Ground Sound

Hörtest 21.June 2008

The Brieden Verlag residens:

The Brieden Verlag is not just Klang + Ton, but also
CAR&HIFI, HIFI TEST-TV-VIDEO, HEIMKINO, DVD WELT, HIFI TEST designedition, DIGITAL HOME, LP - Magazin
and the web magazine LLoxx.de has tests - and Brieden magazines can be downloaded here too.

The giant Schmitti Memorial loudspeaker named after the previous editor of Klang + Ton - Heinz Schmitt.
The bass driver is the PD2450 - Precision Devices 24"=61cm - 37kg - 6" voice coil
A PHL 2520 takes care of the mid-range and the tweeter is a Mundorf AMT 2830


The Measurement Room at Klang + Ton	The "Control Room" - Clio system

First listening installation and preparation of the final setup made by Christian - the day before


The "Linear" setup of the AO - Clio measurements Download the setup: AO_XOW_linear.xow	Christian Gather's "listening" setup of the AO Download the setup: AO_XOW_CG.xow

All the Ground Sound modules were on display
- and even the new Coolback II 600 could be seen for the first time

I would have liked to make the measurements of the AO in the K+T measurement room, but a simple mistake made us believe that the new XOverWizard II had a bug giving a slope of about 6dB/oct. High Pass in the whole frequency range. An hour before the Hörtest participants would arrive – I gave the new XOverWizard software one more shot. Ha – no bug – a simple wrong connection in the microphone amp/mixer. Above you can see the measurement setup – Microphone + stand, mixer amp, some wires and laptop. The software worked perfectly - below some screen shots. The XOverWizard II software is actually capable of measuring in a “normal” living room, because the sophisticated “multi-win” tool is able to "take the room out of the equation".
The “multi-windows” are the pink area of the PIR window in TIW200 and 18W/8545K00 measurements.


Measurement of the dual bass woofers TIW200	Measurement of ScanSpeak 18W/8545K00 mid-range


Measurement of the tweeter Visaton KE25SC	The target for the tweeter set to 24dB/oct. Linkwitz/Riley High Pass at 2200Hz (crossover point)


The optimizer working to get the wanted response	Output window showing the EQ values for Visaton KE25SC tweeter calculated by the optimizer

The "automatic" setup of the AO loudspeakers is shown above. Unfortunately, Christian had to stuff the reflex ports to get a tighter bass, as the listening room at K+T has a giant peak (room mode) at 31Hz. I forgot to remove the stuffing from the port before I made the XOverWizard II measurements. This way I didn’t get the right ported response. Afterwards, it would have been easy to get the “right” tight bass response by removing the room resonance with a notch filter (31Hz – Q=10-20). This is an effective tool to get an authentic / strong bass without room. If the bass is right – the tonal balance can get right too and an aggressive sound is avoided... - and the sound image will still be intact!


A view form the listening position - we are ready to present the AO	The "power" behind the speakers

All seats are taken - people are listening intensively - sometimes with eyes closed ...

The presentation of the "old" XOverWizard software and the "new" XOverWizard II software.
Yours truely, Robert GS, at the Laptop and Christian Gather pointing and explaning how everything works

The Design Amplifier "OP" was used for the passive and full-range loudspeakers

The nice weather permitted "listening in the garden"
When you listen to a system outdoors it does a lot of "good" to the sound (=no wall and ceiling reflections)
K+T has an expression for their cheap loudspeaker projects called Cheap trick # something
- Listening outdoors must be the best cheap trick there is at all...

A few men can't get enough and listen to music and loudspeakers into the evening hours
and of course - Klang + Ton "Leitender Redakteur": Christian Gather (black T-shirt)

Der Holger Barske cleaning after the "party"

A lovely afternoon in Duisburg was at its end...

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