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Othorn - HT capable?

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On ‎9‎/‎26‎/‎2018 at 2:24 AM, maxmercy said:

Keep us updated!!

 

JSS

A bit coming up - thanks for the interest :)

This project is taking its time to coalesce, sorry about that, but things are slowly beginning to fall into place. The B&C 15TBX100 drivers landed some weeks ago, and are just sitting there in their boxes waiting for further action. And just today I've bought a used Crown Macro-Tech 1200 power amp (300 conservatively rated watts/8 ohms)  for use with my upcoming MicroWreckers. I know, the (old) Macro-Tech series are no youngsters anymore, but I friend of mine recommended them despite this fact. Then there's the built-in fans, which supposedly turn into helicopters sound-wise, so we'll have to find a way to mod these somehow for quieter operation. 

The DSP section for the Micro's will not be a Mini-DSP iteration as once pondered, but instead one of Xilica's offerings (a friend of mine uses a Xilica in his all-active DSP setup, with great results). They're more expensive, yes, but frankly more capable, and I'm thinking whether to jump for an option that will allow for a future all-active setup with my main horn speakers. I'm guessing though that won't happen anytime soon, if at all..

The build itself of the Micro's will commence in some 3 weeks time. The 18mm 11-layer Russian Birch ply panels will be CNC cut (CAD-drawings have just been sent off), and then a cabinet maker I know well will assemble them with fitting joinery for a more rugged enclosure. Will post some pics once we're getting there..

/Mikael

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On ‎4‎/‎20‎/‎2018 at 4:08 AM, SME said:

...

As I detailed above, you might want experiment with different (higher) crossovers.  You emphasized integration with the mains as a high priority, and I'm arguing that good integration with mains has more to do with working around room effects.  I didn't explicitly mention it, but phase match between the mains and subs is also crucial.  This is partly addressed by optimizing the sub delay, but that only insures a good match at one (usually the crossover) frequency.  Phase match can be tricky to get right when the mains roll-off rapidly near the XO frequency as yours do.  I believe front-loaded horns like your mains exhibit 24 dB/octave roll-off below their lower limit, similar to vented cabinets.  A lot of people try to cross vented mains at least half-an-octave higher than the point that they roll-off.  So for example, you might consider crossing at 90 Hz instead of at 62 Hz.  I personally cross at 100 Hz, even though my vented mains are tuned to ~45 Hz, because anything lower than 100 Hz just sucks in my room.

@SME I'll tie in a small update of mine with above paragraph of yours. 

I'll receive a Xilica XP-3060 digital crossover within a few days, and will try experimenting with a high-pass of my main horn speakers in the 90-100Hz region once the new subs arrive (the SB16 was sold off just last Sunday). As an outset this will be done with the passive filters in the mains still in the signal path, with the question being if the Xilica is transparent enough being put into the chain. It'll certainly allow for some experimentation here. 

The next stage, if the above turns out well, would be making the bass horn of my mains active. This way the Xilica will be removed from the signal path of the mids and tweeters, and a separate amp will look directly into the bass driver of the mains horn. I'm thinking this could be a truly capable option that would also relieve the amp for my mains (a Belles SA-30) of bass duties entirely. If this could be implemented in a favorable fashion, together with the upcoming MW tapped horn subs of @lilmike - phew.. I'm not ready to go all-out converting my mains into all-active speakers. Running compression drivers from the midrange on up of some 107-109dB sensitivity active is a magnifier of very audible noise. Perhaps at a (much) later juncture.

The build of my MW subs is somewhat delayed. If all goes well they'll be ready in 3 weeks time. Fingers crossed on everything turning out well here.

/Mikael

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Nice ideas here.  I hope that XO processor works out for you.  Definitely experiment with different settings.  Measure and compare if you can and have the patience.

Unless you're using real weak amps on the mid/high horns, you might seriously consider adjusting the passive circuit to attenuate things more.  I don't know if that would be feasible in your case, but it could make a huge difference with regard to noise while also improving safety from faults (both for the drivers and your ears).  Even if you listen real loud, I seriously doubt you need sensitivity that high.  It may be fun to brag about, but practically speaking it's a nuisance with regard to noise and possible safety concerns in the event of a fault.

My speakers have horns covering content above 850 Hz+ that are 108 dB sensitivity without passive electronics.  I have a passive circuit to cut them by 6-10 dB over most their range and I've cut the output gains for them on my DSP an additional 6 dB, meaning that I probably hit like 50W peak before clipping in the DSP, most of which is sunk into the resistors of my passive circuit.  My DSP interface has peak and average indicators for each channel so I can literally watch my headroom.  I listen to plenty of stuff plenty loud, and it's rare for the peak level to exceed -10 dBFS.  Only with a handful of cases do I see peaks up near the top.  One example of some demanding treble (at least for my horns) is the hand-held phaser shoot-out in "Star Trek" (2009) when playing at a MV in which I probably hit peaks > 125 dB SPL (with help from the subs) in other scenes.  :)

Of course, with the kind of subs you're building, you may listen to stuff way louder than I do.  But seriously, those kinds of levels are not going to be good for your hearing in the long-term.  I can play a good dynamic multi-channel concert video at something like "+3 dB" vs. reference level (and a generous house curve on the bass), and it sounds wonderful without even a hint of strain!  The sound is so clean, detailed, expansive, and powerful.  And then after 5 minutes it stops and my ears will be slightly ringing and after a couple hours, my hearing will still be altered.  That's hearing damage territory, and for me, that's *enough* headroom.

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@SME Will have a follow-up to your reply shortly.

May start a separate build-threat next week (or just continue on here), as the ply panels for my MicroWreckers have now been CNC-cut. The cabinet maker I've hired will start the assembly next week, and take some pics of the process. More to come..

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