IRON Mastering Compressor review at Bonedo (featuring audio examples and video)

Sometimes more is really more!

Felix Klostermann from Bonedo presents a very informative review of the IRON Mastering Compressor. There is not only a review, but also some audio examples and a video.

Anyone who hadn’t had the opportunity to test the IRON will get an first initial impression of the wide variety of the IRON.

Features for final touch like AirBass and Tape Roll-Off are also part of the audio examples.

Apart from the detailed review, there are lots of pictures of the inner parts of the unit and a little bit of “nerd talk”.

The IRON gets the full score. Five out of five stars.

Here you can read a small excerpt of the review:

Dreamlike feel

Although I already metioned it before, I would like to do it again at this point: The SPL Iron is a ‘sexy piece of hardware’. The build quality is very good. Everything, including the control elements, has a high quality touch.”

Astounding variety of sounds

Now I was wondering for some time how to explain the many possibilities that the Iron offers and came to the conclusion: It is in actual fact impossible!

That’s why I want to avoid an overly academic approach. You have to feel the Iron! Depending on the rectifier setting and its unique sound characteristics, the operating point (Threshold) is shifted, which among slightly different tone color, other dynamic differences occur.”

It makes little sense to try to adjust Attack and Release, so that they sound fairly the same for different rectifiers. That’s not how they work – and this is really great!”

The different Sidechain-EQs also have a strong influence on the final result and should not be confused with typical SC-Lowcuts.”

The strengh of this compressor is above all its incredible transparent way of compressing music material without negatively influence the dynamics.”


From now on I will have a dedicated 4U-space in my rack for the Iron”.


You can find the review, audio files and video at bonedo.

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All Black Edition

All devices of the mastering series are now available in a third color combination –

IRON “All Black”

Black is the new black! We are currently offering the SPL IRON Mastering Compressor in


Due to Covid19 there are no events scheduled at this time.

What does it actually mean …

In Stock!

The product is in stock in our warehouse in Niederkrüchten, Germany, and will be shipped the same or next working day.

We process the orders after receipt of the order and update the stock in the online shop regularly. If the product is no longer available at short notice due to high order volume, you naturally have the right to withdraw from the purchase (see Right of Withdrawal).

In any case, you will receive an e-mail with details of the delivery and the estimated delivery time.

Available soon!

The product is not in stock in our warehouse in Niederkrüchten, Germany. Usually it will be available again within 5 working days.

In any case, you will receive an e-mail with the details of the delivery and the estimated delivery time.

Of course you have the right to withdraw from your purchase (see Right of Withdrawal).

Product Condition


Brand-new product from the current product portfolio.


Demo, exhibit or return item.
In original packaging, incl. manuals and full warranty.
Only slight to no signs of use.


Demo, exhibit or return item.
In original packaging, incl. manuals and legal warranty.
In some cases clear signs of use, which are documented in photos.


"New Old Stock"
After discontinuation of a product still available new products with full warranty.