Bass reflex box for Beyma 8ag/n

[bubuxxl]

Hi all!

I was wondering if someone could help me sorting some solution for a pair of beymas I have.
I tried the "viech",and although they´re not finished,they really lack bass,but i´m guessing that has got to do more with my living room...
anyway,the viech´s are too big and
i would like to know what other designs I could try out with these modest but
delightful drivers!

thanks everybody

[Scottmoose]

Delightful they may be (can't comment, never heard a pair) but being very weakly damped they're not going to be particularly happy / useful in a small box. Max-flat vented by Keele is about 254 litres for e.g. You might be better off using them on a small OB & crossing to a box bass unit if you need compact.

[GM]

Yeah, it really wants a huge BLH......... Anyway, a quick peek shows that a minimal ripple sealed alignment is about the best size Vs LF gain BW overall, so ~5 ft^3 tuned to ~40 Hz for a ~40 Hz F3 and the 6" dia. x 5" long vent stuffed to suit to damp Fb peaking, though peak SPL will be modest below Fs. Hopefully they can be shoved into corners to help a bit with that.

GM

[bubuxxl]

what a shame...I guess I´ll have to stick with those huge horns after all...
I better have a look at some threads then,about finishing the boxes!
about cheap full range drivers,is there anything new that´s been raved lately?
Here in Portugal,unfortunately,Fostex(and other known brands) only online and from other countrys,which turns the price into something not so appealing...

[GM]

That, or do as Scott suggested, a OB/bass bin system XO'd around 80 Hz.

The various Markaudio designs including the CSS variants have been getting a lot of favorable press lately. Their low Vas, ergo low efficiency to presumably primarily keep the cab small appears to be their major downside. Using two and rolling one off sims OK WRT acceptable vent length without having to go ~aperiodic, though I've read some folks are fine with both running full-range at longer listening distances.

Anyway, what brands can you get locally and/or what countries can you get drivers from the cheapest once shipping and I assume VAT is factored in? I figured that at least Visaton and/or Monacor would be available to you at ~reasonable cost.

GM

[chris661]

I've been raving for some time about the Visaton FRS8M. They're made in mainland Europe, so you should be able to get hold of some. They're good at the price, but not on the same level as Fostex etc.

GM beat me to it...

[bubuxxl]

thanks again for all your posts!
Unfortunately,there isn´t much to choose from driver wise here in Portugal...
The easiest to find though,is the Visaton frs8,but it doesn´t get that cheap either...
The speakers and remaining parts for the project would set me back about 90 euros,and for me that value is a bit steep since it has low spl,which is a major drawback,since I can get some nice Wharfedale Diamonds for that amount,and this would be much more versatile.
The beymas are much more interesting,they can withstand a bigger load,they´re more efficient and can play well with a variety of low budget amps.
It is a shame that despite their large size,they fail big time regarding bass reproduction,sounds really light...
About OB´s with this driver,the addition of a woofer right now would cost me a lot more,and at this moment I´m a bit strapped for cash unfortunately.Maybe someday with a nice amp...

By the way,how could I get the best out of my "viechs" regarding room placement?
How much toe in,near the corners?...

Thanks again for your replies!

[Scottmoose]

The Beyma is nominally underdamped, and has quite a high resonant frequency & Vas. Couple that with a relatively small horn for the driver, and lightish LF is inevitable I'm afraid. Re positioning, basically, it's going to be a case of 'suck it and see.' Every room is different, every system is different. Ten minutes of playing with their positions is going to tell you more than any of us ever could, other than noting you may pick up some more LF gain if you can ram them into corners.

FRS8Ms not coming cheap? You must be really struggling with suppliers; I paid £9 apiece for mine a couple of years back & you certainly wouldn't want to be spending much more on them.

[bubuxxl]

Well...I gave them a go in a bass reflex enclosure and the results are excelent,regarding bass!
I tried the beymas in an enclosure using 10mm mdf,just for testing purposes,without much planning (damping or bracing for instance) and they sound marvelous!
Bass goes way deeper than in the viechs and the sound has a warmer character,without loosing any of it´s best qualities!I may try to build a higher quality enclosure and definitely put aside the giant viechs!
Lovely defined bass!
15 euros for the mdf,48 euros for the drivers,2 euros for clip on terminals,some dracalon
(don´t know if that´s the way it´s spelled) and glue...cheap as chips!

[GM]

Good to know! What are the design details? Don't know what 'dracalon' refers to.

GM