Low-cost DIY practice/coffeehouse tweeterless 110 [long]

[DukeLeJeune]

Looks like I got a bad Basslite from PE. Last night I decided to crank it up a little bit. I'm a reasonable man; when I say "a little bit" I mean that. So far, I'd only played it at low-to-medium levels. Last night I turned it up so that you'd have to yell (not scream) for me to hear you.

That's when I heard it. A ticking noise coming from the speaker. NOT voicecoil slap. I know what that is; I was big into car stereo for many years and know what a bottoming-out sub sounds like. Ever hear a grain of rice or small, light thing vibrating on a surface? That's what this noise is and it's coming from right behind the dustcap. Ticking/buzzing noise. Got to be the voicecoil, or a stray piece of something that got in there during the manufacturing process.

Bummer!

I had that happen a few months ago, I think it was to a 3012HO, and Eminence took care of it. That was the only time so it's not common, but it is a bummer when it's your cab.

 

[mikeddd]

In the past when I had VC lead slap, you could hear and pinpoint the exact spot on the cone where the sound was coming from. The sound I'm hearing is coming from behind the dustcap. I cannot pinpoint where though. I.E. 4 o'clock postition, etc. It's just "behind there." Very frustrating, especially since it takes 7-10 days minimum for anything thing to get to me after it's shipped.

 

[greenboy]

Someone did it before but the angle and lighting were bad so I could only guess. But often you can just lightly pump the cone inward by hand while looking at the leads and seeing what the deal is. IF they seem suspiciously close at some point you can guess that under power they are vibrating on the cone.

That's the funny thing about Projectland; there are a lot of unseen gotachas you don't even think about until they happen to someone. On the other hand, I've sure seen a lot of purchased PA and bass cabs that had problems that needed to be isolated down while program material was playing into them at a fairly high level...

Often it was handles and connector cups that were not gasketed and had bent slightly when getting tightened down, stripped screws here or there, grills that needed one more standoff only on a certain note, or bracing that wasn't glued down in one spot, or a void in the plywood or a tear in a surround that could NOT be seen until it got larger.

Another good one you might examine for is a dust cap that's not fully glued on. Get some good light and look at the cone from the rear, and the spider and the surround, and pump the cone lightly and slowly. Sometimes that reveals something.

 

[DukeLeJeune]

Thank you very much for helping out here, greenboy. Your knowledge and experience here is worlds more extensive than mine.

 

[greenboy]

Ah, trade you some of that for some of those speakers pictured a page or two back, Duke ; }

 

[mikeddd]

Thank you for all the hints, GB; they are extremely helpful. I will do that first thing in the morning. I really appreciate the advice. I got a chuckle out of "Projectland". There are indeed countless "gotchas" that just pop up. The little bolts that hold the Speakon to the plate, for example. Couldn't find 4mm bolts to save my life so I had to drill the holes out to fit 5mm bolts. What if I didn't have a 5mm drill bit? Or a drill? l needed 28 washers to use as spacers for the grill (I know we disagree on this and that's OK). I happened to have a box of washers that size in my parts drawer. LOL; "You know you're a DIY geek when..."

Mike

 

[greenboy]

The main reason T-nuts exist is so that you can constantly remove the drivers and put them back in to see if you have solved the problem without stripping out the wooden holes. The main reason for needle-nose vice grips is to go in through a handle or connector cup hole you just stripped the holes out on, to hold the back side of the T-nuts so you screw the bolt out and can remove the driver again. The main reason for big connector cups or handles is to -

 

[mikeddd]

Years ago I had a monster subwoofer box in my trunk. Thing weighed about 80 pounds. Blew a sub. Found out I had a stripped t-nut. I managed to unscrew it about a 1/4" (that took an hour), just enough to get a hacksaw blade on the bolt threads b/t the bold head and the top of the speaker. Holding the bolt with my left hand whilst sawing with the right, whilst trying not to slice my hand off was a memorable experience.

 

[DukeLeJeune]

The main reason T-nuts exist is so that you can constantly remove the drivers and put them back in to see if you have solved the problem without stripping out the wooden holes. The main reason for needle-nose vice grips is to go in through a handle or connector cup hole you just stripped the holes out on, to hold the back side of the T-nuts so you screw the bolt out and can remove the driver again. The main reason for big connector cups or handles is to -

Oh yes!

And I suspect somewhere down the road we come across the reason teenagers have skinny arms, which is so they can reach that spinning T-nut on the far side of the woofer with those needle-nose vice grips, while dad tries not to cuss too much in front of them...

 

[greenboy]

That said, even the biggest project snafus beat working on most motor vehicles even during summer when girls in cutoffs are walking around nearby.

Well. Maybe.

 

[UncleFluffy]

That said, even the biggest project snafus beat working on most motor vehicles even during summer when girls in cutoffs are walking around nearby.

Well. Maybe.

Yeah. You always end up getting a piece of grit in your eye at just the wrong time

 

[ChuckHubbert]

Dual-speakon jack installed. Wired in parallel, 1+ and 1-.

I want to wire mine this way, and I've tried to tell from the picture, but I thought it would be safer to ask than to assume. All the +'s are connected together and all the -'s are connected together, correct? The + speakon jack terminal that is wired to the + side of the driver is also wired to the + terminal of the other speakon jack?

The back ordered drivers from PE are due in on the 18th, so I'm patiently waiting. I won't have much time this week to play with, I mean work on, the project anyway, but I'll be glad when it all gets here!

CH110, hmmm, not much ring to that...

 

[mikeddd]

Not that I wasn't before, but I wanted to check out all the things that GB suggested.

I pulled the driver and cut the signal wire coming from the Speakon as short as possible. It's not possible for the wire to touch any walls of the cab. Put the driver back. Noise still there.

Pulled the driver (good thing I've got tnuts on the way...the holes are now pretty well stripped out) and looked for the things GB suggested. Confusingly enough I cannot see a darn thing wrong with this driver. No spider separation/crookedness. Dustcap not loose. Surround not loose. I'm puzzled.

Here's pics of the VC leads. They look perfect to me. Doesn't it look like the epitome of "AH! Smells like brand new woofer!" I mean...look at it. Perfect. So...WTH??

Put the driver back again and tested it. Same thing. Something is loose behind the dustcap. Oh well, that's Projectland for you. :scowl:

Got another driver on the way from Leland. Let's see some more builds!

 

[mikeddd]

Stupid Question: Could the absence of padding/batting in my cab be causing this? I may be reaching here but: At higher volumes could standing waves be building up that bounce back against the cone and cause this ticking sound? It does not happen at all at low volume. Starts at med volume and gets horrid at high volume. Just a thought. Need smarter minds than mine to answer this one, please.

 

[DukeLeJeune]

Does the woofer produce the ticking sound when it's not in the box?

By the way, if you have some wood glue, you may be able to rehabilitate those screw-holes using the toothpick smearing/"stirring" technique.

 

[mikeddd]

Good point, Duke. I haven't played the bass thru the woofer when it's not in the cab...didn't even think to try that. The only "playing outside of the cab" has been when I did was the "battery test" to check if the woofer was functional when I took it out of the shipping carton. I will check that out. Thank you.

 

[tealrex]

Hi guys. Here's my little cab build. I started by removing the carpet from the face and part of the sides.

I then glued and screwed 3/4x1 1/2 inch strips of pine to the face so i could have a recessed grill.

Next i gave it little love with my mini belt sander( to smooth out my rough cuts) and added some beautiful new rat fur.

I sourced my grill material from a jeep cj bug screen. I work for a aftermarket jeep parts company so we stock these in our warehouse.

I cut it down to size with a pair of tin snips and took off the sharp burs with a sanding drum.

I bolted the grill down with 10/24 bolts, threaded inserts and 3/4 rubber spacers. I finished it off with pointed corners, 5/8 inch rubber feet, jack plate and a flip out metal handle on the bottom( to use as a tilt back).

Unfortunately the speaker is on bo at parts express so i'm in a holding pattern for the rest. i'm excited to see how its going to sound. I want to say thanks to Duke for the great idea! Duke i do have a question for you. I added 1 1/2 inches to the length of the port. Any idea how much of the port will need to be blocked now that it is a little longer? i play a fiver so i'd like to get that lower tunning you where talking about.
thanks

 

[mikeddd]

Wow, nice! Never would've thought to add material on the front for a recessed grill; you've got a totally customized PE110 now. Nice job recovering it too. I totally suck at any kind of material covering...I'm a spray paint kinda guy. The handle on the bottom is a neat addition.

Those same pine strips you used to extend the cab will be the perfect material to block the port with. Duke will have to chime in as to how much port to block; I'm clueless there. I do know that the port most likely will be a "U" shape in order to not take away from the internal volume of the cab too much.

As for where to buy the speaker, you can buy it from fellow TB'er Leland at his online store, www.speakerhardware.com Great guy to deal with.

 

[jlepre]

Nice idea. Just a thought...wouldn't black grill screws ad a more finished look?

 

[mikeddd]

Nice idea. Just a thought...wouldn't black grill screws ad a more finished look?

I agree. Easy to do. Stick all the screws heads-up in a piece of cardboard or styrofoam and hit'em with some flat black spray paint. I told you I was a spray paint kind of guy.

I've done this w/everything from screws to blank spacer plates for racks; you'd never know they weren't black from the factory.