Miscellaneous designs - Markaudio, Fostex, TB, Dayton, SEAS etc

[wchang]

Sigh. Beats me why, but markaudio.com is outside the g-f-w for me to visit. (Might be the word "upload".) @Scottmoose what are your MA200 physically-small designs and could you post them? Appreciated.

And a smaller (also intentionally simple) standmount with MAOP 5.
...
https://www.markaudio.com/wp-content/uploads/2024/10/MAOP5MA200M-standmount-.png

 

[Scottmoose]

Bizzare. I'll put them all here for sake of completeness.

 

[Pierrick59]

Which of your enclosure designs satisfied you the most when listening?

 

[Scottmoose]

I'm afraid I can't really answer that. Remember, these are not designed / developed for me as an individual, but to cover a reasonably wide number of different requirements for Markaudio buyers. That's the job of a commercial designer -I'm no different in that to anybody else. What I like and use is not necessarily going to suit anybody else -and my opinions / preferences have no wider value, unless you happen to have my system / room, ears and personal taste. That applies generally, not just to these of course. My normal generic advice is to start with something you can actually use -for e.g., there's not much point in making something that doesn't fit the space (!) and work from there according to your priorities, in terms of type, performance characteristics [e.g. alignment], construction / appearance etc.

 

[planet10]

Which of your enclosure design

Only one?

dave

 

[Scottmoose]

I think that's called 'the agony of choice'. 😉

Or a straightforward one -build something by somebody who's a better designer than I am, which [ejecting false modesty -it's the truth] isn't difficult.

 

[Pierrick59]

I think that's called 'the agony of choice'.

yes there too many choice and i will need too choose...
i think in a first time i will use ma 200 alone in a ddvp 20 that i have in stock to replace the sb20 to what it gives but more that i see your design with multi drivers more i'm intrested but i have afraid to loose three-dimensional localization, definition

 

[mp9]

Still doing some work on the Ariels; apologies [in the unlikely event anybody cares 😉 ] it's taking a while, but I'd rather get it right as far as I can do in terms of the spirit of the original design -load, price, low linear distortion on a Harwood type curve, low IM distortion (less of an issue in '25 with some [some] well-chosen tweeters) than it was in the mid-late '90s etc.

In the meantime: three simple larger format MA 2-ways for grins. Same enclosure used for each, different response balance (more LF-biased with CHR-120, roughly neutral with Alpair 12P, lurking somewhere in between but closer to the latter with MA200). Named for UK MOD artillery ranges & vaguely inspired by the evergreen Tannoy Buckingham. Amongst others. Filtering is one of my favourite trad. solutions (since these are by intent trad. type boxes) & based on an offset 2nd order Butterworth; we're targeting power-response & a relatively rich / 'vintage' balance here, so if if your priorities lie elsewhere, other options are likely to serve you better.

I'd like to see a frequency response plot and Impedance plot of the MA A12P MA200 x MA200 and of the 3 x MA200 designs?

I assume they become a 4 ohm speaker due to the two lower vented cabinet MA200 wired in parallel. Could the design work with the two lower vented cabinet MA200 drivers wired in series?

 

[Vix]

I am not Scott, but two MA200 drivers in series would give you 16 ohms. Inductor would become huge (x4) then you will loose a lot of efficiency. So, shortly, no.
Maybe Scott can design something witj four MA200 drivers as bass + one on top ? That way it would become efficient (and a bit more expensive) 8 ohm design 😀

 

[Scottmoose]

I'd like to see a frequency response plot and Impedance plot of the MA A12P MA200 x MA200 and of the 3 x MA200 designs?

I assume they become a 4 ohm speaker due to the two lower vented cabinet MA200 wired in parallel. Could the design work with the two lower vented cabinet MA200 drivers wired in series?

On my laptop at the moment as my heart has gone haywire [again], but will dig them out later when I'm feeling more human.

As-is, no: it would require a complete new crossover due to the changed impedance load and relative sensitivities of the LF and mid-tweet. Possible -although not the most practical unless you've got an amplifier with 16ohm output taps, or a shed-load of power -although admittedly clean Watts are cheap these days.

 

[zman01]

Scott,

Would you be able to share the crossover point for the Otterburn filter?

 

[Scottmoose]

Sure. 700Hz, which is the zone targeted for these speakers. Note it's not tracking a generic filter Q as this is from in-box FR, impedance, phase responses; that, along with the resistors & as-relevant DCR etc. are all factored in and / or functional.

 

[Scottmoose]

...I suppose I should add it here. Shown elsewhere, but this thread is strictly speaking where it belongs:

 

[bambam428]

I built the first design shown in this thread, the <ahem> "standmount" for the FA22RCZ, three or four years ago. It is by far my favorite speaker ever. That said, I also love MarkAudio drivers, and I have the need to tinker. My question is, now that the MA200 is available, and seems to have a mounting dimension within 1/16" of the Seas, how do you think it would sound in that box? Possibly better? A matter of taste? Box is totally inappropriate?

 

[MarcoForehand]

I’m considering the stand mount two way (MAOP5/MA200m combination). Would be very different (for me) as I seem to gravitate towards larger front baffles. I am thinking this design is closer to a “ modern” approach. Which means to me giving up some mid range warmth for ??
Considering this as I’m getting too old to deal with larger/heavier cabinets.

 

[Scottmoose]

You might be surprised. I designed it with a Harwood-style midband EQ curve, a little like I did with some of their production speakers, so you should find the midband to be quite forgiving.

 

[Andrewbee]

Ping Scottmoose,

Question(s) if I may. The Lhotse is described as being a low forced MLTL, is there an unforced version of the Lhotse or a "pure" for lack of a better term MLTL for the MOAP 11.2 and if so what are the tradeoffs, e.g. bigger, less power handling?

Finally, if the unforced version exists or could become a reality , what kind of F6 / power handling approximately could one expect?

Thanks

 

[planet10]

The restricted terminus (aka vent) tunes the box. Its length and taper determine the quarterwavve eigenmode.

If those 2 are far apart the line is forced. ie microTowers.

dave

 

[Scottmoose]

Question(s) if I may. The Lhotse is described as being a low forced MLTL, is there an unforced version of the Lhotse or a "pure" for lack of a better term MLTL for the MOAP 11.2 and if so what are the tradeoffs, e.g. bigger, less power handling?

Strictly speaking it's a bit of an euphemism for 'minimum forcing'; it's about as 'pure' an MLTL as it's possible to go [and is much closer in that sense than most smaller types, since the longitudinal is providing far more of the damping at Fb] while keeping a reasonable balance of other properties. We can have what amounts to an unforced type for roughly the same Fb & general alignment, but the price is a significant increase in size & reduced power-handling.

 

[Andrewbee]

Thanks for the reply. I was wondering how big an unforced MLTL would be and diminishing returns etc.
Now I understand the Lhotse is just about there and as good as it gets in all practicality unless you really want to compromise space and power handling etc without benefit (well bragging rights for the size being an exception).