Comments on: Prototyping a 4-way open-baffle speaker with the miniDSP 2×4

By: John Reekie

John Reekie — Tue, 11 Jul 2017 10:35:55 +0000

Hi Per, yes, I am currently running my next version with linear phase crossovers.

By: Per

Per — Wed, 05 Jul 2017 01:56:05 +0000

Did you get to linear-phase yet?

By: John Reekie

John Reekie — Mon, 24 Apr 2017 09:12:01 +0000

Hi Niclas, I suspect that the reason why 24 dB/octave is “standard” is because that is the optimum configuration for analog implementation. I am for myself moving to linear phase DSP crossovers. More on that when I get my revised version of this project a little further developed 😉

By: Niclas

Niclas — Wed, 19 Apr 2017 09:04:51 +0000

Hi Sir! Cool setup! I’m planing a similar my self.
Have you tried ab testing 24dB – 48dB cross points concerning “natural sounding” sum. 24db is standard on all Pro live concerts. I wonder a bit why .. worth a test! Cheers!

By: Carl

Carl — Wed, 07 Oct 2015 12:35:00 +0000

John great article. I’m working the exact same project with my ,,Emerald Physics 2.4 3 way open baffle design and the miniDSP 4x10hd. Because the drivers are 97db/watt I hear everything . So I have a gain problem . I don’t know how to get the gain noise problem solved . I m using a DSPeaker I front of the miniDSP for my preamp. The quiet passages are not so quite ,full of hissing noise .

Do you recommend a blocking cap on tweeters given the danger of damage ?

Thanks for your advice Carl

By: John Reekie

John Reekie — Sun, 12 Jul 2015 15:52:44 +0000

HI Jonaton, because of the dipole rolloff (see “theory” section in article above), the frequency range of the larger drivers tends to be more limited than when used in boxes. I suppose I should really say “three-way plus sub/s” – in terms of the active crossover needed, it’s (almost) the same. A three-way or two-way open baffle speaker is more demanding on the individual drivers.

By: Jonatan

Jonatan — Sat, 11 Jul 2015 08:41:05 +0000

Hi John. Wht’s the advantage of sound being produced from 4 way over 3 way ? Most of modern good quality loudspeaker can produce tight flat +- 5 dB across audio freq, 20 Hz-20 kHz with 3 way system. Would you mind to reply your answer to my eml please as I’m not sure if you answer through this forum my email would alarmed me. Thank you.

By: Dave R.

Dave R. — Wed, 13 Mar 2013 15:21:41 +0000

So glad I found your article! I just heard the Nightengale Concentus open baffle speakers at Axpona 2013 and started thinking a clone could be a realistic diy project. On the other hand, I’m skeptical of being able to get all of the subtleties down as well as the real thing. I’m hoping that DSP will be able to bridge the gap in real-world performance since I don’t have a team of audio engineers working on my design. My design will probably track their driver usage as closely as I can determine. Dave

By: Unknown User

Unknown User — Fri, 29 Jun 2012 17:03:27 +0000

Hi Klaus, thanks for the comment. Those are both done in Part 2 (link near start of article).

By: Klaus

Klaus — Fri, 29 Jun 2012 13:52:33 +0000

Hi.

Interesting read, though

what I’d do different is

1. that I’d adjust first the time and phase of the drivers before adjusting the levels.

That gives you a much better starting point with the driver level adjustments.

2. instead of adjusting your midrange driver digitally by -18db, I’d add a passive attenuator or I’d buy
better matching drivers.

Cheers