Quick question. Is there any reason not to build a perfectly square box? The sub I'm building it for requires exactly 1.0 cu.ft. of space. Can I build a perfectly square box, or should I put in a small angle on the side I'm mounting the sub?
Replies (12)
ttocs on 10/22/2003 11:03:26
sonically it should not matter, although some audio purists might argue that.... The only reason I ever put a slant on the side, was to give more space and set the box back further.
VRWRX on 10/22/2003 13:55:38
Cool. I didn't think it would matter, but I was reading somewhere that the waves could be messed up by bouncing directly back on itself or something like that. Another quickie - When building the box, do I need to add a little bit of volume to it to compensate for the basket of the sub that sits in the box? In other words, do I need to make the box a bit bigger than 1.0 cu. ft. because the basket of the sub takes up some of the space?
Swez on 10/22/2003 13:44:18
Old school thinking for home/car subs was to avoid square cubes as they can produce standing wave resonaces. Older woofer designed did not recommend cubes.
With the newer subs and technology improvements, this is almost a non-issue. If you add a little fiber fill to absorb rear cone reflections and the issue is pretty much moot. Figure 3/4 lbs of fill for a single 10" and ~1lb fill for a 12" sub.
Swez
ttocs on 10/22/2003 16:44:58
most subs will come with the volume of the driver listed in the specs. add that too the 1 cu ft and build the box to that volume.
VRWRX on 10/23/2003 18:36:11
cool, thanks. Now, I was just reading another post in here that talked about the SubZone boxes. They have a sealed box for a 12 made of 3/4" MDF that is 1.2cf for only $53.99. That seems to be perfect. It's a little bigger than the 1.0cf that is called for, but once I add the sub, it wouldn't be much bigger at all. I probably wouldn't be able to buy the materials much cheaper than that (and my time is worth something), and Swez said they were high quality in that other post. It seems like the right way to go. Any reason (other than the pride in doing it myself) that I should stay away from a pre-made box? The sub that's going in it is an Infinity Kappa Perfect 12 (SVC, 4 ohm). Would I want to use 1" MDF? Does the fact that it's a "Hatch" box matter? Someone in here told me that with the right box, those subs sound awesome. Is that SubZone box the right one??? Any input is appreciated.
Swez on 10/23/2003 18:55:57
On a Kappa Perfect, 1.2 is fine. This sub has a range where it will sound fine. A 1.0cf will give you tight, (Rock/Techno) crisp bass. A 1.25 cf will net smooth, (good overall performance) fat bass with a hint of punch. A 1.5cf box will net heavy low bass notes like Rap, R&B or Jazz.
The amount of sub dsiplacement is ~0.07 cf. Almost a no thing deal right?
About Sub Zone boxes... very good product. The closer you look , the better they get.
Pride???
Can you wear it?
Can you spend it?
Will it make new friends well?
Will it give you bass in 3-5 days?
Maybe not this time, but plan ahead for when you want to port tune a sub. That will give you a sense of pride, doing that project. Takes more thought, planning and wood skill are the same... but a few notches up the difficulty scale.
Swez COFFEE
SeVeNX7X on 10/23/2003 23:11:42
poly fill as you mentioned.. 'fiber fill'.. is more like 'oops fill' .. its more to compensate for lack of space, or.. in many peoples cases, compensate for screwing up dimensions while making their own enclosure. A perfectly square/cube box is not recommended, because as swez pointed out, there is the standing wave issue.. but if it is absolutely necessary.. whether it be space issues, or your lack of enclosure design/building knowledge... You can put odd shaped blocks of wood, etc, on the back wall of the enclosure [directly behind the sub].. that way the rear waves will be deflected in different directions, as opposed to directly back into the sub. You can also use 'egg-crate' .. and put that on the back wall.. Hope this helps?
ttocs on 10/24/2003 04:58:16
somebody did learn something while at school....
SeVeNX7X on 10/24/2003 07:24:41
haha, you know it =)
VRWRX on 10/24/2003 10:55:24
Right on. It sounded like it would do the job, but I just wanted some confirmation from all you experts. Thanks again! :-)
Relax_The_Mind on 10/26/2003 13:13:27
I dont understand...A lot of the even high end home audio subwoofers are in tiny perfectly cube housings. Some of the loudest ones are the market are actually tiny cubes. From the many different pictures I have seen of the "cross sections" they are stuffed full of fiberglass type stuff. With the amp even built right in them(Bob Carver amps anyone?). For those of you that have made it to your local Domes Audio or some other high end A/V store, you know that those little suckers aint no joke with SQ/SPL... (imagine one of those things in your car hidden away)
I think fiber-fil is more to compensate for standing waves that are in just about every box, cube or not cube, IMHO. But then again car audio drivers may be quite different on the engineering side.
My 2¢
RTM
Swez on 10/27/2003 09:34:21
Yes, car subs are generally very different in design as compared to HT and Pro sound drivers. Most are made to work in very compact enclosures for max SPL and fair low end extension. This limits airspace for the cone to travel in and there is so much back pressure behind the sub to prevent over excursion (X-max) at high input power.
As the box gets smaller, the SLP rating is higher, but the low bass gets attenuated (reduced) as the sub cone travel is restricted. You wind up with very loud bass in the 50 - 80 Hz range, but not much deep lows as in RAP, Jazz & R&B music.
Finally, the poly fill does dampen rear cone waves and also slows the speed of the signal a tad to produce smoother, clearer low & midbass. Most sub makers recommend ~ 50% fill.
Swez
Replies (12)
ttocs on 10/22/2003 11:03:26
sonically it should not matter, although some audio purists might argue that.... The only reason I ever put a slant on the side, was to give more space and set the box back further.
VRWRX on 10/22/2003 13:55:38
Cool. I didn't think it would matter, but I was reading somewhere that the waves could be messed up by bouncing directly back on itself or something like that. Another quickie - When building the box, do I need to add a little bit of volume to it to compensate for the basket of the sub that sits in the box? In other words, do I need to make the box a bit bigger than 1.0 cu. ft. because the basket of the sub takes up some of the space?
Swez on 10/22/2003 13:44:18
Old school thinking for home/car subs was to avoid square cubes as they can produce standing wave resonaces. Older woofer designed did not recommend cubes.
With the newer subs and technology improvements, this is almost a non-issue. If you add a little fiber fill to absorb rear cone reflections and the issue is pretty much moot. Figure 3/4 lbs of fill for a single 10" and ~1lb fill for a 12" sub.
Swez
ttocs on 10/22/2003 16:44:58
most subs will come with the volume of the driver listed in the specs. add that too the 1 cu ft and build the box to that volume.
VRWRX on 10/23/2003 18:36:11
cool, thanks. Now, I was just reading another post in here that talked about the SubZone boxes. They have a sealed box for a 12 made of 3/4" MDF that is 1.2cf for only $53.99. That seems to be perfect. It's a little bigger than the 1.0cf that is called for, but once I add the sub, it wouldn't be much bigger at all. I probably wouldn't be able to buy the materials much cheaper than that (and my time is worth something), and Swez said they were high quality in that other post. It seems like the right way to go. Any reason (other than the pride in doing it myself) that I should stay away from a pre-made box? The sub that's going in it is an Infinity Kappa Perfect 12 (SVC, 4 ohm). Would I want to use 1" MDF? Does the fact that it's a "Hatch" box matter? Someone in here told me that with the right box, those subs sound awesome. Is that SubZone box the right one??? Any input is appreciated.
Swez on 10/23/2003 18:55:57
On a Kappa Perfect, 1.2 is fine. This sub has a range where it will sound fine. A 1.0cf will give you tight, (Rock/Techno) crisp bass. A 1.25 cf will net smooth, (good overall performance) fat bass with a hint of punch. A 1.5cf box will net heavy low bass notes like Rap, R&B or Jazz.
The amount of sub dsiplacement is ~0.07 cf. Almost a no thing deal right?
About Sub Zone boxes... very good product. The closer you look , the better they get.
Pride???
Can you wear it?
Can you spend it?
Will it make new friends well?
Will it give you bass in 3-5 days?
Maybe not this time, but plan ahead for when you want to port tune a sub. That will give you a sense of pride, doing that project. Takes more thought, planning and wood skill are the same... but a few notches up the difficulty scale.
Swez COFFEE
SeVeNX7X on 10/23/2003 23:11:42
poly fill as you mentioned.. 'fiber fill'.. is more like 'oops fill' .. its more to compensate for lack of space, or.. in many peoples cases, compensate for screwing up dimensions while making their own enclosure. A perfectly square/cube box is not recommended, because as swez pointed out, there is the standing wave issue.. but if it is absolutely necessary.. whether it be space issues, or your lack of enclosure design/building knowledge... You can put odd shaped blocks of wood, etc, on the back wall of the enclosure [directly behind the sub].. that way the rear waves will be deflected in different directions, as opposed to directly back into the sub. You can also use 'egg-crate' .. and put that on the back wall.. Hope this helps?
ttocs on 10/24/2003 04:58:16
somebody did learn something while at school....
SeVeNX7X on 10/24/2003 07:24:41
haha, you know it =)
VRWRX on 10/24/2003 10:55:24
Right on. It sounded like it would do the job, but I just wanted some confirmation from all you experts. Thanks again! :-)
Relax_The_Mind on 10/26/2003 13:13:27
I dont understand...A lot of the even high end home audio subwoofers are in tiny perfectly cube housings. Some of the loudest ones are the market are actually tiny cubes. From the many different pictures I have seen of the "cross sections" they are stuffed full of fiberglass type stuff. With the amp even built right in them(Bob Carver amps anyone?). For those of you that have made it to your local Domes Audio or some other high end A/V store, you know that those little suckers aint no joke with SQ/SPL... (imagine one of those things in your car hidden away)
I think fiber-fil is more to compensate for standing waves that are in just about every box, cube or not cube, IMHO. But then again car audio drivers may be quite different on the engineering side.
My 2¢
RTM
Swez on 10/27/2003 09:34:21
Yes, car subs are generally very different in design as compared to HT and Pro sound drivers. Most are made to work in very compact enclosures for max SPL and fair low end extension. This limits airspace for the cone to travel in and there is so much back pressure behind the sub to prevent over excursion (X-max) at high input power.
As the box gets smaller, the SLP rating is higher, but the low bass gets attenuated (reduced) as the sub cone travel is restricted. You wind up with very loud bass in the 50 - 80 Hz range, but not much deep lows as in RAP, Jazz & R&B music.
Finally, the poly fill does dampen rear cone waves and also slows the speed of the signal a tad to produce smoother, clearer low & midbass. Most sub makers recommend ~ 50% fill.
Swez
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