A bench style cabinet subwoofer 2x15 closed

[Juhazi]

Isobarick Isobaric loudspeaker - Wikipedia, the free encyclopedia

It only helps to get same output (spl) in a smaller box volume? And only 1x15" membrane area moving the air, if I understand correctly.

I want fast impact and many people say that large membranes is the only way to get that.

By the way this might be a slow project - I have 5 kids and Christmas is coming...
A downlod hint for Cristmas Download free Doris Day – The Classic Christmas Album (2012) [MP3] - Mediafire, Rapidshare, Torrent, Hulkshare « Plixid.com | Bringing music to life

[Juhazi]

Isobaric only gives smaller box i guess and my box makes 400-450L any way. Large membrane area makes the impact, isobarik has only 1x15" area.

Tapered horn would give more spl too but I'm after speed!

This might be a slow project because Christmas is coming and I have 5 kids to remember...

And here a hint for all who are waiting for the Xmas Download free Doris Day – The Classic Christmas Album (2012) [MP3] - Mediafire, Rapidshare, Torrent, Hulkshare « Plixid.com | Bringing music to life

[adason]

you use word "speed" of subwoofer like you know what you are talking about...what makes you sure tapered horn gives speed and isobaric does not?
what the heck is speed of subwoofer btw? in your terms?

[norman bates]

Originally Posted by adason

you use word "speed" of subwoofer like you know what you are talking about...what makes you sure tapered horn gives speed and isobaric does not?
what the heck is speed of subwoofer btw? in your terms?

+1

dual 15"
sealed
qtc .707
Vb = 11ft3
F3 = Fsb = 30hz

I'd use ppsl though.
I'd been tempted to build this.
But I know a 25hz ported would be cleaner due to less excursion.

Dayton Audio RSS390HF-4 15" Reference HF Subwoofer 4 Ohm 295-468

speed of subwoofer has more to do with integration (crossover points, slopes, phase, all that junk), especially when it takes your room a bit to stop ringing down (ceiling, walls, etc).

Norm

[Rojoh]

Originally Posted by Juhazi

Nice comments, I must clarify my intentions:
- the room is a mancave-theater-guest room. Functionality before esthetics!
- I want to make a bench anyway
- I want to try big closed sub. Now I have 2 separate 10" vented subs playing.
- I'm really not after maximum spl but fast and controlled (bass drum, double bass etc.)
- I want to have two elements (subs) because that helps to kill room modes (Geddes multisub arrangement, and I can even have a separate sub no3!)

adason said that no2 is ugly. The top panel is missing in the scetch, I'm planning to make it of a melamine-coated board. The box could be thickest possible LDF floor-board. The openigs for element could be open of with some grill., Yes, the box must be divided internally to prevent standing wave at around 82Hz

I vote "yes" to your sealed wooferbench-idea. Camouflaged as furniture it blends well into the room. Here's what i did with 4x10" Seas woofers/sealed. Nice, well balanced bass.

[Juhazi]

adason, I'm just trying to tell that I want good transient and "controlled" subbass. English is not my native language and I'm trying to avoid tautology.

Many people with lots of experience with subs and full range speakers say that there's no substitute to membrane area! Less stroke needed to move certain amount of air. And many people say that closed cabinets give the cleanest bass (a new definition again) Please see the step response graph from UniBox below (other boxes as suggested by unibox. I don't know where that 1xDayton comes, BP?)

I want to test and try this now myself. I have made my choice of arrangement (2x15" closed), now it's just about how to do it. If I get disappointed, I'll tweak it or make a new different one just like everybody else here!

Norman, what do you mean by ppsl (push-pull slot?)

I checked the elements at PE, the price is 90$ each but cargo is 208$ - jeez! - no deal. Cargo from cental Europe is only 40€.

[norman bates]

A Thread for those interested in PPSL enclosures

[adason]

do not take me wrong, if you decided to make big closed box sub, go for it, I am not against, I just poited out cone sag in first picture, and was not too keen on the look of the second one...see you are striving for perfect transient response and you place the woofers angled in the V corner? how is that supposed to act? you's better stick those in the front like Rojoh did, just a suggestion

[adason]

I did plenty of closed big box subwoofers myself, they turned out ok, but was lately experimenting with open baffle subs, arranged as two 15" woofers on oposite side of the box, acting in unisono, that is as dipole, not as bipole, so no preasure buildup in the box...so far these sound better to me as closed box sub, but you have to place it in the room, just like other open baffle spekers (I am very fond of open baffle sound)

[Juhazi]

Yep, ppsl in getting more attention especially with dipoles (SL, gainphile, Jon) Also the famed Bose is using this in their desktop speakers!

I have thouhgt about that already, but then I found these nice elements for the sealed! It is easy to do with my bench-cabinet. There is a formula somewhere to define the slot volume and opening area. I've read about less distortion and more spl, but is it compared to 1x or 2x the same element (ppsl always has even). These elements are not ideal for dipole or pp because the backside is stamped steel thus disturbing the sound waves and perhaps making the pressurization of the slot un-uniform?

PPSL must be studied here! Perhaps slot loading but not PP. Which (inexpensive ) elements? Slot size and proportions, box volume, type? ? The extra volume of the bench can be used for the amp or sand filling! I have about 6kg of sand inside my XLS10+pr cabinet!

PPSL suits also because I dont want the big cones to get kicked and busted right away! That's the reason for my no2 suggestion in the first post (I've got some experience with kids and precautions).