4 AV15’s but cant do IB – need guidance

[abe]

I’ve had 4 AV15’s for over a year now or is it 2 yrs (procrastination and memory loss what a combo to have). My original plan was to do an IB however I will be moving and an IB in now out of the question. I want to build now while I still have a garage to build something in. Problem is I don’t know where to begin. Help! Need guidance and this is HTGuide.com. ;x(

I.B. is out so I need a box(s)/tube(s) or Dipole?????
Do I need to decide what my goals are first?
Or is the radiating area/ room size the determining factor?
Or enclosure size constraints?
Or my budget?

So where do I start?

I guess one question that may narrow the decision process is – are these subs OK to use horizontally (downfiring position) in other words are they susceptible to sagging or is it recommended to go vertical only? that might eliminate a sonotube design right off the bat.

[SteveCallas]

I'd go for four of these myself.

[Licinius]

Definitely, (big tube + big ports + big subs) * 4 = killer low frequency action. I've got an av15 in a sonotube myself, it rocked. Then I moved into an apartment and its now in the garage =(.

[Owen Bartley]

If you can, I'd go for something like Joe L. did here. I thought it was an awesome project. 4 big tubes will take up a lot of room, and this might be easier to integrate.

[JoshK]

What you need to do is sell 2 of those AV15's to me (I can do IB, but need 2 more AV15s) and just make 2 big mommas.

[abe]

Sorry it took so long to get back - internets been down till now.

Thanks for the replies. But in regards to the sonotubes, I would like to know if the AV15 can be mounted horizontally or is it not recommended due to suspension sag. The first link per steve was an avalanche not what I have which is a stryke AV15 now called acoustic elegance (cant access their forums to ask this question). Anyone know?

Four big honkin tubes or big hairy box would be cool but I dont have the room. I'd like to have as small a footprint as I can get and was hoping with four drivers I could get decent output with a small footprint.

Josh, depending on what y'all come up with, I might do it. email or private message me if you want to discuss further.

[Owen Bartley]

I guess if you wanted a small footprint you could always do a sealed tube (or box) with a driver in each end. I forget whose project that was, but I'm sure I've seen it around before. I don't know how you can get to use all 4 of them though, without blowing apart a small enclosure.

[ThomasW]

My recommendation is build 4 smallish sealed boxes, then use a Linkwitz-Transform circuit to lower the Qtc to 0.5.

This will be somewhat 'portable', able to play low, and loud, with good definition

[SteveCallas]

The first link per steve was an avalanche not what I have which is a stryke AV15

Lol, I'm sorry. The AV15 hasn't been available for some time, I had nearly forgotten about it and assumed you meant avalanche 15. As has been mentioned, 4 drivers in as small a footprint as possible dictates sealed.

[abe]

no problem steve. yah they are that old. Here I am worried about suspension sag and they been in thier original boxes horizontal position for that long.

I'll search for the Linkwitz-Transform circuit thing - hope its not expensive cause I'll need an amp. I do have the berhinger feedback destroyer DSP1124P, ECM8000 and the UB802 that I bought at the same time (did I mention that I'm a procrastinator ......uh I mean was)

[ThomasW]

Cheapest LT I know of...Unless Bob Ellis has some of his PCB's available

http://sound.westhost.com/project71.htm

[Paul W]

If you need to go even smaller, consider Isobaric.

[cobbpa]

My recommendation is build 4 smallish sealed boxes,

This is where I mark my vote! :T

[Mazeroth]

What might help is to know what type of output you're aiming for? Also, how far from the subs do you plan on being and do you have an extension (in hz) goal? Dipole will provide you the best possible SQ but will limit your output. However, four of those 15s should get you plenty deep for music listening, but for movies, you're probably going to want to go sealed/ported.

[abe]

Maz, these will be for movies. You've asked hard questions. Goals - How low and loud would I like to go? Don't really have a clue. What can these four subs do in little boxes? Also, I'm thinking if the setup can reproduce the low freq. but its not really audible or weak sounding, thats no good. What is your suggestion?

All I'm certain of right now is - I don't want anything big or heavy in fact smaller and lighter is better.

I've been looking into the linkwitz transform circuit and it looks complex. I dont have many electrical skills. I soldered resistors in my computer fans to slow em down and done some wiring in the house. Not much really in terms of hands on.

Where do I go from here?

[ThomasW]

4 smallish sealed boxes.

If you sell your BFD and buy a Behringer DEQ2496, it can be used as a LT circuit.

[abe]

Thomas, I noted how you used the word "smallish" that was purposeful wasnt it :W I've read about the DEQ on your pages. Good work btw. Moving forward, I'm left with these decisions:

Budget

LT circuit: make or buy

buy amp: determine power req's

Box size

smallish = what: (software modeling exercises?)

Thanks for everyones input. I will be thinking and working on this some more. I got the hard part almost done: Cleaning, goodwilling, garage sells and trashing stuff in the garage to make ready for some dust. This is hard work cause I'm a pack rat. I dont throw away toothbrushes. ops:

[SteveCallas]

Sealed will get you small. To succeed on the light part, you might want to still go with some short sonosubs - the tube weighs much less than an equivalent, well braced box. Two sonosubs with opposing drivers on each end cap like Thomas has built before will probably be the most lightweight solution.

[ssabripo]

Another AV15 club member!! :T

For your requirements I say:

4 AV15 in dual sealed enclosures, powered by a couple of EP2500s or QSC1450's, add a BASSIS, and BFD, and you are set..... ;x(

[---k---]

I like Steve's last idea the best. (I'm assuming the AV15 can be mounted up/down, no one has answered that.) It would take up less space, and you wouldn't have to build as stout of an enclosure if the drivers are mounted oppoisite of each other.

Powering 4 sealed subs w/ some EQ is going to take a lot of amp. You're probably going to need two amps for all four drivers - think two EP2500 @ $300/ea. Maybe two EP1500, but it is always best to have too much power.

Depending on your budget, and it sounds like you are moving to a smaller apartment, you might want to consider doing just two subs.

BTW, didn't Sherve build his ported sub with ONE AV15 and was really happy with it. You might be able to get by with just one. Goes back to you're goals.

[ssabripo]

.....
BTW, didn't Sherve build his ported sub with ONE AV15 and was really happy with it. You might be able to get by with just one. Goes back to you're goals.

Well, he could just build either a single Ported sub like mine or a la LLT, or go dual AV15's in a sealed, again with an EP2500/QSC1450 + BASSIS+BFD, and be VERY happy.....

and store the other 2 (3) for later, or sell them.....If you do sell them, I got Dibs on them!! :T

ps- you can expect this kinda performance at a minimum from a single AV15 in a large ported sub (the following is absolutely NO EQ, horrible room acoustics, and no placement....imagine with some EQ and tweaking! ):

[WillyD]

I like Steve's last idea the best. (I'm assuming the AV15 can be mounted up/down, no one has answered that.) It would take up less space, and you wouldn't have to build as stout of an enclosure if the drivers are mounted oppoisite of each other.

He could lay the sonosubs horizontally.

[ThomasW]

Thomas, I noted how you used the word "smallish" that was purposeful wasnt it

Yes

smallish = what: (software modeling exercises

Unibox or WinISD Pro.

Steve's correct about tubes being the best choice for lightweight... :T

Tubes could be stacked. They can also be done horizontal if a cradle is made to support the tube. If the cradles interlock then it's a modular unit.

[Dennis H]

I'll second sealed boxes with 2 opposed drivers in each box. The vibration cancelling is a biggie when you're trying to hide them in a small room and make them look/act like furniture. You can put lamps or whatever on top of them without anything rattling or crashing to the floor if you use two drivers.