ProSoundWeb Community

Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Lounge => Topic started by: Mike Henderson on October 04, 2020, 08:17:10 am

Title: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Mike Henderson on October 04, 2020, 08:17:10 am
Hey guys, I sanded and painted the used Cabinet I got and only when I had removed the grill that I noticed the left Port's tubing was missing. I contacted EAW Parts who said they don't have that part anymore but I can use PVC or hard cardboard tubing so I am looking around for a piece of tubing with that 3-1/2" outside diameter which they had stated.

My question is, how important is that port's tubing and what's it's main purpose please? Thx.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Chris Grimshaw on October 04, 2020, 08:40:29 am
Very important for making sure the cabinet is working as intended. The pair of ports will set the low-frequency tuning of the cabinet. If one of them is missing, the tuning will end up somewhere in the 80-150Hz range, giving a really peaky response with no real (<60Hz) bass.

Chris
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Geert Friedhof on October 04, 2020, 09:09:56 am
You also risk exceeding the driver's Xmax, which can result in a damaged driver. So yeah, you should fix the port asap.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Gary Phillips on October 04, 2020, 09:39:35 am
Hey guys, I sanded and painted the used Cabinet I got and only when I had removed the grill that I noticed the left Port's tubing was missing. I contacted EAW Parts who said they don't have that part anymore but I can use PVC or hard cardboard tubing so I am looking around for a piece of tubing with that 3-1/2" outside diameter which they had stated.

My question is, how important is that port's tubing and what's it's main purpose please? Thx.

3” Sch 40 PVC pipe is 3 1/2” OD, but the ID of the tube is more important. What is the ID supposed to be?
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Mike Henderson on October 04, 2020, 09:58:16 am
3” Sch 40 PVC pipe is 3 1/2” OD, but the ID of the tube is more important. What is the ID supposed to be?

Thanks guys. This is what EAW said:

Quote
Here is the description on the part #: PORT TUBE/3-1/2 ID X 15-7/8 LNG X 1/8 WALL They are hot glued in place

I had checked with the local stores and was told that they do not make PVC in 3-1/2 diameter, I can get 1", 1-1/2", 2, 3 and 4" so I would need a speciality pipe. Searching the net for a while now I am only able to come up with this item:

https://www.ebay.com/itm/383273998889?ul_noapp=true

The seller confirmed that it is 3-1/2? max in outer diameter but when asked what does it mean by "insulated" and if it's a hollow pipe they did not give an answer so I don't know.

Also when we took out the backplate to make sure the wiring was correct it had 14 gauge wire so I bought 12gauge to replace it.

Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Jerome Malsack on October 04, 2020, 10:22:28 am
https://www.parts-express.com/precision-port-psp-3tb-3-dia-x-12-long-port-tube--268-374   3 1/8 Outer.  but also there is a port calculator   http://www.psp-inc.com/tools.html   So if you need to alter the tube for a different size that is easier to obtain you can calculate the original tube and then calculate for the new size. 
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Scott Hofmann on October 04, 2020, 10:48:21 am
Thanks guys. This is what EAW said:

I had checked with the local stores and was told that they do not make PVC in 3-1/2 diameter, I can get 1", 1-1/2", 2, 3 and 4" so I would need a speciality pipe. Searching the net for a while now I am only able to come up with this item:

https://www.ebay.com/itm/383273998889?ul_noapp=true

The seller confirmed that it is 3-1/2? max in outer diameter but when asked what does it mean by "insulated" and if it's a hollow pipe they did not give an answer so I don't know.

Also when we took out the backplate to make sure the wiring was correct it had 14 gauge wire so I bought 12gauge to replace it.

You posted info that EAW said the tube was 3 1/2" ID (INSIDE diameter), yet you keep saying you are looking for a tube 3 1/2" OUTSIDE diameter. You can't have it both ways!
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Mike Henderson on October 04, 2020, 11:20:35 am
You posted info that EAW said the tube was 3 1/2" ID (INSIDE diameter), yet you keep saying you are looking for a tube 3 1/2" OUTSIDE diameter. You can't have it both ways!

That is what's confusing me. I had specifically asked the Rep to confirm the port hole size to which he had replied they don't have one there for him to know for sure and had linked him to that same pipe, he said the 3-1/2 would work. My bud said this week we will remove the speakers and try to see about the port hole size to know for sure.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: doug johnson2 on October 04, 2020, 02:01:05 pm
A cardboard tube may be a better choice.  Unline sells a 3 1/4" id. expandable mailing tube.  The larger outer sleeve would be 3.43" id. Close, so not much adjustment of the length needed and should be easy to seal in place.  The is a paper company called Yazoo Mills which will custom make cardboard tubes as well.  They will do single pieces.  There are lots of plastics companies that offer plastic tubing in 3.5" id. but they are stupid expensive for single pieces.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Riley Casey on October 04, 2020, 02:48:45 pm
The biggest consideration here is having a duct with the same internal volume as the original. If you end up using a tube with a larger or smaller diameter than the original simply cut it longer or shorter as needed to keep the volume the same. Another consideration will be getting a reliable glue bond to the cabinet cut out. PVC will be both heavier ( thus needing a better glue bond ) and at the same time less willing to bond with the kinds of adhesives that bond well with wood so stick with cardboard if you can.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Tim Hite on October 05, 2020, 01:10:36 am
Hey guys, I sanded and painted the used Cabinet I got and only when I had removed the grill that I noticed the left Port's tubing was missing. I contacted EAW Parts who said they don't have that part anymore but I can use PVC or hard cardboard tubing so I am looking around for a piece of tubing with that 3-1/2" outside diameter which they had stated.

My question is, how important is that port's tubing and what's it's main purpose please? Thx.

https://www.youtube.com/watch?v=KSvknLzv2QU

You will probably want a 3" ID cardboard mailing tube that is readily available. You'll need to trim it to 11" long. ULINE has them by the case.

If you have any other questions about the design I'd direct them to http://forsythe-audio.com rather than EAW.

Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Chris Grimshaw on October 05, 2020, 02:45:28 am
The biggest consideration here is having a duct with the same internal volume as the original. If you end up using a tube with a larger or smaller diameter than the original simply cut it longer or shorter as needed to keep the volume the same.

I'm afraid this isn't true.
A short wide port will have a very different tuning frequency to a narrow long one.

In order to maintain the tuning frequency, a wider port must also be longer.

Chris
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Mike Henderson on October 05, 2020, 07:48:09 am
A cardboard tube may be a better choice.  Unline sells a 3 1/4" id. expandable mailing tube.  The larger outer sleeve would be 3.43" id. Close, so not much adjustment of the length needed and should be easy to seal in place.  The is a paper company called Yazoo Mills which will custom make cardboard tubes as well.  They will do single pieces.  There are lots of plastics companies that offer plastic tubing in 3.5" id. but they are stupid expensive for single pieces.

Thanks. First I think I should wait until later this week when we should be removing the woofers to wire them with the 12guage wire, then we can take a tape and measure the port hole to know for sure what will be needed, will get back to you guys here on that.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Riley Casey on October 05, 2020, 10:22:39 am
Yup, totally wrong. I needed to pull down my old Weems book and refresh. 

I'm afraid this isn't true.
A short wide port will have a very different tuning frequency to a narrow long one.

In order to maintain the tuning frequency, a wider port must also be longer.

Chris
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Lee Douglas on October 05, 2020, 11:13:03 am
First I think I should wait until later this week when we should be removing the woofers to wire them with the 12guage wire...

If you haven't removed the woofers yet, I would think that there's a very good chance that your port tubes are rolling around inside the enclosure.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Tim McCulloch on October 05, 2020, 11:59:59 am
Thanks. First I think I should wait until later this week when we should be removing the woofers to wire them with the 12guage wire, then we can take a tape and measure the port hole to know for sure what will be needed, will get back to you guys here on that.

The difference between #14 and #12 wire, over the short length from connector to loudspeakers, is absolutely inconsequential.  The port duct, on the other hand, is a major deal.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Mike Henderson on October 05, 2020, 12:13:12 pm
If you haven't removed the woofers yet, I would think that there's a very good chance that your port tubes are rolling around inside the enclosure.

That's exactly what my bud who has 8 of these subs had told me. Why I thought it wasn't loose in the cab was because when I was sanding and painting the cab I did not hear anything at all move inside the cab but maybe it's caught in the damping material inside, will know in a few days for sure.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: John Roberts {JR} on October 05, 2020, 12:18:32 pm
The port duct is tuned (length and diameter). Google a Helmholtz resonator for scientific explanation of resonances, but ported cabinet tuning is more complex. 

Try to use same diameter and same length tubing if possible. The material the tube is made of doesn't matter much as long as the wall thickness doesn't alter volume.

JR

PS; I am not the speaker guy here, but I know a little about it... 8)
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Scott Holtzman on October 05, 2020, 06:11:08 pm
Thanks. First I think I should wait until later this week when we should be removing the woofers to wire them with the 12guage wire, then we can take a tape and measure the port hole to know for sure what will be needed, will get back to you guys here on that.


Why are you rewiring to 12 gauge?  The wire is so short in the cabinet it doesn't make any difference. 
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Tim Hite on October 05, 2020, 07:21:03 pm
Thanks. First I think I should wait until later this week when we should be removing the woofers to wire them with the 12guage wire, then we can take a tape and measure the port hole to know for sure what will be needed, will get back to you guys here on that.

Did you miss the video I posted that has the cabinet internal dimensions?
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Geert Friedhof on October 05, 2020, 08:29:56 pm
Did you miss the video I posted that has the cabinet internal dimensions?

Are you sure the 1000Z has the same port dimensions as the 1000E?
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Tim Hite on October 06, 2020, 12:14:25 pm
Are you sure the 1000Z has the same port dimensions as the 1000E?

As far as I know, the boxes are the identical, drivers are different. e uses RCF, z uses B&C and the z series was made overseas not in USA. Either way, processor settings are the same, which leads me to believe that the two versions are interchangeable.

https://www.soundpro.com/catalog/documents/83694.pdf
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: doug johnson2 on October 06, 2020, 01:46:24 pm
The SB1000e and the z are the exact same cabinet with different drivers.  The e are RCF L18p300s and the z used a B&C, the model number escapes me at this time.  There were also some transition boxes that had 18sound drivers as well.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Rick Powell on October 07, 2020, 09:07:26 am
Somebody should be able to 3D print an exact duplicate in polycarbonate if you can get them the correct dimensions.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Mike Henderson on October 22, 2020, 08:21:04 am
Somebody should be able to 3D print an exact duplicate in polycarbonate if you can get them the correct dimensions.

So guys, we finally removed the woofers last night. The right side port tubing is made of cardboard and I am now understanding what about the "Inner Diameter" being 3-1/2" since the port hole itself is 3-1/2". Seems there is a lip around the port's hole to accommodate the 1/8" wall diameter and it is glued unto that lip. So now I can try to find a cardboard tubing with the dimensions since the missing left side port tube was not in the Cabinet.

Anyways, there were 2 screws missing so I will need to order those, they are hex screws.

Also, the attached is a pic of the woofer, I have written to EAW to confirm the specs of that woofer.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Matthew Knischewsky on October 22, 2020, 12:17:50 pm
So guys, we finally removed the woofers last night. The right side port tubing is made of cardboard and I am now understanding what about the "Inner Diameter" being 3-1/2" since the port hole itself is 3-1/2". Seems there is a lip around the port's hole to accommodate the 1/8" wall diameter and it is glued unto that lip. So now I can try to find a cardboard tubing with the dimensions since the missing left side port tube was not in the Cabinet.

Anyways, there were 2 screws missing so I will need to order those, they are hex screws.

Also, the attached is a pic of the woofer, I have written to EAW to confirm the specs of that woofer.

EAW 804059 = RCF L18-P300
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Mike Henderson on October 22, 2020, 01:04:48 pm
EAW 804059 = RCF L18-P300

Yeah. This is the reply from EAW on the screws:

Quote
Hi Mike,

As I’ve said, there is no manufacturing in the USA any longer. So we are not a source for hardware.

Sincerely,

Any source to get those 2 missing screws please?
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Art Welter on October 22, 2020, 01:12:59 pm
Any source to get those 2 missing screws please?
A hardware store.
Bring a screw along so you can match the thread.
Title: Re: EAW SB 1000e Subwoofer missing one port tubing - replacement?
Post by: Tim Hite on October 22, 2020, 07:09:16 pm
Any source to get those 2 missing screws please?

https://www.copperstate.com