FR driver and EBP

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Hi all,
Can somebody point me to a 5'' full range driver well suited for a sealed box enclosure? It seems that for sealed enclosures a EBP <90 is recommended. What's the reasoning behind this?

For example the Fostex FF125WK has a EBP of 144. What are the drawbacks if I mount it in a closed box (B2) in comparison to a similar driver with a lower EBP? Is it just about bass extension?

FWIW, for this project i don't care about bass extension at all, the system will be complemented with a sub.
Thanks in advance!
 
Good question as I'm going to be using a fostex in a sealed enclosure soon as well. Bass extention also doesn't matter to me.

I'm not much of a cab designer, so hopefully you and I get some good feedback on this. For now though, my understanding is that a driver not meant for a sealed enclosure is just fine in a sealed enclosure. The only problems is lack of bass extension, and that it will require a large cab volume to work effectively. There are some other nuances as well, such as excursion power handling will be better in a vented cab (above tuning).
 
frugal-phile™
Joined 2001
Paid Member
If you are using the FR as a mid-tweeter (ie don't care abou the bass), then one can readily take advantage of a sealed or aperiodic enclosure.

You want to grab a simulator and plug in the driver parameters and see what kind of volume is needed to get a nice smooth roll-off (typically Q = 0.5>0.707), That gives you an idea whether the XO can use the natural rolloff or goes lower than you need (often the case).

Some example sealed sims attached.

dave
 

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Thanks for the answer, planet.
I've entered the driver into WinISD and it calculated a closed box of about 4 litres. (fb=118 Hz, Butterworth response) Quite smaller than I thought :)
Will go ahead!
Any recommendation for a suitable sub design? I'd like something compact for a home cinema setup, maybe around 8 in. Something that fills up a little where the FR gives up...
Cheers
 
Thanks for the answer, planet.
I've entered the driver into WinISD and it calculated a closed box of about 4 litres. (fb=118 Hz, Butterworth response) Quite smaller than I thought :)
Will go ahead!
Any recommendation for a suitable sub design? I'd like something compact for a home cinema setup, maybe around 8 in. Something that fills up a little where the FR gives up...
Cheers


I'd suggest at least 2 woofers, even as small as 6". "HT" use generally implies a surround receiver/processor with full bass management and "self-powered" woofers.

I personally consider outboard (rather than plate) amps the better choice here, and there are many candidates for suitable 6-8" woofers - Vifa, Peerless, SEAS, SilverFlute, Dayton, the list goes on - look for something that's good to at least 2 or 3 full octaves above your final XO point.

Depending on your geographical location, the specific recommendations will vary, but for this application we've used the CSS SDX7 - they work well in boxes as small as less than 1 ft^3, and we have a bunch of them.
 
frugal-phile™
Joined 2001
Paid Member
First thing, you don't want to think sub, you want to think woofer.... to integrate well with a FR used this high the woofer needs decent HF response (i use 1k as a nominal base-line). And you need one per side.

We use the SDX7 alot for situations like this, but now that it is scarce we are looking at others. The Mark Audio/CSS EL166 proved very nice but it is scarce now too (if Mark can be convinced we may see another batch of these -- a killer driver, even if you don't consider its aggressive pricing.

More available in Europe is the similar size Wavecor. A number of Peerless look interesting. I suspect that there are Visaton & Monacor (which we don't see over here) that are good.

With the predominance of 2-way cone/dome speakers, there are lots of good mid-woofers which get better when you don't use them up to where they start getting rough

dave
 
frugal-phile™
Joined 2001
Paid Member
.... CSS SDX7 - they work well in boxes as small as less than 1 ft^3, and we have a bunch of them.

7-21 liters, we usually try for12-17 liter, a pair fit into a cubic foot. Henjan may have some. They aren't inexpensive, and they do need a simple to do mod to clean then up (besides reducing noise thru-out their bandwidth, it smooths up the top octave).

dave
 
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