SB ACOUSTICS TW29R & SB23NRXS4

[Joachim Gerhard]

Thanks, Jeff Bagbys Kairos should also work well.
This kind of low order crossovers need extended drivers that do not have too much resonances in the rolloff.

 

[chefsinc]

S7,

For now they are the best I can get them but that's not to say they won't get better after some constant massaging🙂 .
Itchy fingers never stop. The floor Sanders are now sounding the best they have since I built them in 2006.Constant trial and error adjustments , plus a bloody great tweeter have them now at their best I have heard from them. I have been a bit radical with my designs but the ride has been worth the enjoyment I have gotten from it all.

Ahh the fun and challenge of DIY speakers has been a trip, and hopefully will continue to be so.
Cheers mate I hope to see you tame those MA's one day with really freaky out of the box solution..🙂 🙂 🙂

 

[chefsinc]

S7,

I have a day at home this week where I am going to build some of your parallel crossover suggestions just for the fun of it and do some testing. Need to pick up a few more supplies first.

After that I am away on Holidays in Malaysia for a week so will give me a chance to come back with no memory of what they sounded like. Should be great to hear them again after 7 days.

 

[system7]

What I have found about your filter, and it is one of the best series filters I have seen, is that it works best on a flat baffle, not time aligned. This is unusual. I find it hard to believe you are doing this intuitively, but hey ho. 🙂

Here's the wise words of Mr. Lynn Olson:

When working with rigid-cone drivers, there are some hard choices to make: if you lower the crossover frequency to minimize driver coloration, tweeter IM distortion skyrockets, resulting in raspy, distorted high frequencies at mid-to-high listening levels.

If you raise the crossover frequency to improve the sound of the tweeter, the rigid-driver breakup creeps in, resulting in a forward, aggressive sound at moderate listening levels, and complete breakup at high levels. (Unlike paper cones, Kevlar, metal, and carbon fibers do not go into gradual breakup.)

With the drivers we have today, the best all-around compromise is a 2nd, 3rd, or 4th-order (12-24dB/Oct.) crossover with an additional NOTCH filter tuned to remove the most significant HF resonance of the midbass driver.

See, you're always playing between the tweeter Fs resonance and the first significant breakup node of the woofer. I look at a woofer like this SEAS ER18RNX with glee:
H1456-08 ER18RNX
Notch around 4.8kHz and job done really. 😎

I think that 8" SB woofer is MUCH harder, but you've done OK with it, skipping the notch.

Here's your filter with an easier 6" Visaton W170S unit, and my parallel version. FWIW, the expensive Visaton KE25SC is a tweeter designed for low crossover, The G20SC is more conventional. Phase is exemplary between 1kHz and 10kHz with both setups. Truthfully, I can't see much in it between the two filters.

Oh, sorry. Long post. 🙂

 

[sootboots]

I have Chef's crossover and the drivers running in a repurposed large Advent cabinet and it sounds great! Before I build a proper cab are there any changes anyone would propose to the cabinet size or crossover design?

Thanks!
John

 

[chefsinc]

Thanks SOOTBOOTS,

I would and will eventually put them in a 40 to 50 litre stand mount. but I am enjoying the sound of them as they are son no great rush to build a new box.

I have just moved back to Australia after 13 years in Asia living in Hotel rooms, so once settled and all my belongings arrive back in OZ then I can start to really take this Hobby seriously and build a few more to add to the collection.

keep me posted on the improvements.

By the way I have changed the crossover quite a bit so if you want to try that one as well let me know. I will post a picture.

regards

Jonathan AKA Chef.

 

[sootboots]

I would love to see the crossover. I have your original design right now but it is not permanent on a circuit board. A 40-50litre cabinet is doable but I wonder if a floor stander such as Tony Gee's two-way classic might a viable alternative for theses drivers?

Johm

 

[chefsinc]

SB,

no problem I will put it up once my stuff arrives as I did not write it down and I have to check the crossover to remind myself.
but from memory I took the 22uf in series with the tweeter out and left the lPad in place.
the woofer inducter went from a 2.2 to a 2.7mh
the capacitor c2 went from 10 uf to 18uf and I removed the zobel completely and added a 22uf capacitor where the zobel was.
alittle lower crossover for the tweeter but I have had no issues with it so far with no distortion noticeable.

give that a go and see how you go.

Yes tony Gee's classic large floor stander ported would be good or if you wanted the sealed design then he gives an option for that also.

let me know how you get on.

regards

 

[MrJansjo]

I got impatient and installed the SB Acoustic Satori tw29R into my floor Standers replacing the Vifa XT25.
On initial listening tests without crossover mods they are much much better than the XT25.
Wow the detail is amazing. The XT25 are 1/4 the price of these Satori's but I think it was worth the money.

I've done the same, but with much cheaper SB29RDC-C000-4.
And it is much better, on pair with scanspeak 66000 which i own in other pair of loudpeakers.

Satori is "improved SB29RDC-C000-4", so - probably is fantastic.

 

[Jimmy154]

I think that 8" SB woofer is MUCH harder, but you've done OK with it, skipping the notch.

I'm going to try to match this wofer with a Wavecor TW030WA07 or 08
http://www.wavecor.com/TW030WA05_06_07_08_specifications.pdf

I seem to have the same taste as you.
I like sealed woofers and cone tweeters or at least large dome tweeters.
Although I enjoy the XT25 in limited applications.
TW030WA07 sounds remarkable similar in the high end to the XT25, maybe it's because the off axis FR, is similar, but with way, way more low end
Also it has no ferro-fluid

I wanted to build a 3-way with SB26 or XT25 or ribbon tweeter and Dayton RS52, but I think the cross-over will drive me crazy and I'm not sure I will like it better than a 2-way with a 30mm dome and the SB woofer

Sometimes less can be more
I remember Tony Gee built a 4-way "gattica" was it?
And then a 3-way
And he said the 3-way sounded better
And I was thinking: that's exactly what I would expect looking at the designs

Also I like the 3-way Wharfdale speaker with the two mids
I have a Sansui SP-1200 I listen to now and it is a very good design, best I can tell
the SP-2500 came with ribbon tweeters
Cross over seems to be the weak point though in both

BTW, SB acoustics drivers are really nicely made
If I did not have the Wavecor tweeters I would buy SB29, although I do have SB26
Even the SB26 soft dome has a very low distortion low end
I think Troels or some one measured the distortion and it was so low in the low end distortion he was like: "yup that's what I got for both tweeters", maybe it was "medley musings"

 

[LineSource]

I wanted to build a sealed 3-way with SB26 or XT25 or ribbon tweeter .... although I do have SB26 ...
(Tony Gee) said the 3-way sounded better ... And I was thinking: that's exactly what I would expect looking at the designs

For your sealed box goal...
In a sealed 1cuft volume the 8" SB23NRXS45-4 used in this 2-way thread has -F3=65Hz.

All sealed 3-way uses the 12" SB34NRX75-6 with -F3=37Hz in 4cuft, the poly cone SB17MFC35-8 in sealed 0.5cuft with -F3=70Hz, and your SB26STC-04. Zaph used the SB34 mounted on a front baffle, but a side baffle mount is attractive. Why build a speaker stand when you can add a woofer?
Any interest?