Full Range ASsisTed with woofer: please re-direct me

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Sorry, i am new here (ie read a lot here, but never posted). Kindly point me towards an existing thread if there is.

I am considering to build a 'Full Range ASsisTed w woofer' loudspeaker.

Sofar i have looked at Visaton B200 and Fostex Fe166 for anything upwards from 200-500Hz.
I would appreciate inputs on matching it with a 8" or 12" woofer and any guidance on X-filter, if needed at all.

I like transparent sound: not veiled nor boomy with nicely textured sound.
I am using Luxman amps from the 70s.

My living room doesnt support 'open baffle,' but the build should not be overly complicated (no backloaded horns etc).

Any guidance/advice? Many thanks!!
 
Hi.
You should do a search for terms like "waw" or "fast" and you will have lots to read about those designs.
10F/8424 & RS225-8 FAST / WAW Ref Monitor
This is just one example but would probably fit as it is sealed design. I'm sure though there exist other versions.
Instead of the B200 you can look at its smaller brothers B100&B80 that I like much better.
I prefer a mark audio alpair A7.3 over all those visatons and fostex fe-167e. They are much loved drivers around here so you can search for designs that include them also.

How big can those speakers be? Any preference towards bookshelf Vs floorstanding, footprint?
 
There are many posibilities, some are documented, others not. Look maybe at Planet10's Mark Audio Alpair 7 & 12 MTM build, but the most documented is the build of xrk971 with the scanspeak 10F and the Dayton RS225 found here: 10F/8424 & RS225-8 FAST / WAW Ref Monitor

I did build one with a Mark Audio 10.3M FR and a Scanspeak 26W/8534G00 woofer, but the documentation of it is still not finished (i depend on others for the cad drawings).

On your plans, i would not use both in a Waw, the Visaton B200 is very high qts and mainly ment for OB. The Fostex Fe166 is more ment for backloaded horns. I would also take a smaller FR now, more a 3 to 5" with good response. My favorites are the Mark Audio's, but there is more of course. The woofer must go deep and still be able to reach to 600Hz, as you want to crossover in the 150 to 300Hz region with a low order crossover, so don't take a very big one (maybe a 8 or 10") with enough xmax to go loud and low and a flat response to at least 600hz (before the break up comes)
 
Some drivers

Some time ago I was pondering about building an aperiodic WAW and I had been searching for interesting low QTS speaker drivers, both wide-range and woofer. Because there seemed to be many candidates, I created a simple table.

According to Aperiodic Cookbook QTS less than .45 means that a speaker driver is probably suitable for aperiodic speaker designs. But, if you are not interested about aperiodic, this table may not be very useful for you.
 

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frugal-phile™
Joined 2001
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To add onto what joesd & waxx said (i am slowly doing the CAD, his boxes are fairly simple).

WAW is an area of hifi that is just starting to be heavily explored. You will find a lot of material.

There are a wide range of options.

For now, ignoring the good suggestion of a smaller midTweeter, i have experience with both the drivers you mentioned. Both attempt to get top while stil being able to do bass. But they are both compromised as you go up in frequency. There are some fairly easy tweaks to improve their performance.

Of the my preference would be the B200, but IMO really, really needs phase plugs which deal with the significant HF rise and the laser beam extreme top. Its high Q means that it is hard to put them in a box and not have too much bass bump. As a midTweeter an open-backed heavily damped boffle style box. Once tweaked the real sensitivity turns out to be 89-90 dB.

The FE166 really does need a horn to do any bass, and the top end has some ringinf issues. There are a couple tricks to help ameriolate those issues. They can also use phase plugs (as has every whizzer cone driver i have tried). There are 2 approaches to using teh FE166 as a midTweeter. First in a simple enclosure and cross above the mass corner (about 250-300 Hz IIRC) or mount in an appropriately sized sealed box and use the natural second order roll-off as the low pass filter. I saw this first suggested by Doc Bottlehead. It has the advantage of measing with woofers using plate amplifiers.

Due to the low XO point passive XOs can be an issue, using big parts they can get pricey and one has to deal with the impedance peaks at bas resonance.

Bi-amping makes things easier, there are a growing number of active XOs and one can always design the box with teh aim of living within the constraints of a PLLXO (really inexpesnive and no electronic haze, being passive).

There are tons of good midbasses and dedicated woofers (in the case of the sealed FE166) to choose from. Often sourcing and geographic limitations will help guide that choice. And lots of approaches to loading the bass driver.

Back to the samller midTweeter. A really solid idea. While the drivers you have can be made to work well, they will likely not give the same level of satisfaction as a smaller FR that does the midTop better.

My faves have been Alpair 7.3, A5.2/3 and FF85wk. Waxx uses the A7.3s larger brother the A10.3, but their are many suitablemidTweeters. Some really cheap, like the MA CHN-50 and the 2 small Visatons mentioned (purportedly good but i have not heard them). How big the midTweeter is depends on how loud you need to play and how big your room is (larger tends to allow for louder).

A12pw-MTM-comp.jpg


Ellipsa-1st-veneered.jpg


dave
 
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