat xtreme (10x10") near speaker holes to absorb vibrations. Could be changed with Silent coat 4mm.
• Whole inner door skin covered with "Silent Coat 4mm Noise Isolator".
• Outer door skin - not really sure. Maybe pieces of 12mm noise isolator? Was thinking about Dynaxorb, but as I understood it does not do much in 3 way system (where door speakers mainly play low frequencies)
• Plastic door card - covered in 7mm sound absorber (Silent coat).

Any ideas? @TOOSTUBBORN2FAIL , your help would be greatly appreciated

[TOOSTUBBORN2FAIL]

Hey, I'm headed to be, if I don't get back to you tomorrow I will monday. Super hectic week coming up. Tomorrow alone I have to paint the kitchen, bathroom, and pour concrete lol. Looking forward to sleeping through all next weekend.

[P3tras]

OK, finally got the build started. I "HOPE" to finish within 2 weeks

Started yesterday. Teared all interior plastics (as much as I think will be needed) and removed stock speakers (also removed rear deck, which is not photographed).




Stock woofer versus focal one. Diameter is the same, although focal speaker is deeper and has a bigger magnet:




Mid is once again exact same outer diameter (speaker itself is bit smaller), but this one not as deep due to flat magnet.




Biggest differences are with tweeters. Focal ones are larger diameter and shallower (inverted dome really looks cool). However, it seems it won't be a big challenge to mount them into stock speaker location.







At first I wanted to mount main amplifier somewhere in front, so all speaker wires would be much shorter. But I was not able to find a suitable place, thus I will probably mount it in stock amplifier location:



Next issue are crossovers. They are quite bulky (3-way system), but I want to mount them somewhere in front so I wouldn't need to run 3 pairs of wires through whole car. It seems they would fit on rear deck, but that's too far back for my liking. Here are the best spots that I found, although not perfect.

Passenger side crossover. Just behind side of the dash.




Driver side is more complicated. I already have some extra electronics mounted here. But best that I could think of is mounting crossover like this (just on opposite side of the metal):


Today I will start installing sound deadening. In my arsenal I have:

• 12 sheets of SilentCoat 4mm sound deadener. Not yet sure where to install all of them. Thinking about one sheet on outer door panel (2X), 1-2 sheets on inner door panel (2X), one sheet on rear deck, one sheet near rear wheel arches (2X), one on the trunk behind the carpet and one on the roof. Is it worth to install one in spare tire well? Suggestions are welcome, only one request - it cannot be visible after installing all interior parts.

• Sheet of Silentcoat 35mm sound absorber. Plan to install it behind door speakers as deflector?

• 3 sheets of 15mm sound absorber. Planning to cover backside of interior plastics (door cards, transmission tunnel and back seats side panels)

• And lastly, 4 sheets of 6mm sound isolator. Planning to cover inner door panel and large cavity in the back (near wheel arches).

I also designed mounting adapters for woofers and mids. I hoped friend to 3D print them, but it seems it would take 14h just to print one woofer adapter. Probably will have to think of something else. But might print adapter for mids.




I also think about keeping stock rear speakers (or something better) running from head-unit to fill the rear (I also have passengers in the back sometimes). Deep inside I know it is a bad idea, please talk me out if it.

That's all for now. If I am doing anything "very" wrong, please correct me. It's my first proper audio build.

[TOOSTUBBORN2FAIL]

I'm actually in the process of testing sound absorbers behind speakers. So far it seems to be a tradeoff, at least in my particular test. I'll try to link it up later, but in short, it reduced ringing and second order distortion peaks in the response, but added a single and relatively larger 3rd order distortion peak.

[sly]

Check out the hole behind the rear speakers. You pick up a lot of road noise back there. If you look in the cavity where the rear speakers are mounted, notice down at the very bottom below the floor and back near the rear tire wheel well... The very bottom of this cavity has a hole that extends outside the car. You will probably notice dirt down there. This is road grime being thrown into your car from the tires. If you can seal off this hole you will eliminate a lot of direct road noise and keep your interior cleaner.


For me, the easiest way to make speaker mounting adapters was to simply buy a 2x6 plank of PVC board from Lowe's and cut them out with a jigsaw. I pressed the factory speakers face down onto the board and traced it with a sharpie to make a template. Then I cut this out with a jigsaw, making a proper speaker adapter. It's cheap and easy.


Use speaker baffles. They will waterproof your build and improve the sound. http://www.crutchfield.com/S-VRU4gTm...r-Baffles.html


These speakers are probably infinite baffle but you still need to seal them to the door to prevent wave cancellation from the back end of the speaker. I used the foam baffle to seal the back end of the PVC mounting adapter to the door and then used foam rings to seal the speaker to the front end of the PVC adapter. So the adapter is sandwiched in foam on the front and rear...


Then to make the speaker infinite baffle, I poked a small hole in the bottom of the baffle to let the speaker breath. Without poking the hole I ended up making a small enclosure out of the foam baffle and it raised the resonant frequency of the speaker. Poking the hole lowered it back down to where it should be. Just play around with it. Depending on the acoustics of the car and the speakers, you may or may not need to put a hole in the baffle. If you have low mid resonance modes, you might want to leave the baffle sealed to raise the frequency response of the drivers to avoid exciting these modes. Just be sure to poke the hole (if you need one) at the bottom of the baffle so that water doesn't get inside.


Look at upgrading the speaker wiring. In my WRX they used 24AWG wire which IMO is way too small for any decently powered system. I ran all new wires (14AWG) and left the factory wiring unused.


Running a high powered system you may pick up EMI and RF noise that the factory system didn't have. They make noise isolating power supplies to clean up the power: [ame="http://www.amazon.com/PAC-CSS12-Passive-Filter-Capacitor/dp/B000CEDZBA?ie=UTF8&psc=1&redirect=true&ref_=oh_aui _search_detailpage"]Amazon.com: PAC CSS12 Passive Noise Filter, 12 Amp, Choke And Capacitor Design: Car Electronics[/ame]


Don't use Y connectors for your RCA cables. They give an improper OHM load on your preamp. Build your own if you need to combine signals to a sub: http://www.rane.com/note109.html

[sly]

If you want to build your own fiberglass subwoofer box, here is the article I used:http://legacygt.com/forums/showthrea...ox+Walkthrough
Buy a chemical respirator if you want to do this. The fumes are strong as hell...

[P3tras]

Thanks for all the tips.

• I was planning to cover whole cavity near rear speakers, but I will look for that hole as well.
• Will check if baffles are available locally. I really doubt that sealed ones would work good, as speakers will play quite low frequencies. But as you said, large enough hole would do the trick. If you look carefully into my mounting adapter drawing, it has "roof" over the top of speaker to protect it.
• As you mentioned it, I won't use any of OEM wiring (except for REM cable). Bought quite high end "in-akustik" speaker cables (reference series) today. I will run quad-star cables from amplifier to crossovers to avoid any interference.
• My subwoofer amplifier has line in and line out. I was thinking about connecting its line-out to main amplifier. Thus head-unit > sub amplifier > main amplifier.
• Thanks for the box build guide. very useful! In fact I am planning to build ported subwoofer box, which I have never seen done on BRZ before. Sneak peak of it (alpha stage of design):

[TOOSTUBBORN2FAIL]

Originally Posted by TOOSTUBBORN2FAIL

Well, this was supposed to be a full write up, but 4 tests will have to suffice. Sorry Seafish, I'll have to redo the whole thing later. One of the hurricane nuts backed out, and I'm going to have to tear apart the box to get it out.


So these are measurements of a completely empty box, a box with natural sheep skin wool, one inch thick ocf, and two inch thick egg crate ocf. The test box is about 0.99 cubic feet before driver displacement. The driver is a HAT L6SE. Nominal output was 114db at 0.125 meters. Bandwidth of test is 31.5hz-5000hz. I chose this as its really already past where a 7" midbass/midrange should be used on both ends.

Frequency Response

I've included them all together as well as separate.


This is the empty box frequency response.

This is the sheepskin wool frequency response.

This is the 1 inch ocf frequency response.

This is the 2 inch egg crate frequency response.



Distortion plots are in the same order as above, I put them all together to make them easier to compare. Had testing gone smooth, I would have ended with a second empty box measurement just for consistency, but it didn't turn out. Notice the large uptick in 3rd order distortion around 188hz that almost hits 1% on each treated measurement. Also notice the reduction in distortion at 348hz and 700hz on each treated measurement. This corresponds with modes you'll notice in the waterfall plots.






Waterfall plots. Again, all together to make it easier to compare. Pay attention to 348hz and 700hz.

Here is the testing.

[P3tras]

Moving forward:

Installed vibro damping. It was not a challenge to find where to install 12 sheets.

• 2 sheets on inner door panel.

• 1 sheet on outer skin

• 1 sheet divided to 2 pieces (on rear panel and wheel arch)

• 2 sheets on roof.

• Little bit (half of sheet) on the trunk lid. It didn't seem too bad, but I want to avoid any rattles when subwoofer is installed. Also, for me it does seem that trunk closes quieter now (less resonance)

• Bit on side panels in the trunk and around future subwoofer mounting location.

• After all I added 35mm sound absorber behind the speakers (as I already had it purchased )

• Preliminary amplifier mounting with slightly modified stock amplifier bracket. Note power wire near it (16mm^2 wire was ran through the car)

• Also ran quad-star cables from amplifier to crossovers. As they are high end cables, they are neither flexible, nor small.

Until the next time

[P3tras]

Didn't do much yesterday, because it was raining almost whole day. But still have some updates.

Best thing, is that I found suitable speakers adapters for sale locally. As we know, electronics in this car are basically from Toyota, thus I suspected speakers are as well. Of course, no local shops have adapters for BRZ/FRS/GT-86, but I looked around catalogs and ones from Toyota Auris/Avensis/Corolla/RAV4 seemed very similar. Went to the shop and indeed, they are direct fit on the twins! It may help if you need ones for your twin as well, look for Toyota adapters locally. Here are compatible models on the listing:
• Toyota Auris (2007.03-2012)
• Toyota Avensis (2003.02-2009)
• Toyota Corolla (E12) (2002.01-2007.02)
• Toyota Corolla Verso (2001.11-2009.03)
• Toyota RAV4 (2000.08-2006.02)
• Daihatsu Materia (2004>)

If they had little roof to cover back of the speaker from water drops, then they would be perfect. But I am still very happy that I won't need to cut it myself.



My friend also printed adapters for mids:



I also routed speaker wires to driver's door. Not an easy job, but got it done. No photos this time. Hopefully, on Monday I will get 3D printed adapters for mids and I will be able to install all speakers.

I also decided to keep rear speakers, but not the stock crappy ones. Have several choices (all 3.5" coaxial speakers).

• Rockford P132
• Polk Audio DB351
• Hertz Dieci DCX 87

I am leaning towards Polk Audio ones, as it seems they have best tweeters (although they are most expensive). Cheapest ones are Hertz. Maybe someone has tested any one of these and can give suggestions?