10F/8424 & RS225-8 FAST / WAW Ref Monitor

[xrk971]

I think I might have either a reflection dip at 3.5k due to the throat of the WG or there is a baffle diffraction. But slightly off axis the 2kHz bump is gone.

 

[wesayso]

Keep it for the time being, it might actually sound seductive .

 

[pidesd]

byrtt,

thanks for sharing dsipersion theory. i'm not done with spinorama article yet but it is interesting.

all of this though only points out to a tweeter being the easiest solution to dispersion problem.

myself am thinking about a 1rst order tweeter for the very top, after having about only positive experienced with reduced diameter 2 inch drivers as fullrange for project in the present thread. Rigth now i'm using ta6fc00-04 and it doesn't sound bad at all at low volumes. Higher spectrum clarity makes a difference.

 

[ttan98]

Byrtt,

Examining all your dispersion curves from many FR drivers, what driver or drivers you think would be an 'ideal' one which does not need an external tweeter, and has the 'best' dispersion formation?
Any suggestion(s)/opinion(s) are welcome. Thanks.

 

[xrk971]

I bet it is the SBA65WBAC25-4. Main problem is that it is not a sensitive driver at 83.5dB - but that's about where an 87dB sensitive woofer will be after baffle step losses.

SB Acoustics SB65WBAC25-4 2.5" full range

Mostly because diameter is smaller, dispersion is closer to a dome tweeter. Because it has an aluminum dome, the reach is high like an aluminum dome tweeter.

Used in a tractrix horn though, it can gain some sensitivity and sound very good.

I recall that I picked this driver as my favorite during the Virtual Blind Audition full range driver test threads.

The factory curve shows a mild dip at 1kHz and mild rise at 2kHz - perhaps like Byrtt said about my RS28F in a WG300 waveguide, to give it a sweet head response transfer function (HRTF).

 

[pidesd]

some plastic dome for SBA65 it seems from pictures...

Speaking about small drivers...i'm very curious about the ne65w-04 big button small woofer. i had good experience with Peerless products so far...

 

[xrk971]

Pidesd,
Have you seen all the drivers I tested, measured, and made sound clips with? I think the NE65 might have been one of the ones I tested.

A Subjective Blind Comparison of 3in to 5in Full Range Drivers

A Subjective Blind Comparison of 3in to 5in drivers - Round 2

A Subjective Blind Comparison of 2in to 4in drivers - Round 3

A Subjective Blind Comparison of 2in to 4in drivers - Round 4

The NE65W-4 is here:
A Subjective Blind Comparison of 2in to 3.5in drivers - Round 5

Measurements:
https://www.diyaudio.com/forums/ful...n-3-5in-drivers-round-5-a-14.html#post4494341

It’s the blue curve on the bottom:

 

[perceval]

I bet it is the SBA65WBAC25-4. Main problem is that it is not a sensitive driver at 83.5dB - but that's about where an 87dB sensitive woofer will be after baffle step losses.

SB Acoustics SB65WBAC25-4 2.5" full range

Mostly because diameter is smaller, dispersion is closer to a dome tweeter. Because it has an aluminum dome, the reach is high like an aluminum dome tweeter.

Used in a tractrix horn though, it can gain some sensitivity and sound very good.

I recall that I picked this driver as my favorite during the Virtual Blind Audition full range driver test threads.

The factory curve shows a mild dip at 1kHz and mild rise at 2kHz - perhaps like Byrtt said about my RS28F in a WG300 waveguide, to give it a sweet head response transfer function (HRTF).

I can second that the sb65 has a great reach, very even dispersion, and even though it is an all cone, it does not sound shrill like many other alu cones out there.
To my ears, it sounds ok with voices, but stellar with string instruments.

And I made a makeshift waveguide for it, combined with OB, has given me one of the best musical experiences.

 

[pidesd]

On this site, the ne65w measures like a very good big tweeter, compared to other drivers he tested, if we suppose all drivers were measured the same way.

TYMPHANY - VIFA NE65W-04 (Extended-range 2", 4 Ohm, 50 Wmax)

note: i see that this driver was discontinued on manufacturer site, but i see some retailers still have a supply.


attached is XRK measurements

nothing exceptional in this driver,it seems, but power rating is good.

 

[xrk971]

Hmm... wondering if I should try making a crossover for the SB65WBAC25-4 for this FAST speaker pairing with the RS225 on the bottom. I think it might be simply to make the coil 8mH and use minimal padding resistors. Will require an adapter plate for converting the smaller square bezel to the existing round bezel. Or make a new baffle with a custom square framed rebate for this driver.

 

[xrk971]

anyone do the PS95 version yet- love to see some measurements. also was there a definitive version of the stand mount TL?

The only posted CAD plans are the definitive plans. Tested and verified by Vunce to sound awesome.

Plans here:
10F/8424 & RS225-8 FAST / WAW Ref Monitor

 

[pidesd]

I can second that the sb65 has a great reach, very even dispersion, and even though it is an all cone, it does not sound shrill like many other alu cones out there.
To my ears, it sounds ok with voices, but stellar with string instruments.

And I made a makeshift waveguide for it, combined with OB, has given me one of the best musical experiences.

do you have hints to why or how vocals wouldn't soud stellar too...? What driver sounds best you you for vocals?

 

[xrk971]

Vocals sound best on the 10F/8424 - that driver has an unbeatable midrange as you can see from the graphs that Byrtt posted. There really isn't a smoother driver made in that range (at any price). Maybe a 3in soft dome mid used in professional ATC monitors - but I am not sure they would sound better. TG9FD is also similarly good - there is something to how Scanspeak/Vifa/Peerless use the pentacone technology combined with fiberglass cone. The fiberglass sounds best to my ears for mids.

Spinorama (btw, not a very informative name for a diagram schema):

 

[bvan]

I'm looking at building the FAST TL version. I want to eventually have a multichannel Auro 3D setup mainly for music (lot of off-axis multi-person listening where I prefer matrixed multichannel from stereo sources).

I'm wondering if the 10F/8424 would be ok as in-wall surrounds with the manufacturer recommended "1.5 liters vented box with a 1" diameter vent by 3" long your F3 is 105Hz", and perhaps a 110hz 2nd order high-pass? Would I run into excursion limits with <90db levels, or any other issues I'm forgetting to consider?

Thanks for any input,
B

 

[xrk971]

These are 87dB drivers. You can get 90dB without problems. That’s 2watts input. Driving them down below 200Hz will have appreciable distortion at higher levels like 90dB. You might consider in wall FAST w 6.5in woofer bass helper and cross at 600Hz.

 

[perceval]

Hmm... wondering if I should try making a crossover for the SB65WBAC25-4 for this FAST speaker pairing with the RS225 on the bottom. I think it might be simply to make the coil 8mH and use minimal padding resistors. Will require an adapter plate for converting the smaller square bezel to the existing round bezel. Or make a new baffle with a custom square framed rebate for this driver.

I would love to see that. And then read how the sb65 fared in that setup.
Too bad the rs225 is almost impossible to get here.

I'll have another look at the Usher woofers, after all the rs225 are made there.
But the Usher drivers have not been updated in over two decades.
They are solely Dayton's oem company now.

 

[perceval]

do you have hints to why or how vocals wouldn't soud stellar too...? What driver sounds best you you for vocals?

Myself, I have the w8-1772 here, and once tamed a bit, they sound luscious and sultry on vocals. Could be that big paper cone.

I'm not saying the sb65 are bad, but they don't have the warmth of the w8.
Can't compare with the 10f as I don't have a pair, but I have the Visaton b80, and they're pretty good as well.

The sb65 really shines with woodwind instruments and string instruments.
Guitar, piano, violins, ... They sound so real. I feel I could touch the sound.
The w8 or b80 can't come close to that little driver for this. And the dispersion.

 

[pidesd]

Perceval,

first of all, are you speaking of these drivers tested alone or with assisted bass? in FAST setup, you are hearing the whole thing...

Regarding SBA65, i have never seen any driver built like it so it should sound unique...it's like a mid-tweeter dome with a tiny alu (only alu? how is it bonded?) cone. I have a woofer of that style but it's not the same proportion.

Paper absorbs resonance like few, if i recall, but lacks «speed» and resolution of harder cone, AFAIK. probably it has to do with that.

 

[perceval]

At the moment, I am listening to the SB65 between dual 5x8 woofers in WFW config, on OB.

A MLTL with the 5x8 and SB65 is also in the works.

 

[florianderton]

The speaker already sounds kind of coherent/ smooth without the offset, already without the offset it is a good speaker to my ears. But when I read that XRK mentioned, that there should be about 3in delay to the Scan Speak - correctly speaking - , I thought I really have to do that and try it out. Outdoors without any (almost any) reflections you really kind of dramatically hear the difference. Without offset there is a smearing and limit of transparency, with the offset it sounds on the spot, perfect like 3D of the recorded space (classical music and Jazz). I had one friend who described it as "the overtones gear into each other/ intertwine". I like that expression, I imagine that the two drivers really go hand in hand over the more the less broad bandwidth they both play.
With all the reflections indoors the difference is not THAT big to hear (still big), when you go outdoors it is not very hard to find the very point/ sweet spot.
With the offset the heights more sound like a real tweeter, they are sparkling. Still I miss the tweeter, as some qualities of a tweeter still are missing (I cannot name them), but the resolution is quite impressive though. That goes hand in hand with my friend's description.


Still I am very surprised, that that what the ears tell you, does not go hand in hand with the measurements, which are worse with the offset. I am wondering if anybody could explain this to me.


I have to say, that I have an idea, and this is, that (as more energy is in the bass) - without offset the drivers are perhaps more synchronal in the bass and it therefor measures better, but the "overtones"/ heights are not coherent. With the delay the mids and heights are perfect, but the bass is not (?). Oudoors you can only judge the mids and heights, you hardly hear bass (due to the relatively small driver and the missing reflections). - I do not understand a lot of measurements and filtering/ crossovers (phase shift,...) and the knowledge one needed to explain what I have experienced, but this is a creative idea (...). Still one has to accept, that my offset measures worse.

Hi everybody,


I just came across what XRK posted in thread 1973 a couple weeks ago: In that picture you see, that the top/ highest point of the step response of the woofer is behind/ after the top of the fullrange speaker stepresponse. It seems that my offset puts both tops together, and then it is clear, that the beginning of the line is not that steep as I have shown with my measurements of the speaker with the 6,1cm offset. This explains my different measurement, and the different/ better sounding speaker. My former ideas/ trying of an explanation (above) are rubbish for sure, and I would not say any more it measures worse with the offset. - I can highly recommend to anybody to do the offset, even if it means perhaps strange optics and a different response due to the different front baffle, it is very much worth it!