I was studying more about subwoofers and looking at the marketplace I noticed that 8-inch subwoofers are always recommended in very low volume boxes (around 16 liters).
From what little I have studied and seen here on the forum this seems to be quite wrong, for a subwoofer to reach lower frequencies we need a reasonably large box and 16 liters is something very small...
For a 3-way project, which is what I'm studying most in the future, 16 liters would be too small to store 3 speakers (4", 8" and a tweeter).
When I got the specifications of the 8" subwoofer and put it in winISD, I put an initial 35 liter capacity at 30hz and it still worked until it was "well", this in a ducted box because reading the article on the Eminence website it said that at least QTS of this woofer, the ideal would be a ducted box...
I would like to know the opinion of the elders here on the forum, what would you do with an 8 inch subwoofer? box litter and such
From what little I have studied and seen here on the forum this seems to be quite wrong, for a subwoofer to reach lower frequencies we need a reasonably large box and 16 liters is something very small...
For a 3-way project, which is what I'm studying most in the future, 16 liters would be too small to store 3 speakers (4", 8" and a tweeter).
When I got the specifications of the 8" subwoofer and put it in winISD, I put an initial 35 liter capacity at 30hz and it still worked until it was "well", this in a ducted box because reading the article on the Eminence website it said that at least QTS of this woofer, the ideal would be a ducted box...
I would like to know the opinion of the elders here on the forum, what would you do with an 8 inch subwoofer? box litter and such
There is an acceptable range of volume and tuning frequency for each driver and you get to choose what works best for you and your needs. You also get a range which helps balance trade offs. For example, enclosure volume, tuning frequency, and port size/length impact port air speed, power/SPL, port resonance, and woofer excursion. These are all things a designer would need to balance.
Personally, I have no problems sacrificing (increasing) tuning frequency to reduce the size of the port and increase the first port resonance frequency. It’s an 8” after all, so it’s not going to do much in the 20-30hz range.
Personally, I have no problems sacrificing (increasing) tuning frequency to reduce the size of the port and increase the first port resonance frequency. It’s an 8” after all, so it’s not going to do much in the 20-30hz range.
Hoffman’s Iron Law.
Sensitivity, small box size, LF extension.
You can only have 2, if extension increases, either box size goes up or enitivity goes down, or both.
The Law puts constraints on the combination of function.
dave
Sensitivity, small box size, LF extension.
You can only have 2, if extension increases, either box size goes up or enitivity goes down, or both.
The Law puts constraints on the combination of function.
dave
Size matters, most consumers want small boxes.... physics and reality be dammed!
Calculate a T/S max flat alignment with at least a 0.5 ohm Rs for component insertion losses and up to its 'Re' rating more if planning on playing it loud for any extended periods to account for Vc heating increasing Qts (Qts'):
Vented net volume (Vb) (L) = 20*Vas*Qts'^3.3
(Ft^3 = (Vb)/~28.31685)
Vented box tuning (Fb) (Hz) = 0.42*Fs*Qts'^-0.96
F3 (Hz) = Fs*0.28*Qts'^-1.4
https://web.archive.org/web/20220707003028/http://www.mh-audio.nl/Calculators/newqts.html
Vented net volume (Vb) (L) = 20*Vas*Qts'^3.3
(Ft^3 = (Vb)/~28.31685)
Vented box tuning (Fb) (Hz) = 0.42*Fs*Qts'^-0.96
F3 (Hz) = Fs*0.28*Qts'^-1.4
https://web.archive.org/web/20220707003028/http://www.mh-audio.nl/Calculators/newqts.html
If you're talking about finished subwoofers (in an enclosure, with an amp, ready to use), many are using boosted/electrically equalized designs where a large excursion driver and high power amp are used to counteract the natural roll-off of a small sealed box. It makes for a much smaller enclosure, which is more acceptable in a typical home.
As has been intimated, an 8" speaker is not a subwoofer.
To reproduce quality deep bass you need low displacement and a lot of cone area.
Move a lot of air - GENTLY
To reproduce quality deep bass you need low displacement and a lot of cone area.
Move a lot of air - GENTLY
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Would it be a fair layman comment to say that only if you are listening to gentle music gently. Turn up the volume to bass driven music then how can there be anything gentle?
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A 8" diameter woofer can be a subwoofer. There are 3" classified as subwoofer. In the multimedia for PC sound, subwoofers (driven by 3-15 W amplifiers) were the the norm.
Gotta put it into context.
Gotta put it into context.
They are marketed as "subwoofers" because it sounds cool and promising to noobs.
The word "subwoofer" indicates a driver that is used to reproduce sound (or just pressure) below the woofer passband.
Now you could of course define a 2" fullrange as "woofer" and the 3" to be used below it as "subwoofer". But that's pathetic.
As a counter argument, I get flat down to 50Hz with a pair of 3" drivers, but I live in an apartment and don't want to disturb the neighbours
I have heard a system flat to 10Hz with four 8" drivers, and that went reasonably loud too
The secret? In room!
The room makes a massive difference at LF, and if you are lucky, you can get quite a lot from something small
Where are you going to listen to it?
Can you model that space to predict how the speaker will behave?
If not, can you measure it?
How loud and low do you want?
Brian
I have heard a system flat to 10Hz with four 8" drivers, and that went reasonably loud too
The secret? In room!
The room makes a massive difference at LF, and if you are lucky, you can get quite a lot from something small
Where are you going to listen to it?
Can you model that space to predict how the speaker will behave?
If not, can you measure it?
How loud and low do you want?
Brian
I can add to that, my neighbours in the house next door separated by dual carports can hear my z623 sub doing 65dB. We are in tiny 6x6m prefab homes with foam sandwich walls on concrete. The driver is a 150w 7"