Dual 15" sealed subwoofer DIY project.

[RedLeicester]

OldSkoolRS said:

I thought I was bad for leaving things RL, but at least you might get to enjoy it over Christmas.

Not so much about leaving things as kicking builders and rubble out the way

[OldSkoolRS]

Oh of course, I'd forgotten you had builders in...In my case I'm the 'builder' so I can only blame myself for any procrastination.

[BrightYellowTVR]

OP If I start hearing loud bass, I know where to come and complain lol glass houses....let me know once your up and running and will head over

Cheers Jon

[OldSkoolRS]

I was thinking I could play back a video of your TVR to test the bass, see if you come running out of your house thinking it's being driven off.

I'll let you know once they're up and running so you can come round if you haven't heard them first.

[hman]

Crackie said:

MDF primers/sealers http://www.amazon.co.uk/s/ref=nb_sb_ss_i_0_10?url=... . polyurethane loaded paints & yacht varnishes also make MDF airtight.

Edited by Crackie on Monday 16th December 23:18

exactly.

[OldSkoolRS]

Ah I missed that post by Crackie as it was on the bottom of the last page.

Would I still need to to use the sealant on the internal corners as well though? If not I'll get some and give the insides a coat as I've just put the boxes out in my garage to clear space before Christmas...I might get chance to pop out there and do some preparation though. That'll give it plenty of time for any fumes to disappear before the speakers arrive.

I also need to order the connectors for the speakers, plus cable. The rear sub will be a 14 metre run from the amp by the time it's run around a door frame (behind the architrave which I'll replace) so I need to check what gauge I need to buy. I'm not a believer in expensive cable for the sake of it, but for 14 metres @1500 watts into 4ohms I think I might need to go for 4.5mm cable.

Watched 'Tron Legacy' recorded off one of the HD channels and it sounded very strong in the bass, even with my single BK Monolith, so I've left it on the PVR to check out the new subs once I have them built.

Edited by OldSkoolRS on Tuesday 17th December 23:07

[Crackie]

OldSkoolRS said:

Would I still need to to use the sealant on the internal corners as well though?

The sealer needs to stop any leaks through the cabinet joints and the porous MDF; a couple of liberal coats of a PU type sealer paying particular attention to the corners should be fine. You'll know if there are any leaks as soon as you play any sine test tones at decent volume; that Fi driver will be generating massive pressures inside.

Some great info about sealed subs here http://www.linkwitzlab.com/thor-intro.htm Linkwitz ; Linkwitz is a genius. Have a look at the design section for the sub; interestingly he deliberately adds a tiny leak to the sealed cabinet to make sure the static pressure in the cabinet is the same as the external air pressure. He doesn't eleaborate why this is done in the article but the reason is to try and make sure the drive unit's voice coil is centered in the magnet. The goal is to keep the driver BL as linear as possible on positive and negative cycles.

OldSkoolRS said:

I also need to order the connectors for the speakers, plus cable. The rear sub will be a 14 metre run from the amp by the time it's run around a door frame (behind the architrave which I'll replace) so I need to check what gauge I need to buy. I'm not a believer in expensive cable for the sake of it, but for 14 metres @1500 watts into 4ohms I think I might need to go for 4.5mm cable.

4.5mm will be fine, bigger the better tbh, but it gets tricky to hide.

Edited by Crackie on Wednesday 18th December 18:32

[OldSkoolRS]

Thanks again Crackie. As you say 4.5mm is big enough, plus I have to run one section round a door frame, so I'm taking off the architrave to fit it between the frame and plasterboard. Any thicker and it'll get hard to fit in the gap (I hate seeing any cables on show so I literally only want the last 6" or so coming out behind the subs).

No news on the drivers yet, though they did say it would likely be the week after Christmas. I've probably left it a bit late to order the speakon connectors for the back of the subs and the ones for the input and outputs of the Beringer, but I may as well place the order tonight. Just need to double check what the type is for the amp end, though I think I might need to modify some existing phono cables for the amp input connection.