# Introducing the QA451

**URL:** <https://forum.quantasylum.com/t/introducing-the-qa451/139>\
**Category:** QA45x\
**Created:** [July 23, 2020, 5:12pm UTC](https://forum.quantasylum.com/t/introducing-the-qa451/139 "2020-07-23T17:12:14Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![matt](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@matt](https://forum.quantasylum.com/u/matt)\
**Post date:** [July 23, 2020, 5:12pm UTC](https://forum.quantasylum.com/t/introducing-the-qa451/139/1 "2020-07-23T17:12:14Z")

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> **[Introducing the QA451](https://quantasylum.com/blogs/news/introducing-the-qa451)**
>
> This week we begin shipping the QA451. The QA451 replaces the QA450 programmable load. When combined with the QA401, the QA450 and QA451 products make it very easy to quickly test amplifiers at both 4 and 8 ohm loads, and make a range of measurements...

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**Author:** ![VAR](https://yyz2.discourse-cdn.com/flex032/user_avatar/forum.quantasylum.com/var/32/959_2.png) [@VAR](https://forum.quantasylum.com/u/VAR)\
**Post date:** [May 12, 2023, 6:18pm UTC](https://forum.quantasylum.com/t/introducing-the-qa451/139/2 "2023-05-12T18:18:13Z")

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I noticed at AP has an accessory called a “power cube” that allows you to test more than just a resistive load by adding capacitance and/ or inductance to the resistive load. I got to thinking that what might be more useful would be to actually have the impedance of a real life speaker approximated by some RLC networks. Realizing that the RLC networks and associated switches would need to handle at least 200w, and having not done any reverse engineering to create a network from an impedance plot (ChatGPT?), it may not be very practical, but it would be neat to show someone how their amp should do with their particular speaker. I would be more than happy to provide several measured speaker impedances, including the “amp killer” AR9. 😀