Martello enclosure for FR88EX

[bknabe]

Winisd gives me the strange results in my earlier
post

 

[xrk971]

Your TS params are off try these: HiWave HIBM65C20F-8 3-1/2" BMR Full-Range Speaker 8 Ohm | 297-2156

I used 15 L vol set freq at 45 Hz and get 2.54 cm dix x 3.13 cm long vent

 

[steveww]

I do not know what he used for the BSC. Post on the GR Research forum and maybe he will share the details.

The answer is no he will not share the details but will sell you the components and circuit diagram. Looks like that forum is tied to a commercial organisation.

 

[bknabe]

Thanks. The T/S #s I had came from the HiWave website, but must be off somehow. The PE #s provide more reasonable results using WinIsd, and the MH-audio website.

 

[bknabe]

Finished Martellos

Finally got them finished. They sound pretty good to me. On to my next project.
Cheers,
Bob

 

[Bigun]

Wow - these look really good, how did you get that piano finish ?

 

[xrk971]

Yes, they do look very nice! Great piano black gloss finish. I can only imagine how much elbow grease that took to sand in between coats

 

[bknabe]

Thanks. I put several coats of black spray paint then a few of clear gloss then wet sanded with 1200 - 2000 grit then car polish to shine them up. I was really struggling to get a good finish until I ran across the idea to wet sand from a YouTube video on spray painting auto body parts.

 

[malibujeff]

Finally got them finished. They sound pretty good to me. On to my next project.
Cheers,
Bob

Great looking speakers!

 

[bknabe]

Jeff - Thanks!

 

[bknabe]

Made a second pair! Sound just as good as the first. I have the wood already cut for a third set from the original 4x8 sheet of plywood - no fourth set as the first attempts at cutting weren't quite right!. This diy speaker stuff can become a bit addictive!
Bob

 

[Bigun]

Nice work (again)

 

[larryldspkr]

bknabe where do you get your grill fasteners? I like the look of them!

Larry

 

[bknabe]

Larry:
parts-express.com

An externally hosted image should be here but it was not working when we last tested it.

Pressfit Speaker Grill Guides 8 Pair
Part # 260-366
$1.95
Bob

 

[larryldspkr]

Thanks Bob, I'm going to order up some of those!

Larry

 

[mstang1988]

Any thoughts on how an FR89EX would perform in this design?

 

[FlipInParis]

Hi there,

I'm Philippe, from Paris, France. This is my first post on diyAudio. I'm a absolute beginner in speaker design (I know Qts, Vb, F3, etc. exist but I haven't played with them yet)

I have a few questions about these nice Martellos I'm planning to build (ok, nothing critical when building computer speakers, but I'm rather curious...).

* Why is the port spacer triangle shaped ? Is there some math behind that ? (I did not see any triangle in Dave's "xOnken" designs.)

* Why has the brace such a large "solid" surface (almost creating 2 internal volumes) ? Wouldn't two simple sticks crossing each other rigid enough ?

* Is there a newer version than 0.21b ? Any suggested improvements?

Thanks in advance !

 

[Bigun]

I'm Philippe, from Paris, France. This is my first post on diyAudio.

Welcome Philippe !

I was in Paris last summer, Latin Quarter, a wonderful beautiful place !

Why is the port spacer triangle shaped ? Is there some math behind that ? (I did not see any triangle in Dave's "xOnken" designs.)

My thinking was to avoid pipe resonance associated with Onken ports (I admit I have seen no evidence of such things) and to have a way to better couple the port to the room by having a flared/horn-shaped port. I got this idea from Henkjan: see post 27 here: http://www.diyaudio.com/forums/full...2010-compact-horn-br-alpair6.html#post2320259

Why has the brace such a large "solid" surface (almost creating 2 internal volumes) ? Wouldn't two simple sticks crossing each other rigid enough ?

Yes, it would be better not to have such a solid surface. I suggest you follow your idea and make an improved solution!

Is there a newer version than 0.21b ? Any suggested improvements?

I did not further develop this design, it seems to work just fine. I would suggest using a proper terminal cup for the connections instead of using binding posts - that way you can repair easily if the wire becomes disconnected inside.

I did develop a Martello-2 speaker, larger size and not suitable for desktop: http://www.diyaudio.com/forums/full-range/220047-martello-2-mini-tower-single-2-x-4-a.html

 

[FlipInParis]

Henkjan's project is really interesting... But let's start with Martello and its tiny horn

Thank you Bigun !

 

[MikeRustWales]

Hello Bugun and everyone else who has contributed to this thread!

As a newcomer to building speakers, I am looking to build some mini speakers that I can easily transport each week between home and a flat from which I work during the week - these look ideal!

A few questions:

Are the FR88EX still considered to be the ideal driver for the cabinet design?
Given that the first post was back in 2010, are there any updates, latest thought ideas by way of improvements?

I am reading the whole thread carefully and have yet to absorb everything!

Lastly, as a newcomer to this forum, and with the thought I am looking to build small/mini speakers, are there other resources on the forum I should take a look at?

I have pretty good building skills and a well equipped "man cave" and not worried about the actual build!

Thanks to everyone for any replies and help!

Mike