That's the beauty of CNC, I can work any profile that's beneficial to the sound, as long as it fits inside the enclosure. The plan is to cut several layers of ply with CNC, laminate them together, and finish the curve with hand tools. The horn would end at the front baffle, which would be solid ply. The structure would be extremely strong, and I doubt I'd need to add extra mass to it. Also it allows me to make an exact mount for the full-range driver at the end. Maybe a round version (of larger dimension) of the XT1464 horn with a throat just large enough for the SB65 driver? Rectangular waveguide would be of course easier to build, but I guess that elliptical/round form would get me better sound quality. There must be some reason all the studio speaker companies use rounded waveguides 🙂
Time consuming, yes. Expensive, yes. Beautiful end result that is worth all that work, maybe.
As for the woofers, as I said earlier I have no idea what kind of specs would be important for this application. Thus, I only looked at the fs spec to see what models would give nice low-end extension. Here are some candidates:
Data sheet - H1252-08 | Loudspeaker freaks
Data sheet - 835026 | Loudspeaker freaks
Data sheet - RS225-8 | Loudspeaker freaks
Data sheet - SB23NRXS45-8 | Loudspeaker freaks
Time consuming, yes. Expensive, yes. Beautiful end result that is worth all that work, maybe.
As for the woofers, as I said earlier I have no idea what kind of specs would be important for this application. Thus, I only looked at the fs spec to see what models would give nice low-end extension. Here are some candidates:
Data sheet - H1252-08 | Loudspeaker freaks
Data sheet - 835026 | Loudspeaker freaks
Data sheet - RS225-8 | Loudspeaker freaks
Data sheet - SB23NRXS45-8 | Loudspeaker freaks
I even have a 2-1/4HP plunge router, a circle jig, and box of bits! All loaned from a friend who has more routers than he knows what to do with...
Seems like I am in need of long wood clamps.
The list of tools required just keeps growing...
The days of an xacto, ruler, pencil, hot glue gun are sort of long gone.
You _always_ need more clamps. 😀
fwiw - I'm quite interested to read more about the 3 way, all passive design you mentioned previously in this thread.
CONSIDER: 8" coaxial + 8" woofer in "corner-supported" two-piece cabinet.
For your modest size room and desire for both "rear-main" + "front_desk-secondary" listening options, an 8" coaxial driver in a fast-transient sealed box would provide point-source cohenence from 20Khz down to ~100Hz, where an equalized sealed 8" woofer would reach down to Piano Low-A =27.5Hz. The coaxial could be mounted in a separate sealed top cabinet which could normally be aimed at the rear listening position, or easily swiveled to improve listening at the desk, or pulled into the room for greater wall-reflected ambience. Faital 8HX150, Radian 5208C get good reviews.
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Great Vocals from 8" in our home: Sealed box Tang Band W8-1808 with whizzer cone removed + SB26STCN tweet @1.8Khz, plus equalized sealed woofer.
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Good selection for comparison:
US Speaker - Coaxial Speakers - Coaxial speakers by Eminence Speaker, Beyma, Ciare, 18 Sound and Radian. Coaxial speakers here at US Speaker
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The SB23NRX45-8 is a popular 8" woofer which has F3 of 28Hz in a 2.5cuft ported cabinet, and in a 2cuft sealed cabinet with Linkwitz Transform + room equalization can produce F3 ~20Hz with 8x power boost.
For your modest size room and desire for both "rear-main" + "front_desk-secondary" listening options, an 8" coaxial driver in a fast-transient sealed box would provide point-source cohenence from 20Khz down to ~100Hz, where an equalized sealed 8" woofer would reach down to Piano Low-A =27.5Hz. The coaxial could be mounted in a separate sealed top cabinet which could normally be aimed at the rear listening position, or easily swiveled to improve listening at the desk, or pulled into the room for greater wall-reflected ambience. Faital 8HX150, Radian 5208C get good reviews.
=================
Great Vocals from 8" in our home: Sealed box Tang Band W8-1808 with whizzer cone removed + SB26STCN tweet @1.8Khz, plus equalized sealed woofer.
===================
Good selection for comparison:
US Speaker - Coaxial Speakers - Coaxial speakers by Eminence Speaker, Beyma, Ciare, 18 Sound and Radian. Coaxial speakers here at US Speaker
==============
The SB23NRX45-8 is a popular 8" woofer which has F3 of 28Hz in a 2.5cuft ported cabinet, and in a 2cuft sealed cabinet with Linkwitz Transform + room equalization can produce F3 ~20Hz with 8x power boost.
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The coaxial way is interesting and lately it has been very popular in finnish HT/hifi DIY builders to put PA drivers in big boxes for home use. For example here is a guide of using Eminence Coaxials for a home speaker:
Kaiutinrakennusohje Yksisilmäiset veljekset - hifi-PA-kaiuttimet Eminence Beta-8CX, Beta-10CX ja Beta-12CX -koaksiaalielementeistä | AudioVideo.fi
It is actually the same deal with coaxials as with horns, I'd have to listen to them somewhere to get to know the sound. With coaxials it's however very possible to give them a listen, whilst I don't know anyone who owns a horn system 🙂
However, something with efficiency is probably the way to go with this project. The best speaker I've heard so far have been a pair Genelec 1036As flush mounted into a wall. The very effortless and super accurate quality of the sound was something jaw-dropping. I'm not insane so I know I can't get results that are this good in a home environment with the tools I have, but let's see how far we can go 😀
Kaiutinrakennusohje Yksisilmäiset veljekset - hifi-PA-kaiuttimet Eminence Beta-8CX, Beta-10CX ja Beta-12CX -koaksiaalielementeistä | AudioVideo.fi
It is actually the same deal with coaxials as with horns, I'd have to listen to them somewhere to get to know the sound. With coaxials it's however very possible to give them a listen, whilst I don't know anyone who owns a horn system 🙂
However, something with efficiency is probably the way to go with this project. The best speaker I've heard so far have been a pair Genelec 1036As flush mounted into a wall. The very effortless and super accurate quality of the sound was something jaw-dropping. I'm not insane so I know I can't get results that are this good in a home environment with the tools I have, but let's see how far we can go 😀
You will want to consider the "flexible use" from well executed "corner-supported" cabinets vs. fixed polar pattern from "in-wall" mounting.
1) corner enhanced controlled polar response to main listener.
2) easy to swivel TM top toward desk listener
3) In-room placement for increased short-delay wall-reflected room ambience
Edited pictures of sealed coaxial_8" + 8" woofer.
A few pictures of 3-way sealed Tang Band 8" + 1" dome tweeter + sealed 8" woofer.
From my experience, a full range like the Tang Band 8" (Mms=9.5g) has very good dynamics with excellent low level details. A pro-audio 8" coaxial is often designed for greater dynamics with solid midbass from stronger/heavier cones. You want to consider the size of your room and typical SPL listening levels.
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Yes, I will start a thread when ready. It's going slowly due to the wood cabinet. I would have finished it in 4 hrs if it was made of foam core 🙂
A quick computer model of speaker placements in your room would suggest that "space saving" corner placement is a good option for normal listening. Pulling the speakers into the room for critical listening does increase high frequency SPLs at the listener from additional wall reflections(ambience), and mainly requires bass equalization below 40Hz.
1) Thick absorption material on the rear wall is very important.
2) Carpet on the floor is important.
3) Some absorption material on the side walls is helpful. Few Key locations.
4) Corner placement shows ~6db gain.
5) Textbook placement increases high frequency SPL at listener from additional wall reflections.
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There are efficient speakers with modest SPL_max.
There are efficient speakers with MONSTER SPL_max.
For about 2k€ in the multi-way forum you can put a smile on your face, AND make your ears bleed.
Want some candy little boy??
1) Thick absorption material on the rear wall is very important.
2) Carpet on the floor is important.
3) Some absorption material on the side walls is helpful. Few Key locations.
4) Corner placement shows ~6db gain.
5) Textbook placement increases high frequency SPL at listener from additional wall reflections.
==================
There are efficient speakers with modest SPL_max.
There are efficient speakers with MONSTER SPL_max.
For about 2k€ in the multi-way forum you can put a smile on your face, AND make your ears bleed.
Want some candy little boy??
Attachments
Thanks for the simulations! I like to fiddle with speakers, but for now I'm looking for something that sits in the corner all the time, not something I have to move every time I want to listen.
I've gave this topic some thought, and decided that the Synergy Horn route is probably right for me. I don't have to put too much money on acoustic panels, and the directivity plots just look too good to pass.
One thing left to wonder though. As this whole deal is being run from a Hifiberry DAC+ Pro, which has only 2 channels output, it would mean that all the crossovers would be either line-level (1st order PLLXO) or speaker level. Is this possible with the Synergy Horn?
I've gave this topic some thought, and decided that the Synergy Horn route is probably right for me. I don't have to put too much money on acoustic panels, and the directivity plots just look too good to pass.
One thing left to wonder though. As this whole deal is being run from a Hifiberry DAC+ Pro, which has only 2 channels output, it would mean that all the crossovers would be either line-level (1st order PLLXO) or speaker level. Is this possible with the Synergy Horn?
Look for Bill Waslo's Synergy projects... passive is certainly possible. He has a nice new project going and if it suits you, you could follow his lead.
http://www.diyaudio.com/forums/multi-way/292379-small-syns.html
But he wasn't looking for output down low, just a small form factor Synergy.
Onni's project is interesting too, as well as nc535's current build. Lots of Synergy action on the forums right now.
And don't forget to check out the big thread on driver choices: http://www.diyaudio.com/forums/multi-way/88237-suitable-midrange-cone-bandpass-mid-unity-horn-new-post.html
Even Bushmeisters horns could be adapted to passive, but I don't know if his specific horn's directivity suits you. With active control you have delay as a helper, in a passive design the port actual positions become more critical.
Nothing a few prototypes couldn't solve... 😀
http://www.diyaudio.com/forums/multi-way/292379-small-syns.html
But he wasn't looking for output down low, just a small form factor Synergy.
Onni's project is interesting too, as well as nc535's current build. Lots of Synergy action on the forums right now.
And don't forget to check out the big thread on driver choices: http://www.diyaudio.com/forums/multi-way/88237-suitable-midrange-cone-bandpass-mid-unity-horn-new-post.html
Even Bushmeisters horns could be adapted to passive, but I don't know if his specific horn's directivity suits you. With active control you have delay as a helper, in a passive design the port actual positions become more critical.
Nothing a few prototypes couldn't solve... 😀
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A passive XO is possible and indeed Bwaslo can make that magic happen. He even made his Cosyne transient perfect with flat phase. But mere mortals have a much better chance of success with a DSP based solution. Can your RP use a commercial USB DAC with 4 channels output (Scarlett etc.)?
I am looking into a 4 channel USB DAC right now and wonder if Jriver can now do it all and skip the miniDSP.
What would be possible with a miniDSP that you couldn't do with JRiver? The list is longer of things you can do with JRiver that wouldn't be possible with miniDSP 🙂. After that get some cool vst's and the possibilities become endless.
Jriver and a four channel sound card will be more powerful than miniDSP. But miniDSP has the ability to run without a PC connected. That's useful sometimes.
I can't (or don't) really see it that way. If you build a dedicated audio PC running JRiver you get Home theatre + a full blown Audio setup all in one box, or you use another box, like a miniDSP.
I wouldn't hookup a laptop running JRiver "on the side" 🙂.
That makes it a choice between 2 different kind of black boxes. One more powerful and versatile than the other. But let's not go there, the OP is set on the Raspberry Pi. Yet another (very small) box 😉.
I wouldn't hookup a laptop running JRiver "on the side" 🙂.
That makes it a choice between 2 different kind of black boxes. One more powerful and versatile than the other. But let's not go there, the OP is set on the Raspberry Pi. Yet another (very small) box 😉.
LS,
This is Interesting.
So an 8" full range with whizzer removed can act as a wideband mid-range in a 3way design (instead of a low+high mid in a good 4way) ?
Basically a 8-10" sealed woofer covering the bottom end upto 120Hz
the 8" full range covering 120Hz to 5KHz
and a small dome tweeter from 5KHz and above
Will beaming from the 8", c2c, directivity and dispersion match be an issue on the 5KHz XO between the 8" and the small dome tweeter?
Or is this a normal 2-3KHz XO to a traditional dome tweeter as in a traditional 3way. In that case whats the advantage of using the FR driver?
thanks
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--smooth controlled directivity function--
An LR2 or LR4 crossover ~2kHz between no-whizzer Tang Band W8-1772 and the high'ish efficiency Satori TW29RN should have a smooth controlled directivity function - where the beaming of the W8-1772 is modest such that the 180-degree baffle dispersion still dominates. For a narrow baffle cabinet, two 8" woofers can be combined ~150Hz. With a Fat-Bottom cabinet, a 12" woofer could match the 95db/w W8-1772 efficiency.
--mixing-in high frequencies at the listeners--
Running the no-whizzer Tang Band W8-1772 up to ~5kHz would create a narrowing polar pattern at the listener. If the cabinets are carefully angled to the listener, a horn tweeter like the Fostex FT96 EX-2 will deliver the >5kHz high frequencies to the listener with modest room wall reflections. Tweeter delay, gain and phase controls seem necessary.
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Real works measured efficiency is closer to 92 dB, and typically you want a woofer 3-6 dB more sensitive. Or biamp.
dave
Just a quick Xsim to offer some confidence that the Satori TW29RN tweeter has the efficiency to match the Tang Band W8-1772. Sim'ed with two SB23NRX45-8 woofers.
Cabinet sim'ed: H48" W12" D18" 3" radius on front baffle edges.
Fostex tweeters also look pretty cool.
Cabinet sim'ed: H48" W12" D18" 3" radius on front baffle edges.
Fostex tweeters also look pretty cool.
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