speaker cutout little bit too narrow - problem?

[shivernshake]

got me a 15inch jbl e130 and had to make a new baffle board.
got no router so i used a jigsaw. after an additional hour of sanding by hand i end up with this:


By thecobra1 at 2012-07-30


By thecobra1 at 2012-07-30


By thecobra1 at 2012-07-30


By thecobra1 at 2012-07-30

jbl says i need a 34,4cm diameter, in fact i only got 33,9cm, equals 13,54" versus 13,35". could that lead problems if the speaker if the speaker "bumps" against the baffle?
as i wired it to my stereo, it showed that the "inner" circle puts out the most swings, the second one just lightly. no contact to the baffle sighted...

am i ready to fire that thing up or do i have to sand some more/ do a new turn with the jigsaw`?

perhaps a dumb question, but dont want to ruin the speaker...

[trev333]

photos are too big for me...... taking too long to load here.... ;)

[shivernshake]

Originally Posted by trev333

photos are too big for me...... taking too long to load here.... ;)

edited :)

[macaroonie]

Your photos are HUGE , you should re size them before uploading.

JBL is an expensive drive unit and the cutout is the size it is for a reason. For the cost of a new piece of plywood I suggest doing it again , the right size this time.
Take your time with the jig saw and you will not get the wiggle line. Use a metal cutting blade , it gives smoother cut.

[shivernshake]

back to the workbench then. thanks for your advice

[LeroyBlues]

Or, use a narrow blade designed for fine wood cutting. The narrower the blade, the easier it will be to follow the curve of the line. And you might cut on the outside of your line so you have just a bit larger opening than specified. I doubt the hole you have is really an issue, but if you want to make another baffle, you'll have peace of mind.

[shivernshake]

after another hour of sanding (this time with quality sandpaper... good tools are essential, wasted so much time with that other stuff) i now got a perfect circle with the desired diameter.

but now my transformer is in the way of the magnet... well see what happens

[macaroonie]

Could you reverse mount it ? ----- Like this V

[shivernshake]

edit: gonna try that! thanks

edit2: doesnt work, speaker is too big/cab too narrow. new speaker baffle it is...

its gonna fit real tight with the new baffle, like 2mm distance to the output transformer.. any real risk cause of the heat broadcastet by the OT?

[macaroonie]

If you do something like this diagram you will move the speaker forwards by about 15mm. It will not matter if the cabinet edge covers the frame of the speaker as long as it is not over the cone.

Might work



The blue parts are a new mounting ring to allow the speaker to mount backwards. It will need to be scewed and glued to the main baffle.

Here is the technical diagram for your driver

http://www.jblproservice.com/pdf/Dis...130-4-8-16.pdf

If your baffle is 18 mm you will have 2-3 mm free before you are flush with the front face of the baffle so the cone will not hit anything.

[shivernshake]

the new baffle and a specific positioning of the speaker chassis itself solved the problem; went far better than the first time. i need to do more woodworking...

macaroonie, i dont really "get" what you mean, especially not with that drawing. the speaker is nevertheless screwed on the back of the baffle board, or isnt it?

[macaroonie]

Red is the existing New baffle but cut to allow the whole frame to sit inside of it. You could have 5mm clearance around the frame if you wanted.

Blue is another plate mounted behind the baffle and fixed securely to it with screws and glue. This becomes your new mounting surface and has to be cut to fit the driver accurately.

See if you get it now , I've modified the drawing a little

[shivernshake]

ah, the whole speaker frame sits inside the baffle! thats a ingenius one!
as my current construction "works" i wont make a 3rd baffle now but if im gonna make one i definately consider your advice.

[macaroonie]

You get it now ,,, good.

Here is a pic of a pair of speakers I made where the cabinet is 25mm plywood.
It is cut to 18 mm to allow the whole driver to sit in the hole and it mounts on the remaining ply as you can see. The ledge would be the blue bit in the diagram.

[shivernshake]

thought i would share my outcome:



Uploaded with ImageShack.us

[macaroonie]

Ah yes , I got you now. Bet that sounds good. Have you tweaked your bias ? well worth it now you have a quality speaker in there.

[shivernshake]

yeah it sounds good. huge, loud and clear. honest i would say. its a hairline on the dial between sparkling treble and icepick.

tweaked the bias quite some time ago to 68mv or something, as it was recommend. to be honest, i didnt hear any big difference. with this in mind, i seem to be no "audiophile" in any way.

[macaroonie]

Funny you should say icepick , the band I supply PA to have two guitarists , a tele going through a Roland cube 60 on the blackface setting into a d130 in a decent sized cab and the other guy plays a Epi dot through the same amp as you with a D120 in it. I have never felt the icepick in the forehead with either. Attack yes and they can be as loud as hell but no icepick. Perhaps back you tone off a touch.
The bias thing is interesting , on the low side the amp will sound sterile and uninvolving , 68 is recommended , on the high side it will break up sooner and be a little warmer. My mates amp was set at 90 ish when he got it !!


M

[shivernshake]

for me its hard to distinguish at a certain volume level between ice-pick and just serious loudness with associated treble. i just know when it hurts in my ears and then i back off the treble a bit.

its not that i dont use the guitar controls at all. but i still want a nice sound that doesnt let my ears bleed at the highest frets while having tone & volume full open. especially with a bit alteration of the tone i can get from clean to growl, but if im on a solo, i want the full range of frequencies that my pickup can give me.

[macaroonie]

Originally Posted by shivernshake

for me its hard to distinguish at a certain volume level between ice-pick and just serious loudness with associated treble. i just know when it hurts in my ears and then i back off the treble a bit.

its not that i dont use the guitar controls at all. but i still want a nice sound that doesnt let my ears bleed at the highest frets while having tone & volume full open. especially with a bit alteration of the tone i can get from clean to growl, but if im on a solo, i want the full range of frequencies that my pickup can give me.

When its hurting your ears its just plaiin loud. JBL's are deceptive , with them being so clean they can be LOUD LOUD yet don't sound broken up. I love the attack they have , very responsive to the player's technique etc