I thought it would be a good idea to lay out exactly what the effects of the wrong size box box can be. We all stress the importance that a proper size is essential but for newbies who want to know *why* theres no go-to list. I think after a bit of collabaration, we could make this a tute.
I'm focusing on sealed. But feel free to add effects off too small/large ported box sizes, with too small/large port, etc.
I picked up a ratty, but solid, well moulded FG jobbie off a random forum person for my car. Sits PERFECTLY but unfortunately, it really is way too small for my sub. The sub, a well regarded make, sounds like peaky arse. I knew it would but for $20 it was worth a shot lol.
Different subs suit different types of box. Some sealed, some ported, some both.
It's well known that you can deviate a bit from "recommended specs", by about, say 20%?
But what happens if you go further outside the green zone?
Sealed - Too Small.
Negs.
-Peaky. Just sounds like a one note doof wonder.
-Not musical, no range, so no rythym. You wont notice with dance,
you will for any track with a decent bassline, or other styles of music.
-Wont play lowww. RNB/Classical/rock will sound like arse.
-Won't blend nicely with front stage, no matter what point you set the crossover.
Do not underestimate how much this can ruin the overall "balance".
Pros.
-If you only listen to dance dance revolution music, it will give you
a very punchy, very high power handling box. For simple in your chest
kick a tiny box can make a average sub punch hard. But it *will* be a one
note affair and it will *not* play low. You may also not like where it peaks.
-Can fit one in the corner of your boot no worries, any size car.
-Easy to remove. Low weight.
2
Technical: Effects of too small a box.
Started by Guest_Liquidity_*, Aug 18 2009 02:07 PM
26 replies to this topic
#2
-
- Members
- 624 posts
500 - 1500w RMS
- Gender:Male
- Location:S.E Melbourne
- State:VIC
Posted 18 August 2009 - 03:40 PM
Good info, mate!
I have a very small (too small?) ported enclosure for my DD2512a & would like to know what characteristics too small a ported box has!
I have a very small (too small?) ported enclosure for my DD2512a & would like to know what characteristics too small a ported box has!
X3 3.0d
Head Unit - Alpine CDA-117E
Amplification - RE Audio XT-1600.4
Front Stage - Hertz Energy
Subwoofer - Rainbow Hammer 10
Cabling by Stinger & Aerpro
FHRX Studios
Team Furry Seal Killa
#3 Guest_Liquidity_*
-
- Guests
Posted 18 August 2009 - 03:42 PM
Yeah, I'm not sure if too small a volume (given the same port) shifts the tuning freq up, or down. etc.
#4
-
- Members
- 1,622 posts
1500 - 3000w RMS
- Gender:Male
- Location:Sydney
- Interests:Cars, Boobs, Thats about it.
- State:NSW
Posted 18 August 2009 - 05:06 PM
Well my box it only slightly smaller than manufacturer recommends so i cant really comment. But the info you post so far seems accurate.
VR Calais V8
R34 GTT Skyline (Install Starting soon)
If You Can Hear Rattles, Then It Simply Isn't Loud Enough.
R34 GTT Skyline (Install Starting soon)
If You Can Hear Rattles, Then It Simply Isn't Loud Enough.
#5
-
- Members
- 876 posts
500 - 1500w RMS
- Gender:Male
- State:NSW
Posted 18 August 2009 - 06:13 PM
Liquidity, on Aug 18 2009, 03:42 PM, said:
Yeah, I'm not sure if too small a volume (given the same port) shifts the tuning freq up, or down. etc.
Given the same port but a smaller box tuning will rise. I assume this has limits (as in may not be true in 100% of cases) but certainly is for me.
However, with the correct port length my smaller box actually sounds better than the larger (tuned exactly the same to 31hz).
Jono
Ford Fiesta XR4 2007
No its not a Festiva...
Audax 10mm - Peerless 2.5" Fullrange - Mach 5 MLi65 - RE Audio 05 XXX12
1x SS Rubicon 1002 - 2 x SS Reference 500s - Blaupunkt Burning Desire 2
Eclipse 7200MkII - Optima D31
#6
-
- Members
- 192 posts
25 - 250w RMS
- Gender:Male
- Interests:Photography, music, HiFi
- State:SA
Posted 18 August 2009 - 07:44 PM
what about the effects of a sealed box that is too big?
#7
-
- Members
- 362 posts
Is this the dark side man ?
- Gender:Male
- Location:Townsville
- State:QLD
Posted 18 August 2009 - 08:32 PM
Boomy ,less punchy and possibly bottom out sooner
XC Falcon ute 351 Cleveland Pioneer 8650 DLS up1,up2.5,GR research m165x DLS ra50 IDmax 12 v3 d4
Transactions with Chemhaz , if only... , cosworthpower, DEVINCHY,Damon
#8
-
- Members
- 5,311 posts
Team XS Audio
- Gender:Male
- Location:Adelaide Hills
- Interests:Music
- State:SA
Posted 18 August 2009 - 10:40 PM
But still much better sounding than a poorly designed Ported box...
Just wanted to add that...
Just wanted to add that...
#9
-
- Members
- 1,698 posts
1500 - 3000w RMS
- State:WA
Posted 20 August 2009 - 10:11 AM
thought i could add a few little downsides to all (effect on your driver)
too large of a box - not enough damping for the driver, can cause it to bottom out.
ported tuned high - can cause the sub to bottom out due to lack of damping under the tuned frequency (think of the port more like a big hole in the box when played under its tuning frequency), for example, a lot of SPL subs have an FS of 38hz or there abouts, so you would port around the FS of the driver, in this case, a ported box tuned to 38-40hz, you will come across issues if you try playing say 20hz on the driver.
ported tuned low - take a box tuned to 20hz as an example, this is going to have a steep roll of and you will lose alot of output around say the 50-80hz region compared to a 30-40hz box (ofcourse this has alot to do with the driver, but tuned lower = rolls off lower), there isn't any effects this can have on your driver unless playing under the tuned frequency.
port to small - i've seen some people in here make ports that are only an inch or 2 wide, doing this can cause port compression which can lose output and create an unwanted noise.
too large of a box - not enough damping for the driver, can cause it to bottom out.
ported tuned high - can cause the sub to bottom out due to lack of damping under the tuned frequency (think of the port more like a big hole in the box when played under its tuning frequency), for example, a lot of SPL subs have an FS of 38hz or there abouts, so you would port around the FS of the driver, in this case, a ported box tuned to 38-40hz, you will come across issues if you try playing say 20hz on the driver.
ported tuned low - take a box tuned to 20hz as an example, this is going to have a steep roll of and you will lose alot of output around say the 50-80hz region compared to a 30-40hz box (ofcourse this has alot to do with the driver, but tuned lower = rolls off lower), there isn't any effects this can have on your driver unless playing under the tuned frequency.
port to small - i've seen some people in here make ports that are only an inch or 2 wide, doing this can cause port compression which can lose output and create an unwanted noise.
Edited by Rare177, 21 August 2009 - 11:20 AM.
#10
-
- Members
- 5,311 posts
Team XS Audio
- Gender:Male
- Location:Adelaide Hills
- Interests:Music
- State:SA
Posted 20 August 2009 - 09:39 PM
too small of a box - can cause over excursion from too much damping and damage the driver.
I assume you are saying for a ported box? This is certainly not the case for a sealed enclosure.
With ported boxes the size will depend on the available space and power, a smaller box will take more power than a large box.
I assume you are saying for a ported box? This is certainly not the case for a sealed enclosure.
With ported boxes the size will depend on the available space and power, a smaller box will take more power than a large box.
#11
-
- Members
- 1,698 posts
1500 - 3000w RMS
- State:WA
Posted 21 August 2009 - 12:06 AM
im talking about a small sealed box, imagine if you have a 0.5cuft sealed box for a 15" as an example, the damping is going to be massive and you could over exurt the driver.
not saying ive heard of this happening, it would need to be drasticly small, just makes common sense to me.
not saying ive heard of this happening, it would need to be drasticly small, just makes common sense to me.
#12 Guest_Liquidity_*
-
- Guests
Posted 21 August 2009 - 12:35 AM
I think you mean overheat, with the sub moving against heaps of resistance you'd have to pour power into it to get much volume...over exert suggests a mechanical loss of control which is much less likely in a tiny enclosure?
#13
-
- Members
- 1,698 posts
1500 - 3000w RMS
- State:WA
Posted 21 August 2009 - 11:20 AM
well just thought about it, it wouldn't really cause over excursion as the pressure from the back wont ever exceed the possible pressure from the front, so it will only really limit excursion, i'll edit that out.
#14 Guest_Liquidity_*
-
- Guests
Posted 21 August 2009 - 11:23 AM
Yep, bingo. Which means your sub can "handle" more power, as more is required to move it, but...at a point the benefits are outweighed by the increase in resistance to movement, so it begins to sound poor. It cant breathe enough to extennnnnd to low volume, etc.
#15
-
- Members
- 1,323 posts
500 - 1500w RMS
- Gender:Male
- Location:Redlands City Shire,~Bris
- State:QLD
Posted 21 August 2009 - 05:57 PM
So to summarize:
Small box: Thermally limited
Big box: Mechanically limited
(of course this is not always the case, just the effect that the box will have on a woofer)
Small box: Thermally limited
Big box: Mechanically limited
(of course this is not always the case, just the effect that the box will have on a woofer)
Edited by br85, 21 August 2009 - 05:58 PM.
1 user(s) are reading this topic
0 members, 1 guests, 0 anonymous users
Community Forum Software by IP.Board
Licensed to: Mobile Electronics Australia
