Eminence Delta Pro 18 A in prism sealed 150 liters

[academia50]

I understand the idea, thank you.

Just a doubt, why do you say two guides? to do it in two passes, one on the bottom and one on the top?

I have to review the strawberries that I have in my possession, if I find a 45 degree one, I think that with a single pass it will reach because the thickness of the MDF is 18 mm.

Regards

PS : Strawberries , they are called strawberries here ... the translation is correct ....

Fresas Para Router Madera - Fresas en Mercado Libre Argentina[A:fresas-para-router-madera]

 

[academia50]

An interesting link about the behavior of acoustic cabinets in corners


corner loaded louspeakers

 

[SpeakerBob]

I understand the idea, thank you.

Just a doubt, why do you say two guides? to do it in two passes, one on the bottom and one on the top?

I have to review the strawberries that I have in my possession, if I find a 45 degree one, I think that with a single pass it will reach because the thickness of the MDF is 18 mm.

Regards

PS : Strawberries , they are called strawberries here ... the translation is correct ....

Fresas Para Router Madera - Fresas en Mercado Libre Argentina[A:fresas-para-router-madera]

I have always done stuff that needs to be accurate in 2 passes (from back when I was a tool maker) so I guess it's just a habit of mine.. rough cut to remove the bulk and final cut to make good. (tool is more accurate when it doesn't need forcing ?)

Strawberry caught me out but when you said 45 degree it suddenly made sense

 

[academia50]

I have always done stuff that needs to be accurate in 2 passes (from back when I was a tool maker) so I guess it's just a habit of mine.. rough cut to remove the bulk and final cut to make good. (tool is more accurate when it doesn't need forcing ?)

Yes, I was very perfectionist in everything I did, I understand you, but there is not much time left for details .....

I understand, you say in a first approach and a final.

Well, I think it's better to prevent two passes ... if you exceed, there's no going back ...


Although you can always supplement with a glued lamimate and start again ...

Strawberry caught me out but when you said 45 degree it suddenly made sense

straberry beatles - Google Search

Do not worry, I was many years to understand one day the meaning of The Beatles - Strawberry Fields Forever, and in the end it was just a remembrance, but it is not clear to me, was there a consensual sexual act or a violation? I guess that anyway, the pants could hang, as a war trophy or as a romantic memory ... well I guess the first thing would be more typical of the Rolling Stones
And to think that one believed that he understood the "message" ....

 

[academia50]

I have found a big mistake in my work !!!!

The previous simulations with Win Isd were correct, they correspond to 300 liters of internal volume, but the measurements of the box that I have begun to build are exactly half....

I do not know what happened, but something aroused my suspicions .....
My DTQWTII cabinets are gross 150 liters, and really, these prisms did not seem to be double the size, so I decided to corroborate everything.

Let's go in parts, as Jack the ripper said ...

The base of the prism (irregular) can be calculated in several ways, the most common is multiplying the three dimensions of it, that is:

0.50 m x 0.50 m x 0.70 m = 125 cm2 (0.125 m2)

The height the prism is 1.20 meters.

The formula for the volume is: Base surface multiplied by height, that is:

0.125 x 1.20 = 150 liters

This is the volume taking the external dimensions and without calculating the Vas of the speaker and the reinforcements, in practice, the abundant filling of polyfill will comfortably compensate for this .

I leave all the simulations again, they are final this time, I'm sorry ......


I have not found a way to change the title of the thread, maybe a moderator can do it so as not to create unnecessary expectations when reading "300 liters"...

I sorry again....

 

[academia50]

Last pics sim´s .

Vol : 150 liters
Q: 0.685
F3 : 63 Hz
F10 : 36 Hz

 

[freddi]

(I've been ill for a month - got better then seems like a flu has hit today)

fwiw -

 

[freddi]

and approximate effect of a low loss 500uF series cap

 

[academia50]

Thanks freddi !

 

[academia50]

It has been raining a lot here and the MDF as we know is highly affected by humidity and we must protect it.

So until I can recover from the knee arthroscopy, I added some new stuff in the kitchen of the house.

Here is the new 10.6 ft3 refrigerator !

Now, Waf is beginning to show me that everything has a limit, I have invaded territory of his property .......

"Hey, heal up soon and get those crap out of here! "

 

[academia50]

Almost 1500 readings of this thread and very few answers, just some emoticon in response to my smiling comments would be welcome .....

Humour – the salt of life ! | sethidisha

 

[academia50]

The work has resumed.


The router has not served to cut to 45 degrees, has little vertical travel and the strawberry is very small, does not cover the entire cut.
I did it with the hand saw finally. I think it's good, your judge...


"The important thing is not the tool, it is the operator"

Or in other words:

"The important thing is not the bow and arrow, it is the aim of the Indian"

 

[academia50]

Here you can see the cut in a close view....

 

[academia50]

The baffle panel will be 1.20 meters x 0.70 meters and will have a thickness (very important) of 36 mm.
This is achieved by gluing two 18 mm plates of MDF.
Here you can see the cuts.



PS : Our dog is called Vasco.

 

[academia50]

In blue the plate for the front deflector (1.20 x 0.70 mts) . Very few advances, a lot of rain here prevents me from working in the external......

I would have to comment in the salon section on climate change, but I can not understand the point of view of those who refer articles published by Forbes magazine ... so I better close my mouth....

 

[academia50]

Finally we have good weather here , the panel of a box is already glued.
This baffle panel is very heavy, I tremble at the thought of the total weight of the finished box, because I plan to coat the interior with asphalt membrane, in addition we have to add the reinforcements, the speakers, screws, etc ...
I think I'll be close to 100 kilos per box .....

Tip: Properly level the plane of the plates, once dry, they will be curved, to avoid that you can see that I put extra weights at the ends of the work table ....


I reiterate my request to some administrator of the forum, could you please amend the title of the thread:
It should say 150 liters instead of 300 !
Very thanks !

 

[Turbowatch2]

Did you put any bracing into the boxes? If not they will act as a membrane. Doubling up on the panel does not help very much. Understand the picture, if the driver cone moves in, the panels move out and vice versa. This gives a "muddy" bass, not as low in frequency as simulated. The larger the cabinet the worse it gets. This explains why some are satisfied with a driver installation, while others complain. If the cabinet wobbles, the best driver will not sound good.

The "bass boost" on an amplifier does not have the same effect as a condenser in line with the driver! I know many dislike the concept from the theoretical side, but only until they try it.

 

[academia50]

Did you put any bracing into the boxes ?

Yes, it is planned. I will place two reinforcements similar to these, at that moment I was exploring making a sono tube, which was ruled out due to the difficulty of getting an appropriate cylinder. Until you explore it iron!

See post six :

Materials for cylindrical subwofers ?

The "bass boost" on an amplifier does not have the same effect as a condenser in line with the driver! I know many dislike the concept from the theoretical side, but only until they try it.

The bass boot is switchable and reinforces 6 db to 35 hertz, (I do not use it, obviously, i I search flat response for music) but the subsonic filter is fixed, (-12 DB / Oct / 20 hertz) which is an obstacle, It is implemented by the manufacturer Dayton for BR cabinets.
I thought to write to them to ask for the circuit (Dayton SPA250) and try to cancel it for use in a sealed cabinet.

Dayton Audio SPA250 250W Subwoofer Plate Amplifier

The filter capacitor ........
I did not hace answer of the Freddi forista, the graphics look very nice, but the reading of some articles made me discard it.
You can read them right there.



See post ten, eleven and twelve :

Eminence Delta Pro 18 A in prism sealed 300 liters

(in later post of that same thread Freddi repeats the graphic with and without a condenser but for a 150 liter cabinet.)

I am also willing to experiment with it, it is quite simple to place the capacitor in series in the terminal ( binding post )

Thank you for your kind response, your opinions are very welcome...



Merry Christmas


Rolo

 

[Zero D]

@ academia50

I reiterate my request to some administrator of the forum, could you please amend the title of the thread:
It should say 150 liters instead of 300 !
Very thanks !

I've pinged the mods to do that for you

 

[Mooly]

I reiterate my request to some administrator of the forum, could you please amend the title of the thread:
It should say 150 liters instead of 300 !
Very thanks !

Done

(If you want anything changing then use the report post option, that way we are sure to see it)