About had it with DSP - Options?

S

sk93

Veteran
 Nottingham
Right,

I've just about had it now with the DSP amp in my car.
Ever since my last got flooded out (stupid design flaw if you ask me), I've gone through no less than THREE different amps, all which are supposedly compatible with my car:

2003 DSP Carver / TOP Hifi Coax


So far, I've got:
1x amp that has exactly the same part number as my blown one, that doesn't work at all, which cost me £150 from Poland.

1x amp that has a different part number, but is listed as being a viable replacement on realoem. Worked initially, but when I coded it to be "non-nav" I now get all the sound out of just one speaker and the fader/balance controls make zero difference. f**k knows what I've done to this amp. £290 from Germaly

1x amp that supposedly is compatible with my car but is a different part number to mine. It's a LEAR Redstar 2 DSP amp, and the bmw sticker indicates it's for E83/5/6
It currently works fine in the car, but the DSP options do not show in the headunit, so needs coding to be "non-nav" instead (this is the cause for this).
Problem is, my NCS Expert refuses to communicate with the bastard thing - keeps saying "connection interupted".
The other problem is that it has no coax connector, so my cd changer connection doesn't work.
excellent.
£250 from Germany.


All in all, I've spent £700 and have got precisely f**k all to show for it.
I'm absolutely fuming as, on the face of it, it's fucking plug and play... but oh no... no.. that'd be too easy wouldn't it?!?


Anyways.. I'm now considering ripping the DSP s**t out of the car and going with an aftermarket amp.
I do NOT want to replace the headunit. the facia surrounds, imo, look like warmed up dog turd and I don't want that thanks..
so how do I link the existing unit up to an after market amp?

Subs..
I heard the subs can't be used with aftermarket amps - is that so?
If so - what subs would people recommend? (I do like my bass, but I'd want it to remain close to the existing subs - maybe a fraction deeper... but not overkill)

What about the rest of the speakers? I assume they've not got built-in crossovers and hooking them up to an amp is likely to just fry them?


I don't want to spend any more than £500 on the whole job.
I'm competent with installing sound systems, so would do it myself.
just want advice on what people have or have tried and any potential pitfalls.


I just want my fucking car to be "right" for at least a week... just one week.
is that too much to ask for?


anyways.. we lost football, gf is out working, missed ordering pizza by five minutes, so am now going to get royally pissed on Jack.
screw work tomorrow.
:headbang:
 
Why do you need an amp? If it were me I think I would just wire the speakers directly to the headunit - as is done in not amp'd cars, then once you have that working you could get the bm54 upgrade which is meant to make a really good difference I believe. At the same time you could get the pre-outs fitted to the bm54 and then you could add an amp at that point?

sk93 said:
Right,
I assume they've not got built-in crossovers and hooking them up to an amp is likely to just fry them?
Click to expand...
I don't think without cross-overs you would fry the speakers, you just wouldn't get good sound quality, as I am sure you know the cross-overs just are there to help send the right frequency to the right speaker so wouldn't be a massive problem and not hard to rectify.
 
Edit: apologies for the long post, treat yourself to a beer if you manage to read through it all!

Ouch, sorry to hear of the pain!

Needless to say the aftermarket industry has you covered!

The way I see it, there are a few different ways of getting around the issue of the carver amplifier but the fact that it accepts a digital signal does complicate things.

I'm going to assume that you don't have nav (makes things easier in my opinion).

Option 1:

The easiest way would be to get a non-dsp head unit to allow for an analogue signal into an amp. The only issue you'll face is having enough output channels (as you mentioned, there are no passive crossovers). For simplicity's sake, you'll need 8 output channels. (tweeters x2, mids x2, woofers x2, subs x2)

You can use the crossover's built into most amplifiers these days.

Pros: probably the most simple option

Cons: you'll be left with minimal eq configurations

Option 2

If you're able to stretch your budget, you could incorporate an aftermarket audio processor into option 1. This will give you a plethora of additional tuning options. However the issue here is finding a processor with enough outputs. To get around this you could (for example take an audison bit10) which offers 5 output channels. 1+2 will output signal for both the tweeters and the midrange drivers leaving 3+4 for the woofers in the kick panels and then running the subwoofers in single channel on 5. The amplifier built in crossover will allow you to separate the signal from the mid and tweeter. Alternatively you could run a passive crossover in between the amplifier and the drivers (though you will be susceptible to power wastage through a passive crossover)

Option 3

I think this may be considerably out of budget, but for the sake of helping anyone else who reads this, it may be helpful.

Mobridge makes a unit which accepts the bmw digital signal and then outputs an optical signal in the form of a toslink connector. From here you have a signal to do with as you please (either optical into a digital sound processor or a digital-to-analogue adaptor and then onto the amplifiers)

Option 4
You could look into your water damaged unit being repaired.

Gordon, aka the amp doctor only has good things spoken about him. So it may be worth contacting him to see if he can help.

http://www.ampdoctor.co.uk/about-us/

Amplifiers

Space in the z4 is at a premium. Full range class D amps have come a long way in the past few years so you stand to benefit from better thermal efficiency. JBL, JL Audio, and Rockford Fostage (to name a few) make some excellent class D amps that are incredibly compact.

Personally, I'm a fan of a nice simple setup, pair of tweeters, pair of woofers on the front stage. Three way front stages are perceived for being difficult to sound 'right'. Though I've never has any experience in this department as I opted for a 2 way in my setup.

Subwoofers

I've also read that the carver subwoofers are of an odd impedance. Aside from changing them out, you can adjust how they're wired (i.e. loose the stereo element) to either raise or lower the resting impedance. Also, it is the resting impedance which ratings go by, but once the driver is moving, that impedance does change (leading some to argue that it's somewhat irrelevant to get caught up on resting impedances of a driver)

Aftermarket solutions, well JL Audio offer a 6w3 which seems to be favoured by some owners on the forum. Though not cheap, it certainly offers a lot for it's size.

As for the main pitfalls, my biggest hurdle was where I mounted the amplifier. Initially I wanted it to be behind the seat hidden away, but later opted for it to be mounted on the back wall to keep the power cable as short as possible.

Other options

You could run a parrot (or similar) bluetooth car kit. These have a built in amp that is fed to your speakers. Given the nature of the digital system these would sit between the amplifier and the speakers. Probably the cheapest option from a financial perspective though you'll need passive crossovers and it will more than likely sound awful.

Given the money that is tied up in the other BMW amplifiers, you may be able to sell them to allow for new front speakers and subwoofers. Couple this with option 2 and you'll be on your way to having a system that not only sounds great but can go nice and loud! As for speaker choices, I went with a set of Hertz HSK165. Main reason was they fit the budget nicely and they sound great (these are being run actively, i.e. each component is wired to a separate channel). Audison also offer a similar product, with a different badge. Perks of both companies being owned by the same parent company.

I've found that JL make fantastic subwoofers and amplifiers (slightly biased opinion here, and yeah I'm a fanboy!) but their speakers, for the money, are overpriced and overhyped. Having heard the c2's and c3's they are both incredibly sharp and ultimately ruins the listening experience. The c5's as fantastic as they are...are stupidly priced (in my opinion).

Focal are another company to offer fantastic speakers, so certainly worth considering them.

A final note, do avoid fli, edge, vibe, inphase. Those products sell in great volume due to a higher marketing budget than product development. Certainly not worth your time given you're coming from a carver system.

I'm sure I've probably missed something, but please feel free to pm me or reply here if you have any other questions!

Hopefully it's of some help!
 
Hi neil - thanks for the great long post!

my major concern is not replacing the headunit.
I absolutely hate the look of the aftermarket facia adapter and think it spoils and lowers the overall "classy" look of the interior.
obviously, this is my opinion and may not be shared by others, but it's just how it is ;)


to that end, I was thinking the best thing to do was to buy a decent 5 channel amp and place it in the battery well where the dsp amp was.
feed that amp the high frequency outputs from the headunit, then using the crossovers built in the amp, feed out to the speakers.
i'd rewire the subs to be parallel to drop their impedance down to 5 ohm, or thereabouts, making them much more manageable.


all in, I think this is going to cost about £400 for the amp and about £200 for fitting - hence selling all my stuff lol


The amp i'm looking at is the Alpine PDX-V9.

thoughts?
 
Sorry, I didn't quite make it clear! When I said change the headunit I meant replace it with a Z4 one from either the base stereo or the mid tier one. Without it, it would be incredibly difficult to get sound to the amp aside for a 3.5mm jack to rca. Certainly not the 'right' way of going about things.

I however, do completely agree with you regarding an aftermarket stereo in the z4.

Yep, amp is fantastic and your plan sounds like it should work. You would lose the mid range driver though given the lack of output channels.
 
NeilP said:
Sorry, I didn't quite make it clear! When I said change the headunit I meant replace it with a Z4 one from either the base stereo or the mid tier one. Without it, it would be incredibly difficult to get sound to the amp aside for a 3.5mm jack to rca. Certainly not the 'right' way of going about things.

I however, do completely agree with you regarding an aftermarket stereo in the z4.

Yep, amp is fantastic and your plan sounds like it should work. You would lose the mid range driver though given the lack of output channels.
Click to expand...

I didn't think the headunits were different?
I have a BMW Business headunit...
 
The amp has a digital input so I'm assuming the headunit has a digital output. Easiest way is to take the unit out and put a test speaker on it and see if it works.

Edit: based on these pinouts...you may be right. http://www.z4-forum.com/forum/viewtopic.php?f=2&t=38730
 
Afaik the normal (dsp)amp input is analog, and there is an extra digital input (coax). However that only receives signal from the cd changer.
So afaik there is no digital signal going through the 42 pin connector.
That you don't get any sound may be because the cid/hu switches the amp on&off and that things are not properly programmed.
Certainly that amp from germany worked fine initially?

Personally i'd try to get the original amp working (I know easier said than done, as you said it's not exactly plug&play.....).
I think you'll have a hard time to fit an aftermarket 5 channel amp in the batterybox, so you'll probably have to fit that somewhere in the boot.
 
The headunits are all the same, there isn't a DSP / None dsp headunit.
I come back the original point, you are keeping the original speakers? so you I assume you don't really need stupid amounts of RMS per channel. Why don't you get a bm54 modd'd by the nice chap in London who does it, he can add you an amp to give 40 watts rms on the channels, this would give you enough for the standard speakers, he can also add pre-outs to the standard bmw headunit (there are guides to do both these mods yourself if you feel you wish to) then you have a headunit with 40w rms on the four channels, you have a set of preouts for the subs. I seem to believe he charges less than £100 for the mods so would leave you sorted for a cheap sub and amp setup.
I wouldn't stick the amp back in the boot pit, I would stick it to the rear firewall - this would cut down cable run and also prevent it having the same fate as the original amp.

The current loom runs round the back of the boot and into the pit and I think it would be just long enough to enable you to take the feeds from the amp and put them into the headunit directly, and then remove the current wires from the headunit to the now redundant amp. It would be a bit of work but nothing that is beyond you I'm sure.

Actually you could leave the amp wires in the boot, take them to the firewall and you could fit crossovers there onto the wires directly and then run new wires from the headunit down the centre tunnel to these crossovers. That would keep it neat as well as giving you somewhere to put the crossovers.
The only thing I would suggest might be a slight hiccup is that the front right speaker is dual coil to allow the Bluetooth setup to work and thus you would make adding a new oem Bluetooth hard but I would suggest you would be more happy with a parrot or the like given the lack of nav screen anyway.
 
As an aside, I believe the suggestion above about using the headunits output directly to an amp wouldn't be the recommended option, I am not an expert but I believe that low level inputs are better than a high level input and the low level inputs are easy to find on the bm54 headunit circuit board. As an aside if you were wanting to do this route, bm54 units do fail and so you might be able to pick up a cheap unit as spares repairs and modify it yourself and then sell your original unit on to actually cover the cost of the mod.
 
BM54, not BM45.

BM54 is the general type of radio used in (among) the e46. It is not 100% the same as the z4 unit, but probably enough.

I don't know for sure, but I think the inputs of the amp are low level.
Soldering in other amp ic's in the HU certainly won't give you the soundquality given by a seperate amp. A seperate amp is an amplifier/booster (thus boosting the voltage to get more (and more undistorted) power), and the HU doesn't have that type of schematic.
You're basically getting average headunit quality from something like halfords. Probably better than a standalone OEM HU, but nowehere near the quality and power that the hifi prof dsp provides.
And in a convertible, that is something you'll notice (in a convertible you need more power as both the background noise is much higher and the open roof makes the acoustics very different (open field conditions versus closed room)
 
GuidoK said:
BM54, not BM45.

BM54 is the general type of radio used in (among) the e46. It is not 100% the same as the z4 unit, but probably enough.

I don't know for sure, but I think the inputs of the amp are low level.
Soldering in other amp ic's in the HU certainly won't give you the soundquality given by a seperate amp. A seperate amp is an amplifier/booster (thus boosting the voltage to get more (and more undistorted) power), and the HU doesn't have that type of schematic.
You're basically getting average headunit quality from something like halfords. Probably better than a standalone OEM HU, but nowehere near the quality and power that the hifi prof dsp provides.
And in a convertible, that is something you'll notice (in a convertible you need more power as both the background noise is much higher and the open roof makes the acoustics very different (open field conditions versus closed room)
Click to expand...

So based on that, something like the JBL MS-8 seems to be a pretty decent all in one package.
 
Just looked it up: the jbl ms8 is more like a dsp processor. As an amp it is heavily underpowered 18W/channel (CEA, whatever that is...)

In a convertable you need a decent amp that can provide real power.
 
this all seems so very, very overcomplicated.....

I am not a complete novice when it comes to car audio, and here I was thinking I could hook up the existing front/rear/left/right high-level speaker inputs to a decent 4-channel high to low signal converter.

That would give me four RCA outputs, which I could then plug into an Alpine PDX-V9 amplifier.

The amp would allow me to specifically configure each corner of the car (in regards to frequency range and individual volume/power).

I would also branch the rear left and rear right feeds to form a subwoofer input for the amp, giving me dedicated control of the subwoofers.

Finally, I'd wire in a set of decent crossovers onto the front outputs from the amp, and link the pillar tweeters into them, ensuring only the higher frequency ranges reach the tweeters.



This allows me to keep the existing headunit and allow the car to remain looking "stock" which is of big importance here.

In regards to amp placement - ideally I want everything hidden, hence the reason for putting it in the battery well.
the cause of the original problem has been identified and resolved, so risk of a repeat is very low..


Does this not sound like it'll work to you guys?
 
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