Arrays of tiny drivers are fun indeed, but what about performance in the 1st octave?
I'd like to know in-room SPL @ 20hz, 25hz or even 30hz...
Is that even EQable to such low frequencies?
Correct me if i'm wrong but a typical 3.5'' driver such as TC9 has a air displacement max potential of about 9ml...
Takes a lot to equals a real subwoofer driver. Not to mention the Fs and other limitations..
Takes a lot to equals a real subwoofer driver. Not to mention the Fs and other limitations..
Yes, there are two subs, one a tapped horn, and another sealed sub, to go with the arrays. My arrays go down to about 80 Hz easily. My focus was to get them into the corner as far as possible to get the benefit of the corner directivity as well as the bump in the low end, and because of that goal I had to sacrifice cabinet volume. Weasyso designed proper cabinets for his arrays, and he claims to have usable response down to 17 Hz with EQ. I could probably get mine down to 40 Hz with EQ, but don't want to do that because for me, distributed subs work better, and I also don't want to punish the little TC9s.
The performance is quite good and the bass is very even after being EQ'd it is most certainly possible. Below 30Hz needs to be rolled off more steeply as you go down to avoid over excursion. In measurements I see the same ~8dB rise in output from 100Hz down that you see on generic room gain charts.
You are a long way out on the Vd for the TC9 particularly when arrayed.
25 x 36.3 (Sd) x 0.26 (X-max) = 235.95cm3 for each tower.
Compare that against this chart and you can see what is possible. 30Hz is somewhere in the region of 100dB peak. If you want ear shredding Home Theatre or 30Hz pounding then no an array of TC9's without a sub is not for you. But for music in the 80 to 95dB range that's a different story. Loud, low and small, you can only pick two 🙂
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100db @ 20-25hz is not that much for the ears. In fact, that's ''nothing''...
I would consider something impressive starting from 105db @ 25hz in-room (and not close to a wall/corner where the SPL reading is boosted)
I would consider something impressive starting from 105db @ 25hz in-room (and not close to a wall/corner where the SPL reading is boosted)
and a solid 30hz is mandatory. Anything lower, maybe we can live without but starting at 30hz we need something solid. By solid i mean at the same level or more than the rest of the spectrum... Too often i see curves showing a fall from 35, 40 or even 45hz and down... Can't consider having bass with a -5db in-room response @ 40hz, sorry.
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Too true, too true. If a system can't give me 120dB@20Hz clean at the listening position - I won't even listen to it. Why bother? Don't waste my time!
You don't need to be sorry, what you consider to be important and necessary is up to you to decide, not everyone will agree 😉
I have set my LF rolloff to follow a 24dB/Oct slope from 44Hz which gives an F3 of 22Hz.
I'm not trying to promote my build or suggest that it is a solution for everyone. Only to give as accurate information as I can. You asked if arrays could be EQ'd low and wondered about the Vd so I provided the information.
not 100-105db cruising-speed-SPL but rather max capacities @ peaks
am i biased for living too long with subwoofers?
am i biased for living too long with subwoofers?
fluid, yeah i know and thank you for that, my reply was not meant for you in particular, it was in general
Pano, 120db @ 20hz is completely different than 105db @ 25hz.
The first one will require something like 4x 18 inchers, huge ported or 4th order bandpass and massive amount of power, while the second one is obtainable with a pair of 10's in sealed box and some EQing.
The first one will require something like 4x 18 inchers, huge ported or 4th order bandpass and massive amount of power, while the second one is obtainable with a pair of 10's in sealed box and some EQing.
Sounds like. And you like to listen loud.
I’m happy with 35 Hz F10 anechoic (ie close to 35 Hz flat w room gain) and probably 100 dB peaks.
dave
I’m happy with 35 Hz F10 anechoic (ie close to 35 Hz flat w room gain) and probably 100 dB peaks.
dave
Hardcore HT guys are playin' in the 12-25hz territory a lot.. Drivers with sub 20hz Fs and such. That's another ball game.
Many years ago i did SPL drag competitions (car audio) and we never touched those ultra low frequencies, it was always optimized in the 50-70hz bandwith. I left just before they shifted in the silly 80hz-160hz bandwith...
Many years ago i did SPL drag competitions (car audio) and we never touched those ultra low frequencies, it was always optimized in the 50-70hz bandwith. I left just before they shifted in the silly 80hz-160hz bandwith...
My opinion is F3 @ 35hz in-room-listening-position is not good. Not ''Hi-Fi''. Surely not optimal. There is too much music (and movies!) material in the first octave to afford missing it. Most people can live with that, me included, but not with my main system.
Right now i'm about F3 @ 21hz and that's very good. Sometimes i miss my BR 15's, but F3 21hz is OK 99% of the time.
If you play with an EQ and have the drivers to take it, you'll see that most of the time it's between 25 and 33hz that everything is happening regarding audible pressurisation, that feeling of weight, immersion. Lower than that you barely hear it (and content is rather scarce anyway..) and above that it starts to become ''boomy''. So basically it's ½ octave i'm talking about.
Dave, most of the time i'm listening at 80-90db max.
Reaching 100-105db is not really a challenge, but the low-end is often missing...
I think the ''minimum footprint challenge'' implies that first two octaves are the real challenge, not the higher frequencies. Will put some AMT or hornless CD on a lexan panel and i'll win the minimum footprint-SPL challenge.... @ 1.5khz! 😛😛
Reaching 100-105db is not really a challenge, but the low-end is often missing...
I think the ''minimum footprint challenge'' implies that first two octaves are the real challenge, not the higher frequencies. Will put some AMT or hornless CD on a lexan panel and i'll win the minimum footprint-SPL challenge.... @ 1.5khz! 😛😛
Agreed, there is not much 1st octave in Nick Drake's content.
But what about Yoav ?
Yoav - Beautiful Lie (Engine Room Session) - YouTube
Here is a snapshot of my RTA while Adore Adore from Yoav is playing. Plenty of low-end stuff, including 25hz content (and maybe below) 🙂
An externally hosted image should be here but it was not working when we last tested it.
Something like this for minimum footprint sub Steve's Compounded, Super-Duper Shiva/Sonotube(R) T-line Subwoofers
Fair enough 🙂
I think Pano's reply might have been tongue in cheek.
This is where I get very confused with your posts 😕 You go from saying that 105dB is "nothing" to saying that most of the time you listen at 80 to 90dB and peaks of 100 to 105dB are what is needed. You say you have an F3 at 21Hz which is good enough for 99% of music.
For example my system can play peaks of 100dB or so and has an F3 of 22Hz and sits on an A4 piece of paper. So it seems that for 99% of your listening it would fit very well. I also have a few tracks with significant ULF, my speakers reproduce it but it is a bit scary because I know what it looks like to see 10Hz at high level when I broke them in. I couldn't hear it but I knew it was there due to the cones jumping 🙂
Clearly home theatre and music are very different in the amount of content below 30Hz and the need to reproduce it at any kind of volume to experience what was meant. For that subwoofers and maybe quite a few could be needed to do that at reference levels. Not going to be minimal footprint though.
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