Carver Sub / DSP woes - Help needed!!

[Dirk_D]

Another confused Carver Z4 thread I'm afraid, but, I'm at the end of my tether. Any help gratefully appreciated.

So - I read the PVDX-V9 upgrade thread with great hope of getting sound back in my zed after having suffered a fatal Carver boot flooding.

Idea was to do the same as other users and buy a 5 channel class-D amp, with 3 way passive cross overs and a new head unit with 2 x pre-outs to drive the amp and bring the car into the 21st century using existing speakers. It all read as do'able, apart from spending £400+ on the Alpine.

I didn't quite have that budget and opted for a Kenwood x802-5 to power supply all of the stock speakers.

Long story short - my installer said the 3-way cross overs may not be required and wired the whole lot up (front 6 speakers and 2 x subs in parallel) using the Kenwood on board crossover with the Subs wired to the single sub channel.

Bottom line is - After doing all of the above the sound quality is shocking. Bass nowhere near what I remember from previous old DSP amp, very tinny and quite a lot of buzzing (which may be earth related) on the front left channel.

So - my questions to you clever folks are as follows:

1) Is there a difference between a DSP amp and a class D amp and if so - is the class D amp I bought not up to the job of running the subs?
2) Would adding the 3 way passive cross overs for the front and using the second channel to drive the subs make a difference?
3) Its been a few months since I actually listened to my carver system, are my ears playing tricks on me? Do you think the carver system serves warm rich / deep base - or - perhaps I'm just going mad and is it normal for it to be quite tinny and a bit rubbish?

I really thought this was going to be easy - Any feedback would be gratefully appreciated.

 

[Anonymous]

Hi, I can't help you on E85 specifics but ref DSP vs Class D.

The OE unit was a DSP (digital signal processor) and an amp.

The DSP part and the amp part are seperate systems (although in one unit)

Amps are defined as Class A AB B C and D (amonst others)

Non of those amps give you any DSP capability

So your class D amp does not give you DSP support

The issue in cars with their shape /size and the types and positions of speakers is that its impossible to recreate what you may hear in a nicely set up stereo in a home in a car without lots of tricks.

A DSP gives you that ability in spades and in a way that simple tone controls or equalisers can't match.

Therefore (without knowing the specifics of the E85) I would say that comparing the two will result in the disapointment you are experiencing!

 

[Dirk_D]

Thanks for reply, appreciated.

This was the thread that originally inspired my attempt to get sound back in my zed. https://z4-forum.com/forum/viewtopic.php?f=2&t=67364&start=60

I honestly thought if removing all of the old components and replacing with new head unit and class-d amp the original speakers should just work? Thats how it kind of reads? But what I've found is that they do indeed work, but sound terrible.

can any other amp be used with the Carver subs or do they definitely require DSP built into the amp?

 

[Anonymous]

You're into the complex area of pyscho accoustics or one man thinks their set up is great another thinks its shite!

Then the other issue is value for money vs perfection!

From the maths /purist view your set up will never match or come close to a DSP based set up.

The amp itself I'm sure is great..what you need (IMHO) is to get a combo DSP/amp as well, use that as the main part and then use the amp you just bought to power the subs etc.

As I said I'm not an E85 guy, I did do something very similar on an E89.

DSPs need setting up as well so not a trivial task.

However I can say that when I was setting mine up the effect the DSP has on top drawer speakers and amps is profound and they work as well on cheaper set ups overcoming the inadequacies of those components.

Most modern cars now use DSP to get around cheaper speakers etc..

My article is here https://z4-forum.com/forum/viewtopic.php?f=23&t=116918

 

[Dirk_D]

Thanks - Will give the article a read - that looks like a seriously expensive upgrade there though? I'm currently on about £400 for head unit and amp (before install) and am trying to keep costs down because my E85 is only used a few times a year and I'm not sure I'd get an upgrade like that past the wife!!

The whole Carver Sub thing could end up meaning me having to spend more to replace them if I don't sort this though

 

[Anonymous]

Thanks - Will give the article a read - that looks like a seriously expensive upgrade there though? I'm currently on about £400 for head unit and amp (before install) and am trying to keep costs down because my E85 is only used a few times a year and I'm not sure I'd get an upgrade like that past the wife!!

The whole Carver Sub thing could end up meaning me having to spend more to replace them if I don't sort this though

The problem always with tech is that replacing / repairing advanced old tech is never cheap if you want to do a proper job..

A simple option that I see many E85s is to strip the system back to a more basic system..that way you build a simple sound stage..again others may advise on E85 options...

 

[Silverstar]

You say you had a pro install it? In which case they ought to know what the problem is? To me it sounds like the components aren't matched. In the other thread they didn't install a new head unit and used the stock head unit so not sure if that makes a difference but with your new Alpine head unit and the Kenwood amp, with the correct speakers and wired up correct it should sound great!

Sure a DSP would make the system sound even better but even with just a normal amp without DSP you should get great sound. This is what I did in my E89 with the basic 6 speaker system. I kept the stock head unit, added 2 way aftermarket speakers with passive crossovers (wired in parallel with the front woofers) and replaced the rears with some coax speakers. I powered that lot with a JBL basic 4 channel amp and added two small Kicker subs powered by another amp. It's a budget system and the whole lot cost me around 700€ but it sounds fanstastic, sure maybe not up to a standard that an audiophile might want but for all others it's great, everyone that hears it are impressed and comparing it to my mates 2013 E Class cabrio with premium 12 or 14 speaker sound mine sounds much better.

In your case with a new head unit and the new amp it should sound great but I suspect the issue is with the speakers, maybe how they are wired up or their specs not matching the new equipment, e.g. from the other thread it seems wiring the two rear subs in parallel brings their impedance down to 5Ohms but then with that impedance you won't get the 300W the amp is capable of giving since it does that at only 2Ohms.

I suspect if you were to change the speakers and subs (match to the amp specs) and possibly with passive crossovers for the fronts you will get the sound you want. But I would go back to the guys who installed it since if they are pros they ought to know. You can see my audio thread here:

https://z4-forum.com/forum/viewtopic.php?f=23&t=126024

Oh one other thought, did the installer 'tune' the amp correctly when they installed it?

 

[Dirk_D]

Thanks both - really very helpful. The installer is popping back over this week to try to get rid of some of the alternator noise when the engine is running. I'm going to ask him to try it with the passive cross overs to the front channels and get more power to the subs? Hopefully that might sort it.

Interesting reads above. It seems these things are not always as easy as you think, I'm really glad to read I might not have to rip out the new amp and send it back though. that would be a real headache. Hoping it can be easily salvaged.

 

[Silverstar]

Thanks both - really very helpful. The installer is popping back over this week to try to get rid of some of the alternator noise when the engine is running. I'm going to ask him to try it with the passive cross overs to the front channels and get more power to the subs? Hopefully that might sort it.

Interesting reads above. It seems these things are not always as easy as you think, I'm really glad to read I might not have to rip out the new amp and send it back though. that would be a real headache. Hoping it can be easily salvaged.

I just re-read the specs on the amp, it has 300W to the subs at 4Ohms and your subs wired in parallel will be 5 Ohms according to the other thread so maybe you have enough power to the subs. I would install passive crossovers for the fronts and run them of two channels of the amp and run the rears off the other two channel of the amps. it's important they set the gains on the amp correctly, if you run the fronts via a passive crossover I would set the crossovers to the fronts on the amp to full range (switch off the crossovers on the amp), since the passive crossovers will do that job.

 

[Dirk_D]

Nice. Thanks for checking. I just re-ordered passive cross overs so will await their arrival and give this exact config a try - I sorted the buzzing by adding ground loop isolators - So - Fingers crossed it'll sound way better when the cross overs go in.