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

I have 4 B80s here. Right now, they are in a makeshift Nola Brio clone (on steroids!), but gathering dust.

I really want to hear what X has to say about them against the 10f.
It is easier for me to get the B80 than the 10f.
Then, I have to find a replacement for the RS225... I'm hoping a nice woofer from SBA might do the trick.
 
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I spent an hour listening to the B80 in this FAST speaker last night when I should have been hitting the hay for the night. That might tell you something about it. It sounds very good. It is “different” than a 10F but in what way, I can’t quite put my finger on it. It might have something to do with the fact that the “sound” of a paper cone is different than a fiberglass cone. Or it might be from the fact that the crossover is not perfectly flat anymore. I have not taken out the mic and REW yet. Zman01 played with the B80 in the XSim file for this speaker and it seems to want slightly different values on the inductor and main coupling cap.

I will listen some more before measuring to keep myself from getting biased based on frequency spectrum.

I think 3.2ohms for R1 might be too high still. Maybe 2.2ohms would be better. I think I hear a little more high frequency detail on cymbals and high hats. Saxophone and clarinet sound wonderfully glorious and rich. Stand up bass by Omer Avital has very distinctive textures and forcefulness. Very nice.

@Perceval, the RS225-8 is a unique driver and I have also been looking for another “higher-end” option. However, it doesn’t seem that even spending $400 from another big name like Scan or SBA will get me something as wide bandwidth and smooth. These traits are essential for a first order crossover with a minimum of notch filters, etc.

I was hoping the SB23 would work but seems to be quite different.

It is a good looking speaker though and now both drivers have a similar black phase plug look.
828413d1585383617-10f-8424-rs225-8-fast-waw-ref-monitor-b80-rs225-fast-build-finished-04-jpg
 
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Good... and thanks!

Happy listening.

I can't wait to see the measurements too.

As a RS225 replacement, yeah... not much looks like it might work.
I scanned through SBA... nothing so smooth.
The only thing I found was the TB W8-1722 woofer... but it costs a lot more.

Looks promising though... I know I made TL sim for it and it was insane.

The USHER 8948A, 8945A and 8935A1 look like they might work too... but Usher is too busy making Dayton stuff... they don't care about their own products anymore... hard to get them interested in selling me a couple of drivers at a fair price... they boosted their prices to ScanSpeak range... when they were 1/3 of that 6 years ago....

Series-Drivers – USHER
 
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Some Measurements of the B80 and RS225 in Baseline XO (3.2ohm)

The measurements seem to indicate that the B80 works quite well in the XO designed for the 10F/8424. The phase is not quite as flat, but we have a +/-15deg variation from about 120Hz to 12kHz. These were taken at 0.5m along an axis in between the woofer and tweeter corresponding to my ear height where I sit. Amplifier used was 40w SE Class A Alpha Nirvana fed by a Sanskrit 10 USB DAC. Mic used was UMIK-1 from Cross Specctrum Labs. Data shown using 6 cycle frequency dependent windowing (FDW) to reduce effect of room reflections.

Frequency and measured acoustic phase:
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Distortion vs frequency at level of 2.0vrms:
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Distortion at 8.5W (about 90dB at 1m):
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Step Response:
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As I previously said that I thought the driver sounded balanced but could use a little less padding seems to all be verified by the measurement. I will try reducing the amount of attenuation.

But in general, I think that this is actually a very good performer in a crossover designed for another driver. For the above data, R1 was modified to 3.2ohms by adding a 10ohm in parallel with existing 4.7ohm R1.
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There have been numerous studies by Harmon Kardon that humans prefer a speaker with a slight drop in output from bass to treble of circa -5dB left to right from 20Hz to 20kHz. That is, 20kHz output is about -5dB less than 20Hz and basically a flat tilted line fits the response. It’s psychoacoustics - but can vary from person to person. Sometimes we prefer a “Smile” shape with the treble going up - good for older people who have lost some acuity of the higher registers but like to have some “airiness” in the sound.
 
or the hifi "audiophile" crowd that likes a boost between 2kHz to 8kHz, .... they call it detail... I call it ear screeching! :D

The kind of speaker you can only listen to for 15 min until your head is about to explode!

The tilt down, up to 10dBs for some people, makes for a very easy listening speaker, something you can enjoy for hours, and still have plenty of details... just not in your face details!
 
Trouble is... you don't know their setup....

I bought a set of mixing monitors that were touted to be extremely flat and perfect from Fostex..... Well... they were absolutely not flat!

The musician plays his notes the way he feels them, but his ears are not at the mic level, so what he hears is different from what is recorded, the engineer records them the way he feels to show off the musician best, the producer mixes the album the way he thinks will sound best on most radio out there, and many radio broadcast add they own EQ and loudness settings so it sounds more in your face when you listen to it on their station...

What are you listening to, again? :)

Even if you were in the room when they played and recorded, your position away from the band would have meant a different sound then the one the mics picked up.

It's all a question of perspective, and as long as you like what you hear, it's all good.

But believe me, what you are listening at home is certainly not as the musician heard while recording.
 
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I am thinking of trying out this crossover for the B80 and RS225. It’s got a smaller capacitor and lower value inductor. The predicted phase seems a bit smoother. My parts all arrived and just needs to be assembled on the new XO PCBs. This XO was tweaked with Zman01’s help.

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I've acquired the drivers and crossover components for these and have started my sealed design with a finger joint box that will be laser cut. I'll be using 12mm baltic birch and will add a .25" thick walnut facade to the baffle that will allow the drivers to be flush. I know that XRK spec'd the baffles to be 10" wide, but I had to add another .5" to allow for the walnut baffle to not be too thin around the RS225. My outer dimensions with the walnut baffle will be: 10.5" W x 16.5" T x 12.25" D.
Here is a screenshot of the pieces to be cut:
 

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Here are the new measurements vs the old. Very similar - a bit more of a lift in the highs. Not sure why the shape is so different though around 9k-10k. The phase is not as flat, now within a 40deg band vs 30deg band. However, listening to it, the increased presence around 2k is very nice, and the upper registers sound about to be the perfect balance now.

New (black) old (green) frequency response:
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Measured frequency response and phase:
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Measured distortion at 2.0Vrms:
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Step Response:
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Installing the new XO board:
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Closeup of the new XO board with all Faston tabs connected:
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Will listen some more and give assesment later after a lot more time with various genres of music.
 

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I am very much enjoying how this speaker sounds with the B80. My initital impressions that the sound was very balanced but could use a little more emphasis in the upper registers was confirmed by measurement, and the softness of the treble has been resolved with this modified crossover. Although I wonder if using the stock XO for the 10F/8424 with less resistive padding (ie., replace R1 with 2.5ohms and R2 with 10ohms) would have had a similar effect. there is a bit more 7kHz to 10kHz emphasis that is offered by using the B80.

Subjectively, what I am hearing appears to be more definition in the attack of notes, and this is not just the treble, it extends to all the octaves. But because the frequency response is flat and balanced, all genres of music play equally well.

The usual things like soundstage, imaging, clarity of highs are all great. The midrange and vocal presence feels very crisp and clear, but perhaps less refined than the 10F - which is "glass smooth". I am not complaining though.

All of my familiar test tracks sound great - perhaps on same level as the 10F/8424 - and quite remarkable for a driver that costs about half the price. The B80 is very well made with a cast aluminum frame and nice black aluminum phase plug that matches the look of the RS225. The phase plug seems to have a narrower polar response in that I feel that the sweet spot is maybe a tad less than with the 10F, which has a fiberglass dustcap of same material as the cone.

In short, very highly recommended driver sibstitute for the 10F in this speaker. I think that stock XO works well and I suspect changing R1 to 2.5ohm and R2 to 10ohm will work just fine. If you want a little more high end definition in treble from 7k to 10k, then use the new XO for the B80.

Parts Express offering the B80 sort of makes it a no brainer to order with the RS225-8 at the same time though.