Comments on: Mini Convertible: Crossover

By: John Reekie

John Reekie — Mon, 07 Dec 2015 00:58:09 +0000

Hi David, thank you for your comment. I partly agree with you and partly not. The amps are much more power than really needed for the drivers, so arguably better cost/performance could be achieved with either a lower power amp or (more likely) larger drivers that offer greater SPL. However, I find the comparison with the Yamaha monitor curious – I can buy a pair of HS5 here for less than I can buy the drivers for the Mini Convertible. If your “possibly” were an “actually”, that would mean that DIY is pointless (as the benefits of mass production are such that you can get a complete speaker with enclosure and inbuilt amplifiers for less than the retail of the equivalent drivers alone). Or perhaps it’s simply the particular class of speaker (small active) where this would (might) apply.

I think the real advantage of this particular configuration (two way with the miniDSP amps) is the digital input and passthrough. You can chain the two speakers and then a subwoofer (or two). I do have a diagram of that but appear to have not put it into either article… Then you just connect a digital source (requires digital volume) – no DAC, preamp, or any other extra boxes needed. Unfortunately I don’t have a third amp with which to try this configuration out… perhaps at some point I will.

I’d be interested to learn more about the specifics of what you would suggest as a cost-effective active loudspeaker project. Or if you have a project that you’d be interested in writing up for HifiZine, please send me a note via the Contact link 🙂

By: David Gale

David Gale — Sat, 05 Dec 2015 21:52:13 +0000

Very well executed DIY project! Oftentimes DIYers when designing their projects do not seriously occupy themselves with off-axis performance/measurements. Also I congratulate and like your approach of going fully active.
Nevertheless this project judged purely from cost/performance perspective in the presented implementation with ICEpowered minidsp plate amps makes it utterly expensive (300 EUR for drivers + 600 EUR for plate amps + cabinets etc.). IMHO an investment too large into a system of this size. There are speakers on the pro monitoring market possibly offering similar performance that can be had for less e.g. look at Yamaha HS5/HS7/HS8 monitors (using waveguide on tweeter too). But of course, to make the project more cost effective one case use cheaper/existing amplifiers and do xovers/eq purely in software and feed the amps from computer.

By: John Reekie

John Reekie — Fri, 09 Jan 2015 15:43:25 +0000

Hi Christopher, thank you for your comment and I’m glad my articles helped you.

By: Christopher Snow

Christopher Snow — Wed, 07 Jan 2015 12:57:30 +0000

Thank you very much for taking the time to write and publish this! I have always wanted to build active speakers and have finally decided to begin, and this information has been extremely helpful. I just ordered my mini dsp ice 250 – coming in on Friday. Going to start off with a small 2 way with a seas 12mm woofer and a Vifa ring radiator and see how things pan out,

I’m using Shahunian elf speakers and genelec 1029a’s as my reference.

Once again – thank you very much! Your description of the mini dsp being ” simplicity itself” convinced me to buy it and get started!

– Christopher Snow

By: Milan Stejic

Milan Stejic — Sun, 28 Dec 2014 10:22:57 +0000

Ah, OK. I thought I had the updated firmware, but I will confirm and make sure I have all of my existing settings written down.

By: John Reekie

John Reekie — Sun, 28 Dec 2014 04:49:27 +0000

Hi Milan, thanks for your comments. There was a firmware update to the PWR-ICE a little while back, I suspect the reason for the error is that I’ve been using the new one and you have the old one in your amps? As I recall the new firmware comes with the new 2×2 plugin (download from User Downloads on minidsp.com). Unfortunately if you update to this new firmware/plugin you have to re-enter all your settings by hand, as there’s no automatic update/migrate of existing data.

By: Milan Stejic

Milan Stejic — Sat, 27 Dec 2014 19:23:21 +0000

John,

I have the PWR-ICE125 plate amp and have been very happy with it. I tried opening up your crossover design to get an idea of how you approached your crossover design, but a received this message:

The system settings configurations are most likely incompatible or do not exist. Please load

Do you have any thoughts on what I need to do to overcome this? BTW, I think your mini convertible design is a nice one!

v/r

Milan