HELIX CFMK20 BMW.1

You will receive the tracking number to track the delivery after the order has been processed, usually the evening after the shipment has been collected and will be sent to you by email.

Nationally, we charge shipping costs of 4.90€ up to an order value of 49€, once this amount is reached, shipping is free of charge. Internationally, the costs are different and can be viewed in the checkout for the respective country.

Depending on the receipt of the order, the goods can be shipped promptly and are usually delivered within 1 - 3 days, the exact delivery period can be found on the product page.

You can collect your order from our store in 91224 Pommelsbrunn, Amberger Str. 17, which is located directly on the main street. After confirming your order and selecting collection, you will be informed when your order is ready for collection.

Please contact us with your order or shipment number and we will complain about the transit time of your shipment

✓ 1 - 31,5Kg = DHL

✓ 31,6 - 40Kg = GLS

✓ 40.1 - maximum kg = freight forwarder

✓ Bulky goods = freight forwarder

✓ Dutiable shipments = DHL or freight forwarder

For stock items, orders must be received by approx. 4 pm, are usually disposed of on the same day and transported directly to the parcel center, the delivery times can be found adapted for each item on the product page.

We use several indicators for sufficient transparency in the store. All products are marked several times with the corresponding availability and delivery time. The availability indicator shows a rough overview of the stock quantity; if there is excess stock, the indicator is automatically hidden.

Items that are not available cannot be ordered.
To avoid unnecessary waiting times, we have set up an e-mail notification function for you. As soon as the goods arrive, you will automatically receive a notification of availability after entering your e-mail.

Manufacturers who provide data sheets or operating instructions can be found at the end of the item description for download.

Unfortunately, it is difficult to give a general answer, as all woofers and speakers are constructed differently and have different coils, plus the amplifier, which must be designed for the connection impedance. You can simply use our wiring assistant, enter the number of speakers, resistance and wiring variant and have it calculated. If the amplifier can handle the connection impedance, nothing stands in the way of the wiring.

Amplifiers which have a release up to e.g. 1 Ohm can also be connected with 2,3,4 and higher impedance.

Our port calculator shows you which tuning your enclosure has! The net volume is always particularly important here. Calculate the pure recorded chamber of the subwoofer beforehand to arrive at the correct result. The net volume is calculated minus all displacements and is important when designing the enclosure.

The net volume design for your woofer size in music mode can look like this

Bass reflex:

✓ 6.5" (16.5cm) = 10 - 15 liters

✓ 8" (20cm) = 20 - 30 liters

✓ 10" (25cm) = 40 - 50 liters

✓ 12" (30cm) = 60 - 80 liters

✓ 15" (38cm) = 100 - 125 liters

✓ 18" (46cm) = 180 - 240 liters

✓ 21" (54cm) = 230 - 290 liters

If you prefer to listen to charts, rock, pop or e.g. techno, the tuning should be a little higher and is usually in the range of 40Hz and higher. The range of RnB or Ami HipHop usually plays in the 30 to 40Hz range.

In short, clipping is an "unclean signal". You can usually recognize clipping in woofers when there is an electrical smell, the woofer stinks and becomes hot. With loudspeakers, it can also be noticeable through unclean reproduction. The fun is over when the coil has unwound from the carrier. Many amplifiers now have a clipping LED integrated in the output stage or in the bass control; if the LED lights up, you should definitely turn down the volume. If the amplifier does not have an LED, the only way to position the gain correctly is to use an oscilloscope or other aids. However, this requires a certain amount of basic knowledge in order to set the amplifier correctly.

We almost exclusively offer products and manufacturers that we use ourselves and install regularly, true to the motto "quality not quantity", so we can usually tell you what to expect. All products are sensibly designed and selected to cover a wide range, for reasonable sound optimization and, above all, to achieve the desired goal. If you have any questions about your setup or plans, please contact us!

All payment methods are displayed for the respective country in the checkout, for Germany usually
- Bank transfer
- PayPal
- AmazonPay
- Klarna
- VISA
- GooglePay
- ApplePay
- Sofortüberweisung

Payment by installments is possible with PayPal and Klarna, simply select the desired provider, view offers and check out. The rest of the ordering process is then fully automated.

The business premises are located in 91244 Pommelsbrunn, Amberger Str. 17, directly on the main street.

When picking up the goods, payment can be made on site by cash, Paypal or real-time bank transfer.

The best way to reach us is by email at info@mtaudio.eu,
via Whatsapp or by phone on +49 160 7603014.

The invoice can be downloaded via the attached link in the order confirmation email.

The company was founded in April 2015 and has been active ever since.

With a car hi-fi team of almost 40 people, we are regularly represented across Germany and internationally at various events/competitions, and we share most of our journeys via Instagram stories.

All items come with a 2-year warranty

The best way to contact us is by e-mail so that we can send you the appropriate service forms and, if necessary, labels for shipping directly, depending on the product and damage pattern. The item will be checked upon receipt and the damage pattern determined. After checking the damage, we can determine the cause and act accordingly.

The processing time depends on the product and defect, usually a few days for amplifiers and 1 to 2 weeks for loudspeakers. If it is a material defect and the repair is not foreseeable, the item will be replaced.