Totally agree about that amplifiers now can easily get at least 300W and above especially using class D approach ... now i am using class D TDA8950 module gives around 300W in bridge mode cost around MYR(Malaysian Ringgit) 100 = close to around USD 23 with barebone parts total up (eg the amplifier module ... bass boost circuit ... toroid transformer and power supply parts)
Hi colmo
Think you need to state a bit more on your needs.
Does have to be a small box?
When you say 2 x 8" is that because you want it to be not too wide?
What amp will you be using?
Do you have possibility to use DSP?
What level do you need?
What are the speakers they need to match?
Price/budget?
For both HT and music I would aim for fs = 25 Hz.
A small sub could be made by 1 x 10" + passive, and will be more cost efficient than a dual 8".
Put a Earthquake TremorX-10-4 + M10 in a 20 l box with plenty of power and a bit of DSP.
2 of these for a stereo system will rock, and will be quite cheap.
Earthquake Sound
90 Euro
Earthquake Sound
60 Euro
(not sure how these are available in UK though)
.... hard to beat that price performance
Think you need to state a bit more on your needs.
Does have to be a small box?
When you say 2 x 8" is that because you want it to be not too wide?
What amp will you be using?
Do you have possibility to use DSP?
What level do you need?
What are the speakers they need to match?
Price/budget?
For both HT and music I would aim for fs = 25 Hz.
A small sub could be made by 1 x 10" + passive, and will be more cost efficient than a dual 8".
Put a Earthquake TremorX-10-4 + M10 in a 20 l box with plenty of power and a bit of DSP.
2 of these for a stereo system will rock, and will be quite cheap.
Earthquake Sound
90 Euro
Earthquake Sound
60 Euro
(not sure how these are available in UK though)
.... hard to beat that price performance
35Hz -3dB simulated (most specs are used with -3dB btw, very rarely seen -8dB specs)
I deliberately said that it should be enough.
35Hz is easily manageable with a decent 8 inch closed subwoofer, with a reasonable amount of SPL and gives a fairly good compromise between all kinds of music and all kinds of rooms.
Even holds up when people do want to watch a movie.
But without a budget and a sense of size/volume, we can debate till the cows come home.
I am building some 3 way sealed speakers with 7 inch bass units which have a f3 of about 63hz.
I feel I could do with going a bit lower and because the mains are sealed feel the subs should be too.
The subs will be built into the bottom of the mains and 8inch dia is max I can go to in the width. I want one each side incase I hear where the bass comes from. There is enough space for 20/22 litres. I was looking at the Wavecor SW223 BD03 but wondered if othe units may be more suitable.
I will be using one amp to drive both subs so two in parllel, therefore 8 ohms each will be best.
It is an Hypex plate amp which I have in a separate box model DS40
I feel I could do with going a bit lower and because the mains are sealed feel the subs should be too.
The subs will be built into the bottom of the mains and 8inch dia is max I can go to in the width. I want one each side incase I hear where the bass comes from. There is enough space for 20/22 litres. I was looking at the Wavecor SW223 BD03 but wondered if othe units may be more suitable.
I will be using one amp to drive both subs so two in parllel, therefore 8 ohms each will be best.
It is an Hypex plate amp which I have in a separate box model DS40
I recall Linkwitz had come up with some sealed 10" subs that use LT to get the low end boosted a bit more. Used a Peerless 830668 IIRC. If I needed small subs, I would go with a pair of those and some EQ to boost low end. Depending onocal price, they looked like a good value. I think some have upped the box size some, but am unsure where I read that. Probably end up smaller than a Ported 8".
That series of woofers is quite nice for the price.
I use the 830669 and like it.
The 8" from that line, the 830667 could work in ~20l or a little more.
Subwoofer Peerless SLS-P830667 specifications.
The Dayton Audio RS225-8 would work too.
The big question will be what the Hypex DS4.0 does to that speaker alignment
and if it lines up nicely; though I guess it will judging from the sim.
It has a built in bass boost 20-50Hz that can be adjusted from 0-6dB.
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Have you seen my Overdrive 10 design? Not cheap, but definitely small and capable.
"Overdrive 10" a PR-bandpass sub...
Wolf
"Overdrive 10" a PR-bandpass sub...
Wolf
I don't understand te question. 'End' ? But I used WinISD to calculate the box and tuning.
Use WinISD to simulate.
I just got my self a Tang Band W8-740C with an Earthquake M8. Cheap but very capable.
More high end I would chose SB Acoustics SB23MFCL45-4, or Dayton Audio RSS210HO-4, or UM8-22, or Wavecor SW223BD02_03
But in 20l box you'll need a passive radiator .... Earthquake or Wavecor ....
Again WinISD is you friend 😉
I just got my self a Tang Band W8-740C with an Earthquake M8. Cheap but very capable.
More high end I would chose SB Acoustics SB23MFCL45-4, or Dayton Audio RSS210HO-4, or UM8-22, or Wavecor SW223BD02_03
But in 20l box you'll need a passive radiator .... Earthquake or Wavecor ....
Again WinISD is you friend 😉
With the bass boost of the module I think he can easily get away with a sealed enclosure and still have plenty of response down to 30Hz.
The Wavecor SW223BD02_03 is quite interesting and needs little volume! Not cheap though.
I agree wholeheartedly.
If you want to use brute force to get lots of SPL from a tiny package just make a tiny box, stick long throw 8" with the baskets and magnets facing out on four sides of it, and have an external amp with DSP force feed it gobs of power.
Not my kind of solution, but I really do not appreciate the reliability issues caused from heat and vibration, from having all the stuff that gets hot and vibrates -in the same box... That, to me, screams of horrible planning and execution.
If you want loads of power to compensate for a tiny box, you've got to plan for how to get rid of the heat IMO.
Personally I'd just make the box a tiny bit bigger and rely less on power, but apparently I'm a minority in this discussion.
Edit:
I am just wondering Colmo, since you have a limit on how wide you want the box, can't you just stick a 12" on the side of it instead? Or would that make it too tall?
Edit2:
Seeing as you're in the UK and you want 8" drivers, I am not sure if there's any better choice than the Beyma 8BR40/N.
You could use double Beyma 8BR40/N per box for some force cancellation and more membrane area, fix the response with DSP, they're 44£ each on Bluearan. Beyma : Beyma 8BR40/N :: PS44.87 IN STOCK (8 Aug 2021)
If you buy "Subwoofer drivers" of some sort, you get a few mm extra xmax, but you usually end up paying more for the bragging rights.
Fun to watch drivers flap about and all, but it takes power, causes distortion, reduces durability.
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Take a look at this project.
Toucan-SF (Silver Flute 8″ Bandpass Subwoofer) – AmpsLab
A bandpass with a cheap driver.
I built a pair.
If you are looking for home theater type of bass to shake you up this will not work but for music yes, it is not a "one note wonder" like many car subs but quite musical. I don't consider it to be a sub as it goes down into the mid to upper thirties whereas a sub I feel should be at a minimum 20 Hz but consider how much music has any signal below ~ 40 Hz.
Toucan-SF (Silver Flute 8″ Bandpass Subwoofer) – AmpsLab
A bandpass with a cheap driver.
I built a pair.
If you are looking for home theater type of bass to shake you up this will not work but for music yes, it is not a "one note wonder" like many car subs but quite musical. I don't consider it to be a sub as it goes down into the mid to upper thirties whereas a sub I feel should be at a minimum 20 Hz but consider how much music has any signal below ~ 40 Hz.
30-40Hz is still a reasonable point to tune at. You have to keep in mind room gain too, especially if you're designing for a budget and specific room.
@Andrew: In mastering we deliberately don't have much infrasound because it can cause trouble. Especially when it's inaudible for most people, and eats your bits (of which I have 16) away quickly.
I use a transmission line with an 8" driver that was made for sealed enclosures and works in a fairly good ported box too. I can easily get to 26hz at 100dB. If you want to go lower and are not willing to go for a better suited driver, then a relatively simple TLine can get you there. But there are compromises.
@Andrew: In mastering we deliberately don't have much infrasound because it can cause trouble. Especially when it's inaudible for most people, and eats your bits (of which I have 16) away quickly.
I use a transmission line with an 8" driver that was made for sealed enclosures and works in a fairly good ported box too. I can easily get to 26hz at 100dB. If you want to go lower and are not willing to go for a better suited driver, then a relatively simple TLine can get you there. But there are compromises.
Humbledeer, thanks, yes I follow.
I also have another pair of subs, They are maybe 20 years old by now or close to it, sealed Rythmik Audio servo subs, with a 12 inch driver which I consider "real subs". I bought along with the drivers the recommended 350W plate amp but modified for 24dB crossover. I have not "upgraded" these as I doubt I would get any improvement.
I also built maybe 5 years ago a Table Tuba by Bill Fitzmaurice. That is some serious output, for me unbalanced sounding but for sheer bass output - WOW.
I also have another pair of subs, They are maybe 20 years old by now or close to it, sealed Rythmik Audio servo subs, with a 12 inch driver which I consider "real subs". I bought along with the drivers the recommended 350W plate amp but modified for 24dB crossover. I have not "upgraded" these as I doubt I would get any improvement.
I also built maybe 5 years ago a Table Tuba by Bill Fitzmaurice. That is some serious output, for me unbalanced sounding but for sheer bass output - WOW.
Filters and EQ causing higher group delay can be easily fixed. But you do still need a filter on the vented one 'cause vented boxes do also unload. You don't want to risk it.
Neither are an option for the OP. From what I understand he is looking for a single 8inch driver for a 22 litre cabinet. The sub needs to cover 30 - 80Hz if possible. He will then build of two of them.
One theory I want to propose: if the main speakers are to remain full range then is their any advantage in porting them? In this instance would the high roll-off be advantageous, creating less overlap between woofer and sub?
e.g Tune the main speakers to 60hz and let the sub handle the rest. I had a similar system which offered surprising benefits.