Wozza's Honda Accord ICE Thread

[djwozza]

For anyone interested, Sunday 16/8 I'm at Japfest 2 @ Rockingham. I'm going on the Honda Karma/H-Tune stand for this event, I've been getting huge pressure to attend on the forum due to interest in my ICE build, so I caved in today. I'm also attending a Honda meet that evening from 6pm at the Ace Cafe. Sleep? Who needs sleep?

 

If you are coming to either, pls say hi & grab a demo if you haven't already.

[djwozza]

Updated system diagram as it will be once the custom front door cards are constructed

[NickT]

Oh wow. ... I'm impressed, and I rarely say that. .

[djwozza]

Thanks Nick, it's had great feedback so far, but this will take it to the next level. It's gonna take time tho.....

[Tony]

Gulp.......

[djwozza]

So the door cards have arrived, the speaker cable arrived from the USA this morning too, IU just need my pal that has an enormous amount of Fibreglass & Door Card fabrication to find time to give me an hours time. He is very busy completing another car install & his own big build in a VW Sharan with 12 Subwoofers etc, plus he gets married in a few weeks along with working his full time job. 

 

We need an hour or so to take the door cards off, take a look underneath & with the speakers on hand make some detailed measurements, then things will become clear as the plan going forward. I know what I want the finished custom builds to look like, but whether  !). the speakers are mounted to the door directly, then the door car is used purely as a semi discrete cover, or 2). whether we reinforce the door cards and fit the speakers directly to it, and then add additional secure mountings for the door card to the door itself. At first glance I am thinking option 2 at this stage, as the metalwork behind where the speakers will be, houses part of the window mechanism. Nothing is ever easy with this ICE build, but it has been worth it so far with all the trails & tribulations, so when this is completed I think I will be happy with the results. 

 

If not, I won't stop until the door cards are completed to my total aural & also visual satisfaction.

 

[Tony]

ICE, patience and perseverance seem to fit the topic...... But do you know what? Some of the most beautiful babies come from a difficult birth. 

[djwozza]

That would be me lol

[Tony]

[djwozza]

OK I officially have an ICE addiction problem. I'm buying another Subwoofer to mount in the front passenger footwell firing straight at the front seat. As bass is mono & not really directional it will integrate fine. It's cheap as chips on eBay plus I just sold my old 32gb iPhone 5 so it's already paid for.

 

Everyone needs more bass right? Oh come on its only a small one but will kick hard where my large 12W7 Subwoofer starts to roll off at 80-120Hz. It does mean that my 3 driver door builds will now drop to 2 as I have no more room so cannot fit any more amplifiers, but as most people think 1x set of C3's in the front doors is enough already, it should still be sufficient upgrading to running 2x sets in the front doors & this additional 250w RMS Subwoofer

 

http://www.jlaudio.co.uk/8w3v3-4-car-audio-w3v3-subwoofer-drivers-92148

 

It will require a custom box similar in construction to this so as not to take up too much footwell space.

 

Once I have installed these planned speaker/amplifier upgrades, please refer me to medical staff if I EVER mention "upgrading my system" at ANY point in the future....

[Tony]

Oh my word more bass .......

 

 

Ok pump up the volume then.....

 

[parthiban]

Wow - I think you may have a problem! 

 

Seriously though interested to hear how this sounds - can't say I felt there was any bass lacking in the demo so this should make it kick even harder! 

[djwozza]

It's not going to really pump like the rear Subwoofer does, it's just going to fill a small gap when the tuning of the Subwoofer box response starts to roll off (around 80/90Hz) and where the front speakers pick the lower frequencies up again frequencies up again (100/120hz), the sort of frequency of some larger drums.

 

The 6.5" front door speakers can hit those frequencies, but not when you play them as loud as I do, so you set a high pass filter on the amplifier to allow all frequencies from that point upwards to flow freely, where the bass frequencies are set to tail off to stop too much bass coming through & causing distortion.

 

The way to get around this is to drive the speakers less hard, but to double them up or triple/quadruple them. As they are individually being pushed less hard, you get zero distortion at the lower frequencied, but then can introduce imaging problems due to the sound coming from different places. The more drivers, the more likely the problems.

 

Another solution is to run a 10" or 8" Subwoofer to take the mid bass strain off of the door speakers, but where would I put another 10" Subwoofer? Tbh I'm already out of room. An 8" in the footwell might just work tho.

 

This relatively small 8" won't be pushed anywhere near its limits though, it will only be used to fill the gap or handover point from the 12W7 in to boot to the front doors. It's an 8W3v3-4.

 

To break that down is like tyre markings. The 8 means it's an 8" driver, W3 is the position in the JL Audio range, v3 means it's a mark 3, the -4 means it's 4 ohms voice coil.

 

The JL subwoofer range topper is the costly W7 (available in 13.5" 12" 10" 8") then W6, then W3, then W1/W0 and others etc getting cheaper all the time. The starter Subwoofer 10W0 is only around £60, whereas this little 8" the 8W3 retails at £170 and obviously the build quality of the Subwoofer is vastly improved along with the rated output which in this case is 250w RMS. JL Audio are well known for a lack of exaggeration in their power rating figures.

 

This Subwoofers rated power is overkill for what it will be used for, but for the secondhand price of £50 it just means it will not be working very hard & last forever pretty much. The 12W7 in the boot I have owned now for some 8 years, and from the W3 range upwards you really do get top quality R&D with terrific engineering.

 

So to recap it's not to hit hard, just to fill in a small gap where the 6.5" door speakers struggle to accurately reproduce at very high volumes.

[parthiban]

Ahh ok that makes sense, do you feel there is something missing then between the mid and ultra low frequencies?

[djwozza]

Yes but it's only a small gap. The Subwoofer box is tuned to go very low (less than 32 Hz) which in turn rolls of the response at the higher end of the subs output. It's barely noticeable but I'm such a picky so & so & my ears are very very hard to please. I'm pretty close to audio nirvana & should nail it once my upgrades are done & everything is dialed in.

 

Also I have seen this morning a car with the same 8W3v3-4 Subwoofer mounted in the passenger footwell in a custom fibreglass enclosure.

 

 

Looks pretty awesome huh?

[parthiban]

That is actually a lot more discreet than I thought, it's barely taking up space. Plus that's a Porsche 911, I imagine your car has more space in the footwell. Should be pretty cool if it'll make a noticeable difference

[NickT]

Most people with ocd go to the n'th degree.

 

I'm afraid Mr Wozza goes to the (n×1000)'th degree.

 

You must have some good hearing to analyse the sound. I'd love to see/ hear the end result Mr Twin

[Tony]

I like....I like a lot.... I  do admire quality workmanship

[djwozza]

It's hard to illustrate & explain my reasons for this additional upgrade being needed but I will try without getting too technical. It's all really a compromise.

 

In bassic terms (see what I did there?) you can't get a quart in a pint pot. Taking brand & cost factors out of the equation here, Subwoofers of different sizes (10" 12" 15" or 18") put out different bass frequencies more efficiently than others. The all create bass & make sound, but the cone surface are dictates whether very low bass you feel in your guts is produced, or the higher kick you feel like a fast slap in the back.  In the same way a 1.0L 2.0L 3.0L or 4.0L cars put out different bhp/torque they all make a car move, but how they go about it is entirely different.

 

The larger the Subwoofer cone area the more movement is generated in the air, to generate the very lowest lows takes a larger speaker, the fast bass of a tight kick drum needs a smaller faster reacting driver to reproduce the sound accurately. An 18" driver isn't suited for that and will provide huge lows, but will sound almost flabby when the faster higher bass notes are needed & it won't sound right. Also a 10" subwoofer needs a smaller enclosure to operate efficiently, say 2/3rds of a 12", 1/3rd of a 15" or around a 1/4" of an 18" Subwoofer. 

 

When you build a Subwoofer box you can use porting to provide a bit of help in tuning the Subwoofer to put out extra bass at certain frequencies. A bass-reflex or ported enclosure makes use of a tuned port which projects some of the sound energy from the back of the loudspeaker to come out of the port at exactly the same time to reinforce the bass output from the front of the box, energy which is otherwise lost in a sealed enclosure. If you get the timing wrong, the port can actually cancel out some of the bass & cause terrible stress on the speaker cone. If you imagine someone helping you exhale in time with your breaths by squeezing/hugging you very tightly around the chest. Wow a big breathe out boost. Then imagine trying to then breathe back in again and the person squeezes you again very hard at the same point. Potentially fatal consquences!! Not distrous at lower volumes but as you crank the power up the effect becomes much more marked, & you can litterally tear the speaker cone apart at higher volumes.

 

So with a correctly tunes port this has the effect of projecting bass frequencies from the port in phase with the sound from the front of the cone & reinforcing the output. The overall effect is the increasing of bass efficiency and the extension of the bass response to lower frequencies. So if you tune the port length & size correctly in an enclosure of the correct volume, you not only make the bass louder by being more efficient, but also you can change where that bass frequency is in relation to the output, so where this extra bass is produced, you can move the actual gain slightly higher or slightly lower. 

 

In the example of a 12" Subwoofer, you can tune the port so it almost pumps lower bass like a larger 15" subwoofer would produce & give you the really low lows you want, without having to house an enormous 15" sub in the boot which takes up a much bigger space as it requires a much much bigger box. However, in the same way a putting a small or a large turbo on a N/A car there is a trade off. A ported enclosure tails off at the upper end of it's frequencies much earlier than a sealed box otherwise would. Also the lower you tune the bass gain, the quicker the upper frequencies roll off too so you look a bit of the upper bass "kick". A bit like a smaller turbo on an engine, lots of grunt low down, but at the top end runs out of puff much earlier. 

 

So in my cars case, I have a 12" Subwoofer that is in a ported box I built with the port "tuned" to proved deeper bass than a 12" would normally provide. Significantly so in fact. The trade off is at higher bass frequncies of 80Hz upwards the bass acts like someone turned the volume down, and in fact the higher you go the steeper the gradient that the bass is cut off until it becomes so steep a line to become vertical. In such an occurance you are then looking at the other speakers to come & pick up the frequencies and take over as you move up the frequnecy spectrum, a bit like a relay runner transferring a baton. 

 

To illustrate, the two vertical arrows show where frequencies tail off at the crossover point between a subwoofer & mid range (the tweeter crossover point is illustrated to but there is no relevance as that is handled by the dedicated crossovers you have already seen in the thread). The -6dB shows the volume drop off at those points, & bear in mine a 3dB drop is equivalent to half the volume.

 

Ideally the gap between the arrows should be a tiny as possible, but in my case the gap is more pronounced due to the Subwoofer box port tuning. To get around this (as stated on the previous page) where the tuning of the Subwoofer box response starts to roll off (around 80/90Hz) and where the front speakers pick the lower frequencies up again frequencies up again (100/120hz), you then have to rely on your front door speakers. The 6.5" front door speakers can hit those frequencies, but not when you play them as loud as I do, so you set a high pass filter on the amplifier to allow all frequencies from that point upwards to flow freely, where the bass frequencies are set to tail off to stop too much bass coming through & causing distortion. The solution is drive the speakers less hard, but to double them up or triple/quadruple them. As they are individually being pushed less hard, you get zero distortion at the lower frequencies.

 

My solution is going to be  run this 8" Subwoofer in the front footwell to handle the gap between the upper roll off of my 12" Subwoofer & take the mid bass strain off of the door speakers. It will take a fair bit of effort to integrate the gains correctly between all the speakers, but with a fair bit of tweaking it should fill the gap between the arrows. A gap no one else has seemed so far to hear lol, except for my damed fussy lug holes. I might buy an external RCA controller to help be adjust how hard the 8" Subwoofer kicks and mount it in my dash driver side cubbyhole. Much easier to adjust from there than a trip to the boot & fiddling with a screwdriver.

 

It's gonna be a few months off ATM, I need to construct custom fibreglass door builds, then also make a fibreglass Subwoofer box for the front passenger footwell. Add to that the other jobs I already have to finish, but at least I have a working work in progress that I can use as a daily & enjoy the sounds until the final stage work is all ready to be installed.  The guy who will helping to guide me is still away on honeymoon plus it's JAE in a couple of weeks too. 

[djwozza]

Most people with ocd go to the n'th degree.

 

I'm afraid Mr Wozza goes to the (n×1000)'th degree.

 

You must have some good hearing to analyse the sound. I'd love to see/ hear the end result Mr Twin

Any timwe you are down London way shout me beforehand and I will endeavour to give you a demo. Alternatively I will be at JAE on Sat 13th Sun 14th September & that is much closer to you......

[Tony]

It's going to take me a while to absorb that. Don't forget i did my apprenticeship with a Binatone five star which sounded like an elephant walking on bubble wrap

[djwozza]

It's easier to explain in person, I did try to keep it simple lol

[NickT]

Thanks Mr Wozza,I'll let you know the next time I come down south

[djwozza]

My pal with the huge amount of fibreglass experience is still on honeymoon, so I have been doing some research on the footwell subwoofer build, and fibreglass construction methods for Door Panels in general. 

 

I have 3/4 options on where to mount the 8" subwoofer. I need to measure when mum is in the car as to the best site for it as she is disabled and her access is very important. 

 

1.) underneath the glovebox at an angle firing downwards

 

2.) In a lower position retaining as much foot space as possible. This example picture is angled too low, but the picture is an example. Rather than firing upwards I would probably go for a vertical panel firing straight towards the seat cushion.

 

3.) (and my currently preferred option) at the side of the console firing towards the door.

 

The last option is in the kick panel itself, but as the mounting depth required might be too large and cause to much of an invasion into the footwell, this is unlikely, but still an option.

 

A really great walkthru guide to using the fibreglass & making a speaker pod (in this case for the kick panel)

https://www.youtube.com/watch?v=cTdk0cYfv2s

 

I'm being realistic in the time frame as having everything on my install completed by next Spring ready for the Club Meets/Show Season including the custom door pods and the front subwoofer box. plus boot finished  with perspex ampl rack panel.

 

This will take the install to it's final level & a noticeable audio step up from where it is even now. 

[Tony]

Side of the console seems the most realistic but the stealth will be done with such a big speaker. Shame the top part of the foot well where the mat is can't be used.