Subwoofer option for mac equipped wagons

[jp928]

Well, this ageing set of ears begs to differ about the Mc std unit being better than average, at least in My 08gtb. Previous car was an 05 Outback, single CD HU, no Mp3. I replaced the facia with a JDM split one with a double din aperture, fitted a JVC DV6105 (dvd + Mp3 reader), got a huge improvement in fullness and richness of sound.
Traded in on the 08 with the Mc (but kept the JVC HU). Back to poor sound - pathetic equalizing capability - pretty much none at all - no Loudness, just some tone and balance adjustments, no body to the sound at all. Recently got the JDM facia for dual zone ac fitted, put the JVC in, and even with no amp at all, back to much better sound, with Loudness, several different std equalizer setting, plus a user tunable one, line in and out, sub woofer out, video out, front aux in jack etc.
jp 08 gtb 6mt wagon

[Gambit]

I am not a very discerning car audio person, to the average lay like me, it sounds pretty good, though i am sure if i jumped into something that was well setup. I'd be able to tell the difference.

Anyhow here is a photo i took of the sub, i am yet to anchor it down.

[05gtwagonman]

JP- not knowing your background and not hearing your system specifically- I guess I don't know the whole story. But this post is all about fixing the sonic shortcomings of the mac. The mids and highs are really well balanced, and they are remarkably smooth. This is the hallmark of sound quality. What we are all acknowledging here is that it lack fullness bottom end or bass. This mod fixes this. The thing that blew me away and the reason for posting this in the first place is this is a rare system as the amp will push an efficient sub in a large enclosure. Put a high power sub or one in a smaller or closed box- and the power is no longer sufficient. then it becomes a matter of going to much longer lengths to sort out a completely new system. This will yield a better result, but this mod is for those that can't or won't go to that trouble. Further more- even with access to impossibly expensive home audio via my work- I was so impressed with the mac after this mod- I didn't go any further with audio in the lib that this...
Gambit has the right idea- looks good mate.
A cheap and non invasive solution to fixing the sub is to run a tie down strap in a loop from the steel retaining loops at the back of the seat on each side. Im not explaining this really well- am I ?

[Boxer]

My educated guess is that a lot of car subs in smallish boxes would come back in the low 70's or high 60's. Remember every 3 db difference sounds half as loud or twice as loud

Adding sound deadener will not increase the volume, it will take out unwanted resonances or distortion.


I have a background in Audio engineering- .

hmmm the first two paragraphs contradict the third

Sorry to come in late - just took a peek as I did the same quite some time ago (should be a thread if you search back into 2007 somewhere), but used a sealed box as I dont like ports

[05gtwagonman]

Not like you boxer- to come in and snipe late in the piece...
What's so out of place to make you infer that I don't have experience in Audio?
I'd be happy to be educated by someone who knows more if this is the case...

[Boxer]

Sorry, yes it was bitchy wasn't it I shoulda used emoticons :p- Similarly I'm happy to be educated where its been a pattern though. Although I'd confess I have posted some frustration and lack tolerance in the past for bs & un substantiated comment. (dont get me started again on the ticking noise a contracting exhaust pipe makes:D)

My points being -

+/-3dB is either double or half the power - this does not make it twice as loud or half as loud. To acheive a perceived double in volume you require 10dB. Hence a 20w amp will not be twice as loud as a 10w amp, but it is a 3dB gain in power. To acheive double volume you would need a 100w amp (or 10dB gain).
additionally a high 60's early 70's dB efficeincy speaker would be attrociously poor in response

Adding sound deadener - you are right won't neccessarily INCREASE volume but it will help in reducing standing waves in the box/enclosure/door space. In turn less standing waves will reduce phase and signal cancellation and therefore limit any reduction in output from this phenomena. Also Sound deadener will do nothing to reduce distortion. Distortion comes from poorly designed/cheaply constructed drivers allowing harmonics and square waves to be produced or amps running into clipping. Sound deadening will help a speaker sound better and tighter, but its due to the absorbtion of the aforementioned standing waves

[Sentinel]

I am not a very discerning car audio person, to the average lay like me, it sounds pretty good, though i am sure if i jumped into something that was well setup. I'd be able to tell the difference.

Anyhow here is a photo i took of the sub, i am yet to anchor it down.

Mine looks very similar to this, but a much bigger box. I'm running a Kicker 12", ported. The sub is a very low impedance items seems to be well suited. (I'm not a true audiophile, but I know what I like and this set up ticks that box - that's what is important to me. ) Anyone who went on the last Vic cruise could attest to it's performance off the std amp.

As others have said above, it doesn't fix the Mac problems, but it does create some "volume" in the bass department.

Boxer - nice write up mate. I understood your explanation clearly.

[05gtwagonman]

Boxer- you have put it better than me no doubt. Looking back over my posts, I have not been as clear as I would have liked at times- there is a good chance some of those posts included red wine to help the lack of clarity...
I have been trying to say most of what you just said.
My point about the (say) 69-72db subs might have been a slight exaggeration, but I stand by the comment as although I have not measured some of the worst I have heard, I guarantee having seen and heard little sealed box / sub combo's that flat refuse to get up at all until they have several hundred watts up their asses.

AT any rate, I am an enthusiast in car Audio, this isn't core to my job, nor has it been. I still stand by the core of the advice in this thread, there are now several people who have the gist of things, and it works well for those that are looking for a solution like this. If the bass performance is not sufficient- then take another look at the box / driver combo and get one that performs well with little wattage. You can get combos that do this well.

I also stand by the thought that your predilection for sealed enclosure response will not suit this application, as it won't utilize the energy off the back of the driver. Port to a suitable frequency and use the energy off the rear. Somewhere near 60hz will get the perception of loud and fairly deep pretty easily, tune to taste though...

To allude to any increase in volume out of sound deadening is absolute rubbish. Beneficial- absolutely. the only phenomenon that could lead anyone to state an increase would be a reduction in sound floor at road speed increasing the volume in relation to... Boxer is right onto the money as to some of the most common benefits otherwise...
/rant.

[RAN94A]

Hey guys,

As this has just recently been renewed it has caught my eye and is particularly interesting because in my previous car i used to have a stereo system with some serious "doof" lol. which i sorely missed once i got into the lib but decided not to go down the route of replacing any audio due to having to replace the H/U, Amp and speakers to really get a major difference.

I did however always wonder if you couldnt just hook up a sub to the stock amp and have an improvement over the subie's stock "sub".

(ps the whole thread has seemed pretty easy for me to understand. Mediocre amp + desire for bigger bass = requirement for power efficient sub.) Hasnt seemed that hard to grasp lol.

Anyway my questions are:

has anyone with a sedan tried this and is the upgrade noticeable enough to get the bass through from the boot (not so much a problem for you damn wagon guys with your open air boot )
What sort of sub options do you have to purchase (i dont want anything top of the range because im not that much of an audio expert with finely tuned ears, but i understand that a decent sub is also required for the efficiency.) so whats the bottom end of these efficient subs i could look at?

[05gtwagonman]

Glad to hear it was easy to understand...
Hope to not upset anyone with smilies and estimates but he goes...

Just tried an older coustic amp and 12 sony sub in a sealed box high level out off the standard audio in the xr6turbo i just sold. Rattled the shit out of the boot and did nothing in the cabin.
My thinking for you at this stage would be to try something with regard to using the area the sub takes up in the parcel shelf to access greater air movement in the boot. what do you think about these two ideas:
1. If memory serves- the link between the head unit and the amp (under the passenger seat)is still speaker wire rather than shielded or coax style pre cabling. So it is just as viable to take a high level out down the back at the sub, send power down, and earth- thus you can then utilize an amp with a high level in, screwed under the shelf, thus to power a less efficient but more powerful driver in the same place. I would say you would hear the difference, but the result would be less than I have experienced in this thread in the wagons, as an 8" really doesn't move much air. Jaycar has a driver that might suit for this.

2. still keeping the high level in amp idea may still be good for this too.

But - big box, efficient driver, but look to either keep the 8" hole open and maybe even look to pipe the port or the driver face to the hole in the shelf to get as much air movement into the cabin as possible from the same type of solution as described previous in this thread. Dropping one side of the rear seat would sort this air movement out too, but I would not want this as a rather permanent solution, so I assume you would not either...
There's no doubt that you will have a little more trouble than the wagon boys.
It is all about moving air- and it is restricted significantly by the design of the sedan.

Let me know your thoughts. Happy to trouble shoot some more.
Can't remember exactly which guys it was- but at least two of the other sedan guys have gone the whole hog system exchange to solve the problem. I understand trying to avoid this, but it obviously proved to them to make sense when they looked at it. I would follow trying theses ides first though...
All the best.