I have decided I want to build my own sub

[BigSkreen]

I cut and started assembling my sub box. One of the pieces is not quite cut correctly. The best solution would be for me to go buy another piece of 13 ply and recut it. The issue with this is cost. It will cost me another $50 for a 4x8 sheet plus I have to either rent a truck from lowes or borrow one, either way that's another $30+. I am hoping to find a smaller piece.

I have some MDF laying around. If I am planning to finish it by painting would it make a difference if I replace one of the sides with MDF?

 

[annunaki]

I cut and started assembling my sub box. One of the pieces is not quite cut correctly. The best solution would be for me to go buy another piece of 13 ply and recut it. The issue with this is cost. It will cost me another $50 for a 4x8 sheet plus I have to either rent a truck from lowes or borrow one, either way that's another $30+. I am hoping to find a smaller piece.

I have some MDF laying around. If I am planning to finish it by painting would it make a difference if I replace one of the sides with MDF?

Probably not. They can rip the sheet down into more manageable sizes for you free of charge there too...

 

[Shock]

How many nuclear power plants does it take to power that sub?

 

[BigSkreen]

Hopefully only one because that is all I budgeted for. On a completely unrelated topic does anyone know if sound quality is affected by radiation?

 

[BigSkreen]

And the build is complete. I will post pics when I get a chance. Something is wrong though. The performance is lackluster. The first issue was with the EP4000 dip switch settings. It turns out that the settings in the manual were incorrect.

When playing the opening scene of Transformers I think the sub is bottoming out on the bass from the chopper blades. I'm not running this at high volume. I don't think this is what I would get from even the lowest end of subs.

Maybe I should remove the DCX and see if that is the issue. My receiver settings could be incorrect but there really isn't much in there. To be fair I haven't properly placed the sub I wanted to kick it on and see how it sounds.

 

[TLS Guy]

And the build is complete. I will post pics when I get a chance. Something is wrong though. The performance is lackluster. The first issue was with the EP4000 dip switch settings. It turns out that the settings in the manual were incorrect.

When playing the opening scene of Transformers I think the sub is bottoming out on the bass from the chopper blades. I'm not running this at high volume. I don't think this is what I would get from even the lowest end of subs.

Maybe I should remove the DCX and see if that is the issue. My receiver settings could be incorrect but there really isn't much in there. To be fair I haven't properly placed the sub I wanted to kick it on and see how it sounds.

Make sure you don't have leaks on your box or round the driver. That box really needs to seal. Make sure you have a high pass filter at least second order below 25 Hz.

Also check the degree of boost.

From what you say it seems leaks or inadequate subsonic filtering are going to be your issues.

 

[BigSkreen]

Make sure you don't have leaks on your box or round the driver. That box really needs to seal. Make sure you have a high pass filter at least second order below 25 Hz.

Also check the degree of boost.

From what you say it seems leaks or inadequate subsonic filtering are going to be your issues.

I did a cursory check for leaks. I put holes for feet in the bottom of the sub which could be leaking but they have T-nuts and screws in them. I haven't sealed them yet. Would a leak that small affect the sound?

As far as I know there are no subsonic filters. In fact I think I turned them off (at least I know I did on the amp, I'll have to check the DCX). I guess the best place to put them in would be the DCX.

The output from the receiver is set to 0db gain. The Amp is turned up to full (per a recommendation I found from the manufacturer). The input to the DCX is set to +15db and the output is set to 0db.

 

[TLS Guy]

I did a cursory check for leaks. I put holes for feet in the bottom of the sub which could be leaking but they have T-nuts and screws in them. I haven't sealed them yet. Would a leak that small affect the sound?

As far as I know there are no subsonic filters. In fact I think I turned them off (at least I know I did on the amp, I'll have to check the DCX). I guess the best place to put them in would be the DCX.

The output from the receiver is set to 0db gain. The Amp is turned up to full (per a recommendation I found from the manufacturer). The input to the DCX is set to +15db and the output is set to 0db.

It does not take much of leak to cause a lot of trouble. However if you do not have the DCX set to roll off below 25 Hz you will be in a pile of hurt and very likely ruin your driver.

 

[BigSkreen]

I added a cross over at 25Hz. Still having the same issues. I took a video but because my camera mic sucks you can't really hear the issue that well but maybe you can see it. I also have a pic of the x-overs

Here is the album http://picasaweb.google.com/jmmoses/Subwoofer?authkey=Gv1sRgCJDAzfiNkJylcw&feat=directlink

[edit] I also checked for leaks but couldn't find any at least not by feel [/edit]

 

[WmAx]

You need to start a new thread with the appropriate subject heading to get a large number of people to help.

Where is this sub sitting? By the video, it looks almost like you have it sitting in the middle of the room - if which is the case - could cause your bass output to be far lower in output as compared to placing near a front corner.

-Chris

 

[annunaki]

If your amplifier's gain is set to maximum, that could be an issue.

There could be many issues at play here.

If you have eq set improperly it could be an issue as well.

 

[TLS Guy]

I added a cross over at 25Hz. Still having the same issues. I took a video but because my camera mic sucks you can't really hear the issue that well but maybe you can see it. I also have a pic of the x-overs

Here is the album http://picasaweb.google.com/jmmoses/Subwoofer?authkey=Gv1sRgCJDAzfiNkJylcw&feat=directlink

[edit] I also checked for leaks but couldn't find any at least not by feel [/edit]

To me that driver looks totally unloaded. I have a strong suspicion that there are leaks in your enclosure.

I have noted that most of the DIY projects here have butt joints. In my view they are unsuitable for loudspeaker enclosures.

 

[BigSkreen]

I found online where someone did the push test on the sub. I did that and sure enough I have a leak. I plan on filling the leak from the outside. The next step is caulking the inside. Should I be looking for anything in particular when I get the caulk. I have some latex caulk with embedded silicon lying around here but I'm not sure that is sturdy enough. Any comments or suggestions?

 

[TLS Guy]

I found online where someone did the push test on the sub. I did that and sure enough I have a leak. I plan on filling the leak from the outside. The next step is caulking the inside. Should I be looking for anything in particular when I get the caulk. I have some latex caulk with embedded silicon lying around here but I'm not sure that is sturdy enough. Any comments or suggestions?

Latex sealer should be fine. Don't forget the speaker interface to the box, nor the terminals. They are potent sources of leaks.

 

[lsiberian]

I have noted that most of the DIY projects here have butt joints. In my view they are unsuitable for loudspeaker enclosures.

What joints do you suggests?

 

[TLS Guy]

What joints do you suggests?

I recommend the Dado joint for loudspeakers. These produce the strongest joint with the best seal.

Also you can use pre veneered product which makes the speaker look much more professional.

Here you can see the joints.

If you make this type of dado on visible surfaces you can use factory veneered product, which is a lot cheaper and easier than using veneers.

You then can use quarter round which curves the edges and stops them being sharp. This is better acoustically and helps prevent damage over time.

In this method no fasteners are used, Just glue and pressure. This tends to make for a much more airtight joint.

 

[lsiberian]

I recommend the Dado joint for loudspeakers. These produce the strongest joint with the best seal.

Also you can use pre veneered product which makes the speaker look much more professional.

Here you can see the joints.

If you make this type of dado on visible surfaces you can use factory veneered product, which is a lot cheaper and easier than using veneers.

You then can use quarter round which curves the edges and stops them being sharp. This is better acoustically and helps prevent damage over time.

In this method no fasteners are used, Just glue and pressure. This tends to make for a much more airtight joint.

I never even thought of that. I take it you use your table saw to cut the dado's.

 

[TLS Guy]

I never even thought of that. I take it you use your table saw to cut the dado's.

Yes, but you can use a router, although it is much slower. You have to use a router for some of the internal grooves.

 

[lsiberian]

Yes, but you can use a router, although it is much slower. You have to use a router for some of the internal grooves.

Yeah I'm still not sure what type of saw I'm going to buy when i get a shop. My wife and I are house shopping at the moment so I'm looking at a table saw or panel saw. A panel saw would be easier to use with one person operation, but a table saw is so versatile. I'm considering either a milwaukee panel saw or a safety stop table saw.

I do plan on a router table too. Not sure what brand I'll get there, but I figure it would be easier to cut dado's with a router table than a table saw.

 

[highfigh]

I cut and started assembling my sub box. One of the pieces is not quite cut correctly. The best solution would be for me to go buy another piece of 13 ply and recut it. The issue with this is cost. It will cost me another $50 for a 4x8 sheet plus I have to either rent a truck from lowes or borrow one, either way that's another $30+. I am hoping to find a smaller piece.

I have some MDF laying around. If I am planning to finish it by painting would it make a difference if I replace one of the sides with MDF?

Is there a way to adjust the size and shape of the other parts that would allow you to make the smallest difference in the box's volume, so it would still work for your design? That way, you don't need to go through all of this.