Introducing Ground Sound

[Robert GS]

Hello my name is Robert, owner of Ground Sound. This introduction is made mainly to satisfy curiosity about the reason of the company and who I am. The company was founded in the mid 80’s. It all started out at the pro-stage (amps, speakers and other gear). From ’90-‘95 I had the distribution of the Lab.Gruppen products, in Denmark. Then again from ‘99 until recently I have had contact with Lab.Gruppen as a subcontractor. In these years I have build thousands of amps and parts of amps and learned a great deal about amp design.
The interest of DIY started in the early ‘80s. Over the years, I’ve built speakers, amps, active analogue crossovers and a little bit of lighting equipment. One of the things that have had my interest was pro subwoofer horn and I think that I’ve achieved some pretty good designs. Early on, the HiFi part of DIY was concentrated on amplifier design and somewhat later active crossovers. I will highlight two experiences that I’ve had over the years:
The first was when I build a Lab clone to a friend of mine. He owned a pair of Martin Logan CLS and at the time he had had quite a few amps to drive them. None of them really doing the job and the last one had blown up. He was ready to experiment with my stuff. At first we started with a Lab.Gruppen LAB1000 with fans. This worked and the sound was quite okay, but the fans did mess up even though quite low noisy. So the next step was taken with a passive cooled amp clone with rather small PSU in terms of capacitors value to limit the budget. It worked fine, but I persuaded him to invest heavily in capacitors and sound got to another dimension in terms of clarity, bass control, frequency balance and room positioning. After that, we did a lot of tests concerning Class AB and Class A to see if something could be gained – nothing at all. This has led me to conclude that Class A amps often sound good because they don’t work unless the PSU is heavy in capacitors and that is their gain. My advice of amps: Use a sensible engineered amplifier and a low ESR PSU.
By the way, he called them the shoeboxes as the boxes he made looked like that.
The other experience was my introduction to digital crossover filters. This was around ’92, I think. Lab.Gruppen was developing the later DSP24. The demonstration was A/B on a pair of HiFi speakers driven by a small NAD amp. I simply just didn’t believe what I heard. Amazing. That was the next item for me. The software math was based on an advanced kind of FIR filters demanding less MIPS. When the DSP24 went into production, I bought a pair to the pro stage activities. But I was sorry, because it was damn difficult to make a satisfactory setup with the clumsy software. The hardware was also rather complex with software controlled multi settings of output level. A too efficient input clip limiter making levels of +20dB sounding okay just with less dynamics and compressing the sound risking burned drivers to the inexperienced sound engineer. The DSP24 was also rather noisy when used with high efficiency pro drivers. The DSP24 flopped totally also being a 2 input and only 4 output device and no real display.
Anyway, I was hooked on the digital crossover filter idea. The resent years, my interest has evolved into home cinema. As I wasn’t satisfied using active analogue crossovers, not to mention passive crossovers, I began searching for a DIY digital crossover, finding absolutely none. Destiny suddenly gave me the opportunity to make the DCN23 and the rather convincing XOverWizard software. The amplifiers are developed and adapted to the DCN23 from the clone. I want to emphasize the unique profile of the amplifiers, it is much better at heat transferring than normal profiles, more stable than direct mount of power transistors.
Ground Sound’s products might not be as DIY as many of you people would want. As the DCN23 only could be constructed with SMT which is very difficult to hand solder, I chose to make all products with as much SMT devices as possible. This also makes the modules smaller in size.

I know this could be seen as advertising and I suppose it is a kind of. I have considered posting some replies on the threads that involve Ground Sound for some time, but as it will be time consuming, I’ve made this introduction and I hope you all will be able to understand that I seldom will post replies/comments. Finally, I can recommend the technical pages at Lab.Gruppen and the work of the founder Kenneth Anderson, especially the superior class TD incorporated in the first model LAB2000 from 1990, the still superior C-series models and soon coming fP+ models with 12kW+ specs. Sadly he has left the company. Last comment: I will not disclose any schematics of any Ground Sound products.

Thank you for your time reading this introduction, I hope you will be inspired to DIY some more.

[planet10]

Welcome to the forum Robert. It is always nice to have people like yourself participating 1st hand in the forum.

Any chance we'll see the XO software running on OS X natively (easy enuff now to run it under Windows on the Mac, but Windows is such a kludge)

dave

[Robert GS]

Hi guys,

and Planet10 thank you for replying. It's not very likely that the XOverWizard run on other than Windows, as time is limited. But now it's ready for download at the link on the DCN23 page. Do have a look and try it out, but I'm sure you are missing the best part unless you buy the hardware - sorry

By the way you can se what Stefan Woessner did with his DCN Kit at Customer Galleries..

[planet10]

Originally posted by Robert GS
Do have a look and try it out, but I'm sure you are missing the best part unless you buy the hardware - sorry

Won't be able to do that until i get an Intel Mac, but i have it bookmarked.

Thanx for the link.

dave

[Kay]

Hello Robert,

I see you program and this looks good for me,
but I don't need the DCN23.

It's possible to get the SW and the controller (Atmel?),
so I can make my own hardware?

At this moment I need only one audio channel for my
planned DBA (Daul Bass Array).
I need a delay, three parametric EQs and may be a limiter.

For AD/DA I like to use the TLC320ad77, it's enough for
my game.

[Robert GS]

Hi KAY.

I think exactly - that you need the DCN23 and all of its possibilities.
It's right for the job. Why do you want to waste a lot of energy to get a less performing crossover/eq/room correction device?

I think that all loudspeaker systems would benefit of an active setup with a digital crossover.
We are currently working on a similarly product as the DCN23.


The new product will be named DCN26DAV. The DCN26DAV will have stereo input - automatically choosing between 1 AES3 digital input, 2 coaxial digital inputs and 1 analogue input.
3-way stereo/6-way mono processing and a digital controlled master volume at the output – optional hardwired bypass of the volume – if you want to use your own volume control. The board also includes PSU and relay circuitry.

There are also plans of a very nice chassis for the DCN26DAV.


Robert

[Kay]

Hi Robert,

I understand your arguments,
but if I need a complete crossover, than I buy a
Behringer DCX.

I like to have only a "intelligent Subwoofer" for my
home theater. May be, for my DBA, I need two Sub-channels,
but not at the same location. So a Stereo-PCB is not the
best idea.
O.K.,
I'm thinking about wireless digital audio transmission
too (Nordic Semiconductor), but in this case, I need
delays for all 7.1 channels.

[Robert GS]

Hi KAY.

I am sorry - then I can't help you. Have a nice hunt for the right solution.

[peranders]

Hej, Robert, välkommen till världens bästa DIY audio forum. Anyone who not understood this

I am also the biggest SMD fan here, quite exotic in DIY circles.

[djQUAN]

Originally posted by peranders
Hej, Robert, välkommen till världens bästa DIY audio forum. Anyone who not understood this

I am also the biggest SMD fan here, quite exotic in DIY circles.

I don't.

I also like building SMD stuff.