SEAS KingRO4Y Mk III Active Loudspeaker Kit - as an OB?

[msegel]

SEAS KingRO4Y Mk III Active Loudspeaker Kit - as an OB?

Hi,
I was looking at the Madisound kits and was curious if you could do the KingRO4y as an Open Baffle speaker.

I seem to recall reading somewhere that for an OB, you want drivers with a QTS greater than .6?
Thought I could do one w the plate amp in the base?

With the 10" driver ... how wide would the baffle have to be?

This was just a thought that crossed my mind. More of a thought exercise than actual project.

Thx

 

[mordikai]

It can certainly be done but will require remeasuring and a new implementation of the dsp; the response of the speaker will be significantly different in open baffle. The q of the drivers is immaterial because you have all the dsp on hand.

 

[Norgaard]

The 10" driver is well known for OB, for LX521.4 and also LX Mini +2, Studio.
You should check out the linkwitz website if you haven't already, as it is a treasure cave of information on OB - and constant directivity design.

The recommendation of a high Qts is really only valid if you absolutely want to run passive. Personally I avoid high Qts (in OB) as I'm yet to hear one where they do not exhibit a quite characteristic "honk" sound.

 

[msegel]

[Edit to clean this up...)] I am familiar w the Linkwitz site. The LX521 is one of the speakers I'd love to build but would go with the
all in one ASP and Amp boxes. At the same time, the mini s without the subs would also work in one area... although the subs would be even better.

I was just looking at the Madisound site and saw the Seas kit. Definitely a high end build and when I saw the speaker spects I saw the QTS values and thought about if you could OB the kit.

If I just went w the drivers, I could go passive.
(Which is what made me think about the QTS and going OB. )

I figured it wouldn't be too expensive to prototype an OB using the kit and if it didn't work out... make the regular boxes.

Again its just a thought exercise... unless I win the lotto. ;-)

And yes, I'd have to modify a copy of the DSP files which means taking one of my linux boxes and loading windows on it.
(Everything else is Linux and MacOS.)

Thx for the quick responses and the sanity check.

 

[msegel]

The recommendation of a high Qts is really only valid if you absolutely want to run passive. Personally I avoid high Qts (in OB) as I'm yet to hear one where they do not exhibit a quite characteristic "honk" sound.

Huh?
I thought that you wanted to use drivers w a high Qts?
Or is that backwards?

 

[Juhazi]

For dipole bass, please double the number of bass drivers and connect in series because of impedance. FA253 has enough power for that.

C18 in the kit is a pure midrange with very little excursion. Better suitable version linked below. Still, try to find baffle size and xo frequency that gives best compromise with bass to avoid too much excursion
https://audioxpress.com/article/test-bench-seas-e0060-08-06-6-5-king-coax

4-way dipoles came from the difficulty to match bass and low mid...

Mid-tweeter xo doesn't need modification, but you might want to add an extra backwards tweeter later on...

 

[msegel]

Well I wasn't trying to do a 4 way, but the 3 way of the kit.
But I see your point. (Hence the Linkwitz design.)

Did a quick look at the review.
Good read, thanks.

 

[Norgaard]

although the subs would be even better.

That could still be a (backup) plan 🙂
I have build two sets of LX521's and the LX-mini's - the latter build just for the fun of it just before I finished the first 521's. That was a bit of a shocker, lesson learned; don't underestimate the Mini's.... great value for money.

And yes, I'd have to modify a copy of the DSP files which means taking one of my linux boxes and loading windows on it.
(Everything else is Linux and MacOS.)

I know the pain

Or is that backwards?

Not really, it just means that the old phrase "there is no such thing as a free lunch" also holds true here.
Ultimately you trade off quality for quantity when going for high Q, or resonance ports or.... passive resonance (peak) filters.
These come with a backside - unless you are in the church bell business then the higher resonance peaks the better - until the poor thing cracks that is.
It's just not great if you want to stop the ringing with immediate effect.

Clearly we all have our personal preference for what is the perfect balance and what we are happy to trade off/in.

I noticed a setup using the Seas LROY's with a Great Heil (which I also use in my own experiments) I'd expect that to be beyond what's feasible for the 10".

True alu membranes are normally not masters of wide or full range as the membrane cannot be curved to accomodate this. Stiffness is a lot better - hence they are great for low end. That is not to rule out that they cannot be used higher up and the break up's be controlled. But it does take an extra effort, not only on the driver but also the filter side.

If you go for dual woofers - you can also add a bit of series resistance, e.g. using a coil with some series resistance for low-pass on only one of the two => fill in on the low end to reduce needed baffle width. Needles to say, if you overdo it, you are back on the high Q unit performance.

I figured it wouldn't be too expensive to prototype an OB using the kit and if it didn't work out... make the regular boxes.

Welcome to the rabbit hole 😀
Should be a fun experiment with several options if it's not to taste.