And we got to fill it up yaking about drum machines... Oh well, on to the next x-way thread...Only 21 posts to go ...............
I like that. It's close to what I use now - 2-way with a horn, with 2 mono front located subs below 50Hz. No offense to waveguide users. I'm agnostic about horn vs waveguide, and both should be explored.
Perhaps the thread should be collaborative instead of just yours. I think it will help keep it on the rails.
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This has drifted for 500 pages because there is no focus.I'm not sure keeping 500 pages without drift to be possible...
This has always been collaborative and never solely mine otherwise it would never had a chance...
I'm just a priority in the sense that I'm the one spending money on these ideas that we discuss...and I'm the one asking most of the questions...as I finish putting together this system......anyone else is free to join in and always has been....
The only thing is that "reference monitor" or "mastering monitor" comes with a certain set of expectations, and we have a decent number of sound engineers who would like a place to shed ideas without the ability for people to wander us into the world of subjective SQ.
This has drifted for 500 pages because I recognize the valuableness of the access to People like Gm and Dr. Geddes and Mitchba and Ro808 and Mabat and WelterSys, and Fluid and Mark100 and Krivium and the admin here...and the list goes on, this is literally the most talented group of people I can find on the internet concerning this topic.... So instead of wasting this priceless resource by letting it sit, I ask questions, and then another, and then another, and then another.....
I've seen others start project pages here and without a certain group of people, things get real subjective real fast....
This thread is fortunate to have a certain group of people subscribed to it...I am fortunate to receive consultation from them.
Everything I claimed I wanted....all the information I was taught.....led me to the above....It truly is a quality configuration for a woofer section. The woofers can be swapped but I don't think there are very many, if any flaws in the above....because its not special....its really simple....its been done before. This is how its done....Large, efficient, quality woofers, in large efficient quality enclosures.
A mastering monitoring establishes an expectation of at least 30hz play back near 0 transfer function.
I am not so certain about this 115db/1 meter at Cutoff.....requirement....Yet, it has given me everything I wanted.....
Low Amplitude Distortion
High Direct Energy
High Spl Low Distortion
Scientific SQ
Full Spectrum...
Large baffle width, large horn/waveguide and large radiation source area kill those birds quiet well
As long as we stick with big woofers MTM/TMM 2 way can do this Vented.... or Sealed, a 2.5way can achieve this....or you can call it a 2.2 system, using a 2 way. Or should we call it a 3 way and be done with it.
With smaller woofers we have to consider something like 4 sub woofers
85db is the recommended mastering spl level....what if I created a system that had smaller drivers and reached half xmax on 4 small subwoofers at 30hz/85db/1m?
is this still acceptable for mastering? 2 - 8" mid woofers can cover down to 100hz with low excursion, as well.
85db is much more forgiving....The 15" 2 way can cover this down to 30hz at 85db/1meter, especially in a vented box......With 2 more subs added to just a 15" woofered 2way...we can achieve 30hz with a only a few Millimeters! This is an option many can exploit correctly for 2-3 thousand dollars or maybe less and have a top notch mastering system.
This is my iteration of ideas.
Your results may very.....
Creating the best form of 2 way - 15" midwoofer + Horn/Waveguide + Subs.... is a Pinnacle for a lot of people.
We will discuss this beyond this thread, but we have been able to call this thread a place to discuss this topic for 2 years now. It would be nice if we were not limited in such way to have to create another thread to continue off from here. I'm sure the admin can make adjustments at the beckon of the community.... The thread could be made a sticky thread if thats what the community desired. The title sure works.
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camplo, I was having a little joke with phase_accurate.
As some members know, threads used to go to part 2. The new forum software doesn't have the same limitation. If there's something I can do, let me know
Which components are used for this sweep?
The UM8-22's look exactly like the description: "Dayton Audios Ultimax Series DVC subwoofers are purpose-built to move air and create clean, articulate, fast bass. Optimized for small enclosures".
Air pumps so to speak. They'll probably perform as advertised, but need humongous amounts of power when high levels are required.
I seriously doubt they'll integrate well with a highly efficient 2 way system.
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It appears the UM8-22 isn't capable of / designed for high output levels:
"Now, it didn't play very loud, and even after I dialed it back to keep the cone from bottoming out and flapping from the test sweep, the distortion at lower frequencies was significant.
When it bottomed out, the distortion products were more than the fundamental. Dialed back down to avoid obvious bottoming out sweep results...
10 Hz Fundamental @ 72.7 dB,THD 34%
14 Hz Fundamental@ 81.1 dB, THD 56.5% (maximum%)
15 Hz Fundamental@ 82.5 dB, THD 53.9% (maximum Distortion Amplitude)
But from that as frequency rose, distortion dropped...
20 Hz Fundamental@ 86.9 dB, THD 23.1% (less than half than 15 Hz...
25Hz Fundamental@89.7 dB, THD 10.5%
30 Hz Fundamental @ 90.8 dB, THD 7.21%
40 Hz Fundamental @ 92.6 dB, THD 3.9%
60 Hz Fundamental @ 93.6 dB, THD 1.83%
80 Hz Fundamental @ 91.7 dB, THD 1.47%
120 Hz Fundamental @ 91.0 dB, THD 0.732%
133 Hz Fundamental @ 92.0 dB, THD 1.6%
From 140 to 200 Hz (at the crossover implemented) output stayed from 92-95 dB (at the particular sweep level) and distortion stayed under 1%, sometimes dropping near 0.5%."
"Now, it didn't play very loud, and even after I dialed it back to keep the cone from bottoming out and flapping from the test sweep, the distortion at lower frequencies was significant.
When it bottomed out, the distortion products were more than the fundamental. Dialed back down to avoid obvious bottoming out sweep results...
10 Hz Fundamental @ 72.7 dB,THD 34%
14 Hz Fundamental@ 81.1 dB, THD 56.5% (maximum%)
15 Hz Fundamental@ 82.5 dB, THD 53.9% (maximum Distortion Amplitude)
But from that as frequency rose, distortion dropped...
20 Hz Fundamental@ 86.9 dB, THD 23.1% (less than half than 15 Hz...
25Hz Fundamental@89.7 dB, THD 10.5%
30 Hz Fundamental @ 90.8 dB, THD 7.21%
40 Hz Fundamental @ 92.6 dB, THD 3.9%
60 Hz Fundamental @ 93.6 dB, THD 1.83%
80 Hz Fundamental @ 91.7 dB, THD 1.47%
120 Hz Fundamental @ 91.0 dB, THD 0.732%
133 Hz Fundamental @ 92.0 dB, THD 1.6%
From 140 to 200 Hz (at the crossover implemented) output stayed from 92-95 dB (at the particular sweep level) and distortion stayed under 1%, sometimes dropping near 0.5%."
I think where I was going with that, is that, these ideas can be scaled.....
I am not sure if 115db/1 meter has any real world merit in the terms of Mastering. Having 20-30db more headroom in the amplifier seems to be thing....but having 20-30db headroom from the drivers....when peak is 85-95db....there is no reason for 115db linear playback, unless you desire more Sound quality, and this type of dynamic potential is the side effect. @weltersys and @mark100 brought up the dynamics of a fork drop with mic 1 meter away....it was 11X db?
OK now lets drop back into application.....When will we achieve 115db while listening to a movie.....or music....or tv.....Never?
So if one wanted bare minimum for Mastering at 85db....couldn't one base the woofers in that system around 85db at 30hz aka Cutoff. Or 85db at 20hz if aiming for Cinema Mastering. Personally I would still aim at using the largest bass drivers practical, and keeping this 85db within half xmax. My design philosophy is to design towards max spl goals using one channel but if the norm is to consider all channels.....
4 of those Dayton 8's should be able to hit 85db at 30hz near half xmax at one meter, in halfspace. 600watts should due lol.....
Personally, at a 85db peak goal...4 18"s would be perfect...and what ever the cheapest 18 you could find, would likely cut it, unless I missed something.
Visuallizing 4 subs around the listener.
At that volume and 1 meter distance a 15" two could serve as mains reaching down 30hz with little excursion in combination with 2 more auxiliary subs
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Cheapo JBL Car Subwoofer in 100L BR tuned at 20Hz.
Diaphragm displacement at 92 dB: ±0.55 mm out of 5.4 mm.
Diaphragm displacement at 92 dB: ±0.55 mm out of 5.4 mm.
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My first system for sound engineering were KRK v8"s...then I added stereo v12's....and eventually tried v4's on top as well.And the pendulum swings! You started with KRK and a sub or subs no?
85db 20hz for cinema Mastering??
Rob
1+4+12 isn't very bad at 1 meter. Its actually really good with the 130hz and 2.1khz xo on the mid.
85db is recommended peak spl for mastering and 20hz is a good cutoff for Cinema Mastering? No? How low do we need to go?
^ No it's not peak but rms.
It's not the bandwith but the spl the issue: rather than 105dbspl peak i've seen it to 115dbspl ( for the sub). It wasn't in a mastering room though.
Camplo, what made you think you won't need 20db crest factor for mastering? Or have you reevaluated your reference level ( the one at which you work)?
It's not the bandwith but the spl the issue: rather than 105dbspl peak i've seen it to 115dbspl ( for the sub). It wasn't in a mastering room though.
Camplo, what made you think you won't need 20db crest factor for mastering? Or have you reevaluated your reference level ( the one at which you work)?
I thought you were ultimately dissatisfied which lead to this thread. You seemed to be going back to where you started. The 85 dB is reference/calibration level I believe with 105db peak and 115dB peak in the LFE. You would need a system that has additional headroom to cleanly master the peaks no?? Here is a sub used with the M2. The Pro cinema boxes use this driver in pairs! Run!
Rob
https://jblpro.com/en/products/sub18
85dB is the calibration level with -20dbFS Pink noise read on a dBC meter with slow setting. Setting the monitor level to that point and reading 0 on a VU meter means there will be 14dB headroom before 0dBFS clipping.
THX Reference Level is 85dB with 20dB headroom meaning 105dB peak.