diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Full Range (http://www.diyaudio.com/forums/full-range/)
-   -   Finally built a prototype, dual FRS8 in pentagon-TL (http://www.diyaudio.com/forums/full-range/184519-finally-built-prototype-dual-frs8-pentagon-tl.html)

▀art West-VL. 6th March 2011 09:08 AM

Finally built a prototype, dual FRS8 in pentagon-TL
 
It took a very long time to get to this enclosure but I'm glad it's getting back on track now, it floated around in my head for years!

Today I have put in the the two drivers, FRS8 - 8 Ohm and hooked them up in parallel, to a channel of my amplifier. They sound surprisingly good.

If anyone is curious enough to put it in a simulation program, I would be very happy and interested. Let me know what numbers you need.

The thought of a pentagon was preceded by a triangle but the problem here is, that the volume of the TL is reduced by half compared to a rectangular box while a pentagon is larger than a rectangle. I didn't want to use a rectangle because of the parallel sides that support standing waves and it looks nice!
The length is the standard width of a sheet of plywood; 1m22cm.
Pure theoretical this would give a frequency resonance of 70Hz, way lower than the drivers can produce properly.

So, being a prototype and awaiting the build of four definitive boxes for home theatre, all input is greatly appreciated.
At the moment I do not have much time on my hands, working overtime and living alone, only lets me play around half a day at weekends.

My original thread about this:
http://www.diyaudio.com/forums/full-...me-cinema.html
I had some questions in another thread, if anyone would like to have a look, they are related to this project too:
http://www.diyaudio.com/forums/full-...ml#post2474736

Thanks for watching!
http://i53.tinypic.com/kluvd.jpg

norman bates 6th March 2011 01:35 PM

there were the pentachord speakers (2 way crossing to sub and a tall colum also crossing to a sub). Both used dual 50mm bandors per speaker I think.

Ideally, you'd want the line to resonate lower than the drivers to add bass down there.

I have a love/hate relationship with my dual 4" tang bands (see my avatar).
But it's doing better with 8" sealed run with it now.

Good luck with playing with them !!!!!!!!!!!!

Norman

▀art West-VL. 7th March 2011 06:22 PM

Hello Norman,

It seems to me you've changed your avatar since you posted that reply. :)

Where can I find more about those speakers?

I hope to find some time this week to play around, thanks!

planet10 7th March 2011 08:28 PM

Bart,

I love the shape :)

Quote:

:confused:How do I put an expanding thumbnail-picture to my posts?!?
You need to use [img] not [image] tags

dave

norman bates 7th March 2011 08:44 PM

http://i959.photobucket.com/albums/a...ates/001-1.jpg

you may need a bit more cone area.



Norman

Squeak 7th March 2011 10:11 PM

Why not just use a tube, for the non prototype? It would save you a lot of cutting and assemblage problems, You'd just need a single short angle plate to mount the drivers on.

▀art West-VL. 8th March 2011 06:49 PM

Dave, thanks for the complement.

Norman, This TL needs to have three brothers and a center speaker, total of ten little drivers. But it's my goal to give them a break beneath 80Hz and cross to a decent sub. So this is mostly a HT setup but I know they will sound good for some occasional or background music too, as one box already sounded surprisingly good and nice without any filtering.

Squeak, I can't find a tube nice enough and/or rigid enough to use for this project. The finish would not be so nice because it can only be painted. A wooden box can just be varnished and show the grain. Also a pentagon is a total different thing to look at then a regular tube.
But you're right of course, it would be the same result with the only difficulty, being the baffle plates.

Am I correct to conclude that these five boxes can deliver 102dB if they're fed 100W in total? (efficiency is 82dB/W/m)
That would be 108dB at 300W, right?
These drivers can handle 30W nominal and 50W peak(music).
How much RMS would this be? I guess 15W.
Just trying to put a number on those maximum dB. For HT I think I can go with the music power handling of 50W, so this means they will be more then sufficient for HT I reckon.
A lot of people tell me 82dB/W/m is not enough for HT... I think it Ýs! ;)

Squeak 9th March 2011 06:53 AM

I just think it's going to be a pain in the butt to get the joints to look good unless you are an excellent woodworker. If you absolutely want to have the wood look you could veneer the tube with very thin slices, otherwise there is plenty of options with wallpaper, paint, or fabric.

planet10 9th March 2011 07:41 AM

Quote:

Originally Posted by Squeak (Post 2497215)
unless you are an excellent woodworker

Lots of excellent woodworkers here.

And you don't get good without practise. Nice to see something other than another monkey coffin.

dave

AEIOU 9th March 2011 07:44 AM

3 Attachment(s)
Quote:

Originally Posted by Squeak (Post 2497215)
I just think it's going to be a pain in the butt to get the joints to look good unless you are an excellent woodworker. If you absolutely want to have the wood look you could veneer the tube with very thin slices, otherwise there is plenty of options with wallpaper, paint, or fabric.

MDF is easy to shape, fill and sand smooth, easier than plywood.


All times are GMT. The time now is 11:17 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ę1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2