Fast, fun, Inexpensive OB project

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John has made a few tweaks to the crossover, that's all. The baffle has not changed.
Yes, the version with the 3806 is the best so far. The only downside is that's it a very expensive tweeter.
Speakers are room dependent, so any crossover ought to be tweaked for the room, anyway.

I think John will chime in soon. Thanks Jerome for the links to the drivers.
 
Here comes an image of my "test baffle", as requested:)
 

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Manzanita tweeter comments

Thanks to all who pitched in to provide the requested info for schro20.

Would like to make a few comments concerning the differences between the original Manzanita using the Seas TDFC and the current "upgraded" version that uses the larger, way more expensive Scan Speaker D3806.

Baffle size. My latest version is a bit wider than the original. This lowers the F = a touch and seems to provide just a little more weight to the bass, and better overall tonal balance. Overall width is currently 16.625". 1.25" of this is provided by the thickness of the wings. So the net baffle plate is 15.375" wide. Overall height is 27.5" These dimensions are not critical, +/- .5" is close enough. For best performance, the tweeter(s) should be flush with the baffle surface, however they will still work well if you do not have a way to do this. The woofer requires nothing other than an appropriate diameter cut out. Another plus for the Peerless. BTW, I added one more inch of wing depth in my latest version. Any more wing depth, and you really start to produce cavity resonance issues. Very audible.

The original design using the TDFC, in keeping with the "keep it simple and costs to an absolute minimum" goals, required a couple of significant compromises. The TDFC version:

1) Is intended for low to moderate power inputs, say 30 WPC program. This limits usable spl's to around 85-91 db continuous, 94-96 db peak. Any louder, and the TDFC runs out of xmax.

2) With the TDFC the presentation will be laid back, this is because of a broad, but shallow response droop of 2-3 db through the crossover region, from around 1.2K to 2.5K. A concession to the limited lower mid range output abilities of the TDFC. However, this yields a very forgiving, low fatigue presentation.

3) The TDFC offers excellent "air". The Peerless - TDFC combo images better than most box format designs.

4) And, the TDFC is such a bargain. One of the best "bang for the buck" tweeters available that can play down in the 1,350 - 2,000 Hz area.

The Scan Speak D3806:

1) Can play flat to 1 Khz, yet has surprising "air" and imaging abilities. No droop needed through the crossover region. However, "Droop" if desired, can be engineered into the crossover if one prefers to have it. This gets to the main strength of the D3806, it allows flexibility in the design the TDFC can not.

2) A more dynamic presentation. Better overall power response.

3) Greater power handling. You can push the system to the point you run out of Woofer. 100 wpc program is now the upper limit with most music. This means you can play in the mid 90's with peaks over 100 db, in other words, live levels for most music.

4) The down side of the 3806 comes at a price, literally. Wholesale it's about $120 USD, and consumer it's around $195 USD last time I checked with Madisound. The cost of a single D3806 exceeds the cost of the entire original Manzanita. And it should be used with a resonance trap, which adds cost and complexity.

5) Better harmonic integration with the Peerless woofer. The D3806 low end sonic signature mates well with the Peerless upper mid range signature. The two playing together can disappear. Many who listened to the D3806 version at LSAF made this comment. A couple of visitors to my room at LSAF stated the Manzanita was the ONLY speaker there that could "disappear".
 
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Thanks John, that clears up a lot of things. :up:

The ideal here would be to find a 2~3" full range driver for tweeter duty. Something that will play as low or lower than the 3806 and still stay as clean. Not easy, at least the clean part. The D3806 is a wonderful driver, but ouch! the price.
 
One could try the SB25STC :
SB Acoustics SB25STC-C000-4

Despite its "only" 19mm in diameter, this one has almost double the linear displacement volume compared to the SB29 (though not as much as the D3806) and is really cheap too.
In addition it goes low and has an impressive on-axis high frequency extension.

Michael

Thanks John, that clears up a lot of things. :up:
The D3806 is a wonderful driver, but ouch! the price.
 
One could try the SB25STC :
SB Acoustics SB25STC-C000-4

Despite its "only" 19mm in diameter, this one has almost double the linear displacement volume compared to the SB29 (though not as much as the D3806) and is really cheap too.
In addition it goes low and has an impressive on-axis high frequency extension.

Michael

..it's .6mm, the Hiquphon line is .9mm. ;)
 
..more than double, but still quite a bit less than the Scan Speak (and with wider dispersion in the two top octaves).

There are also the tweeters from fostex that were designed specifically for first order electrical use (FT28D and FT48D). No xmax listing though.

Ahh -on quick research I found Hiquaphons selling for EUR 200 - 250,- in Europe,
- LSV Dieter Achenbach

whereas the SB25STC sells for < $ 30.- a piece at Madisound.

For this low price of the SB25STC one may even consider a stacked tweeter arrangement in putting them in series - bypassing one with a capacitor to let them work together only in the XO region and slightly above.

Michael
 
As per Pano's reply, your room size is fine. One important issue is distance from the front of the baffle to the rear wall. 1 meter to 1.2 meters is typical. This usually provides the best tonal balance and image - sound stage. Naturally, every room has it's own sonic qualities, and some speaker placement experimentation is required. Moderate toe in can also help with image depth and width. Please let us know what ends up working best for you.