I'm sure this has been discussed numerous times, but I did a search and only have so much time to sift through threads. Sorry about that.
What happens when you use digital EQ to push f3 lower in a sealed box? I have 4 of these in a ~1.83 ft.³ or 52 liter enclosure. PE site says one in 1.53 ft.³ / 43L has f3 49hz. I would like to get close to 40hz. If not practical it's fine, I can use subs. I'm in a concrete apartment and listen quietly without much bass anyway. But it would be nice to get these down near 40hz.
Also fs is 52hz, but I think I remember reading that going below fs in low freq. isn't a big issue.
Also if you wonder about the arrangement of 4 drivers in a smallish enclosure, I'm making sure some things are feasible and then will make a build thread. It will make sense...maybe
What happens when you use digital EQ to push f3 lower in a sealed box? I have 4 of these in a ~1.83 ft.³ or 52 liter enclosure. PE site says one in 1.53 ft.³ / 43L has f3 49hz. I would like to get close to 40hz. If not practical it's fine, I can use subs. I'm in a concrete apartment and listen quietly without much bass anyway. But it would be nice to get these down near 40hz.
Also fs is 52hz, but I think I remember reading that going below fs in low freq. isn't a big issue.
Also if you wonder about the arrangement of 4 drivers in a smallish enclosure, I'm making sure some things are feasible and then will make a build thread. It will make sense...maybe
Hi,
ESP - The Linkwitz Transform Circuit
52hz to 40hz, should do but you'll sacrifice 6db for overall spl. I won't try lower than that thoug ( 6 db in a LT is the reasonable limit ime).
ESP - The Linkwitz Transform Circuit
52hz to 40hz, should do but you'll sacrifice 6db for overall spl. I won't try lower than that thoug ( 6 db in a LT is the reasonable limit ime).
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Putting 4 of those in 1.83 ft3 will change the response: you'll have a 3.5 dB peak (Qtc = 1.4) at about 95 Hz and a f3 of about 59 Hz. I modeled three configurations using WinISD: a single driver (blue trace), 4 drivers (red trace) and 4 drivers using a Linkwitz Transform to achieve a 40 Hz F3 (green trace). All configurations used a box size of 1.83 ft3 and were fed 8 watts. I chose 8 watts since it drives the 4 driver boxes to 100 dB. I included graphs for the transfer function, SPL, cone excursion and required amplifier power from WinISD.
Attachments
Oh wow, thank you both! Especially for those graphs. Looks like the Linkwitz transform is exactly what I want. I'll read the paper on it and also re-familiarize myself with winISD. It's been about 10 years. I'm embarrassingly rusty.
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Also, you might want to take a look at what Linkwitz himself wrote about it. There's link to a convenient spreadsheet that Charlie Laub made for component selection in that section, too:
Highpass EQ
Highpass EQ
Would someone please model this driver in a sealed box and size required small as poss it will fit in 2cu
With eq Linkwitz how much low end gain
https://jblpro.com/en-US/site_elements/2206h-j-data-sheet
I have got mini dsp so was thinking the same sealed instead my listening levels have took a huge downturn moving house
Trying to decide which drivers to keep
With eq Linkwitz how much low end gain
https://jblpro.com/en-US/site_elements/2206h-j-data-sheet
I have got mini dsp so was thinking the same sealed instead my listening levels have took a huge downturn moving house
Trying to decide which drivers to keep
12 inch JBL sim in 20 litre sealed box.
Hey Charlie,
I have attached a sim of your driver, I am guessing that the H and J versions have different impedance?
Hope this helps?
Cheers
A.
Hey Charlie,
I have attached a sim of your driver, I am guessing that the H and J versions have different impedance?
Hope this helps?
Cheers
A.
Quick question, from reading up on the smaller ATC sealed monitors-
what wd you say is the minimum sealed F3 you wd accept? I understand there are different needs etc
what wd you say is the minimum sealed F3 you wd accept? I understand there are different needs etc
I have looked at your pdf response thank you very much for taking the time to look at it and model it
Does it mean that I have to pump 600 watts to get a decent f3 /30hz @ 100db
Power is not a problem several qsc audio 1450 amps at disposal with bridging
Thing is I was wanting to go a lot lot lower amplification power wise and space maybe move onto 1st watt nelson pass or valve amplification
Very small room neighbours either side
If u fart they tell you
Hiya Charlie,
Happy to help.
The simulated 105 dB at 35Hz continuous (with 111dB peaks assuming 6dB of headroom and the 2,400 watts required power!) is before room gain ie in a corner you will gain real world 6dB to 8dB over and above the sim SPL's... Thats loud!
You will find that in the real world your amps will be running at low to medium power most of the time ie 5 to 10 watts with around 50 to 100-watt peaks and that will be loud music.
You will reduce the SPL's by 3 dB with each halving of input power so:
600 watts = 105dB
300 watts = 102dB
150 watts = 99dB
75 watts = 96dB
37.5 watts = 93dB.
I think you will enjoy this article which details the theory and practical results from the extented low frequency "ELF" subwoofer principal of small sealed box with DSP / Eq and high power amps.
Sub-Woofer Controller
by Rod Elliot... He is an internationally respected audio engineer with over 40 years successful trading in the industry.
Happy to help.
The simulated 105 dB at 35Hz continuous (with 111dB peaks assuming 6dB of headroom and the 2,400 watts required power!) is before room gain ie in a corner you will gain real world 6dB to 8dB over and above the sim SPL's... Thats loud!
You will find that in the real world your amps will be running at low to medium power most of the time ie 5 to 10 watts with around 50 to 100-watt peaks and that will be loud music.
You will reduce the SPL's by 3 dB with each halving of input power so:
600 watts = 105dB
300 watts = 102dB
150 watts = 99dB
75 watts = 96dB
37.5 watts = 93dB.
I think you will enjoy this article which details the theory and practical results from the extented low frequency "ELF" subwoofer principal of small sealed box with DSP / Eq and high power amps.
Sub-Woofer Controller
by Rod Elliot... He is an internationally respected audio engineer with over 40 years successful trading in the industry.
Thanks so far
I am well versed in the inverse square law
But if I use this driver it is in a multi entry horn meh
I have to many compression drivers
Mid drivers
And mid bass drivers
Need to make a short list of what is practice for my new small room....
Bear in mind at present I have twin jbl 4638 bass cabs with loads of horns /waveguides altec 511b jbl2380 jbl 2440
2445/2426/celestion 10f1020 celestion 1735
Pair of spendor s9 with center
Monitor audio full rs kit
Arcam alpha Fmj am
5 pa amps
Pair of eminence alpha 15a
Can not possibly use it again