10F/8424 & RS225-8 FAST / WAW Ref Monitor

[nas3000]

Hi xrk and others,


There is one pretty forgotten driver in Dayton range: RS75 4 and 8 Ohm versions.

Did anyone tried it with this speaker? There is just one post I find on diyaudio.com
Aesthetically it looks like a small brother to big RS225 woofer, price is affordable, sound signature should be similar. Looks like built very well. The only negative thing i see from photos that could be a problem - big magnet which is pretty hard to fit to small cutouts.



Literally no info about that driver. What are your predictions?

 

[xrk971]

No I have not tried that one. Any decent 8ohm driver can work with adjustment of resistors to match sensitivity with woofer.

 

[moutik2]

Hello, all the wood is cut and partially glued. i receive the cone and loudspeakers and it's going to go quickly now i hope!

can i fill up the hole of the in the labyrinth with dry sand?
bye !!

 

[xrk971]

Yes, sand or other heavy filler. Make sure it doesn’t rattle of using rocks etc. or leave it empty. Make sure it is airtight though on the seams and joints.

 

[TubaV]

Will the Fostex ff85wk be a good fit along with the RS225? I already have these. What mods to the crossover are needed? Thanks.

 

[xrk971]

Yes, those will work great. Just adjust R1 and R2 to get the relative levels balanced. FF85wk is 86.5dB sensitive. This is very close to 10F/8424 so it might be a drop in. There may be some adjustment needed on the notch filter (R and C between terminals) but that requires a microphone and playing with a Xsim. Try it as is and it may work fine.

 

[TubaV]

How much do the big TL cabinets weigh each? Bad back and triple hernia surgery here affecting how big a DIY project I undertake. Thanks.

 

[zman01]

TubaV,

I put my ones on the scale - these are built with 3/4" ply.

The cabinet with the drivers installed weighed around 45 lbs. There might some inaccuracy due to the large size of the speaker cabinet and how well I managed to place it on my bathroom weighing scale; but with the drivers and XO weighing approx 7-8 lbs, it should be pretty close.

 

[xrk971]

That sounds about right - I would have guessed 45 to 50lbs. One can use the front facing vent as a convenient hand grip to pick it up and stabilize the back wall with other hand. This avoids having to stoop down to the ground to get your hand under it. I was able to carrry it up and down stairs by myself without too much trouble.

 

[TubaV]

Are the stand mounted bookshelfs pictured at the beginning of this thread a good alternative? Dimensions on those? Thanks.

 

[xrk971]

From the first paragraph of Post #1:

The design ended up as a 24 liter volume for the woofer and a 1.1 liter 3-sided pyramid Dagger for the 10F/8424. The important external dimensions are: 10in wide baffle and 24 liter internal volume (sealed). You can make the height and depth to suit your individual case, but it will need to be deep enough to house the Dagger. The internal dimensions I settled on were 8in wide x 12in deep x 16in tall. The short sealed TL is made of three 6in wide x 12.5in long triangles. Construction will use 1in thick pink XPS foam and regular foam core for the short TL. The front baffle will also use a thin sub-floor plywood in order to provide adequate support for the heavy 8in driver.

And post 1424:

The cabinet is about 10in wide x 13.5in deep x 18.5in tall. This is my Baltic birch ply 3/4in thick.

The sealed box sounds excellent - was my main speaker for years until I made the TL. The sealed box goes down to 50Hz (-3dB) whereas the TL goes to 30Hz.

 

[moutik2]

hi, i've working on the loudspeaker this week-end and i hope everything is going well. I use 18mm mdf, glue the cone and prepare the place for the crossover and put the speakon connector. Bye!! and thanks again.

 

[zman01]

Looking good moutik2.

 

[moutik2]

Thank you Zman01!

 

[xrk971]

Nice work, Moutik!
Looking forward to seeing your completed build soon.

 

[ttan98]

Nice work, Moutik!
Looking forward to seeing your completed build soon.

Xrk971,

I like to ask a question the main purpose of the "orange" funnel-like housing used to protect the Full ranger? I think you are using a similar object too. Thks.

 

[zman01]

ttan98,

You are correct, the "orange funnel" (actually a sports cone) protects the wide-band (full-range) driver and acts as a separate cabinet for the driver. That way the woofer cannot inter-modulate the wide-band driver.

Also the tapering shape helps suck the driver back-wave, and the non-parallel surfaces reduce reflections coming back to the driver cone.

 

[ttan98]

ttan98,

You are correct, the "orange funnel" (actually a sports cone) protects the wide-band (full-range) driver and acts as a separate cabinet for the driver. That way the woofer cannot inter-modulate the wide-band driver.

Also the tapering shape helps suck the driver back-wave, and the non-parallel surfaces reduce reflections coming back to the driver cone.

I suspect so thanks for a good explanation. The orange funnel is made from plastic does it need to have a certain dimension?

 

[zman01]

Yes, the funnel / sports cone is made from plastic.

Approx height of the cone is 225 mm and the base is 145 mm x 145 mm.

Something similar to this:

(23cm - 6 Pack, Multicolor Cones) - Juvale Plastic Sports Cones for Physical Education and Sports Training, 14cm x 23cm , Orange and Multicolor: Amazon.com.au: Sports, Fitness & Outdoors

I cut of ~38 mm from the narrow end of the cone, so that it would fit in the first section. A pic is attached.

 

[xrk971]

You can also make a DIY 5-side pyramid. The so called “Dagger” rear chamber. The 5 sides is asymmetric and does not support any standard plane wall resonance mode. The cone is not bad either and easier to do. Volume is not critical. Needs to be more than 1.5L.