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

[perceval]

There is an easy way to solve the bass "problem".

I've become addicted to my WFW as well...

This thread, X, has been amazing, making me think about ways to do things the way I like them.

It's in here that I started thinking about my WFW, and now you are sharing that you would like to try a woofer in a TL with a smaller driver on top...

Which is exactly what I am planning to do next. I already ordered a pair of racetrack drivers 5x8 from SBA, along another pair of the wonderful SB65 to place on the top of this thin MLTL tower. The 5x8 sims nicely.

I should get my drivers as soon as the new 3.5" fR driver from SBA comes available to my distributor. I want to give that one a try as well.

 

[xrk971]

So I have had these SB23’s on hand for like 2 years now it seems, baffle precut to accept them with 10F/8424. Despite what factory curves would say that SB23NRX245-8 would or would not do with the current XO, I said what the heck, let’s slap it together in a 30min experiment and see how it works. I decided to go open baffle because I wasn’t concerned about the bass but more the mid bass and mid range. I had a PS95-8 on hand and it has the same bezel cutout as the 10F. So they went together. A little Makerbeam and bluetape later - and I am listening to it. And Wow! What a fantastic sounding speaker!

Even in skinny little open baffle frame - there was nice mid bass. Great balance.

You can listen to it here (video from my phone):

XRK Audio on Instagram: “Testing new FAST speaker in open baffle configuration. PS95-8 full range plus SB23NRXS45-8. Sounds (surprisingly) very nice with crossover…”

Edit, video got blocked for copyright- I will see if I can post a sound clip via mp3 later.

 

[xrk971]

Here are some pictures and an mp3 sound clip. Change the .asc file extension to .mp3 to listen. Recorded with UMIK-1 USB mic and Audacity at 48khz and converted to 192kbit MP3.

One thing that I am seeing from this experiment is that this speaker also works well as an OB if you like. The bass extension won't be a low so yhou will need a sub to fill it out - but if you like the OB ambiance - it can be very pleasing.

 

[xrk971]

Typo in the part number of the woofer in above post. SB Acoustics has a very logical naming system, but it is terribly long and hard to remember.

SB23NRXS45-8 : SB (company) 23 (nominal dia in cm) NRXS (NRX series) 45 (voice coil dia mm) 8 (impedance in ohms).

http://www.sbacoustics.com/index.php/download_file/-/view/1326/

Dayton PS95-8 : PS (Point Source) 95 (nom dia in mm) 8 (impedance in ohms)

https://www.parts-express.com/pedocs/specs/295-349--dayton-audio-ps95-8-spec-sheet.pdf

Above test using this XO (with bipolar electrolytic cap instead of a big film cap, and two smaller 2mH ferrite core chokes instead of a big air coil):

 

[perceval]

Sweet!

Now, you'll need to make a second one, pull it away a bit more from the wall behind and listen to OB magic! Be careful though... once bitten by OB, .....

Next, you'll need to get your hands on the SB65... It has the reach of a tweeter, but the punch of a woofer.

I'm really falling for SBA. Great drivers, reasonable pricing. Plus, they look good too!

 

[xrk971]

I do have SB65’s. They are 4ohm though and would not be a simple swap into my XO. I do like them very much and in fact, voted for them in the blind test thread years ago. I can build the stereo pair easily enough. The baffle is there - just need to drill some holes for the mounting screws.

 

[pidesd]

Be careful though... once bitten by OB, .....

yes it sounds super «fast» with great dynamics details and effortlesness, and even more so in free air without baffle, if the idea taken to the extreme. Also, with room reverb you have a second chance to hear the little sound detail you missed

 

[BYRTT]

Hi X thanks speed down a bit using 2 years work flow as we others probably more than often do ...

Great subjective it sounds good for whatever simple setup used so far, that said the Ref monitor naming in my way of thinking is obligatory to smooth reponses and other stuff to be superior so would like to see those big woofers filtered out above 1kHz or use two smoother woofers per side in a smaller diameter or whatever, for example two times SB17MFC35-8 will in Dunlavy way ballance vertical dispersion and help on Le difference to midtweeter in the wide 1st order transition band : )

Beside the critics here is some constructive data this is basegraphs from respective datasheets, below is using Dayton scales and SBA is offset minus 25dB plus its datasheet only cover up 10kHz so above that point is VituixCAD automatic interpolation or prediction for SBA:

Below is using SBA scales which cut x-scale at 10kHz and DA is offset minus 25dB:

 

[xrk971]

Thanks, Byrtt. I wonder how it’s going to look under measurement? We know it cannot be as flat as the 10F/RS225 Ref monitor. To do this right, I am going to have to measure 3 sweeps (M, W, M+W) import FRD into Xsim or PCD and try to crank out another XO.

That’s a lot of work actually.

 

[pidesd]

evaluation cabinet almost finished, cutting done with leftover plywood and a 12v sawzall. Not so «snail» after all... for this one at least

 

[xrk971]

I started a new thread for the SB23NRXS45-8 in an OB. I found that a simple parametric EQ makes it fairly flat:

-6dB peak at 700Hz and Q=0.60
+6dB low shelf at 250Hz

New thread here:
OB FAST with 3.5in Fullrange and SB23NRXS45-8

 

[xrk971]

side by side comparison...

 

[sarathssca]

Can this speaker be in the form of slim floor stander and more bass extension?? Or have the woofer be moved to sides for slim floor stander ?

 

[xrk971]

I would suggest you go with the standard sealed cabinet for a floor stander if you want more bass. The open baffle is a huge loss in bass effciency (-6db per octave starting at 800Hz, so 100hz is =18dB less than a sealed cabinet - to put into perspective). If you want OB bass, you need at least a single 15in or 18in and preferably dual 15in like typical OB systems).

 

[sarathssca]

I would suggest you go with the standard sealed cabinet for a floor stander if you want more bass. The open baffle is a huge loss in bass effciency (-6db per octave starting at 800Hz, so 100hz is =18dB less than a sealed cabinet - to put into perspective). If you want OB bass, you need at least a single 15in or 18in and preferably dual 15in like typical OB systems).

sorry my question was not clear, was refering to the sealed stand mount cabinets in my question .. whether we can have them as slim floor standard instead of stand mounts and get more bass extension .. may be ported or mltl ? ..

 

[pidesd]

sorry my question was not clear, was refering to the sealed stand mount cabinets in my question .. whether we can have them as slim floor standard instead of stand mounts and get more bass extension .. may be ported or mltl ? ..

discussed a few pages back and Atto built a BR in post 1 for instance:

sometimes a minimum of curiosity pays off!

 

[xrk971]

You can make a taller standmount or TL or BR as long as the baffle width is preserved and woofer is on top. Taller standmount will have more volume and deeper bass extension as a sealed. Less cone control though so less maximum power.

 

[pidesd]

XRK,

can you explained very briefly why the woofer must be on top? i thought only the fullrange driver had to be at ear level....

edit: or maybe it,s the woofer that must be on ear level...i must look it up

 

[xrk971]

To get an extra 3in of time-of-flight time delay for good time alignment (“transient perfect”). Assuming woofer is closer to ear level. A stepped baffle could allow full range to be on top.

 

[pidesd]

XRK,

so i take it that it has more to do with practical, actual listening position consideration than fundamental theory of speaker design.