Sound insulation in the new Arto 88 from Niesmann + Bischoff

Hello everyone,

Some of you may have followed: This year (2025), our family switched from a caravan to a motorhome. As a result, we'll be traveling much more as a camping business to attend offline events – VW bus meetups, dealer trade shows, etc.

From caravan to motorhome – decision & manufacturer selection

There wasn't much to consider when it came to choosing the manufacturer of our future motorhome. The important thing was: enough space for four people plus a dog. We looked at many models, but stylistically most manufacturers were still quite outdated in comparison – and for a lot of money, you still ended up with a lot of caravan-like features like sharp-edged doors, pop-out doorknobs, etc.

It quickly became clear to me that we had to look at Niesmann + Bischoff's offerings. I've had them on my radar since the Flair was introduced with its new interior. We did glance at other vehicles for good measure, but the conclusion came quickly:

That's not ours!

The style, the quality, and the "Made in Germany" factor were clear selling points for us. Even the new luxury liners were out of the question – simply too much.

First impressions & critique of the sound system

However, something that bothered me considerably was the so-called "High-End Sound System." I'm someone who likes to tick the box for better sound in cars. But here, the result was disappointing—almost an insult for a vehicle in this price range.

Point 1: The engine is located under the dashboard – inside the vehicle. It's separated only by a thick polystyrene sheet. The 2.0L Mercedes Sprinter engine (170 hp, 5.5 t) is hard-working and loud. That's hard to accept in a €300,000 vehicle.

Point 2: The Jehnert sound system appears to be poorly integrated. The midrange speakers are suspended without enclosures in plastic parts, and the subwoofer is barely audible. Driving at 80 km/h, you might as well just put your smartphone on the dashboard – the sound experience is the same.

Standing on the ground, it sounds okay – but only okay. And that's not enough for me. As long as the engine is running, the vibrations destroy any depth of sound.

Solution approach – Insulation & sound optimization

I divided my plan into two steps:

1. Dampening of all vibrating plastic parts in the interior
2. Sound insulation on the engine compartment side

Working in detail – step by step

Step 1: All removable parts of the dashboard were carefully disassembled. Important: N+B has coated the parts with a rubberized material – visually appealing, but practically a disaster. Dirt sticks to it, cleaning is difficult, and the surface is extremely sensitive. A synthetic leather covering would be significantly better.

Step 2: Hollow, vibrating surfaces were covered with Panther Comfort Mats – the knock test immediately showed an improvement.

Step 3: Next, a 10 mm layer of foam was added to prevent rattling and dampen the airflow in the dashboard. The difference was clearly audible. Watch the video of the knock test.

Step 4: Reassemble everything – it's best to take photos to remember the screws and their positions. The materials are extremely sticky, so work carefully.

Step 5: Insulation of the side panels is still pending – the disassembly process is currently unclear.

Engine compartment insulation & result

I sought advice from Manfred Sack (ADMS-Shop) regarding engine compartment insulation. He recommended:

• ADMS Premium Heavy Layer – spot-bonded to the polystyrene surface
• Triflex felt – spread over the entire surface

The whole process took about 30 minutes. Then came the practical test – in the rain, of course. The result: a night-and-day difference. The engine is still audible, but no longer disturbingly loud. On level ground, the Arto travels almost silently between 80 and 100 km/h. Wind noise? Hardly noticeable.

The sound is significantly more stable acoustically. However, for a truly concert-like experience, it still needs DSP fine-tuning and possibly new subwoofers. For that, I'll be going to Jehnert themselves.

Conclusion & Outlook

Niesmann + Bischoff builds fantastic vehicles – no question about it. But in my opinion, they skimped on the sound system. The €1500 surcharge isn't worth it. For €2500 or €4500 with a truly excellent result – yes, that would have been worth it.

My modifications cost around €150 and have significantly improved the driving experience. Perhaps this post will reach N+B directly – the issue could easily be resolved at the factory. I would welcome that, because one thing is certain: this Arto will not be our last.

I'd love to hear your thoughts: How do you feel about your motorhome?