Looking for Electro Voice Sentry III Speaker Port Length

[totem]

Sentry III series CAD drawings.

Looking back over the great CAD drawings that jorb posted in the previous pages, only wish I had the ability, I wanted to thank him for his work
on the Sentry III cabinet drawings.

 

[jorb]

totem

Looking back over the great CAD drawings that jorb posted in the previous pages, only wish I had the ability, I wanted to thank him for his work on the Sentry III cabinet drawings.

Thanks for the Kudos'
The below image is how I built the cabinets out of solid core doors,
I removed all the wood with a dado blade up to the 1/8 " veneer.
Then I routed out where the port boards go.
On the brown and blue colors, I applied carpenters grade glue.
The top, sides, bottom and front panels were all glued and bar clamped in one step.
Before putting the back on, I glued along the inside corners and glued in the port boards.
Then I glued and bar clamped the back panel on.
When the glue dried I routed the access veneer hanging over the edges.
Then cut out the woofer hole.
Then I glued along the back panel inside corners.
Then I routed the veneer that was covering port holes.
I did not use one nail anywhere on the cabinet.
Just one note, The glue that is mixed with the saw dust in the door, gums up the dado blade.
Which dulls the blades, you have keep the glue off, by filing them with a file.


totem

Never did find an EQ, the SEQ was the model spec'd but the D series I think was the same with the other models needing modification.

If you are interested in making a SEQ EQ out the any interface equalizer box. There is always some on eBay.
Below are the resistor values and where they are located on the circuit board.

I also have the schematic.
What is interesting, the Sentry III is suppose to be tuned at 28 Hz with bottom port closed.
The above chart says 32 Hz is the frequency they are boosting 6 db, not 28 Hz.
Why did they use 32 Hz instead of 28 Hz ?

Sorry for delayed response, had to put out some fires.

 

[totem]

jorb
The above chart says 32 Hz is the frequency they are boosting 6 db, not 28 Hz.
Why did they use 32 Hz instead of 28 Hz ?

I have noticed this also, and can only guess that a change in design spec,s was made leaving both figures out there. Although in the case of the D the next model in the series its still shown.

 

[02County]

Hello - My apologies for resurrecting a very old thread but....

I've been trying to figure out the exact details on an EV Sentry III build and this thread has been amazing.

I did have a question though - What are the dimensions of the front baffle and other sides of the enclosure? I can't seem to find any details online. Every time I try to back into them using the broader dimensions of the speaker, I end up with numbers that appear to be correct but don't come anywhere near the cubic volume requirements listed in this thread.

For example, the official EV brochure for the Sentry III Series II lists the "cabinet" at 34.5" high, 28.5" wide and 20.5" deep.

The SM120 horn on top is 10" high and sits on the top of the main enclosure. Assuming a few layers of 3/4" material plus the depth of the horn, and I am guessing the front baffle is about 23" high. Assuming the width and depth are unchanged, that would give me a cabinet that is 23x28.5x20.5.

Without accounting for the ports or the addition of the 15" driver, the various online speaker volume calculators give me a projected volume of 6.38 cubic feet.

Per EV, the volume should be closer to 7? Im fine with building a cabinet based on these measurements using 3/4 birch ply from the box store but wanted to at least get in general ballpark of an actual clone. Can yall help me with what I might be missing?

 

[flavio81]

Hello - My apologies for resurrecting a very old thread but....

I've been trying to figure out the exact details on an EV Sentry III build and this thread has been amazing.

I did have a question though - What are the dimensions of the front baffle and other sides of the enclosure? I can't seem to find any details online. Every time I try to back into them using the broader dimensions of the speaker, I end up with numbers that appear to be correct but don't come anywhere near the cubic volume requirements listed in this thread.

For example, the official EV brochure for the Sentry III Series II lists the "cabinet" at 34.5" high, 28.5" wide and 20.5" deep.

The SM120 horn on top is 10" high and sits on the top of the main enclosure. Assuming a few layers of 3/4" material plus the depth of the horn, and I am guessing the front baffle is about 23" high. Assuming the width and depth are unchanged, that would give me a cabinet that is 23x28.5x20.5.

Without accounting for the ports or the addition of the 15" driver, the various online speaker volume calculators give me a projected volume of 6.38 cubic feet.

Per EV, the volume should be closer to 7? Im fine with building a cabinet based on these measurements using 3/4 birch ply from the box store but wanted to at least get in general ballpark of an actual clone. Can yall help me with what I might be missing?

Since the Sentry III is an awesome speaker... I would suggest to get the Dayton Audio measuring system and measure the woofers. In this way you'll get the actual Thiele-Small parameters and thus simulating/calculating a box, reflex or non reflex, would be easy.

 

[02County]

It is an awesome speaker or so it sounds. I scored some drivers - the mid horns and the tweeters and have some EV 15Ws that Im going to try to make work. But I'd really like to get the cabinet as close to correct as I can - Not sure how the Dayton Audio stuff works.