TEST: Grossmann SG-Box

One man's joy is another man's sorrow. Even if it is objectively more than understandable that not everyone around us can warm up to a properly cranked up amp sound, the combination of volume and sound puts every guitarist in a quandary at some point. While the electro guys with their synthetic sounds can easily work on their sonic collages in any rented apartment at room volume, a good to very good guitar sound is unfortunately inevitably dependent on a minimum volume. At the latest now the hour of an Iso Box strikes, as it is offered for example by the company Grossmann. Can the Grossmann SG Box help us out?

The new woes of young G.

We all know the problem, especially if you live in a rented apartment with several parties in the house. Especially with all-tube amplifiers, even if they have only 1 watt as output power, the feel-good factor about the personal sound in relation to the volume starts far above the limit that the neighbor still considers tollerable. Especially if you want to equip your instrument with a decent sound for a recording.

As is well known, especially all-tube amplifiers act from the point where you drive the output stage razor-thin into saturation with the maximum sound, which at the same time turns out to be much too loud for an intact neighborhood. But even transistor amplifiers need a minimum of speaker activity to produce a decent sound. The quiet chirping in room volume can really not be expected by anyone on a recording. Of course, you can also buy a Kemper or similar, but we do not want to open the barrel about the sonic quality of these products or their robbery of the classic amplifier culture today.

The only other option is a professional recording studio with room-in-room construction or, precisely, an Iso Box. But what exactly can an Iso Box do?

How an Iso (-lations) Box works

The principle of an Iso Box is in principle very simple but in detail more than just clever. How do you get a noise generator to be quiet? Quite simply, one packs as thick and heavy plates as possible over and under him, seals all joints lets the sound in the inside dead run. Then you decouple it as much as possible from the floor and make sure that the surrounding material vibrates as little as possible, because that is the sound that we perceive now.

This means at the same time that our great amplifier / loudspeaker combination outside the box sounds like bowl, only inside the box comes the true sound to bear. So never get the idea to equate an Iso box with a load resistor between amplifier and cabinet in terms of sound, that doesn't work. Of course, this means that a good iso box must have one or more elaborate miking mounts. So let's see how the Grossmann SG Box fares in all these respects.

The construction of the Grossmann SG Box

If you want to dampen sound (please don't confuse this with damping), you need mass. The heavier the better, what is heavy does not resonate so easily. But the whole thing is of no use if the individual components are so heavy that they cannot be lifted. Here, the Grossmann SG box with its weight of 27 kg (without speakers) is exactly at the limit. In order to lift the upper part from the lower part, you should have a strong shoulder/arm combination, otherwise you will quickly get stuck on the microphone mounts. Yes, it's exhausting, no, it can't be done any other way, because see masses!

The Grossmann SG Box comes in three parts, top, bottom and speaker. The speaker port was designed for a 12 inch speaker, a good choice since probably 95% of all guitarists prefer this speaker size over 10 or 15 inches. However, a 10 inch reducer ring also allows the use of a 10 inch speaker. In principle, you can install anything you want here in terms of manufacturer and wattage. I chose one of the most popular and flexible speakers, the Vintage 30 from Celestion. However, you should be careful with the final volume, a 100 watt all-tube behemoth will destroy a single speaker of this power class very quickly. Therefore, either use amps of maximum 20 watts or choose another speaker.

Also included are three mounting arms for three microphones, the appropriate cabling plus all adapters for the different speakers and all the necessary screw fittings to attach the mounting rails and the microphone clamps. Very important also, 4 very soft and highly erected cone feet made of rubber to decouple the construction with regard to resonance from the floor.

Both the upper and lower parts of the Grossmann SG Box are lined to the maximum with foam and mineral mats to prevent any form of reflection. Who likes to work with rooms, please add in the mix using plug-ins or outgear. Regarding the required cables, everything is already prepared, for the microphones three XLR cables are hardwired together with connection sockets on the bottom part, color-coded with white, black and gray. In addition, the speaker input is located below the microphone jacks.

As we all know, every centimeter counts when picking up a guitar, so maximum flexibility of the microphone rails is an extremely important point. Here Grossmann has really done everything right. In the X-axis, the rails with 2, respectively three holes can roughly decide how far the microphone moves towards the dome. The Y-axis has a control range of about 25 cm, so that you can move the microphone right up to the speaker, thanks to the lack of a front cover, or choose a more indirect pickup. Due to the fact that the microphone stands can rotate at their screw connection to the housing, one can also move the microphones in the Z-axis, which allows for more sophisticated miking techniques, such as the Fredman method.

A little attention should be paid to the deflections of the microphones to the side and especially upwards, so that when you put the hood on, you don't move the microphones or worse, push them out of their mount, because in this case they can fall on the speaker and possibly damage it. If you have a microphone clamp that can be screwed on tightly, such as the one supplied with Heil microphones, you are generally on the safe side. In the case of the cheap clamp variant, as supplied with microphones such as the SM 57, it is advisable to secure the microphone with some gaffa tape if necessary.

The Grossmann SG Box in practice

I was truly curious about the sound insulation and the sound of the Grossmann SG Box, especially since the system has to hold its own against an extensive guitar miking system in my studio, which consists of 10 different cabinets and 14 different microphones. Let's start with the soundproofing.

In order not to overload the Celestion Vintage 30 speaker at all, I limited the output power of my H&K Black Spirit 200 to 20 watts. Now various factory sounds, as well as my stage sounds were used, in which the resonance control is used much more strongly and the box in the bass range strongly demanded. The result was impressive!

Up to a master volume of just under 12 o'clock, the Grossmann SG box just spreads room volume. The 22 mm thick MDF panels resonate slightly and spread the sound of a simple portable radio to the outside. This volume can also be used in a rented apartment without any problems. At full load, it could be a bit loud in a rented apartment, but a detached house can easily handle this volume. It's easy to forget how incredibly loud 20 watts can be on a speaker. At regular intervals, you should briefly take off the hood and briefly realize how strong the insulation actually is, you might hardly think it possible.

Due to the very soft and high feet of the speaker, vibrations towards the floor are also very well cushioned, a real gain in terms of damping. In terms of sound, the system can also only be given top marks, although the sound is of course highly dependent on the amplifier used, the microphone and the knowledge of the perfect positioning of the same. Spatial recordings are of course not possible with the Grossmann SG Box, but in my opinion this also has an advantage. It is often forgotten with the vaunted spatial component within the guitar recording that it only makes sense if you actually have a very good sounding, acoustically optimized room whose recording is worth it. In that case, I would always give preference to a very good plug-in or Outgear Reverb to place the guitar in a room.

Conclusion

The Grossmann SG Box is a perfect tool to eliminate the main problem of all guitar recordings, the given combination of good sound with high volume. With disciplined handling, you can also drive your beloved all-tube amp into saturation and still make your recordings very high quality in a rented apartment.

For all guitarists who do not have their own recording studio, but still want to generate maximum sound quality of the old school, an absolute must!


Additional Informations:

- A guitar isolation box, also known as a guitar booth or guitar cabinet isolation box, is a specialized enclosure designed to isolate the sound of a guitar amplifier, speaker cabinet, or combo amplifier. These boxes are commonly used in recording studios, rehearsal spaces, and home studios to achieve a clean, isolated sound while reducing overall volume.

The concept of a guitar isolation box is relatively simple. A guitar amplifier or speaker cabinet is placed inside the box, which is lined with acoustic foam or other sound-absorbing material. This material helps to reduce the amount of sound that escapes from the box, allowing for a lower overall volume level while still maintaining a clear, full-bodied tone.

Guitar isolation boxes come in a variety of shapes and sizes, depending on the needs of the user. Some boxes are large enough to accommodate full-sized amplifiers or speaker cabinets, while others are designed to fit smaller combo amps or even pedals. Many boxes feature removable or adjustable panels to allow for different microphone placements or to change the sound of the isolated guitar signal.

One of the primary benefits of using a guitar isolation box is the ability to record or play at lower volumes without sacrificing tone or clarity. This can be especially beneficial in situations where high volume levels are not practical, such as in apartments, shared living spaces, or late-night recording sessions. Additionally, isolation boxes can help to eliminate unwanted noise and interference from other sources, resulting in a cleaner, more focused sound.

While guitar isolation boxes can be purchased commercially, they can also be built at home using basic materials and construction techniques. There are numerous online tutorials and DIY guides available for those interested in building their own isolation box.

Overall, a guitar isolation box is a valuable tool for any guitarist or recording engineer looking to achieve a clean, isolated sound without sacrificing volume or tone. Whether purchased commercially or built at home, an isolation box can be an effective and cost-efficient solution for a variety of recording and playing situations.

Fredman microphone placement is a recording technique that was popularized in the 1990s by the Swedish metal band, Meshuggah, and their producer, Fredrik Thordendal. This technique involves placing two microphones in front of a guitar amplifier, one slightly off-axis and the other directly on-axis, and mixing the two signals together to achieve a unique, full-bodied tone.

The Fredman microphone technique is named after its creator, Fredrik Thordendal, and is often referred to as the "Fredman mic technique" or simply "Fredman miking". The technique is commonly used in heavy metal and hard rock recordings, but can be used for any genre where a full-bodied guitar tone is desired.

To set up the Fredman microphone technique, two dynamic microphones are placed in front of the guitar amplifier, one slightly off-axis and the other directly on-axis. The off-axis microphone is typically angled at around 45 degrees from the amplifier, while the on-axis microphone is placed directly in front of the amplifier speaker. The two microphones are then mixed together to achieve a balanced tone.

The off-axis microphone is often positioned closer to the center of the speaker cone, where the tone is brighter and more focused. This microphone captures more of the high-frequency content of the guitar tone, resulting in a more detailed and articulate sound. The on-axis microphone, on the other hand, captures more of the low-frequency content of the guitar tone, resulting in a fuller, more rounded sound.

The two microphones are typically mixed together in a 50/50 blend, although the exact mix can vary depending on the desired sound. The resulting tone is typically characterized by a full-bodied, heavy sound with a lot of midrange and low-end punch.

The Fredman microphone technique has become a popular recording technique in heavy metal and hard rock circles, and is often used by producers and engineers to achieve a unique guitar tone. However, it is important to note that the technique may not be suitable for all genres or styles of music, and should be used judiciously to avoid overloading the mix with too much low-end or midrange content.

In conclusion, the Fredman microphone technique is a unique and effective way to capture a full-bodied guitar tone in heavy metal and hard rock recordings. While it may not be suitable for all genres or styles of music, it can be a valuable tool for producers and engineers looking to achieve a distinctive sound.