In general, car audio is pretty crap. Can you think of a worse environment in which to listen to music: high and variable noise floor, shakes and rattles, harsh surfaces, poor speaker placement and an off-centre listening position?
The optional 10-speaker car audio I had in my previous BMW was not bad at all, as they go. The 'Premium' audio system with the euphemistically titled 'subwoofer' in my current car is greatly less so. It has the ability to make everything sound different, primarily by missing out chunks of the frequency spectrum rather than any blatant colourations, with a very hot treble and bass that goes boomy rather too often.
It does have redeeming features like the superb built-in USB drive supporting mp3 playback as well as Bluetooth which can play Spotify directly from the phone in surprisingly good quality.
I'm going to do what I've done at home on several occasions, take a plot using my trusty test CD and Radio Shack sound pressure meter. I don't expect the results to look pretty and with the limited graphic equaliser I doubt I'll be able to do much to compensate. Still, it's worth a try as I spend a great deal of time in the car and I want it to sound good.
I nearly gave up when I checked the onboard 'graphic equaliser' and found it had only 5 sliders! So, very rough adjustment was going to be the order of the day and I wasn't expecting much in terms of improvement. Still, soldier on and see what can be achieved. The first plot below, in red, shows the frequency response at normal listening level with the SPL meter approximately where my head is and the equaliser set to the 'flat' position. Yikes, that is one mother of a midrange suckout. No wonder my music sounded strange!
The next step was to map the changes I needed from the graph onto the 5 sliders as best I could, then take another plot. After only a small tweak, I achieved the plot in blue. Quite a lot better, really surprisingly so. The sliders now look like this:
More importantly, music sounds a lot better now, less boomy and with far better vocal clarity. It was definitely worth the effort and I'm glad I tried the experiment.
Test equipment: Radio Shack digital SPL meter; Sheffield Lab A2TB test CD; Microsoft Excel.
Thanks for posting this Martin, my last car was and Alfa, which sadly had the top of the range Bose system in it. It was ofcourse, dire. The current buggy is a Seat Altea XL it has bass, mid and treble and I've adjusted it by ear. In September I'm getting the top of the range Volvo V40, I understand this has a graphic EQ capability, I will certsinly follow you methoology.
When Viv and I were co running the UK Jeep Club, we had JBL speakers, Sony head unit and a sub that I designed and built using a pair of JBL drivers and a JVC power amp in one of our his 'n' hers matching Cherokees. Sadly, the cars I drive now are leased, so no chance to change the stereo.
In many years of car ownership I've never had a car with even a half decent stereo as standard. First job for me on getting a new car always used to be to replace the head unit and front speakers immediately. I used to find Alpine were best VFM. I would greatly have preferred if cars came with no stereo at all so you could just slot in the one you want.
Problem in the past few years has been that the stereo is usually linked to the trip computer etc etc so it's no longer a simple thing to replace it.
Cyrus StreamX Signature, DACXP Signature, PSX-R2, Bryston 4BSST2, Kef Reference model 3~2
I believe my Honda SD Navigation / Audio head is a unit made by Clarion and I doubt it could easily be improved on, if at all. As for the drivers, now you're talking and they're always worth investigation.
I decided to improve the so-called subwoofer (it's more of a woofer really) in my car as bass is loose and very one-note. Great for the street kids, not so good for me.
First job was to remove it, far more difficult than I had imagined and required virtually the entire hatch compartment left-hand seals & panels to be removed before I could unbolt the sub and remove it. Inside I found a half decent driver...
...and an empty compartment. Nice and resonant, I'm sure!
Some nice speaker wadding and a while later, I had shaped the stuffing as best I could to fill the void and make the air volume appear larger acoustically and reduce the resonances. While inspecting the driver, I noticed that the mastic used to hold the cone surround in place was coming adrift. Out came my trusty speaker repair glue and custom clothes pegs (!) and I repaired it. We've been here before.
Has it transformed the car's sound? No, but it has at least controlled the bass end of things and improved intelligibility. Next I'm going to remove the four main drivers and see what's behind. By all accounts they won't be easy to remove either.
If you can get a sample quantity, try Angel Hair which is some fancy wadding sold by a company in Holland. I used it in the Wilsons and I've tried it in the car system because it seems to have a much better low end absorption than the conventional speaker wadding. You'll find supply details on Google and they were happy to supply samples ( more than enough for what you need for the car speaker)
Last night I managed to remove the rear speakers, again quite tricky. Behind them was open space, so I packed a big sheet of wadding behind each driver and reinstalled everything. Fading to rears only, they do sound cleaner.
The fronts are going to be a right pain, I will have to strip the entire doors to get at them
Yesterday I was in my local car electrics repair place and he had an Audi Q7 in there which was fitted with the full B&O package. Sound was ok but what really got me were the tweeters which on switch on rose from the top of the dashboard. Worth the price of the car just for that. Who cares what they sound like!
Just for clarity, when I say rose from the dashboard, I don't mean by floating upwards in space. IT wasn't that clever. The just appeared and rose up about 4 inches so the actual radiators where pointing at the driver/passenger. He let me have a go with the system but it was too complicated to adjust quickly and see what the optimally adjusted system would sound like. Our old Cayenne is getting close to replacement time so I might just go for one of those. No more crazy than the Saab I bought in 1997 on the basis of its sexy drinks holder which emerged from the dash. Sad or what?
Martin, it is quite large. We bought a Porsche Cayenne a few years ago because we go to Austria a few times every year so a large capable 4 wheel drive vehicle that can cruise the autobahns at 125mph and manage snow covered mountain roads is essential. I hadn't thought of the Q7 but now I've seen those speakers.....
It's no larger than comparable cars from BMW and Mercedes. And although it is a tad bigger than my Kuga in width and height (3 inches or so) the main difference is length - it is half a metre longer than a Kuga. The published mpg numbers are, in common with all cars, based on myth and fantasy.
I worked a few years ago with the reasonable setup in my previous Honda to get better sound quality (see above). The basics were there, the speakers just needed some wadding behind them, the 'subwoofer' needed some too, and then a little work with the graphic equaliser and I was done.
So, on to my current Subaru. Upon first inspection, things looked quite promising. It has bluetooth and a graphic equaliser and four speakers. I could stream Radio Paradise from my phone. The model is a BRZ 2.0SE Lux with better equipment. How bad could it be? Read on.
Listening to either radio or a Bluetooth stream with all the default settings, the tortured shrieking emanating from this setup was so bad that I could see dogs running away. Never mind the scary running lights and menacing demeanour of my car, I need only turn the radio up and people in front of me would dissolve away. I was eternally grateful that I had installed a loud manifold and exhaust system so that I was spared the worst excesses of this truly execrable system. I either drove in silence (nope, not with my exhaust), or I could be seen driving with tears running down my cheeks as I desperately tried to identify any of the music being played. This system had the ability to mangle songs I knew well into a gathering of noises that could not be reconstructed into music in my brain. I kid you not, the number of times I heard something and wondered what it might be, only to look at the display and realise it was a familiar song, was so frequent that I burst out laughing - not advisable whenever a well ripped bodyguard was crossing the road in front of me. The speaker drivers couldn't even dream of matching those in the average table-top radio. A phone would run rings around them. The braying of dingoes would have more fidelity to ugly noise than these things. You get the idea. Actually, no you don't as it's not possible to understand how unmusical this car system sounded.
I don't know why I'm writing in the past tense, as if all is resolved now. I'm sure you're waiting for the big reveal, having spent a couple of tons on the latest Pi'neer with the space shuttle display, 10 speakers and a brace of power amps. Nope.
What I did do was go through all of the considerable audio settings and turned every 'enhancement' with names like bass boost, voice smoothing, speed volume and acoustic selector off. I set the graphic equaliser to flat and listened. It's nothing short of utterly terrible. I then set about working the graphic by ear (never mind measurements, this thing is way beyond that) until I got something vaguely approaching music out of it. Try not to laugh, but the curve now looks like this:
Yes, I had to set an upper bass hump and roll off the treble to get some semblance of midrange so as to communicate a few musical cues to my poor brain. The 60Hz slider is laughable, varying between nothing much and clipping as the feeble amp gives up. There's little sign of bass in any position. I still need the loud exhaust to provide some 'dithering' so that I'm less aware of the appalling sound and can hear bits that help me recognise the music. Even so, I often need the display as a reference.
Now, being a piston-head, the engine often provides my 'orchestra'. However, to cut the monotony of the daily commute I do like a bit of Radio Paradise to get me in the right mood. I have succeeded in improving the sound to just plain very bad. Short of ripping it all out and starting again, there is no rescuing this system. I give up.