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

On a flat baffle, the tweeter will need to be on a waveguide to give it about 3in of setback to get the time alignment right. Harsch is for DSP really as it uses 4th order on woofer and 2nd order on tweeter with a large time delay. For passive you want to use a 1st order XO. I did design a Harsch passive for my PMC clone TL but it turned out to be very complex (probably $200 in parts for XO alone, so $80 minDSP is indeed king).

I think you have seen this already as you posted below it.
512416d1446479846-low-cost-pmc-inspired-tl-monitor-dc130a-dc28f-xsim-diag-pmctl4-xo-v2-fix-typo.png


Low-Cost PMC-inspired TL Monitor with DC130A and DC28F

512384d1446449857-low-cost-pmc-inspired-tl-monitor-dc130a-dc28f-pmctl4-pcd-xo-sr-v2.png
 
Nice work Perceval! Glad you can hear what I have been talking about. And do you agree that before hearing it, you were not sure what you were missing and it’s basically “you don’t know what you don’t know”. But having heard it, you can’t go back to what was before. You know it’s great when it makes you re-listen your collection. Congrats!
:cheers:

I had heard that tight integration before, such a long time ago when they came up with the THX WOW laserdisc.

I watched it in a highly optimized room, and it was intense. Ever since, I have been trying to reproduce the punch hit in the first minute of the demo disc, when Indiana Jones and father get punched. It's a clean snappy hit that can be felt.

Yesterday was the closest I have ever been to achieve. It was fun!
 
Hi Perceval,
Can you share sketch of your setup and he XO used? Maybe a photo even?
This gives me great hope that this speaker project that I started but left unfinished has great promise. An RS28A tweeter in a waveguide and a B80 mid with an RS180P woofer with two 6.5in passive radiators. I was going to do the B&O “Hole filler” XO.
 
Hey X,

remember, I told you this is a work in progress! :)

When I was back home last summer, I came across a shop selling electronics, and they had some cheap iron core inductors, so I grabbed a couple of 4.8mH. Over here in Taiwan, I can only get up to 1mH aircore. Recently, I found a place selling enamel wire by the kilogram, so I might try to make my own inductors!

So, picking up the W8-1363sbf, and adding the 4.8mH inductor isn't the prettiest. I think it would work better with a 3mH, for a more natural curve because the W8 starts falling off at 100Hz. The 4.8mH makes it even worse.

Moving on to the mid range. I had the Nola Brio clones with TC9s. I tried to see if using B80s instead of the TC9s would improve the sound. Not so much. The dual B80s in a Brio has a wide bump in the mid range, and it would need a pretty broad notch to sound good. So, I set them aside. Also, the volume for the B80s in a Brio is too small at about 2.7 litres, and it starts falling at 200Hz.

Since I got a pair of ribbons last month, I swapped the top B80 for the ribbon, added a 2.2uF cap, and a 10 Ohms resistor to pad it down. Made a REW sweep, and found some magic!

So, as it stands now, it is the W8 with a 4.8mH, the Visaton in a too small enclosure falling naturally at 200Hz, and running wide open on top with only a resistor to pad it down. The ribbon has a 2.2uF cap and a resistor.

Things to improve...

Give the B80 a bigger enclosure to let it breathe more. That should extend it to about 140Hz.

Probably try a 3mH inductor so the woofer does not fall so abruptly after 100Hz.

Add an inductor to the B80 top. I can hear comb filtering when moving around. Some spots are perfect FR, others have a dip at 6kHz. I have a few inductors laying around with 0.120mH, 0.46mH and 1mH.

Will do some updated sweeps of each drivers when I place the B80s in a better enclosure than the Brio.

Anything else you'd like, X?
Feel free to ask.

I never thought I'd be missing a tweeter with some of the nice full rangers I have here, but it does bring an amount of clean airy sound that the 3-4" cones don't have.
 

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I think it would work better with a 3mH, for a more natural curve because the W8 starts falling off at 100Hz. The 4.8mH makes it even worse

Hi Perceval,

You can always unroll some turns and measure the inductance with an LCR (or DATS). A coil that is too big is not a problem, in general.

Your box looks great - that XPS is working some magic. A good trick is to take a thin layer of foam core and cut a hole in it to match the outer bezel of the mid and tweeter and make them flush mount. You will reduce your baffle diffraction ripple by -3dB to -6dB sometimes. It is audible and sounds smoother.

I would not take the B80 below 250Hz, if you can push your woofer up a bit that would be much better. Unwind that inductor! The B80 distortion really starts climbing below 300Hz.

Rounding the XPS edges is a good idea to reduce diffraction. Your tweeter maybe could use some setback behind the mid - although your step response shows it to be well aligned.

This looks really nice and I can imagine the sound you are getting.

Cheers,
X
 
Thanks for the suggestions.

I'll play with XSim too see what I need for an inductor to get the W8 to behave a bit better. It might need a 2nd order to help the curve and reach 300Hz at least.

The XPS is fun to play with when doing demo boxes. So easy to cut and assemble, light construction.

Foam core is crazy expensive here, no dollar store with that over here.
Same size of 3cm XPS is cheaper than 0.5cm foam core! I'll keep it for building mini-ks!

The plan is to make them in hinoki (Japanese camphor wood) when all is settled, so yes, it will be flush mounted.

But I'm having way too much fun playing music on them right now. I'm so afraid to lose the magic! ha ha!

Anne Bisson sounds amazing, and while I was listening to a link you provided in another thread with Civil Wars playing Billy Jean, there was a cover of Jamiroqai Bee Gees mashup by Pomplamoose that was so much fun to watch and listen, the energy was palpable and it was like they were playing in my living room!

Jamiroqai Bee Gees mashup by Pomplamoose

I'll work on improving the speakers soon. Maybe swap the B80 for the TC9. Would reduce cost of the speakers.
 
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Maybe swap the B80 for the TC9. Would reduce cost of the speakers.

As a wide band mid in a 3 way, the TC9 is perfectly suited for this. If you have a TG9 (8ohm) it is almost as good as a 10F for 1/5th the price.

Sometimes, there is disappointment in switching to wood from foam. It has happened to me, and I think you too on Karlsonator. Maybe consider wood veneer on the XPS?

Great cover of Bee Gees. Finally can understand what the Gibb brothers were actually saying without the falsetto. :)
 
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Well,

I've been trying, but the drivers I have, being subwoofers, they all have a drop after 100Hz that is too great to use as regular woofers.

Been trying to contact Usher to get the 8945A, but no reply yet. I think I'll have to drop by the factory myself and grab them!

Usher 8945A 7" Carbon Fiber/Paper Woofer

In the mean time, I have been going back to my OB setup, and I really enjoyed them.

Tonight, I switched back to the little ones using the B80s, and it was a shock.

The big OB setup is nice, and the music is out there, all around me.

But with the B80 setup, the music plays "inside" my head. It's like wearing headphones.
The sweet spot is not somewhere on my couch, it is inside my head.
The feeling is intense and its intoxicating.

I'm staying with this, even if there is a small dip at 200Hz, I don't really feel / hear it.
Until I get a real woofer.
 

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zman01

Member
Paid Member
2011-02-04 11:35 am
Dhaka
zman,

I'd love to tell you, but there are no markings on this ribbon.

I took a chance and bought it online over here. No mention where it is from.

Here's picture of them, if that helps.

Hi Perceval,

Thanks for sharing the pic. I am not sure, but that driver looks more like a planar magnetic tweeter.
 
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Hi Perceval,

Thanks for sharing the pic. I am not sure, but that driver looks more like a planar magnetic tweeter.

Those look like AMT type tweeters and not ribbons. AMTs sound very good actually. My best tweeters are Heil AMTs. they sound so natural.

Another similar alternative on Ali for $30/pair are 94dB and XO at 3.5kHz. Also no-name.
Sounderlink 2PCS/LOT Hi Fi Planar audio speaker unit AMT ribbon tweeter-in Speaker Accessories from Consumer Electronics on Aliexpress.com | Alibaba Group
 
Hey X,

Have you thought about making a MTM version of this?

Reason is, I'm enamoured by the Usher CP-777, and it could emulate this using your version of it.

So, the 10f (or equivalent) sandwiched between two 8" RS225 ( or equivalent).

That could have some punch!

In an MTM, the 10F or tweeter will need to be recessed in a 3in deep waveguide as you can’t just put it underneath anymore to get the time alignment. But with miniDSP it would work very well. It would get +6dB more sensitivity which would bring it to 88.4dB at 2.83v overall. It would sound quite nice.

Even better would be to make the Bushmeister style point source horn with dual 8in woofer and the 10F/8424 as full range with 600Hz XO. The waveguide would be one of those huge 2.5in throat JBL cast aluminum ones. It would sound fantastic. Perhaps the SB23NRX45-8 as woofers.
 
Those look like AMT type tweeters and not ribbons. AMTs sound very good actually. My best tweeters are Heil AMTs. they sound so natural.

Another similar alternative on Ali for $30/pair are 94dB and XO at 3.5kHz. Also no-name.
Sounderlink 2PCS/LOT Hi Fi Planar audio speaker unit AMT ribbon tweeter-in Speaker Accessories from Consumer Electronics on Aliexpress.com | Alibaba Group

At first, I liked the air that they brought to the system, but after more listening sessions, they are starting to annoy me with some sibilance. I'll try to EQ out a bit between 5-8kHz, see if that helps.
 
In an MTM, the 10F or tweeter will need to be recessed in a 3in deep waveguide as you can’t just put it underneath anymore to get the time alignment. But with miniDSP it would work very well. It would get +6dB more sensitivity which would bring it to 88.4dB at 2.83v overall. It would sound quite nice.

Even better would be to make the Bushmeister style point source horn with dual 8in woofer and the 10F/8424 as full range with 600Hz XO. The waveguide would be one of those huge 2.5in throat JBL cast aluminum ones. It would sound fantastic. Perhaps the SB23NRX45-8 as woofers.


I'm not a huge fan of the "horn" sound. Completely the opposite, I prefer OBs.
But, I agree that a dual 8s with a FR on the horn would probably be good... just not the sound I'm looking for.

Hmmm... I don't think the tweeters are 3" back in there.
 

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