Hard to make choices with DIY subwoofer

[diystuff]

Hey guys,

This is my first time posting here (I joined just a bout a week ago )

Anyways, soon I'm going to start my first DIY subwoofer project. I have never done anything like this so I'm very nervous. My dilemma is that I have to choose from a 12 inch ported subwoofer being powered by 300w rms or a 15 inch sealed subwoofer being powered by 500w rms. The drivers that are in question are the Dayton reference HF (12 and 15 inches). This sub will be used 40% for music and 60% HT. The boxes will be 5.4 cu feet for the sealed and 5.7 cubic feet for the ported. THe f3 of the ported is 19 hz and the f3 of the sealed is 30hz. My living room is where the sub is going to be and it is very large and open. I already have a polk audio psw125 (12 inch ported) and that couldn't fill the room with bass properly. Common sense tells me to use the ported because of the crazy f3 but I'm afraid that my speaker building skills aren't sufficient and I will mess it up. However, I will get the wood panels and such cut by someone else because I don't have the tools or skills. Also, I found this tangband subwoofer:

Tang Band WQ-1858 12" Aluminum Subwoofer 264-897

I calculated a f3 of 17 hz in a 5.89 cu feet box but I don't know if this subwoofer has a good SQ. These calculations are all from the diyaudioandvideo calculators. I just got winISD, however, it is hard to understand what I should do. I will play with it and figure out the software soon enough.

(BTW guys I live in europe so will parts express ship here? And will the BASH amps work with the 230v 50hz electric output we have here? if not can i use a transformer?)

What do you guys think? Hopefully soon I'll get to making sketches on google sketch

 

[epa]

for a sub plate-amp in europe try hypex.

 

[diystuff]

for a sub plate-amp in europe try hypex.

Thanks for the recommendation! But, European amplifiers are waaay too expensive compared to what I can get from the states. I'm on a budget of about 500 dollars for the driver and the amplifier. The less, the better

 

[bjorno]

..Anyways, soon I'm going to start my first DIY subwoofer project... I have never done anything like this so I'm very nervous..This sub will be used 40% for music and 60% HT. I found this tangband subwoofer:

Tang Band WQ-1858 12" Aluminum Subwoofer 264-897

I calculated a f3 of 17 hz in a 5.89 cu feet box but I don't know if this subwoofer has a good SQ. These calculations are all from the diyaudioandvideo calculators. I just got winISD, however, it is hard to understand what I should do. I will play with it and figure out the software soon enough..

Hi,

Here is a suggestion that shouldn't be too difficult to start with as once the dimensions are established stuff it with speaker damping material counted from the closed end leaving~1/3 of the length empty.

b

 

[diystuff]

Thanks for the suggestions guys! But I have decided to go with the Dayton Reference HF 12" subwoofer with dual flared 4" ports. I have some graphs from unibox but I can't figure out how to attach images when I post? Anyways, The problem is that from around 25-35 hz the xmax of the driver is passed by about 3mm. The xmax of the driver is 14mm and at around 28 Hz the cone excursion is 17mm. Btw this is calculated using 400w as nominal power but I will be powering this driver with a 300w rms oaudio bash amp. Is this ok or is the excursion too much?

 

[WaVeInFoRm]

well its ony going to pass the xmax when it is on full volume and a tone within that frequency plays. and even 3mm past xmax isnt much of a deal if its just happens in the odd explosion, not exeeding xlim, it should not realy be a issue.

the other option is to raise the tuning frequency, this causes the driver responce to be rolled off sooner to be replaced by the port output sooner. and as woofers always move more the lower they play.. tuning slightly higher will mean it moves less with the same imput. (in theory, but you may end up with 2 boomy higher bass)

 

[weltersys]

the other option is to raise the tuning frequency, this causes the driver responce to be rolled off sooner to be replaced by the port output sooner.

And the speaker will unload (go over Xmax) at a higher frequency also.

 

[diystuff]

See, the amp power is 300w rms and probably 600w peak. However, the driver's power handling is 400w rms and 700w max. So what value should I use in Unibox? 300w, 600w, 400w? So you guys are saying that the driver will only unload if the volume is on max? Also, on unibox it gives me three different port lengths and diameters, and like 2 different subwoofer box volumes. Which one should i follow? Standard design or Design by Vb, Fb and Q?

 

[WaVeInFoRm]

for example... if 87db=1watt 97db=10watts 107db=100w 117db=1000w

depends how loud a signal is , the low rumble may be 10w but a explosion may be more. depends how loud you have it

 

[sreten]

See, the amp power is 300w rms and probably 600w peak. However, the
driver's power handling is 400w rms and 700w max. So what value should I
use in Unibox? 300w, 600w, 400w? So you guys are saying that the driver will
only unload if the volume is on max? Also, on unibox it gives me three different
port lengths and diameters, and like 2 different subwoofer box volumes.
Which one should i follow? Standard design or Design by Vb, Fb and Q?

Hi,

You should use the amplifier RMS power and rather than using
standard alignments optimise the alignment to your requirements.

Compared to a maximally flat vented alignment I prefer either
reducing box volume for a suggested low tuning frequency,
leaving the tuning frequency the same, or the same box
volume and reducing the vent tuning frequency for a
suggested high tuning frequency, both are valid.

rgds, sreten.

rgds, sreten.

 

[sreten]

See, the amp power is 300w rms and probably 600w peak. However, the driver's power handling is 400w rms and 700w max. So what value should I use in Unibox? 300w, 600w, 400w? So you guys are saying that the driver will only unload if the volume is on max? Also, on unibox it gives me three different port lengths and diameters, and like 2 different subwoofer box volumes. Which one should i follow? Standard design or Design by Vb, Fb and Q?

Hi,

Use the amplifiers RMS power. The Dayton 12" RS 4
ohm models best to me in around 4 cuft tuned to 20Hz.

rgds, sreten.

 

[mdocod]

For a 5-6ft^3 box size, You might also consider the DCS450. It'll produce a more natural "rolled-off" response that should balance well with room gain while providing higher maximum SPL capability through most of the musical bass range. It's $25 cheaper and weighs even a touch less (won't cost any more to ship) than the RSS315HF. I would suggest vented, tuned in the 19-24hz range.

 

[pinkmouse]

Thanks for the recommendation! But, European amplifiers are waaay too expensive compared to what I can get from the states. I'm on a budget of about 500 dollars for the driver and the amplifier. The less, the better

Don't overlook the hidden costs, as well as shipping, you will have to pay import tax and a handling charge from the courier, and this can be very expensive. You also need to make sure any amp you buy works on European voltage, not just US.

 

[diystuff]

Yep, I checked all the hidden costs and the price of the oaudio bash 300w amp should be far below the european amp prices. And Oaudio amps work here in europe too

On unibox, I chose the option 'minimal fill' as opposed to 'no fill' , 'heavy fill' and 'walls covered' for dampening. How much is minimal fill? How many lbs/kgs per cuft^3/liter? And is minimal fill good enough?

**Also**, I have decided to go with 3 4inch flared ports. Because, according to unibox, this will keep the air speed of the port under 17 m/s. Unfortunately each port has to be 44.5 inches long or 133 cm

I'm sure I can use some elbow joints and so on. I don't plan to buy pre-made ports but I will probably buy lots of abs pipe and precision port 4" flared ends and fashion three preposterously long ports.

I guess my sub will look more or less something like this (probably much worse on the finish) PB13-ULTRA - SVS

 

[diystuff]

And guys I know that the Oaudio 500w bash amp has a variable subsonic filter. THe 300w version doesn't have a variable filter but does it have a subsonic filter that is built into the amp itself? I know the non Oaudio version has a filter set at 18hz. Because if it doesn't have this subsonic filter then below 18 hz the sub is going to start to bottom out badly.

 

[mdocod]

Comparison of the DCS450 18" sub, to the RSS315HF 12" sub, each in 5.5ft^3 tuned to 18hz modeled at 250W amplification (Xmax limited on both drivers at about that same level).

It's all trade-offs but I personally like the way the 18" models out a lot better.

 

[diystuff]

Comparison of the DCS450 18" sub, to the RSS315HF 12" sub, each in 5.5ft^3 tuned to 18hz modeled at 250W amplification (Xmax limited on both drivers at about that same level).

It's all trade-offs but I personally like the way the 18" models out a lot better.

Hey...first of all thanks for taking your time and making graphs for me

I've tried using winISD but when i enter the parameters for the Dayton RSS315HF 12" sub, winISD calculates a ridiculous Fs of something like 200hz


Anyways, here are my unibox graphs...I would prefer to sticking with the 12 inch













What do you guys think?

 

[sreten]

It's all trade-offs but I personally like the way the 18" models out a lot better.

Hi,

So do I by the looks of it, more room friendly. What does max SPL look like for both ?

rgds, sreten.

 

[diystuff]

aaaarrrrgh

Change of plans again...I can't make my mind up

Instead of the three, front-facing 4" ports. I will have two, front facing 4"ports, this is because I wont have enough room to accommodate those ports on my front panel.

I just read an article that elbow joints for the ports can increase chuffing. However, my port needs to be like 80 cm long...is it ok to use elbow joints (do elbow joints even exist for abs piping? can i use the dayton audio elbow joints?)

 

[diystuff]

BTW Here are the new and updated graphs with the dual 4" ports instead of the triple 4" ports