Sexual intercorsa...

D

dumdum

Noob
Now Ive got your attention...

Welcome to my build log of my little euro hatchback, a 2009 Vauxhall Corsa

basocally I owned a van last year and learnt that sometimes issues are too big to circumvent for SQ competition, I will be doing my first full season of competition in the next year, I’m far from green however as I’ve been involved in car audio for 20+ years in one way or another (including being top 3 in the world in dB drag) I have chosen the corsa from a variety of cars that I could pick from

so here begins the build log, you’ve picked up approx 6 days labour into the job 👍🏼 Pics will follow...
 
Update, I have invested in a Topping D10, reason being... using my iPhone as a source I have a 12v converted Apple TV for a digital streamer previously and noticed more detail, so the topping followed so I can build a dock to integrate the iPhone XR into the car properly

so I broke out the umik and rew and using the exact same 16bit, 48k pink noise file I measured the response from each of three sources (alpine 178bt via bt and usb, and also topping d10 via some 75ohm van Damme coax with rean plugs as 75ohm rca plugs don’t actually exist technically, nearest are crimp on Neutrik plugs, but even they don’t meet the 75 ohm standard to which bnc is ‘the connector’ of choice)

so I was expecting a different freq response maybe to explain the detail I was hearing, for example cymbals sounding like actual cymbals with nice decay and a little clearer

so imagine my shock when the response from 150-19k was bang on the same!

what I didn’t expect was the difference at 20k (I cant hear it so not too fussed!) of approx 8db, for the first time it didn’t drop off the planet!

but more serious was the low end... the alpine over usb and bluetooth closely resembled each other, literally mirrored each other to 0.1db, this explains why by sounds similar to usb... the usb input isn’t making full use of the extra digital data in the stream vs bt, anyway I digress, the low end showed a massive (7db at 20hz, 12db at 10hz, and tapering from the 20hz difference to the midbass freqs roughly, I knew the bass sounded fuller with the digital input, this would go someway to explaining the difference in the bass end of the spectrum

its enough for me to go ahead and make some kind of dock for the phone to fit into and maybe obtain a FiiO M11 for permanent figment in the car with some kind of dock to suit both :)

anyway, ramblings over, yes all levels were closely matched and the same dsp settings were used for the measurements, I will also do a measurement with the tiny $9 dac from lightening to 3.5mm jack as I am reliably informed that is actually a pretty good dac in itself despite its cheap price!
 
Not sure if you are a neuro-surgeon , but , you would make a great one !
My Zuki eleets 4 channel adds a lil at low end ( warm sound ).
 
dumdum said:
Update, I have invested in a Topping D10, reason being... using my iPhone as a source I have a 12v converted Apple TV for a digital streamer previously and noticed more detail, so the topping followed so I can build a dock to integrate the iPhone XR into the car properly

so I broke out the umik and rew and using the exact same 16bit, 48k pink noise file I measured the response from each of three sources (alpine 178bt via bt and usb, and also topping d10 via some 75ohm van Damme coax with rean plugs as 75ohm rca plugs don’t actually exist technically, nearest are crimp on Neutrik plugs, but even they don’t meet the 75 ohm standard to which bnc is ‘the connector’ of choice)

so I was expecting a different freq response maybe to explain the detail I was hearing, for example cymbals sounding like actual cymbals with nice decay and a little clearer

so imagine my shock when the response from 150-19k was bang on the same!

what I didn’t expect was the difference at 20k (I cant hear it so not too fussed!) of approx 8db, for the first time it didn’t drop off the planet!

but more serious was the low end... the alpine over usb and bluetooth closely resembled each other, literally mirrored each other to 0.1db, this explains why by sounds similar to usb... the usb input isn’t making full use of the extra digital data in the stream vs bt, anyway I digress, the low end showed a massive (7db at 20hz, 12db at 10hz, and tapering from the 20hz difference to the midbass freqs roughly, I knew the bass sounded fuller with the digital input, this would go someway to explaining the difference in the bass end of the spectrum
Click to expand...

DumDum , you are so 'thorough' in your assessments , air on top end . .. low end at 10 hertz , love it !

Cheers
 
Well I now have a variety of speakers to try in a variety of places and a zapco 150.6ap on its way! Going to try a fair few locations for both 6” and 8” midbass, and for scan 10f, gz nuclear 80mm mids, sb acoustics sb17mfc-4, L4SE and maybe some others I have kicking about, tweeter if needed will be a choice of SB29BNC-c001, gz nuclear 22mm and whatever else I may try, thinking dash end corners for mids perhaps or buried below the dash level for mids and tweeters in the pillars... or a tweeter above the mid also... I like dynamics so perhaps the 6” mfc will be nicer on the corners of the dash, it all depends on phase issues that are present in various locations and how the phase issues allow me to play the speakers in better pass bands to avoid the issues...
 
So now I have source options... I have a 10” Lenovo tablet that will integrate with the topping and give coax out with tidal, I have an iPhone XR for Bluetooth which sounds better than the alpine if I’m honest with alac filed in music, I can also use the 178bt... but perhaps a big kick in my ass is the possibility to use optical from a CarPlay stereo in the form of a clarion nx807e sat nav, CarPlay, CD player and radio with the possibility of dab with a plug in also... apparantly clarion have ceased European sales so I snapped it up brand new very cheap... I think it’s a case of what fits where... clocks will probably be central with the double din below them and maybe the tablet in front of the steering wheel if it actually gets used or fitted permanently as it may just get a mount in front of the clocks for multi media competition use :)
 
Today’s job was make some form of enclosure to prevent the back wave coming forth, it’s way too small for the sb acoustics 6.5” and L4SE (both need 5-6litres roughly) but will give us an idea of reflection issues and where any phase issues will occur in the frequency response, it’s is big enough for the scan 10f which I have a set of kicking about
 
All right, some pictures! I can't wait to see this project come to fruition. The pics you have shown me so far have been crazy, I'm glad you're sharing some with the forum. Keep them coming! :D
 
Santa came late...

clarion with 96khz optical output, cd/dvd, sat nav and Apple CarPlay :)

plus a legendary bar of gold for sq duties :D
 
dumdum said:
Not sure if sarcastic... :shrug:
Click to expand...

Not at all, I really like the stacked work you did for the midrange on the dash. Curious with the way you have them aimed, looks like it would work quite well. Don't see a lot of builds in the states here with a large midrange/midbass up high, so I'm always intrigued to see them :thumbup:

Are those the SB? I hang on to a complete set of SB Acoustics from a previous build just because of how amazing sounding they are.

Curious to hear your thoughts on that Zapco processor too.
 
chithead said:
Not at all, I really like the stacked work you did for the midrange on the dash. Curious with the way you have them aimed, looks like it would work quite well. Don't see a lot of builds in the states here with a large midrange/midbass up high, so I'm always intrigued to see them :thumbup:

Are those the SB? I hang on to a complete set of SB Acoustics from a previous build just because of how amazing sounding they are.

Curious to hear your thoughts on that Zapco processor too.
Click to expand...

Ah ok, well observed! the zapco is a 150.6ap, I will be using a helix dsp pro 2 for now ���� Yes they are sb17mfc for now, if it works as I hope I will upgrade them to satori’s :)

so tonight I have been busy getting the passengers side in roughly the same place as the temporary enclosure... but with more volume behind the drivers, I spent a night trying the small enclosure in twenty different places and aimings. Kicks, and dash are pretty much identical responses, as the bulkhead kinda slopes away like a people carrier as it has a very deep dash... I even tried a few special aimings, it works out that the locations I thought would work nicely did work nicely :) I am going to try and cross the mids over at 100 ish just above the phase dip, and then play a 10” front sub upto 100 and get proper upfront bass as easily as I can

currently with the mids where they are I have a very good stage, I have a centre that is pretty good for saying I e not eq’d anything as yet, just set up time alignment with rew and a modified head rest with a hole for a mic at centre of the ears position plus an inch or two forward as I don’t drive around with my head pressed into the headrest, stage is the base of the very deep windshield currently approx 1.6m in front of the listening position

the plan so far is a ground zero plutonium 10sq off 500rms, then four other channels with 150rms to the mids and tweeters built into the dash corners
 
I should add with the mids somewhat playing off the screen as they are to an extent the mfc’s play upto 8-9k with relative ease, they definitely surprised me I must admit, and the SB29RDNC-C000-4 tweeters seem to take a 2.4khz crossover very well, I think they will take lower, I have seen a design with a 1.4khz lr4 passive crossover, and one with a lr6 at 1.1khz... I think being such a big tweeter they take a lower than most crossover and seem very neutral and not in your face while having some hammer (well you have to try stuff out loud, the dynamics of the 17cm drivers and bigger tweeters is pretty damn crash hot!
 
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