Home Theater Forum and Systems banner

Fi SP4 18" Build

29K views 135 replies 9 participants last post by  3ll3d00d 
#1 · (Edited)
Fi SP4 18" x 4 Sono Sub Build

4 Fi SP4 18" drivers. Custom made for home theater (low F's)

I tried to work with Nick at SI, then after he took four weeks to get me a shipping quote I decided to take up CSG on a deal for the ZV4s. That took forever (over four weeks) so I cancelled that order and contacted Fi.

I sent an email that said - " call me now if you're there " and got a phone call in ten minutes. Scott was great to talk with. I let him know what I had been through over the last couple months and asked if he could deliver on a specific date. He said he could, we discussed that date, and I paid him.

The four drivers were delivered on time and in excellent shape.

I will add that Jacob from Sundown was great to deal with. But....by the time I was talking with him I was weeks past the ship date for my drivers.

Nick from SI was no fun from the beginning, which is odd because I bought six SI HT 18s and Nick was great. I guess it's hit and miss with him. I wouldn't order a driver from him if it was the last driver on earth. He treated me that bad, and he treated the DIY community the same.

I was warned by mods to not explain all the SI / NICK details. PM me and I will share all.

Washing machine Technology Architecture Audio equipment Personal protective equipment


Bumper Automotive exterior Vehicle Auto part Technology


Audio equipment Wheel Rim Auto part Subwoofer


Metal




Tire Wheel Automotive tire Rim Auto part


Audio equipment Bumper Loudspeaker Auto part Technology


Look at that little SI 18 in the background! No slam against SI, that very well could be a Dayton. BUT .... I'm thinking I'm going to blow that little 18" up with pure amp power.

Audio equipment Loudspeaker Technology Floor Electronic device


Check out the break - in videos. I found these max at 60 Volts @ 20 Hz in free air after some break in period. You can of course give it more when you first hook them up.

I had a little over excursion incident (more on that below) and it turned out to be glue from spider joint at the former. It was the upper joint, and because of the spider spacer design the debris was trapped between the two spiders. After talking with Fi we came up with drilling a 1/2" hole and shaking out the debris. Worked like a charm.

Here's some pictures of that process.

Blue Cookware and bakeware Wok Frying pan Plant

Water Sky Material property Metal

Helmet Headgear Electric blue Automotive exterior Bumper

Helmet Audio equipment Bumper Auto part Personal protective equipment

Text Paper Paper product Font Drawing


Here's my floor plan for the speakers - up....never mind. The photo is too large. :rolleyesno:
 
See less See more
13
#72 · (Edited)
I did wrap it all the way around. I put down some spray adhesive as I wrapped, and when I got within about two inches, I quit the adhesive. At that point I overlapped and cut through both layers. After that I folded back my seams and finished spraying, then used a rolling pin to flatten, an push the seam tight. It looked flawless. But after a couple weeks the edges started lifting in a couple spots. I kept pushing it flat but it kept lifting in random spots. I finally tried super glue, and it seems ok, but I think something made for vinyl, or automotive would be better. The method I used was suggested by my friend who uses that stuff a lot. It seemed reasonable enough. Plus the seam is in the corner so nobody really sees it. People compliment it all the time. I used the same grill on top that SVS does so it matched my SVS. Parts express, 5 bucks, scratch n dent.(not sure where). I'd love to hear of another way to do the seam, if you know one! My DIY sub is on the left. (I need more pics)
Will
 
#77 ·
That looks awesome! Nice work :T. I keep kicking myself for passing up (really a miniscule chance) a full up acrylic tube probably 18" diameter, 5' tall, 0.5" thick walls. Thought it would be a really cool looking sub, but couldn't get a hold of it because it was used in an industrial setting for other purposes.

That section looks great though to get a glimpse at the driver!
 
#78 ·
That looks awesome! Nice work :T. I keep kicking myself for passing up (really a miniscule chance) a full up acrylic tube probably 18" diameter, 5' tall, 0.5" thick walls. Thought it would be a really cool looking sub, but couldn't get a hold of it because it was used in an industrial setting for other purposes.

That section looks great though to get a glimpse at the driver!

:gulp: :gulp::gulp:

That would have been very neat!

I was at the plastics store I got my acrylic at and they have a product that literally welds the acrylic together, water tight.
 
#79 ·
Lets say you have 55mm mechanical excursion. (more than enough) SO I would then look at where the cone rests and measure from there. Maybe you would be comfortable with 75mm tall from the cone.

I was only 2.5" above the cone on my build. And if I had the SP4's I would have kept it the same. For the cone to push itself past the height of the surround looked like 20mm at least on my subwoofers. SO no way was it going to go much further.

But this is just my opinion. Some people want to say you need 4" legs minimal above the surround.
 
#80 ·
Ya Dave - I'm not much worried about hitting the glass as much as I am what it does to the sound quality. There is a great post here with calculators, pictures, and explanations but i can't find it now for the life of me.

Sounds like you're saying you didn't have any SQ issues. Hmmmm.... pending further confirmation and research I'm very tempted to cut those dowels down. At the same time, if there's enough tilt in just one of those suckers it could throw the entire alignment off. Decisions......
 
#81 ·
I think Bosso said you could have about .5-1db of gain from placing the base plates close to the woofers cone. I asked him a hole bunch of questions before I did my build. Don't know where those responses are but I am pretty sure thats what he aaid.
 
#83 ·
Willis - here is the material I was talking about. It's used to hide seams. The second picture shows how it's designed to open up and accept staples.

It does have a bit of a nylon look to it, the exact vinyl match to the material I bought was out of stock. I think it would look good with your carbon fiber material.

I have a glue that welds the vinyl to vinyl surface so you don't have to staple into the sonotube. If I have enough to send you I can throw in enough glue for you as well.

Let me know if you're interested and if so how much you'd need. No charge of course.

Tire Automotive tire Bicycle tire Wheel Rim




Hand Finger Pen




Clothing Black Shoulder Leather Dress
 
#85 ·
Thanks Doug.

The two enclosures with acrylic are in a holding stage until the paint dries up some more. Otherwise done.

Got a couple more coats to add to the down firing enclosures which I will do tonight.

Going snowboarding tomorrow, watching House of Cards season two all day Saturday, then Sunday will apply the vinyl, speakons, polyfill, etc..... on hopefully all four enclosures.

Did I mention I hate paint? :hissyfit:
 
#86 ·
Hey Matt, those babies are lookin great! That's a creative idea for the plates. I've been trying to come up with something like that for my next build/s. I also love sono builds. I think it was bd55? Who said he missed that 18"ish acrylic. Lots of potential there. $$$ too!
You were definitely right. I saw that seam piping, and it was head to hand. For some reason it never occurred to me that there was an easier, smarter, more finished way to do that. Hindsight=20/20. Lol. So yeah, it looks like it would work great, if you really wouldn't miss it.
So you love painting huh? Lol
Will
 
#88 ·
^^ ya i thought that too. Tons of $$ for that acrylic tube. My two 19" diameter 1/2" thick were , i think, 90 / piece cut. How long is your seam? Ie, how much material do you need to hide it?
Oh duh.. Seem is about 38". My tube is 36", but It goes up under the grill. I was looking at buying some acrylic tubes to build my own octobans for my drum kit. ...not after I showed my wife that build sheet!
 
#94 ·
Jealous....:D Havent been skiing in years. Someday I'll go back.
You really cant forget about it. Even i get caught up in life, projects, etc and slacked on going this year but every time I go, especially on these 55* days, I am always glad I did.


Last year I had ~40 days out and this year Im up to 6 or 7! Been a bad snow year combined with projects at home.

Sent from my iPad using HTShack
 
#93 · (Edited)
Thats a beauty Willis. Where ya from? Boats,jet skis, or? I was big into jet skis for a few yeas. Grew up on boats and skis, so having a dock and sunsets like that definitely get my attention. I had a full dry suit so I could ski through November. I loved being on the water, and loved it in some ways even more when it was dark, dreary, raining, foggy, etc. Sent from my iPad using HTShack
 
#95 ·
Well, we are in central MN. Land of 10,000 lakes, as they say. Water skiing as a kid, then discovered wakeboaring. I love it, but we spend a lot of time dragging kids around on tubes nowadays. Adults throw 2 out and we have battle tubes! Love fishing too. We have a couple nice ski "hills" too, for winter, but this year we had around 50 consecutive days below zero, and more than a few in the minus 20-30 range, no wind chill. Brutal.
 
#96 ·
Hey Willis - I'm going to have to get the rest of that roll of trim so Ill have some for you, just not sure when. Hoping to pick it up tomorrow.

I would never do this again without foam. While not visible unless the flash or light hits it just right it s hard to work with and at leas for me trim work was needed on the bottom perimeter plus the vertical seem.

In a ht room like mine that is mostly dark, you will never know. But I know. And that bug me. Then again i paint the underside o counter tops lol.

Put a very light coat on bottom and side perimeters then dropping in drivers.

Good thing two are hidden. They are getting no special treatment. Flat black paint and down firing drivers. HA!
 
#98 ·
Hey Willis - I'm going to have to get the rest of that roll of trim so Ill have some for you, just not sure when. Hoping to pick it up tomorrow. I would never do this again without foam. While not visible unless the flash or light hits it just right it s hard to work with and at leas for me trim work was needed on the bottom perimeter plus the vertical seem. In a ht room like mine that is mostly dark, you will never know. But I know. And that bug me. Then again i paint the underside o counter tops lol. Put a very light coat on bottom and side perimeters then dropping in drivers. Good thing two are hidden. They are getting no special treatment. Flat black paint and down firing drivers. HA!
Hey realtor! Thx for the nod. Totally agree with the foam thing. Wouldn't take much. I will use it next time too. Even though your hiding those 2, they still came out great! Practice pair?lol. I was thinking if doin a pair like that but with drum hardware eg: lugs, rims, and legs like a floor tom. (Yeah, I play drums) But WAF=0. "That's what the studio is for!" I hear the "but I know" too. It's just motivation right? Keep it up!
 
#100 ·
I'm headed out to the upohlstry shop tomorrow morning (ok -noon - lol) and with any luck will be getting enough seam concealer to reach from Oregon to wherever you're located. :)

Man- I expected to have all four enclosures in their locations, drivers installed ..... tonight!
 
#102 · (Edited)
Here is where my relay boxes ended up. They're resting on a piece of wood that is part of my screen frame. One box for each amplifier. They fit nice and snug back there and aren't resting on carpet or anything similar (flammable!).

Bumper Automotive exterior Auto part Vehicle


Zoomed out shot sub #1s location. Just to the lower right are the relay boxes.

Ceiling Sky Floor Material property Room


Mega driver going into one of the enclosures that will be hidden (front right and left)

Cookware and bakeware Dutch oven Crock


Same driver installed and placed where it will rest comfortably and serve mama and papa for many many movies. :) Same thing on the front left.

Light Lighting Sky Room Design


Duplicate. Or you can focus on the 15KW of Peavey IPR 2 amp power and the mini-dsp 4x10.

Light Lighting Sky Room Design


Here is one of the acrylic topped enclosures. All but has the top fastened down.

Sky Light Table Cloud Technology


Bad picture quality. It's a dark room even with the lights on. It's as much as dedicated as I can get it and still keep my wife. :rofl2:
 
#103 ·
Ehh... I give up. Until we can get some decent photo tools here I can't spend the time messing around with it.

HTS admins I'm willing so kick down some dough to get the photo feature updated. I like it here but the photo thing is kind of ridiculous when trying to document a month long build in an organized manner.

I know I could spread it out over 30 pages but I prefer to have one thread with my step by steps.

My 2nd post, which I already spent hours formatting, has just been completely messed up. Sorry guys, I just don't have the time to reorganize it again. I already had to do that once because the edit feature on the iPad/phone completely scrambles the formatting. *sigh*

Please feel free to delete the entire thread. It's a complete formatting disaster at this point, and I won't be fixing it. :(
 
#104 ·
Do you mean your 3rd post?

And it seems like everything above "I got a lot done," is a duplicate. The first photos above it are new but everything else was a copy. I could fix what I think is out of place for you if you like?
 
#106 · (Edited)
All done. Headed down to clean up and program the MiniDsp with the basics. Easter Sunday is not a good day to start maxing out four 18s so I'll wait until Monday after everyone goes to work/school.

I did run 100 to 20 hz sweeps to test each sub, and I'm getting a bit of resonating coming from the 1/2 acrylic.

At first I thought it was simply a matter of tightening down the top plates, but it doesn't appear that way. I can only hope my sweeps were at 10db hot levels (I have no clue where the dsp levels are) and won't show up while playing movies.


Product Technology Tire Electronic device Audio equipment
 
#107 ·
Wow man, I can't believe 1/2 acrylic would resonate in that small diameter. (Relatively speaking). I would think at those frequencies it would be too rigid. I hope you get that worked out, cause they look great!
Btw, did you have to calculate for reverse sag or anything? Or no matter cause they're sealed?
 
#109 ·
SAG is the phenomenon that occurs with weak suspensions and down firing drivers. The FI's dont have this problem. AND almost all car audio subwoofers dont have this problem either.

After working out in the yard I came back to your thread and saw you deleted the pics from post 3. I would have corrected them but I just didnt get time to do it yet. Sorry about that.
 
#110 ·
SAG is the phenomenon that occurs with weak suspensions and down firing drivers. The FI's dont have this problem. AND almost all car audio subwoofers dont have this problem either. After working out in the yard I came back to your thread and saw you deleted the pics from post 3. I would have corrected them but I just didnt get time to do it yet. Sorry about that.
Huh.. Never heard of it, but thats no surprise. Glad its not an issue i need to worry about cause I am so done!

Haha. I just dusted, cleaned the leather chairs, etc etc.

Gonna add six more 2x4 sheets of oc703 tomorrow and hopefully be fully tuned by deadliest catch premier!!

No worries on the pics. I'll re-do the process all at once.

If its easy to add some blank posts that I could reserve that would help.

You see, i upload all the pics from my iphone/pad because it auto sizes and rotates, and then add captions from the computer.

Once I add captions I cant add more photos via the iphone because it dismantles any formatting like paragraphs.

That leaves me resizing and rotating pictures so I can upload from computer. It gets cumbersome.

Anyways..... Some extra posts would help if possible.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top