I’ve heard too many ported speakers at shows and in dem-rooms that just go WOOOOF….WOOOOOOOOF at low frequencies; this, along with own demoes and A/B tests with groups of customers, completely made me loose interest in vented enclosures that go loud for the sake of it. The room rules in the modal region and the best way to control this is with subs as per Dr Geddes and specifically with closed as Dr René Christensen has shown. I personally find it very hard to make multiple subs play nice, but ‘this is the way’ as the Mandalorian says.
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Tannoy for many years built two-way speakers that were loud, subtle, low distortion and very wide-band. They were large, of course.
https://m.hifidatabase.com/Tannoy_Super Red Monitors SRM 12X_5400.php
That is by far the cheapest way to get serious high SPL 2-way I have seen for ages.
Only downpoint is 800Hz x-over for TAD, but thats ok for sound reinforcement reasons.
This cabinet and design has so many advantages that its not easy to DIY.
Just repaint in x-colour and "go": https://www.ebay.com/itm/154939345544
Only downpoint is 800Hz x-over for TAD, but thats ok for sound reinforcement reasons.
This cabinet and design has so many advantages that its not easy to DIY.
Just repaint in x-colour and "go": https://www.ebay.com/itm/154939345544
Have you looked at cinema subwoofer specsheets? Some list the sensitivity using multiple drivers/boxes. You can get crazy SPL's using multiple subs. Don't forget about mutual coupling. Look at one vs 4 in the specsheet.
Rob
Multiple would be needed for sure....the thing is, once you get excursion down, why use an expensive woofer...I wonder if Lavoce and Oberton are still priced low...I should have grabbed 4 18"s not 4 15"s.....
I have those speakers and then some, unless this 130db is coming from more speakers than in this picture...I have a hard time believing hes playing 13hz at 25hz and low distortion ie low excursion, over 6ft, let alone at 1m
What part of it is bothering you? I only really care about a very small spot. Tuning to one small area creates better results than trying to average over a larger area....
Can you please point to what you are talking about hear?
Multiple subs and sealed or vented, are two different topics. Regarding the woof woof, wouldn't you just assume that those products where not designed well or maybe performing at too high of a level for what should be expected? If enough Sd is used there shouldn't be any "WOOF WOOF", as long as the port is tuned low enough and big enough...
The dual 18" 513liter BR tuned to 20hz with a 500cm2 CSA port, 115db/1m at 20hz. If you had 4 of these, there is no "Woof Woof" I don't think. I thought below 15m/sec was pref.
Supposedly I can do this with my current woofers;
I think I can hear a difference in the sound by that amount of excursion, The 4 15's I bought, in BR, tuned to 20hz, I can just make it to 20hz, 115db/1m under xmax
The 2 front sealed in combination with the 2 rear BR subs should be just enough to do 115db, without strain. Combining sealed with low tuned BR, sounds Iffy.
Sure:
https://www.audiosciencereview.com/forum/index.php?threads/analytical-analysis-room-gain.23211/
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The driver resonance is now that of the driver+enclosure known as Fb
He's missing the point, We already know not to use a vented enclosure below cutoff....obviously tune the cab lower, but with multi sub, excursion is so low, below cutoff...You can tune to 10hz and still get an increase in efficiency over sealed. How low do you need to go is the question. According to my own ideas, I should at least tune to 15hz. 20hz would work well too I'd guess.
My point is his argument as to why sealed would work better is incorrect in application....I need flat response down to desired system cutoff, not 0hz lol unless 0hz was the desired cutoff. If cutoff desired was 10hz, tuning a BR to 10hz should suffice because who cares what happens below 10hz.....with enough big woofers, the excursion will be accommodatable, but the desired or mostly used passband may be much above 10hz. The increased efficiency from the vent seems to be the prize, at least when done correctly.
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Good writeup.
The key comment in the paper being "We have been considering ideal conditions with low loss rectangular rooms and probably more importantly no leakage. " All rooms leak, some more than others hence this "flat" region will be dominated by the rooms leakage. I always try and seal the room as much as possible and this does accentuate the VLFs, but the leakage is always going to dominate the end result. I also agree that closed boxes will accentuate this effect, while ported ones will eliminate it. A fairly big factor in my book.
Just to be clear, that paper uses the widely known approximate formula for the modal function. It is accurate only when the absorption is low and occurs in the air, not at the walls as it actually does. The effect of this limiting assumption is not clear and one that I have looked into somewhat, but it is important to keep this in mind when using these modal equations.
Any enclosure designed to go loud for the sake of it... is either a professional cab or something to show off.
If you read my comments carefully, you should notice that I am very critical and very specific in my reviews.
I certainly don't just listen to the measurement data on a screen.
I listen to individual trees, but never loose sight of the woods.
The perception of music (reproduction) is and remains primarily a personal matter, in which a frame of reference plays a dominant role.
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Perhaps I deviate because I absolutely do not blindly rely on what some (so called) scientists, specialists, let alone politicians claim.
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