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DIY Sub Upgrade - 4 x 18" SI - Page 3

post #61 of 125
So with regards to the Dayton HF15, lets say that a person has room for a pair of cabinets that are at max, 20 cu ft each. What could be gained by going with a pair of Dayton HF15's with each of them in something like a 14 cu ft or 12 cu ft enclosure? Would these HF15's go down to pretty low? (assuming these will be powered by a single EP4000).

I would like to get some really good entension and still have some decent output as well. I have the room for as large of a pair of enclosures that I could possibly imagine. Suggestions?
post #62 of 125
Thread Starter 
Quote:
Originally Posted by Martycool007 View Post

So with regards to the Dayton HF15, lets say that a person has room for a pair of cabinets that are at max, 20 cu ft each. What could be gained by going with a pair of Dayton HF15's with each of them in something like a 14 cu ft or 12 cu ft enclosure? Would these HF15's go down to pretty low? (assuming these will be powered by a single EP4000).

I would like to get some really good entension and still have some decent output as well. I have the room for as large of a pair of enclosures that I could possibly imagine. Suggestions?

Bigger boxes will just lower your power handling; you would hit xmax a lot sooner with a much bigger box. Mine are in ~4.7cf boxes and are flat to 10Hz in my weird shaped open room.

If you have that much room, use 4 of them (or 8 if you want 20cf total) and get more output at every frequency.
Edited by bradthebold88 - 4/18/13 at 9:46am
post #63 of 125
Thread Starter 
I was looking for wood to start building some boxes and found this Arauco at Home Depot: http://www.homedepot.com/p/Arauco-32-sq-ft-Pine-Cabinet-Panel-781850/202519005#.UXGX8JPFXXI

I couldn't find the Arauco name anywhere (they call it cabinet grade), but the sku number matches what I found. I thought Arauco was 7 ply, though, and this was 11 plus 2 thin veneers I think. I would rather try this to save weight over MDF, but I'm not sure about how many voids are ok? How does this wood look?





Are these small voids ok, or should there be none? This and MDF are both $35 I think, which should I use?

These pics look a little better than I remember. There seemed to be at least a few 1/4" wide 2-4" (that I could tell) deep voids on the long face shown. Would it even matter if a 1/4" void goes through the whole board if it's only 1 out of the 11 plys?
Edited by bradthebold88 - 4/19/13 at 12:25pm
post #64 of 125
Thread Starter 
There are a lot of different specs for this sub. Is the consensus that a 4cf box with 1000W is good?

Ricci, MTG90, and SI all have pretty different T/S specs that call for greatly different box sizes.


Using 4cf, the Qtc is much different.


Excursion seems ok with all of them up to 4.5cf.
post #65 of 125
yes. 4 cft with 1000 watts is good for the SI18
post #66 of 125
as for the wood. that stuff is fine since your painting them imo. be careful of soft spots where there are voids right under the outer ply. its not Auroco. it looks like the Asian Birch stuff. some sheets will be better than others so pick through it.
post #67 of 125
Thread Starter 
Thanks. If the the stuff is going to have 3-4 voids per side and is the Asian stuff (which I haven't read anything good about, like crappy glue), should I just use MDF which I know for sure won't have problems?

The baltic birch I found at a lumber supply store was ~$100 for a 4x8 sheet. They also had Arauco for ~$55 I think they said.
Edited by bradthebold88 - 4/21/13 at 10:09am
post #68 of 125
Personally, I won't use that Asian Birch anymore. Too inconsistent. Baltic birch or mdf for me. Do you have a Lowes by you? I ordered 4 x 8 sheets of 13 ply Baltic birch from them for like $70 a sheet.
post #69 of 125
Thread Starter 
I do have a Lowes. I asked about the Arauco they have on their website, but they said they couldn't order it, so I wouldn't be hopeful about the baltic birch.

It's probably not worth it to me to spend twice as much on the BB to paint it black though. I'm moving soon and it would be nicer to carry 4 80lb subs down 3 flights of stairs than 4 110lb ones. 30lbs a box probably isn't worth twice the price, assuming I could get it that cheap.

Every Home Depot around me says they carry the Arauco online at least, so maybe one actually will. For the same price as MDF, the weight savings would be nice, but for something that would sit in the same place almost all the time, it's probably not worth it to pay more if I can't find Arauco.
post #70 of 125
i think that 11 ply stuff in the pics will be fine if you can get good sheets of it.
post #71 of 125
Thread Starter 
I called around and no one has the actual Arauco, it's all the 11ply cabinet grade stuff. One guy said they switched after the fire and the website must not reflect it. So for $35 I could get this 11-ply stuff or MDF. I'm not sure what a good sheet is or how many voids are ok. There were a few boards that looked like there was a gap between layers for a few feet of the side, but most just had small looking voids.
post #72 of 125
Yeah. That's why I'm not a fan. If your ok with using MDF I would go with it.
post #73 of 125
Thread Starter 
Ok. An extra 30lbs a box for guaranteed void-free, flat wood is probably worth more than risking using the Asian stuff. I'll just use MDF again.
post #74 of 125
Thread Starter 
Brian, how do these compare to the horns you had? Did you lose some output, is the deeper extension noticeable, how does sound quality compare?

A pair of F20s are considerably larger than 4 - 4cf boxes and their required orientation would be very awkward in my living room, but it seems like they would have more output >20Hz using 1/6 of the power, half the drivers, and it would be $1000 cheaper.
Edited by bradthebold88 - 4/22/13 at 9:03pm
post #75 of 125
Unfortunately The only room I had both of these in was my living room and it had terrible acoustics. Also I never had two of each running. Only one at a time. I didnt measure either one in that room. I never had the horns setup in the basement like I have the SI's now which measures pretty good.

Just totally subjective, I would say the horn had an advantage above 20. Below that its no contest. The sealed subs go way deeper

It's all a trade off. The horns are cheap, easy, lots of output and sound great. Downsides are they're huge and drop lock a rock at 20 Hz. The tht and the f20 anyway.
post #76 of 125
Thread Starter 
How would you compare sound quality above 20Hz? Was spending $1k+ more worth the extension capabilities of the SI's compared to building another THT?
post #77 of 125
sound quality was very clean. the SI's have a "thicker" sound to them.

i had two THT's. they were my original plan. the only reason i sold them was because they were not going to fit into my basement plans anymore. no room. was it worth the money? for my situation, yes. the smaller boxes can go where i need them to and its easier to fit more if i want. the extension is nice as well, but placement was my #1 reason for the switch.
post #78 of 125
Thread Starter 
Ok, now I'm a little confused after looking at measurements.

Lilmike's F20 graphs shows about 117dB from 20-80Hz, ground plane 1m
A Gjallarhorn gets 123.6dB 20-80Hz long term avg, ground plane 2m
A sealed SI 18 gets 113.3dB 20-80Hz long term avg. ground plane 2m

The gjallarhorn and SI measurement should be comparable since they're both from data-bass. So 4 SI's should theoretically outperform a gallarhorn with less money and less space, as well as outperforming it from 10-80Hz.

Assuming they were measured the same, 2 SI's should outperform an F20 from 20-80Hz and do much better below 20Hz. If the F20 was measured at 1m, then it would be outperformed above 20Hz by a single SI 18.

If this is true, that makes picking the SI's an easy choice: less space, more extension, more output.

Comparing a 1000W SI 18 vs an F20, LTD02 said, "the f20 will slaughter them both. more than 10db higher spl at 25hz and about 6db higher in the upper bass". If it can really output that much more, it would only be a couple dBs shy of a Gjallarhorn, and outperform a DTS-10, which couldn't be true. A reply to the thread pointed out the data-bass info, but no one replied.
Edited by bradthebold88 - 4/23/13 at 11:11pm
post #79 of 125
Thread Starter 
Data-bass actually measured at 2 meters and the F20 was measured at 1m. So at 1m, a single sealed SI 18 would output 119.3dB from 20-80Hz and the F20 only does ~117dB.
Edited by bradthebold88 - 4/26/13 at 8:26am
post #80 of 125
Thread Starter 
I called around and found a lumber supplier who said they had Arauco for $50/sheet. It kind of sucks that it's $15 more a sheet when they used to be the same price, but I may try it for the weight savings if it's actually Arauco.
post #81 of 125
someone else can chime in, but i wouldnt be scared to use that 11 ply stuff as long you could make it where no soft spots were on the outside. and thats just for aesthetic reasons. i have a pair of speakers made with it and they are fine. im pretty sure Gorillas DO Daytons were made with that stuff as well.

im just saying its not my personal favorite. that doesnt mean its not acceptable material
post #82 of 125
Thread Starter 
Quote:
Originally Posted by brian6751 View Post

someone else can chime in, but i wouldnt be scared to use that 11 ply stuff as long you could make it where no soft spots were on the outside. and thats just for aesthetic reasons. i have a pair of speakers made with it and they are fine. im pretty sure Gorillas DO Daytons were made with that stuff as well.

im just saying its not my personal favorite. that doesnt mean its not acceptable material

Yeah, if I can use that I will. If the little voids are going to cause some structural or acoustic issues, then I would be wary. Otherwise I'm painting it black, so I don' care what it looks like. I went and looked at the Arauco today and it was not impressive. He had a whole pallet and there were a good amount of voids; more voids than the Home Depot stuff and they were bigger since they were there were less plys. It had a big Arauco label on the pallet.

So the only options are $35 MDF, $35 HD cabinet ply, or $90-120 marine or baltic birch plywood. I'll probably use the HD stuff if it's acceptable because it definitely is lighter.
post #83 of 125
Just avoid the "11" ply chinese made stuff with thin veneer for an outer layer. The 7 ply AC Fir has been the best stuff available to me up here in AK.
post #84 of 125
Quote:
Originally Posted by Jay1 View Post

Just avoid the "11" ply chinese made stuff with thin veneer for an outer layer. The 7 ply AC Fir has been the best stuff available to me up here in AK.

yeah, thats the 11 ply stuff in the pics Jay. some of it has soft spots right under the top layer. im sure thats what your referring to.
post #85 of 125
Thread Starter 
The 11 ply stuff at HD does have a very thin veneer on each side. I've read the thin veneers can peel and cause problems and that voids can lead to air leaks. The 7 ply Arauco I saw had multiple 3/4" voids on the side I saw though, so it didn't really look any better. The guy there said Arauco isn't supposed to be void free though and he's never seen any that has been.
post #86 of 125
There's always going to be voids in ply wood unless you pay out the a$$ for real BB. The chinese 11 ply was horrible to work with, very poor quality. The 7 ply stuff is really solid.
post #87 of 125
Quote:
Originally Posted by bradthebold88 View Post

The 11 ply stuff at HD does have a very thin veneer on each side. I've read the thin veneers can peel and cause problems and that voids can lead to air leaks. The 7 ply Arauco I saw had multiple 3/4" voids on the side I saw though, so it didn't really look any better. The guy there said Arauco isn't supposed to be void free though and he's never seen any that has been.
I've used nothing but 5 ply 1/2" Arauco for my builds for about four years now and never had an issue with it.
Quote:
The 7 ply AC Fir has been the best stuff available to me up here in AK.
Before Arauco came along I used 5 ply 1/2" fir. It works OK, but it's heavier than Arauco and has a much rougher grain. Arauco is almost as smooth as BB.
post #88 of 125
I would love to have better ply wood readily available. Only 9 more months in AK smile.gif
post #89 of 125
Thread Starter 
This what the Arauco looked like. There were multiple voids per sheet on the side I saw like this, except they were 2-3 times as wide. The voids were similar to the Home Depot wood pics above, but they were thicker because the Arauco has less plys.

500x1000px-LL-bff653fa_Auraco3.jpeg


So is the Arauco going to be fine regardless of the voids because it has no thin veneer and better glue compared to the HD chinese ply?

I don't really care how it looks or how it is to work with, I just want something that will make a box that won't cause sound issues or peel apart.
post #90 of 125
That's the one I would grab .
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