[tys777]

What is the drawback besides being inefficient to putting a 12" or 15" or maybe even two 12" or two 15" drivers in a smaller enclosure with lots of power and heavy eq?

For instance if you had two nice 300 watt 12" or 15" drivers, dropped them into a 3.5 ft3 enclosure, added a 1000 watt amp, and eq'd them with something like the reckhorn b1? What is the downside or would this work?

 

[Prize78]

I'm in the process of having a dual 12" (push pull) Acoustic elegance sub built. It'll be roughly a 40 litre sealed box, powered by a behringer ep4000. The drivers will take 1000 watts each, and the amp is more than capable of delivering such power. Projected figures say that it will be at around 89dB at 7 or so Hz, 95dB at 10Hz and around 107dB at 20Hz. As long as the build has got the right dimensions, and the sub is correctly set up, this will do for me.

 

[tys777]

Is that with heavy eq?

Why don't more people do this? there has to be a reason...??

 

[mjg100]



Quote:
Originally Posted by tys777 /forum/post/18265280


Is that with heavy eq?

Why don't more people do this? there has to be a reason...??

To get the kind of power that you need, you need to use large plate amps, pro amps or really expensive HT amps. So cost is one reason. Using pro amps is another. I use pro amps, but many will not use them because of the following:


Noise.

Not familiar with pro audio equipment.

Some people think they get better sound quality using HT amps.

 

[Stereodude]



Quote:
Originally Posted by tys777 /forum/post/18265280


Is that with heavy eq?

Why don't more people do this? there has to be a reason...??

The reason is that most DIY'ers aren't so tightly constrained on space so they'll use a larger box and get even more bass.

 

[Bill Fitzmaurice]



Quote:
Originally Posted by tys777 /forum/post/18264044


What is the drawback besides being inefficient to putting a 12" or 15" or maybe even two 12" or two 15" drivers in a smaller enclosure with lots of power and heavy eq?

Distortion. It rises with excursion. And cost, of course. Watts are cheap, but they aren't free, and neither are drivers with longer excursions.

 

[Drew Eckhardt]



Quote:
Originally Posted by Bill Fitzmaurice /forum/post/18266767


Distortion. It rises with excursion. And cost, of course. Watts are cheap, but they aren't free, and neither are drivers with longer excursions.

Excursion required to reach a given SPL is the same regardless of box size. A smaller box just takes more power to get there.


People accept that you can't equalize ported systems which leads to a small box implying a sealed enclosure (which doesn't have an excursion decrease around port resonance and therefore has lower excursion limited output at that frequency) although that is an over-simplification.


Although ported and passive radiator systems can't be boosted below port or passive radiator tune (driver excursion increases to what it would be without the additional resonant device and output drops rapidly since the two sound sources are 180 degrees out of phase), the driver can be equalized to overcome the stiff compliance from a small box to match a resonant device at a lower frequency.

 

[Drew Eckhardt]



Quote:
Originally Posted by tys777 /forum/post/18264044


What is the drawback besides being inefficient to putting a 12" or 15" or maybe even two 12" or two 15" drivers in a smaller enclosure with lots of power and heavy eq?

For instance if you had two nice 300 watt 12" or 15" drivers, dropped them into a 3.5 ft3 enclosure, added a 1000 watt amp, and eq'd them with something like the reckhorn b1? What is the downside or would this work?

Thermal compression and distortion can be problems.

 

[kgveteran]

The only problem with a smallish sealed pair of subs is explaining to your friends, who have ported subs, why yours sounds so much better

Oh boy ........

 

[jeff76]



Quote:
Originally Posted by kgveteran /forum/post/18268353


the only problem with a smallish sealed pair of subs is explaining to your friends, who have ported subs, why yours sounds so much better

oh boy ........

lol

 

[jpmst3]

I have that problem all the time.

 

[LTD02]

small boxes are inefficient. inefficiency raises cost because amp power is expensive relative to box size. for

 

[kgveteran]



Quote:
subwoofer design is simple. establish your goals, your contraints, and pick a solution. engineering 101.

True dat !!

 

[bossobass]



Quote:
Originally Posted by tys777 /forum/post/18265280


Is that with heavy eq?

Why don't more people do this? there has to be a reason...??

Most people do 'do this'.


Velodyne, SVS, Krell, JL Audio, Epik, Seaton Sound, Martin Logan, Thiel, Paradigm, RBH, Rythmik, Hsu, Kleiss, Revel, etc., etc.


These companies don't market undesirable, underperforming products as a road to their obvious success.


"Subwoofer design is simple."


LTD, that one was a chuckle. Send me one you've whipped together and I'll let you know what I think.

Bosso

 

[penngray]

Welcome back Bosso!

 

[LTD02]

"LTD, that one was a chuckle."

argumentum ad hominem is a logical failure.

 

[brandonnash]

And here....we go!

 

[jpmst3]

I think it's about time to resurrect the ported vs. sealed debates.


Everyone is too horny now.

 

[Prize78]



Quote:
Originally Posted by tys777 /forum/post/18265280


Is that with heavy eq?

Why don't more people do this? there has to be a reason...??

Initially, no. I'm going to see what sort of a response i can get with placement and audyssey. Failing that, i think i'll try a BFD. The pro amp i'll be using will be delivering 1000 watts comfortably to each driver.