New Build - T30s and then Otops to follow

[gzc_stageTech]

Arr see, now you have to read fully.
Switch mode power supplies cycle faster to keep power up to the rails, and since that's what Class D amps have as a generalisation:

It tells you in those specs what the fuse rating is, dependent on country model.

It's not about the maximum power your amp can output as transients, it's about the most power it can consume (before the fuse will blow) to produce that output

So if you have eg 240V power, the fuse is rated @ 6.3 amps. If the fuse does it's job, that means it will blow after or around 6.3 amps. Which means that maximum required power from your power source would be 1512W or thereabouts.
Given that, you would think that, with a little overhead a 2.5Kv genny (or inverter) should be ample.

I imagine you would be well into hard clipping if you were running the amp to a level that was making fuses blow, much less any inbuilt protection circuitry.

You're correct though, you do need enough power for instantaneous requirement. We can't run a small stick welder or a medium sized compressor on our (old) 2.5Kv genny on the farm. Most noticeably the compressor, where all the load is trying to get that motor to turn the piston over that very first time.
We can hear the motor on the genny bogging down with an electric drill or an angle grinder.
All these things though are motor driven tools, and I'm sure that a switch mode power supply isn't quite so demanding...

Very good Grant. Excellant synopsis. And clearly articulated, especially in terms that we can understand. This description is both easy to understand and retain.

It points to the strengths and shortfalls of a generator driven power source, especially with the switching power supplies, which are rapidly becoming the norm for the class D series of power amps.

Thanks again for you input.

Oh, and I just added a battery drill & combination (Porter-Cable) to my toolbox. It's nice to finally be liberated from the extension cord when driving screws into a cabinet. Sure, the torque of a wired drill is nice to push larger bits through a stackup of wood, but but mobility of the battery systems is sweet.

Heck, its an investment, right?

[bitSmasher]

Not all battery powered stuff is created equal. I have the ryobi lithium ion battery 18V circular and it shreds just about anything it can sink its teeth into.

I have the same saw.

Same, bright green Ryobi - favourite tool... though I have noticed that is slows and stalls if the blade rubs, especially on angled cuts.
Supporting both sides of the cut helps a lot, as does being wary of how the saw twists in your hand as your moving it along.

[Zack Brock]

I have a cheap rechargeable circular saw from Harbor Freight that does just fine on 1/2" plywood. Bought it four years ago for $20 and it hasn't had any trouble. Battery isn't lithium ion though, but I can get through a couple sheets worth. Its now $30:

http://www.harborfreight.com/18-volt-5- ... 68849.html

^ Same model as mine except mine is blue plastic housing instead of the red color they use now.

Another one of the best purchases I made was a Dewalt Track Saw; allows me to make absolutely perfect cuts, as good or better as I can on the table saw with a fence. And faster with less setup, just lay the track along the cut line. Smaller kerf blade too than my table saw. I can stack and clamp three sheets on top of one another on a bed of styrofoam, draw the layout on the top one, then cut out all three sheets at once perfectly with the track saw in no time.

And another vote for the panel jig - I use it extensively, it almost never leaves the top of my table saw. And then I dedicated another table saw, a Skilsaw brand, to tweeter cutting duty with Bill's tweeter cutting box jig. Works great!

I've also had great luck with local pawn shops. I picked up a router, a second table saw, a circular saw, my Bosch jig saw, two battery drills, all of them used on the cheap but in great shape by working a deal with the local pawn shop owner in my small town.

[escapemcp]

The 5 minute wood adhesive gel which is listed on the "European Suppliers" page is out of stock. Would the 30 min variety be ok and perform as well (except for the fast drying obviously!)?

5 min gel: http://www.tool-net.co.uk/p-324986/ever ... 310ml.html
30 min gel http://www.tool-net.co.uk/p-324991/ever ... 310ml.html

Thoughts?

Thanks,

Aidan

[Chris_Allen]

The 30 minute stuff is better. 5 minutes is very little time when you are trying to align, clamp and screw a panel.

[Bill Fitzmaurice]

The 5 minute wood adhesive gel which is listed on the "European Suppliers" page is out of stock.

Good. You don't want to use it.

[88h88]

I wish the 30 minute stuff were named accurately, it's at least an hour before it sets fully. If you've got all your panels pre-cut then you've got a lot of downtime between fitting them all. (of course at this point you're assembling tweeters and the like for your other builds... )

[iamlowsound]

I have a cheap rechargeable circular saw from Harbor Freight that does just fine on 1/2" plywood. Bought it four years ago for $20 and it hasn't had any trouble. Battery isn't lithium ion though, but I can get through a couple sheets worth. Its now $30:

http://www.harborfreight.com/18-volt-5- ... 68849.html

^ Same model as mine except mine is blue plastic housing instead of the red color they use now.

Another one of the best purchases I made was a Dewalt Track Saw; allows me to make absolutely perfect cuts, as good or better as I can on the table saw with a fence. And faster with less setup, just lay the track along the cut line. Smaller kerf blade too than my table saw. I can stack and clamp three sheets on top of one another on a bed of styrofoam, draw the layout on the top one, then cut out all three sheets at once perfectly with the track saw in no time.

And another vote for the panel jig - I use it extensively, it almost never leaves the top of my table saw. And then I dedicated another table saw, a Skilsaw brand, to tweeter cutting duty with Bill's tweeter cutting box jig. Works great!

I've also had great luck with local pawn shops. I picked up a router, a second table saw, a circular saw, my Bosch jig saw, two battery drills, all of them used on the cheap but in great shape by working a deal with the local pawn shop owner in my small town.

I would love one of those track saws, I am trying to convince my dad to buy one as we share shop space

lowsound

[Bill Fitzmaurice]

I wish the 30 minute stuff were named accurately, it's at least an hour before it sets fully. If you've got all your panels pre-cut then you've got a lot of downtime between fitting them all.

PL takes at least four hours. Good things come to those who wait. And you should not pre-cut all your panels.

[88h88]

Impatience is not a virtue, luckily I'm in no hurry.

[escapemcp]

The 5 minute wood adhesive gel which is listed on the "European Suppliers" page is out of stock.

Good. You don't want to use it.

Aah, bugger, this evening is going from bad to worse! I didn't see that message before I found a different supplier, and only just read it now I ended up getting 4 tubes of the 5 minute stuff! If I plan everything out and work quickly, is it still usable, or is there a fundamental reason why I shouldn't use it?

AND just checked my new Lab-12 and it doesn't work. Looks brand new, but totally dead. Checked resistance.. nothing.

And also trod on my earphones and broke those.

Things happen in 3's, eh!

On the plus side, I understand 95% of the plans now!

[88h88]

or is there a fundamental reason why I shouldn't use it?

I've used it, am using it now for my current build. There's nothing really 'wrong' with it but if this is a first build there will probably be mistakes with panels and the quick setting time doesn't give you much time to rectify things before it becomes permanent. With the 5 minute stuff it starts to go off almost immediately after leaving the bottle/tube so you're already having to rush to get things lined up perfectly as well as clamped up/screwed into position...

[escapemcp]

or is there a fundamental reason why I shouldn't use it?

I've used it, am using it now for my current build. There's nothing really 'wrong' with it but if this is a first build there will probably be mistakes with panels and the quick setting time doesn't give you much time to rectify things before it becomes permanent. With the 5 minute stuff it starts to go off almost immediately after leaving the bottle/tube so you're already having to rush to get things lined up perfectly as well as clamped up/screwed into position...

Ok many thanks. May well get some of the 30 minute stuff as the place that didn't have the 5 min stuff when I originally ordered gave me a fiver off my next order I am guessing that I may well use the 5 min stuff for plugging joints and the like, as there is no readjustment needed there.

Just the speaker to get swapped out now then, and I'm back on track!



Another quick question though: In the instructions, it mentions about acrylic latex caulk for filling gaps between the woofer gasket and the front of the frame. What is this please? Does it have a 'European' name

It also mentions on page 10 about using screws to attach the drivers, and then mentions that the screws must be long enough to go through the frame and driver gasket plus 1 to 1 1/4 inches. I thought bolts and T-nuts were used for attaching the driver? Also what is the extra inch or so for? And is the gasket the hard foamy spacer attached to the speaker (that is visible in the pic), or the extra papery spacer which comes with the driver (which was taped to the foamy spacer thingy)? Does that make sense? Attaching the driver (for checking fit) is the one area I was not 100% on, and I'd like to have it clear in my head before I begin.

Thanks in advance for any input

A

[88h88]

Another quick question though: In the instructions, it mentions about acrylic latex caulk for filling gaps between the woofer gasket and the front of the frame. What is this please? Does it have a 'European' name

It also mentions on page 10 about using screws to attach the drivers, and then mentions that the screws must be long enough to go through the frame and driver gasket plus 1 to 1 1/4 inches. I thought bolts and T-nuts were used for attaching the driver? Also what is the extra inch or so for? And is the gasket the hard foamy spacer attached to the speaker (that is visible in the pic), or the extra papery spacer which comes with the driver (which was taped to the foamy spacer thingy)? Does that make sense? Attaching the driver (for checking fit) is the one area I was not 100% on, and I'd like to have it clear in my head before I begin.

Thanks in advance for any input

A

Latex caulk would be shit like bathroom sealer HOWEVER some of them give off fumes and don't like rubber very much so I can't advise on what to actually use there as I've never actually done it.

Bolts and T-nuts are what I use, you could use screws but the security of bolts is preferred. Make sure to epoxy your t-nuts in place, Harley posted up a completely bombproof method which involves getting the t-nut in, putting a wee screw next to on of the prongs to stop any possibility of twisting and then epoxy over the top. Here we go: http://billfitzmaurice.info/forum/viewt ... 14&t=18206

You get two gaskets with certain drivers, the Lab12 has two and they're for mounting in different situations. The one actually attached is the one you'll be using, the papery one is for rear mounting so feel free to throw that. Between the driver and the spacer you should use some speaker gasket tape to make double/triple sure of a decent seal. I use this stuff: http://www.bluearan.co.uk/index.php?id= ... nufacturer

[Rune Bivrin]

Bathroom sealer is NOT latex, it's silicone. Generally speaking you only use that for sealing bathrooms (duh!), aquariums and other wet areas.

Latex caulk is just that. Used in finishing for filling cracks where it needs to be somewhat flexible.

Go into any store that sells paint and they will readily sell you that stuff. Comes in many colors and is easily painted over.