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Finished My Ed 18 inch sono's - Page 3

post #61 of 672
I'm not half as experienced as half the posters here, but I say do it! Everytime I've heard multiple sealed it just makes me smile. There is no way in the world you would regret it (unless cost is a concern). As you already know, there is no replacement for displacement. This set up would be loafing at rediculous volume levels.
post #62 of 672
Thread Starter 
I know it should be better, but if you heard the current setup you would maybe say don't bother. If that $800 amp can truly power all 8 drivers(connections?) to high levels then it would make things interesting.
post #63 of 672
Quote:
Originally Posted by MKtheater View Post

Bosso,
Which amp could power all 8 drivers? I am using two MPA-501's, they are 5 channel amps. So I have 10 channels. I am also using a PF-2501 which is 2 channels and if I were to do this that leaves me 4 channels of amplification short.

For an example, the amp I sent to Sherv/Chas to eval is $799 with free shipping from HERE.

You could wire parallel/series/parallel and present a nominal 4 ohm load from all 8 drivers. The amp is rated at 4500W into 4 ohms.

As it has been mentioned above and many times before, there is no replacement for displacement. That is not entirely correct. As you know, room gain (BG/PVG) and acoustic coupling add much more output than an increase in displacement.

One driver is 90.5dB 1W/1M. Eight drivers is 99.5dB 1W/1M. That's eight times the output for the same input with only 3 times the displacement increase at 20Hz. Room gain can push that to 100 times the output with no increase in displacement.

Bosso
post #64 of 672
As stated, experiement with the equipment you have. Make some new top caps, take the drivers out of two of the tubes and try twin, dual sub sono's in a push pull config. That should further help lower distortion.

If you like it, all you have to do is build two more top caps.
post #65 of 672
Thread Starter 
I am no way displeased with the bass I have now. It is down right scary. This is what if type of thing. If there is distortion then I don't know what distortion sounds like.

Bosso,

How does one wire the subs like you say?
post #66 of 672
Quote:
Originally Posted by MK View Post

I am no way displeased with the bass I have now. It is down right scary. This is what if type of thing. If there is distortion then I don't know what distortion sounds like.

Yes, your proposed idea to buy 4 more drivers, more amps, EQ, modify your existing enclosures, and then bring down the top end so that you stay relatively flat into the single digits would essentially be one large and expensive experiment to see if more single digit capability would add anything to the experience, and that would virtually be limited to select movies. If you are into experimenting, go for it - if you can think of anything else you'd rather spend all that money and time on, I think it would be the better choice.
post #67 of 672
Quote:
Originally Posted by MKtheater View Post


Bosso,

How does one wire the subs like you say?

See attached.

Bosso
LL
post #68 of 672
Thread Starter 
Each one of my drivers are wired in 2 ohms, will this still work?
post #69 of 672
Quote:
Originally Posted by MKtheater View Post

Each one of my drivers are wired in 2 ohms, will this still work?

Yes.

Bosso
post #70 of 672
Thread Starter 
Bosso,
You just made it cost effective for me now. I hope that amp controls the drivers well. It will look out of place in my rack. Does it come in black?
post #71 of 672
Thread Starter 
I ordered a Behringer EP 2500 to blind test for my mains. I am curious how it sounds. If it soungs good enough I will go ahead and seal these up, but with a catch. I was told that they will be too big for a sealed design so I would cut them in half. They would be 248 liters(3 feet by 2 feet round). Dual 18 inch with 850 watts into each driver. I would lie them down and have them fire sideways. What this does is free up space vertically. Why? Because cutting them in half leaves me with 4 more sono's at 3 feet each. If the behringer works out, I see 8 subs in my future, all sealed, dual opposed 18's. Someone please help me, I am losing it
post #72 of 672
You already lost it. Might as well enjoy the ride. That sounds like an awesome plan by the way.
post #73 of 672
Thread Starter 
That is what my wife says. This is all dependent on the Behringer. The 4 dual sealed will come first. I know those 4 empty sonos will drive me nuts.
post #74 of 672
which eD drivers are those? I cannot find them on the website.
post #75 of 672
Thread Starter 
the 190v.2 D4.
post #76 of 672
Thread Starter 
Ok, I have decided to go with the plan. 4 subs, 8-18 inch drivers, 850 watts/driver, opposed to each other and 3 feet tall.
post #77 of 672
Sounds good. What will you be using for EQ? Are you gonna try LT?
post #78 of 672
Thread Starter 
I have alot of room gain at 5 hz so all I will be using is Audyssey. What is LT?
post #79 of 672
Quote:
Originally Posted by MKtheater View Post

I have alot of room gain at 5 hz so all I will be using is Audyssey. What is LT?


LT emulates so to speak a LOW TUNE. Say you want extension to ...4Hz or so. It will apply corrections to the signal to get a pretty flat curve all the way to that point.

LT is great for an array of subwoofers,like you plan on doing.Or what I have...a wall and two half sides of subs. Even if the boost is very major down deep,the multiple drivers manage as their culmulative displacement will allow you to get both outstanding extension and good output down very deep.

Most of the time this extreme LF signal will not be at a high level(compared to most bass conent)so bottoming a well configured sealed array with a matched LT is not an issue.

For example an LT in a singular smal low displacement driver would be a waste,as the driver would have to go beyond its linear and even max displacement to be of much worth.

LT's are a big plus with high displacement drivers and multiples of these...even better.
post #80 of 672
Quote:
Originally Posted by MKtheater View Post

I have alot of room gain at 5 hz so all I will be using is Audyssey. What is LT?

Linkwitz Transform. A fancy precision tuned EQ really, usually for boosting down low. It's kinda what Sherv was trying to emulate with his DCX. Arthur's description works.
post #81 of 672
Thread Starter 
How does one apply LT?
post #82 of 672
The "correct" way would be to install said subwoofer (eD 18 inch) into your sealed box of whichever size you want. Measure. Then apply the necessary filters in a LT circuit. I don't know much about how to use them other than that so you will have to consult an expert. An LT can be built like a circuit or emulated with some of the more powerful EQ's out there.

The cool thing about an LT is that you can have it set for whatever Qtc and F3 you want. Obviously, the device is not magic and physics still apply.
post #83 of 672
Thread Starter 
Sounds cool but I don't know if I need it, time will tell.
post #84 of 672
Quote:
Originally Posted by MKtheater View Post

Sounds cool but I don't know if I need it, time will tell.

You definitely won't need it.

8X18" sealed in 2300 cubes of space = INSANELY CAPABLE.

I'm not usually one to make such exclamations, but you gotta be kiddin'. This system in that room has no limits with any source I know of at reference level playback.

Bosso
post #85 of 672
Thread Starter 
Bosso,
The system is like that now. This will increase the low end(really low) and making it flatter to the midbass region(room gain). Besides I want to hear what the sealed subs sound like as well without losing spl.
post #86 of 672
The only area where SPL will be less (or maybe just not as efficiently produced) would be in the 10-20hz area where you had your ports tuned. Above and below you will have more SPL than before. Shouldn't sound any worse or quieter.

Not disagreeing with Bosso or anything but it couldn't hurt to try out some EQ down low. You certainly will have the Vd and amp power to do it. Would love to hear the setup EQ'd flat to 5hz and with all that headroom all the way up to 18khz.

How soon will you be doing this?
post #87 of 672
Thread Starter 
hopefully within 2 weeks
post #88 of 672
The truth is that the so-called sensitivity advantage of the ported version is only seen in a computer model.

Every large ported sub is grossly under ported for the maximum output graphs that the models project.

Those 18s would probably need 3 times the port area they actually have to produce the modeled max output graph with no port compression.

The reality is that there is 2-4dB of compression at maximum output, and with huge non-linear distortions.

OTOH, the sealed system will show virtually no compression down low with much lower distortion.

The point is that what a model shows as a difference in maximum output at tune doesn't equate very well to the real world.

The max output from 10-20Hz will be basically the same, with much less distortion from the sealed system. The headroom above and below that will be 6-8dB. The transient response will be better by 2 octaves.

It's hard to predict anything from a subjective viewpoint without in-room measurements, but the systems, as a comparison on paper, are significantly different, across the board.

Should be fun in any case. Looking forward to impressions and details.

You maniac.

Bosso
post #89 of 672
Thread Starter 
It will be fun. I will cut the tubes in half and have 3 feet tubes. I will have 4 extra tubes after doing this, maybe 8 subs will be in my future.
post #90 of 672
Thread Starter 
I have changed my mind again. Instead of 4 dual opposing subs I am going with 8 smaller subs. I will have them front firing and this will allow me to move my screen back further. What I am going to do is build a flat platform above the subs and put my speakers on that with all the eight subs underneath on the floor. This will allow me to position my speakers much better behind the screen and maybe in the future put 2 more bigger subs(dual opposing) in the corners on the platform. What do you guys think? 8 singles that are 22 inches long and 24 inches round or 4 doubles that are 3 feet tall and 24 inches round? I guess I could lie the subs down and give me the same depth either way but one setup would be firing into the seats and the other would be side firing into each other and the side walls.
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