audio set-up for beginners [continued]

[jhnkvn]

For the past several weeks, I had also been looking at full range class-D amplifiers but as you've said, they're expensive. Settled for class AB one (Kenwood KAC-8406) plus a mixed class AB/class D (Kenwood X700-5).



Same dillema as you with regard to space being occupied by the sub and more importantly the size of the enclosure (esp. depth) I can possibly make for the area in my vehicle where I could put the sub enclosure.

Really wanted those Pioneer shallow mount subs (online purchase) but ended with the relatively shallow Polk MM1040 (local purchase).

Good purchase. Kenwood is not distributed locally but it's highly distributed in the US. They have a solid reputation naman to back them up as they're like Alpine's little brother (Pioneer and Alpine are behemoths kasi in their industry).

All driver performance is dictated by an iron law called Hoffman's Iron Law. It's called an iron law is because nobody has ever managed to get all three criterias. As with engineering, there's always compromise in speaker design. This is highly relevant in subwoofers is because you can only get 2 of the 3 criterion.

Truthfully, people overestimate the amount of bass they need. In a car, an 8" subwoofer in a 1cu.ft sealed box is enough. Still, a 10" will be better.

My stance on slim subwoofers is I try to avoid them unless space is a premium. By making a subwoofer driver "slim", you sacrifice quite a lot on the guts of the subwoofer - voice coils, magnet structure, and even the basket. These attributes isn't bad if you need the space truthfully. It's not like your pumping 120dB out of it when your everyday person just needs some bass reinforcement. What I dislike is the price premium that goes with it.

[jobo_ph]

2. Is there a way to connect the processor without splicing/cutting the wiring harness of the car. Specifically, my factory speakers connect to the wiring harness of the car via plugs. Would it be possible to use the plugs of the stock speaker and extend the wiring all the way to where the processor will be placed (under the seat or the trunk)?

In my opinion, it will be TOO much work routing several wires from each speaker location going to the processor and you'd be having too long a wire which could possibly degrade signal quality (longer wires have higher resistance).

What I did:

- Cut off the Nissan OEM head unit connector and put connectors on the factory wiring ends. I also separated front and rear speaker connections from power, ground, power signal (acc on), etc.

Used these for speaker connections


Used these for power, ground, etc.


I also didn't want to cut off the connectors to the OEM speakers and I used these to tap into the wire



Bottom line, I can reinstall OEM head unit and speakers, if needed.

I also solder the wire to connectors (instead of just crimping) and use heatshrink tubing whenever possible

I dislike cutting into wire insulation to tap and prefer proper/neat wirings and terminations.

Anyway, this is from a perspective of a DIYer. I'm located in Los Banos, Laguna and don't know of nearby "reputable" car audio shops to run to.

[pbi76]

Thanks, jobo_ph. I figured that the wiring scheme I had in mind is not the most efficient way to go about things.

It turns out that my head unit has different equalisation settings depending on the volume which is for protecting the stock speakers. It also does not have a digital out. This really complicates things as it sort of becomes necessary to use an external volume control to avoid changes in equalisation. So now it seems that I should really consider an aftermarket head unit which significantly changes everything including what I'll end up spending.

[markygy]

Thanks, jobo_ph. I figured that the wiring scheme I had in mind is not the most efficient way to go about things.

It turns out that my head unit has different equalisation settings depending on the volume which is for protecting the stock speakers. It also does not have a digital out. This really complicates things as it sort of becomes necessary to use an external volume control to avoid changes in equalisation. So now it seems that I should really consider an aftermarket head unit which significantly changes everything including what I'll end up spending.

Out of curiosity, what's your car sir or what's your current head unit?

[pbi76]

As an update, I went to Mickey's and several things came up.

I initially wanted to put the amp/s under the front seats but it turns out that my car has vents underneath the seats so there isn't much space. The shop recommended amps from the Punch PBR series. If I were to get "regular-sized", amps, I would have to do quite a bit of trunk work which I really want to avoid.

Based on my music preference (rock), the shop recommended Focal's Expert series (either Flax or Polyglass if I remember correctly). Cheaper options would be JL's C2 series. Equivalent DLS speakers are okay too but I was informed that the sound signature is quite laid back. I was told that an outboard processor (Bit Ten) is optional but based on what I have read on my head unit and the benefits of an outboard processor, it seems to be something that I should go for already so at the very least, I square away the source signal section of the setup. We also confirmed that my rear doors have separates and while I don't necessarily have to change the speakers, the guy I spoke to recommended it so that my front and rear are matched in terms of sound signature (or just turn of the rears and avoid the expense altogether). Regarding the subwoofer, he suggested an under-seat system from Focal prior to seeing the car but with the vents underneath, that's a no-go so I'll have to go with the conventional sub box in the trunk route (or forego the sub altogether).

I did some quick math and it looks like the entire system will reach P100k so I'm going to have to think long and hard about this.

[jhnkvn]

When it comes to head unit problems, madami yan. Volume attenuation, filters, etc.

Would an external volume control solve your problems?
That will depend on how the signal is runs through your chain. The only way you can bypass it is via digital. Because a digital out will automatically make your head unit just "decode" the musical binary data of 1s and 0s (ex. if you feed it a CD) but it then send the signal data to your processor for processing and in doing so it bypasses the filters (which is usually at the amplifier-section of your head unit). Since your processor does your decoding, the master volume control is at your processor.

If you're running through it via analog. The signal is first processed in the head unit but is then compensated by the processor. However, because it is "compensation", you're already sacrificing something and this is usually in the form of dynamic headroom (because most processors use digital gain or attenuation as compensation). You usually feel this when you ramp up the volume and distortion happens. For the volume, you can both control the volume of the processor and the head unit. The best route here is to find which volume the head unit starts going whacky and use the volume just below it while you control your "master volume" via your processor. Then again, if you want to use the head unit's volume, feel free to do so naman since the performance degradation isn't as grave as it sounds.

What do you suggest I do?
Okay, Mickey's Autosound is one of the biggest car audio installers in the country. In fact, they're usually #1 when it comes to the sheer volume of car audio stuff they sell. Truthfully, I'm a bit curious on which car we're talking about - since your have rear door tweeters, a highly integrated head unit system, and vents under your seats (all which are uncommon in 90% of the typical cars you see in the Philippines)

Your BitTen is going to cost Php16,000. Mickey's going to source that from Musico Mobile Audio who's the distributor of Audison stuff in the country. The Focal Flax is probably the 165FX which is at Php22,000. When it comes to the subwoofer and box, this will depend on your subwoofer driver. Most dislike paying "affordable" so they usually go for more popular models like the Polk MM1040 (around Php9,000) and a sealed box of their choice (which is usually mga 3,000php+ sa mga big name shops). For the amplifier, a 5-channel amplifier will go Php20,000 upwards. To sum it up, equipment cost mo palang nasa 70,000php without wires. This will then jump with the inclusion of labor and wires.

Truthfully, I am tempted to suggest the Focal RT500 which is kinda a DSP-subwoofer-amp rolled into one. Problem is, you lack the necessary channels as you'll be needing a 5-channel amplifier minimum (4 for your speakers and one for your subwoofer). Doing anything less is doing a disservice to your DSP which you won't be able to harness properly which throws this option out.

If it were me, I'll do it this way.

Stage 1
BitTen - 16,000php
JBL GTO5355 - 13,000php
Focal Access AS165 - 10,000php

Stage 2
A small subwoofer of your choice in a small sealed box. I would recommend an 8" Infinity 860W (<3,000php) and a small sealed box with an internal volume of around 0.5 cu.ft (trust me, maliit yan.. it will fit in the bottom of a Honda City's rear seats with plenty of space to spare)

For your amplifier, just put it at the rear alongside your processor. You do not need trunkwork. Just get a plank of wood -> mount your amplifier, processor, and wirings (like fuse holders) there -> and just securely fasten it to your rear so it won't move around.

(?) An idea I'm toying around is attaching it (amplifier and processor) to your front passenger foot well by raising the floor a couple of inches using an open (for ventilation) false wood flooring. This way, you can reduce your wiring costs a LOT because you're wiring just a couple of meters. Not 5 meters-worth of wirings per connection.

(!) I do not recommend mounting your amplifier and processor on your subwoofer box.

For the wires, keep it budgeted. Truth be told, I'm not a believer of expensive wires. I'm on that camp. Since car audio is typically limited to the likes of Tsunami, Firland, Stinger, and for the more.. "rich" ones, TchernovAudio wires, you might want to take a look at home audio wires in Shangri-La Plaza or Makati Cinema Square where your selections would be more hence you have more leverage on the pricing. Good brands to look for are QED, Audioquest, and Chord. Don't think you can't mix them up. In fact, Tchernov is a home audio speaker brand. For the speaker-wires, buy them un-terminated.

[pbi76]

Hi jhnkvn,

Thanks again for all the inputs. My car is a Jetta and the head unit is a VW RCD310. Because the car is uncommon, even a place like Mickey's hasn't done an installation on a car like mine.

[ketzch11]

Sir, i saw this post in another topic,

"Front: Separates (Channels 1&2 JBL GT5-A604)
Rear: Coaxial (Head unit)
Sub: Sub (Bridged channels 3&4 JBL GT5-A604)
JBL GT5-12 with 1 cu.ft. "

Will it be better than my original plan with the following set up, all pioneer

separates front Ts-a1605c
Rear stock
4 channel amp gm-a6604 (1&2 seps/3&4 subs)
Subs ts-wx305b (set)

Hu is stock JVC KB-BT22 22rms on an SUV/ but planning to swap with pioneer deh-x4650bt 14rms

at kaya ba nung 3&4 bridged pioneer ampli yung pioneer prefab sub?

Ano po assesment nyo? Thanks

[jhnkvn]

Sir, i saw this post in another topic,

"Front: Separates (Channels 1&2 JBL GT5-A604)
Rear: Coaxial (Head unit)
Sub: Sub (Bridged channels 3&4 JBL GT5-A604)
JBL GT5-12 with 1 cu.ft. "

Will it be better than my original plan with the following set up, all pioneer

separates front Ts-a1605c
Rear stock
4 channel amp gm-a6604 (1&2 seps/3&4 subs)
Subs ts-wx305b (set)

Hu is stock JVC KB-BT22 22rms on an SUV/ but planning to swap with pioneer deh-x4650bt 14rms

at kaya ba nung 3&4 bridged pioneer ampli yung pioneer prefab sub?

Ano po assesment nyo? Thanks

Will it be better? Won't really matter. Both are great reputed brands.

Kaya ba ng 3&4 bridged ampli? Yes.

I will advice that you get a subwoofer driver and have your installer fabricate the box instead. It's more light on the wallet that way.

[ketzch11]

Sir, thanks a lot!