Newbie wants to learn the best 'Original' aftermarket audio system for BRZ

[indio22]

Originally Posted by FR-S2GT86

Can you explain to us what kind of audio signals you have coming into the amplifier? And can you show us a picture of your amplifier, specifically a picture of the crossover/filter set switches or dials? (or list the brand and model of it so that we can try and figure out the best set up for you in your case). You may be able to work something out if you can make some pre-amp crossover adjustments and if your head unit has the correct type of filtering.

Right now, I see only problems arising without the use of some sort of band-pass set up on your door speakers, which CAN be done IF planned out and set up properly. It took me quite a while to weigh the pros and cons of my set up and even longer to actually find the right equipment to make it work, but I did finally make it work (technically, I am STILL making it work as my project is on hold for the moment). See some of my posts about it from last year.

Yes I was thinking of doing a small write-up with some photos of what I did. I'll link to it here. Basically I used the advice from this forum, including the coupler which allowed not having to cut any stock wires when swapping to the new amp. One thing I did different though was use a jumper cable for my battery-to-amp power cable, lol.

[FR-S2GT86]

Originally Posted by indio22

Yes I was thinking of doing a small write-up with some photos of what I did. I'll link to it here. Basically I used the advice from this forum, including the coupler which allowed not having to cut any stock wires when swapping to the new amp. One thing I did different though was use a jumper cable for my battery-to-amp power cable, lol.

Nothing wrong with a temporary set-up using jumper cables to test things out.

Are you using the OEM radio or have you gone aftermarket?

[indio22]

Originally Posted by FR-S2GT86

Nothing wrong with a temporary set-up using jumper cables to test things out.

Are you using the OEM radio or have you gone aftermarket?

Using OEM radio and speakers. Only the sub was added along with upgrade of the rear amp. Here is a link to a write-up with some details:

https://www.ft86club.com/forums/show...98&postcount=5

[Daily86]

Have you tried switching the amp section for the door speakers to LPF to see what that would sound like? Also, how have you secured the sub box?

Sent from my SM-G930V using Tapatalk

[Daily86]

So, do the front mid range speakers get a full range signal (that also goes to the amp for the door speakers) with a crossover that sends the highs to the tweeters? Or does the front signal go to a crossover which sends lows to the amp for the doors, mids to the dash mid range speakers, and highs to the tweeters? Or something else. Thanks.

Sent from my SM-G930V using Tapatalk

[soundman98]

Originally Posted by Daily86

So, do the front mid range speakers get a full range signal (that also goes to the amp for the door speakers) with a crossover that sends the highs to the tweeters? Or does the front signal go to a crossover which sends lows to the amp for the doors, mids to the dash mid range speakers, and highs to the tweeters? Or something else. Thanks.

Sent from my SM-G930V using Tapatalk

the full range signal is split. one part goes to the tweeter, which has it's own built-in crossover, as well as a jumper wires off the tweeter(it's got a 4pin connector) that goes to the midrange, with it's own crossover. both of the midrange and tweeter crossovers are simple 6db/oct type.

the other part of the full range signal goes to the door speaker amp, which has it's own filtering as part of the amplifier circuitry.

[FR-S2GT86]

Originally Posted by soundman98

the full range signal is split. one part goes to the tweeter, which has it's own built-in crossover, as well as a jumper wires off the tweeter(it's got a 4pin connector) that goes to the midrange, with it's own crossover. both of the midrange and tweeter crossovers are simple 6db/oct type.

the other part of the full range signal goes to the door speaker amp, which has it's own filtering as part of the amplifier circuitry.

And the rear output of the head unit powers the two rear speakers which also have their own 6b/octave high pass filters. I assume the head unit rear output is a full range signal as well.

I also haven't heard of anybody doing any testing to see exactly what crossover frequency and slope values are built into the factory door speaker amplifier.

[soundman98]

I just rechecked my old '14 rear speakers, and there aren't any visible components on the rear speakers to indicate they get anything other than a full range signal. I believe the professional term is 'acoustic crossover.'

No one's really put effort into understanding the factory amp because it largely doesn't matter. There's no adjustment in the factory equipment, so there's no need to dig into how it does what it does so poorly.

[FR-S2GT86]

Originally Posted by soundman98

I just rechecked my old '14 rear speakers, and there aren't any visible components on the rear speakers to indicate they get anything other than a full range signal. I believe the professional term is 'acoustic crossover.'

No one's really put effort into understanding the factory amp because it largely doesn't matter. There's no adjustment in the factory equipment, so there's no need to dig into how it does what it does so poorly.

Really, no capacitors at all on the rear speakers? There must be some sort of high pass filtering built into the deck for the rear channels then or else you would get too much low end distortion on them when playing heavy bass-laden music, and people would be complaining about them. The major complaint I had was the door speakers causing too much vibration inside the doors. The rear speakers sounded fine to me, for the time that that were in use in my car.

[soundman98]

Take note of the environment. There's no enclosure, just a big hole they install over the top of, and their suspension is relatively stiff.


With the low end being amplified by the door drivers, I doubt they get loud enough to distort. I know for a fact my aiwa stereo uses a similar trick:

I've taken up collecting those speakers after taking apart the original set in a fit of curiosity. There is a subwoofer with its own enclosure and also a high frequency driver in a separate enclosure, with extremely stiff suspension--the crossovers were designed into the main amplifier stages, so the speakers themselves don't have any extra components, but the suspension and independent enclosures lend themselves perfectly to acoustic filtering.

By wiring the speakers in series, they work with any stereo, and sound quite good without any audible distortion well into the "neighbors asking to turn it down" range.

[FR-S2GT86]

One of these days out of curiosity, I'm gonna bench test the factory head unit and amplifier combo just to satisfy my own curiosity. This would be a good test for that Audio Control DM-RTA that's available.

[soundman98]

a dayton omnimic would likely be a better/cheaper tool for the job, just A/B a set of speakers with a different known-clean amplifier for a control.

alternatively, an oscilloscope would also be a great tool for the job. a DSO nano is only $100

[FR-S2GT86]

Originally Posted by Darryl_Jackson

Any instructional videos or short books on this subject? Please share, they will help me a lot.

You can find many topics related to what you are asking at this blog site:

https://www.audiofrog.com/audiofrog-tech-blog/