Harvey Builder's Thread

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I'm starting this so there is a dedicated place for people who have, or want to build Harvey and related speakers both to take some load off the "spawn" thread, and to collect information relevant to these speakers in one place -- in the spirit of the chang thread.

I will be starting my pair of Harvey 1.1s this weekend -- my first speaker project in nearly 25 years, and although I've read through the entire spawn thread, I still have some questions particular to this design.

Just to start, my pair will be built in baltic birch using beech mortises for joining the sides, and will be built for a pair of Fostex F120A drivers.

So, my first question is if there are any general tips, hints, do's and don'ts, and any other suggestions folks may have. Especially helpful at this stage would be some sort of description of recommended building sequences. We can get to things like tuning, finishing, etc. later.

Thanks,

Jim
 
One tip...

Build a jig for the port.
It's 3/8 wide and 1/4" from the back...
I'll send a jpeg of the jig.

I built the center section as a complete unit.
I'll send a jpeg

My supplier of Baltic Bich didnt have 19mm (3/4")
so I had to use 18mm...This did change a few things.


Phil
Santa Fe
505 466 7575h
 
A few photos

The spacers
 

Attachments

  • dsc_0020_2.jpg
    dsc_0020_2.jpg
    51.1 KB · Views: 2,061
Build the center section first???

I'm not sure if this is the best way to procede but it seems to be working for me.
The idea of trying to build the center and glue it to the side at the same time was too scary. So I drew out the layout on some FLAT plywood and started.
The first to be done were the inside baffles that made up the CC. Those need to be spot on. Make sure that are square to each other and to the base. I let them dry over night.

PS
I cut my flat pack first hoping the angles would be in the ballpark...they were.
I used a homemade tendon jig to cut the angles.
I am waiting to cut the out sides untill I have an exact measurement re the overall width. Thats where the 18mm thickness will bite you in the ***.
 
My build does not look nearly as good as yours, but I also built the center first and then glued the whole thing to the side. If I screwed up on something I needed to have an out without wasting so much wood.

They look difficult to build, but they were my first wood working project period and it was not too bad.
 
Home Made Tendon Jig

This jig is made from 3/4" plawood. You simply clap on your part that needs an angle (2 clamps) adjust the rip fence to the right distance and set the angle on the saw blade. Because it about 2 feet long you can cut large parts. Make sure the work piece is square to the table as you snug up the clamps. The cool thing is the cut is totally repeatable and perfect.
 

Attachments

  • tendon jig.jpg
    tendon jig.jpg
    49.3 KB · Views: 1,924
Just a me too reply until i catch up on an already full page thread.

A few of my cuts are done for the Harvey for FE127e.

Have any of you done extra front baffles to practice on or do them one-off?

Also a thing I found in 2 different drawings several months apart was the wave divider at center rear. The more recent drawing doesn't have it and the CC spacing is different.

Also, I'l l be using hole saws of 4" and 5". The drawing does not show a chamfer on the 2 cutouts. What have you done there?

I was figuring on clamping the back to one side and then mounting everything on the side panel a piece at a time.

But I'll be able to look at the jigs better during the day.

Better to look at that when I'm fresh.
 
Dave,

How big is the wedge, what is it made of, and how is it positioned?

Also, is the brace set horizontal, vertical, or front-to-back?

Unfortunately not building today. No way to get the wood to the shop, and it seems pretty silly to try to build a speaker without wood. :)

-- Jim
 
frugal-phile™
Joined 2001
Paid Member
jrebman said:
How big is the wedge, what is it made of, and how is it positioned?

The wedge would be (at maximum) a 1/4" high piece with a 45 degree triangle profile. This makes the 2 orthogonal sides 9/32". A peice of 1/4" 45 degree right angle moulding hypotenuse side to the cabinet back would do the trick. This runs horizontally centred on the inner back of the cabinet so as to "point" directly into the compression chamber exit.

dave
 
frugal-phile™
Joined 2001
Paid Member
The Half-Chang drawings include an explicit holey brace. Note that if the driver is centred then 1 side of the holey brace is alighned to centre (setting the panel just off centre. This breaks up the primamry resonance mode & as a side effect provides a surface where damping can be placed so that it is dead centre.

dave
 

Attachments

  • halfchang3d.gif
    halfchang3d.gif
    50.9 KB · Views: 1,690
a silly millimeter shorter

I'm using some cabinet grade play that says it's 18mm rather than 19mm.

Haven't any of the Compression Chamber (CC) laid out yet.

First cutting will be for the front baffle 2 pieces and then the back 2 pieces. I'm giving my cutter the job one setup at a time to avoid confusion.

Only setup I have ready to take to him is the front baffle: outside measure is 12 5/8 with 60d on edge.


How much resizing is necessary for the other dimensions? Quite frankly the only real picky area I see is at the vent at rear which is only 1/4 deep. Maybe a bit inside the CC
 
frugal-phile™
Joined 2001
Paid Member
Re: a silly millimeter shorter

loninappleton said:
How much resizing is necessary for the other dimensions? Quite frankly the only real picky area I see is at the vent at rear which is only 1/4 deep. Maybe a bit inside the CC

You have spotted the critical dimensions, the others aren't going to care about a mm or 2, I would shrink the outside dimensions and adjust the panel dimensions to account.

dave
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.