C43_AMG_NJ

Does anyone know how to remove those small panels that hold the speaker covers, I have new carbon fiber door panels and don't want to remove the entire door panel. Thanks

Geokop

I think you will have to remove the door panel to get access to the clips that hold them. Removing the door panel is only 5 minutes work. Do it properly to avoid damaging the clips and the panel its self

gsd99mg1

You have to remove the entire door panel. There´s no other way to take them out. Removing the door panel is easy, there´s a video on youtube explaining how to do it.

damianw

The clips are tide. Even with door panel removed it is still not easy just push to release it for clips.
I tried to do it but then I broke one of the clip and decided that without proper tool it will be not possible to remove this trim w/t destroying clips.
Check this link - it is shown how the clips looks like and what kind of tool can be modified to use to unlock this clips:
https://www.drive2.com/l/471561296773382722/

nobbyv

janusgrimnitz (if you're still around): can you share of few more details about your system? It looks like you're using the Morel Virtus 603 component set, correct? I am interested in that, as it looks like (based on Mike5215 and vladarh's excellent research) it'll fit the FrontBass enclosure, as it's mounting depth is only 64mm. Is that the route you went? Are you running the Virtus set full-range, or are you taking a high-passed output from the A20 amp? If you're running full-range, what did you use to do the high-level to low-level conversion to the GroundForce amp's inputs?

Also, can anyone that has replaced their system (especially the front speakers) comment on any persistent "rattles" or "vibrations", such as those that this YouTube user recorded from his Burmester:

He believes the distortion is coming from the grilles, but I suspect it's actually the speaker cones distorting due to their cheap construction. I notice it quite a bit on my Burmester when playing piano-heavy music and vocals where there aren't a lot of drums/guitars/bass to mask the distortion. It's disappointing, and as much as I've moved away from the days in my 20's where every car I owned needed "a system", I'm not sure I can live with the Burmester as-is.

nobbyv

Just FYI: there is indeed a relationship between impedance and frequency for any particular driver/speaker. When a driver/speaker has an impedance printed on it (or has one spec'd), that's a "nominal" impedance: basically, an "average" value across the range of frequencies the driver is designed to reproduce.

In the real world, the impedance that a particular driver/speaker presents to an amplifier is a complex impedance: it varies dramatically with frequency based on things like driver diameter, cone construction, suspension compliance, etc. Manufacturers generally take an impedance plot across the typical frequency range for that driver, and figure out where it goes lowest (since lower impedances have greater probability to damage "wimpy" amplifiers). The "nominal" impedance is then given as that value rounded up to the nearest even number.

So a particular 5.25" midbass may be an easy 10-12 Ohms to drive around 200Hz, but it may drop down to a more difficult 2-3 Ohms at 1000Hz. Incidentally, that's why measuring speaker impedance using a DMM isn't necessarily indicative of the impedance an amp driving it is likely to see (though it's often good enough for a baseline): a DMM applies a DC current to test *resistance*, but impedance is actually an AC measurement.

Mike5215

I can tell by your level of expertise that you're never going to be happy with the Burmester as-is.

I think the vibration is happening in the piece of door trim (being transmitted by the grilles). If you press on the panel and there's give, some felt or foam tape can firm it up and stop the noise. As far as the speakers distorting, I haven't experienced that. I have a set of Focals up front but I left the rear door speakers stock. On the Prima I can isolate any speaker (or set of speakers) and I heard no noise from the OEM speakers. Granted, the Prima is putting out at best 35 watts per channel, and the rear door mid and tweet are sharing that 35 as a set, so probably not enough to over-drive it. Very possible an amp with more power could shred the OEM speakers though. There's almost nothing to them.

I think the factory EQ has them playing way lower than they should be to fill the gap between them and the Frontbass. They're happiest just playing from the mids to highs. There are so many f'ing 4" in the car (7 total) that suppressing the mids seemed like the main tuning feat.

Wow! Science. You're way more informed on this than I am. I put a meter on the posts and if I see 4 ohms I'm happy.

damianw

I do not heard Burmester but I could imaging with speakers quality and types that can be a lot of to do to impress SQ.
About the "rattles" or "vibrations". Again only standard Audio20 which do not have Burmester grills. I do not hear any of those with standard grills. And I can confirm that these are pretty solid - after dismount door panel I checked them all. No damping material was install as I didn't see that this is necessary. I have quite a lot of damping mats which I bought for old car and never install but I do not see the point to install them on door panels as there is only 4' mid (each 40W RMS).
Coming back to the point. After installation of new speakers (all audison prima) which are more power full even supplied by HU didn't hear noises from door panels or other plastic. Only noises are coming when I did some tune on DSP (increased low freqs.). Modified front woofers which are now supplied by 135W RMS each (audison prima 8.9bit channels in brigde mode - left and right - by the spec these are 70W RMS - 210W peak). But to be honest it can be everything under/closed to dashboard (there is a lot of plastic parts, cabling and this speakers are "kicking" as a woofers). What I discovered when I get the car from dealer rattling was coming from rear sensor indicator (while driving) which is installed in rear part of roof panel. Now when I increase volume I can here it all the time. It is making me crazy but I will modified this. As mentioned before I still driving the car not fully assembled to be ready if any of mods are necessary. And after 3 days I can see that there will be a lot of job to tune the system according to my expectation. And yes adding a sub with 250W rms to the trunk require to damp all panels. As for now it is just testing but the final configuration will have 2 subs in ported enclosure (still thinking how to integrate box in the trunk to be easy removed).

damianw

For speaker impedance - it is changing with freqs. If you will check the speaker specyou will see it (below woofer which I installed):

nobbyv

Didn't mean to beat anyone over the head with a bunch of technical terminology; I'm a BSEE with strep throat who has been banned from the office until I'm non-contagious. Unfortunately, I also have a non-working VPN, so I don't have much "work" I can actually do...so I read through this entire thread. Again, you and vlad (and others) did some great work on this system.

That's a good idea about the rattles/vibrations; I think I'll pull the door panels this weekend and hit the trim pieces with some felt tape.

And I agree; a 4" midbass should be crossed over MUCH higher than what it seems the Burmester system is doing.

Mike5215

Typically for maximum drive and the most flexible tuning options you'd want to go active up front on the 3 ways (Frontbass woofer + 4" mid + tweet). That would use up six of the eight channels, with the remaining two for the rear doors. So nothing left to bridge.

What's the configuration and channel assignments you're planning? Are you using more than one Prima?

damianw

My config is:
- 1. & 2. ch. bridged woofer left (135W @ 4 ohms)
- 3. & 4. ch. bridged woofer right (135W @ 4 ohms)
- 5. ch tweeter and mid left front door (tweeter with passive crossover) (35W @ 4 ohms)
- 6. ch. tweeter and mid right front door (tweeter with passive crossover) (35W @ 4 ohms)
- 7. ch. coax rear left door (35W @ 4 ohms)
- 8. ch. coax rear right door (35W @ 4 ohms)
- 9. ch. (pre out) for AP1D (300W @ 4 oms) for a sub

I decided to use passive crossover for a front tweeter as I didn't want to run new cables to the doors for tweeters. I know that it could be better but with passive crossover happy too. I could connect front doors (tweeter and mid) in parallel and have the channel in 2 ohm (65W rms then from prima) but then could be a problem with tweeter.
I preferred to how more power on frontbass.

Mike5215

Ok that's how mine is set up as well. I was confused about the 135 watts to each of the Frontbass woofers. 35 watts per channel bridged would get you 70 watts right?

damianw

Actually it is 130W, I just checked the specification:

1 Ch @ 4 Ohms giving you 35W.
1 Ch @ 2 Oms giving you 65W.
And I just check wikipedia and this is written:
The × 4 myth
It is sometimes stated that operating an amplifier pair in bridge mode can give four times the power (of one of the pair). This statement makes reference to the fact that power is proportional to the square of the voltage, implying that if the output voltage is doubled – as it is in bridge mode – then the power available increases by a factor of four. This would be true if the amplifier in bridged mode were used to drive loudspeakers of the same impedance used in stereo mode. However, in this case, the current through the loudspeaker and the amplifier would also double, which could exceed the amplifier ratings and lead to overheating and finally destruction of the amplifier. In fact, the minimum impedance of the loudspeaker in bridged mode should be double the minimum impedance rated for stereo mode..
So that is why in bridge mode min load is 4 ohms which is double of min impedance of 1 ch (2 ohms).

And as a conclusion: before installing all equipment in the car I did some various tests in my home - speakers connected as free air, small sealed enclosure (like 2l) and ported (around 10l), connected in single ch. and bridge - of course ported was for me the best (fast and quite low) but it was because of box volume. Sealed was fast and "kicky" with a big difference between 35W and 130W. And as we know in original place enclosure is very small and no possible to make it ported ( i closed the car construction hole and added some damping material - acoustic 6 mm sponge to avoid back wave as this this all metal).
Final tune is still in progress but I could hear that even w/t sub these are playing low enough - of course as for 6,5" woofers in small sealed enclosures.

Mike5215

Hmm. My understanding was that if you're running in 8 channel mode, in that mode each channel has 35 watts into 4 ohms. Or the amp can also be run in 4 channel mode, where each channel has 70 watts, or 2 channel, where each channel has 140 watts.

In other words there's a finite amount of total power the amp can produce, but you can apportion it in different ways depending on how many channels you run.

In my system I'm running 8, but two are bridged for a total of six (same as yours). Aren't the two bridged channels simply combining their 35 watts to produce 70?

damianw

Actually this can be mix. You can mix them but always in a pairs:
1/2, 3/4, 5/6, 7/8.
So it is correct what I wrote : 4x35W and 5/6 bridge 135W and 7/8 bridge 135W.
And to proof it you can check manual with section where they are showing configuration without PC (preset):
- preset 1:

- preset 2 is similar
- preset 3:

- preset 6 is similar of mine (for channels config)


So as you see if the factory presets are design this way and according to this the power output from amp is giving this values so with PC soft it will be the same.
If I will get proper tool I could check if the values are real (not talking about amp meter and multimeter which I tested already with and I get more then 70W while playing my tests).

Mike5215

Interesting! So I've got 130 watts to each Frontbass speaker (Burmester gets two), not 70. I should probably upgrade those speakers

damianw

Yes you have . If you did already so much and you have both of speakers installed (in my case it was only one) so I would go with option to change them by other. The most difficult part is to remove carpets to get an access to the speakers. But even with this you will need one weekend.
Frontbass speakers are easy to disassembly (basically only flex glue so with screwdriver or special tool for clips it is easy to remove the grill). After that small adaptation with new speaker - which are not difficult as well. And as you have Burmester you have a cables already on a place.
Speakers are more the 6,5" (I think for Burmester are around 8") so you will be able to get from the system even more.

Mike5215

I bought a spare Burmester Frontbass module on EBay and gave it to my shop to experiment with. There was a Focal that fit in the OEM housing but I never moved forward with it.

damianw

You should. I can say that with almost no modification my AP6.5 are installed. Almost p&p.
The only problem is that the place where it is install - generally the enclosure is to small and you will not get as much as speaker can give you. But we have what MB gave us - generally not a perfect background for mods.
Anyway I am sure that this will sounds better then original speaker.

nobbyv

This is great info. I downloaded a test tone generator app and plan to spend some time this weekend testing each speaker corner to see if I am hearing any resonances or vibrations. I bought a piece of Dynomat and some felt tape that I'll use to damp any buzzing if I find any. I think once I see what noise I can eliminate, I'll have a better idea of a potential upgrade path.

damianw

If possible buy also some tesa tape (like this: http://www.mobilesolutions-usa.com/s...rior_Tape.html ). I found this extremely useful for me actually all. It is thin so you can stick it almost everywhere.

damianw

Some pictures from amps integration in my trunk. The only cable visible is usb which will be disconnected as soon as I will finish my tune.
An issue I found is a driver woofer which probably blown yesterday (yes, my mistake - I overload the speaker probably (or speaker overheat), there is less space - smaller enclosure then on passenger side and carpet is really close to speaker). Passenger woofer is playing nice. I will replace driver woofer as I still have spare AP6.5 from a APK6.5 which I bought for previous car but never install.
As HU does not have a progress bar for a volume control and we do not know when is max volume (especially undistorted) so before configuration I used an PC oscilloscope to check the signal - with Prima AP8.9bit there is a CD where you can find 50Hz tone and 1kHz tone. I played this signal I checked on what is a signal output from HU. It is going quite high w/t distortion but you can find it - so as I mentioned before I will have to install LED to see when distortion is coming. Anyway Prima 8.9 bit in configuration wizard is showing you if signal is clipping or not at the step of inputs config.
I will post some more picture later today with DRC installed and fuse holder close to battery as this can be also a good for someone which is planning to run new cables for an amp. In my config I have 4awg cable run from battery and then some kind of splitter installed in trunk for +12V and ground - this is under amps but quite nice done (I used 2 bolts in the trunk which where not used, prepared a plate and the I split the cable for 2 amps - power cables for both amps are 8awg as requested by Audison - max. cable size).

Mike5215

Nice! Very clean. We went one layer further down in the trunk, under that floor panel (Burmester cars have a little audio rack right under where your stuff is so we used that. The actual Burmester amp is under the liner on the right quarter panel.) If I recall, if you run the configuration wizard in the Bit software while using the CD Audison provides it will automatically set the Prima's levels as high as possible just short of clipping.

Sucks about blowing out a woofer already. What's weird is that we're configured the same and I still have the relatively wimpy Burmester Frontbass speakers getting 130 watts each and I've never gotten close to blowing one.

benzw205

Hello,

Also interested to get the best sound improvement possible for not too much money.
So please could you tell me what is the easiest solution without having to read 12 pages of this thread ?

Thank you so much.