I'm looking for suggestions or links to relevant past discussions.
Small studio nearfield (<1.5m) monitoring. Long rectangular room 2.5x8m and speakers 1m out from the corner.
I would like to build a 2-way with constant directivity down to crossover at 500-800hz. Bass is for another day. I would like some advice or pointers as to the best alternative to achieve a focused, linear, Wideband/Full range solution.
I've read about constant directivity, but not heard. Logically speaking, in my listening environment, the minimisation of sidewall reflections with all information arriving in a small sweet-spot appeals to me. I am standing (working) in a fairly localised area/space in the room at quite discreet volume levels (by choice as its a sound-proofed room).
I have read Patrick Bateman's thread on his Unitized Image Control Wave guide with interest and have considered building a pair. Also, I have considered Kali IN-8. The Geithain product line is unfortunately out of my price range as I would have pushed the button long ago!
Currently considering either the ESS AMT or the B&C Planar product ranges. Confused about how to load each of these to work best for my needs.
Feel free to put me on the best path if I'm going in the wrong direction.
Small studio nearfield (<1.5m) monitoring. Long rectangular room 2.5x8m and speakers 1m out from the corner.
I would like to build a 2-way with constant directivity down to crossover at 500-800hz. Bass is for another day. I would like some advice or pointers as to the best alternative to achieve a focused, linear, Wideband/Full range solution.
I've read about constant directivity, but not heard. Logically speaking, in my listening environment, the minimisation of sidewall reflections with all information arriving in a small sweet-spot appeals to me. I am standing (working) in a fairly localised area/space in the room at quite discreet volume levels (by choice as its a sound-proofed room).
I have read Patrick Bateman's thread on his Unitized Image Control Wave guide with interest and have considered building a pair. Also, I have considered Kali IN-8. The Geithain product line is unfortunately out of my price range as I would have pushed the button long ago!
Currently considering either the ESS AMT or the B&C Planar product ranges. Confused about how to load each of these to work best for my needs.
Feel free to put me on the best path if I'm going in the wrong direction.
A coaxial on a small baffle will get you there. You will need some thick insulation behind it to absorb the back wave.
What's your total budget and size constraints?
What's your total budget and size constraints?
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Probably £100 per driver. Maybe £600 for the project minus wood, as I have plenty and will build myself.
So you are suggesting semi-open baffle, as it were?
So you are suggesting semi-open baffle, as it were?
Just enough baffle to fit the drivers.
Good coaxials are a bit pricey. Another really good option is to use a small fullrange driver like the best in class ScanSpeak 10F and a larger woofer handling everything below 800hz or so.
Good coaxials are a bit pricey. Another really good option is to use a small fullrange driver like the best in class ScanSpeak 10F and a larger woofer handling everything below 800hz or so.
Yes, thats a good one. I have some 3fe22 around also. Although I'm not sure how that gets me any closer to the controlled directivity I'm guessing might aid my mixing?
Coaxial perhaps like this; B & C :: B & C 4CXN36 PS81.82
Thats within budget.
If I'm insulating the back of the driver, why not mount it in an enclosure?
Am I right in thinking that if you delay the back wave with insulation, you can create some sort of phase cancellation to the rear and avoid sound reflecting off the front wall. As I write this I am laughing at how simple I make it sound ;-)
Coaxial perhaps like this; B & C :: B & C 4CXN36 PS81.82
Thats within budget.
If I'm insulating the back of the driver, why not mount it in an enclosure?
Am I right in thinking that if you delay the back wave with insulation, you can create some sort of phase cancellation to the rear and avoid sound reflecting off the front wall. As I write this I am laughing at how simple I make it sound ;-)
Is there a better alternative than Dutch & Dutch 8c?
https://dutchdutch.com/wp-content/uploads/2018/11/8c-Spec-Sheet-2019.pdf
2-way: Waveguide + Cardioid-like
https://dutchdutch.com/wp-content/uploads/2018/11/8c-Spec-Sheet-2019.pdf
2-way: Waveguide + Cardioid-like
No....but they are $10,000-$15,000 a set.
Best bet for controlled directivity down to 500hz in a desktop sized speaker is to miniturize D&D's enclosure around a small fullrange speaker and run a small sealed or ported woofer portion below it.
If D&D's design is too complicated, consider running the fullrange open baffle or no baffle above a sealed or ported woofer.
Any other option becomes cost and/or size prohibitive unless the frequency of controlled directivity moves up.
Best bet for controlled directivity down to 500hz in a desktop sized speaker is to miniturize D&D's enclosure around a small fullrange speaker and run a small sealed or ported woofer portion below it.
If D&D's design is too complicated, consider running the fullrange open baffle or no baffle above a sealed or ported woofer.
Any other option becomes cost and/or size prohibitive unless the frequency of controlled directivity moves up.
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One of these:
https://en.toutlehautparleur.com/media/catalog/product/datasheet/sica/Z004091P-8+8.pdf
And a test enclosure with variable enclosure depth to fine tune the of axis cancelation would be a fun project. A time consuming one but interesting and fun.
High frequency is controlled by the cone and it acting as a waveguide. Upper midrange gets support from baffle and the acoustic cancelation takes care of the lower mid.
https://en.toutlehautparleur.com/media/catalog/product/datasheet/sica/Z004091P-8+8.pdf
And a test enclosure with variable enclosure depth to fine tune the of axis cancelation would be a fun project. A time consuming one but interesting and fun.
High frequency is controlled by the cone and it acting as a waveguide. Upper midrange gets support from baffle and the acoustic cancelation takes care of the lower mid.
Nissep. £10k ! And the build discussion seemed to be inconclusive and complex. Too much room for error based on my limited knowledge.
The Sica looks nice, although a touch over budget. Why this driver specifically?What do you mean by variable depth enclosure? You mean a box obviously?
Ernie. I love your practicality. Your suggestion is beautifully obvious and reminded me portable mic booths like this.
I could try this with one of my 3fe22 or TC9's on a small baffle mounted in the middle and flush to the curve of the absorbers, leaving open space around all sides of the baffle. I'm not going to be measuring directivity electronically, but I can eq flat to 500hz or so with measurement, then subjectively listen for directivity. Clearly, side reflections (and ceiling, to a degree) should be largely eliminated this way.
I guess if that works, I'll invest in a small coaxial to control the highs.
The Sica looks nice, although a touch over budget. Why this driver specifically?What do you mean by variable depth enclosure? You mean a box obviously?
Ernie. I love your practicality. Your suggestion is beautifully obvious and reminded me portable mic booths like this.
I could try this with one of my 3fe22 or TC9's on a small baffle mounted in the middle and flush to the curve of the absorbers, leaving open space around all sides of the baffle. I'm not going to be measuring directivity electronically, but I can eq flat to 500hz or so with measurement, then subjectively listen for directivity. Clearly, side reflections (and ceiling, to a degree) should be largely eliminated this way.
I guess if that works, I'll invest in a small coaxial to control the highs.
Armchair designer ...
Not even an armchair. A free sofa that has been shredded by cats for several years 😀
Doesn't have to be a horn speaker but a conical or simialr horn guarantees your HF and MF constant directivity. For your planned crossover, you should be easily able to achieve your goals with a 10" or 12" waveguide and probably a woofer of same size. A small woofer and (usually) horn same diameter, ideally within the 1/4 wavelength of the crossover frequency also gets you better frequency and polar response.
This must be a fairly common format. I've not seen his, but you can read up on GedLee speakers which are highly regarded. I'm sure there is an enormous range of compression drivers, horns, woofers and so on to select from. Unless you need truly ridiculous dB ability, your search should be easy.
Not even an armchair. A free sofa that has been shredded by cats for several years 😀
Doesn't have to be a horn speaker but a conical or simialr horn guarantees your HF and MF constant directivity. For your planned crossover, you should be easily able to achieve your goals with a 10" or 12" waveguide and probably a woofer of same size. A small woofer and (usually) horn same diameter, ideally within the 1/4 wavelength of the crossover frequency also gets you better frequency and polar response.
This must be a fairly common format. I've not seen his, but you can read up on GedLee speakers which are highly regarded. I'm sure there is an enormous range of compression drivers, horns, woofers and so on to select from. Unless you need truly ridiculous dB ability, your search should be easy.
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Yes......you’re on the wrong track if nearfield monitoring is your goal.
High mids through treble are the easiest to control and treat in your space.
Low midrange and bass is where the critical monitoring process is the most challenging.
Our ears cannot resolve the excess information, phase issues and complexity.
Those corners you mention?.....spend the $100 or so on Rockwool and make some DIY corner bass traps floor to ceiling filling about one half meter of space.......and listen to your music’s clarity improve exponentially. Spend another $100 on a calibrated measurement mic and freeware software to create a visual of what you are hearing.
And as a work ethic......don’t trust your ears anymore than an hour at a time at 88db or more.......you’ll need to rest them in order to trust them. Listening fatigue is real.
High mids through treble are the easiest to control and treat in your space.
Low midrange and bass is where the critical monitoring process is the most challenging.
Our ears cannot resolve the excess information, phase issues and complexity.
Those corners you mention?.....spend the $100 or so on Rockwool and make some DIY corner bass traps floor to ceiling filling about one half meter of space.......and listen to your music’s clarity improve exponentially. Spend another $100 on a calibrated measurement mic and freeware software to create a visual of what you are hearing.
And as a work ethic......don’t trust your ears anymore than an hour at a time at 88db or more.......you’ll need to rest them in order to trust them. Listening fatigue is real.
Good advice there. My room is treated acoustically (although not bass traps on the front corners as a window covers most of the front wall !) and is now packed with synths and cabling so it is literally easier to build new speakers rather than re-treat the room further lol. I currently use convolution based room correction for my Adam A7x's. But I'm in no doubt the room (like life) is not perfect.
As there is so much information and experience on it, a large waveguide/horn may be what I end up doing, I'd rather work on something with a smaller footprint as it gives me more options on placement. I am still only considering 300-500hz in/on its own structure, at low spl and will deal with bass placement once I find a decent solution for the rest.
Nissep "And a test enclosure with variable enclosure depth to fine tune the of axis cancelation would be a fun project. A time consuming one but interesting and fun."
The penny's dropped. Small baffled enclosure for a coaxial, leaky (perforated) side-walls, rockwool stuffing - plenty, adjustable back-wall depth (mechanism similar to a flower press or vice perhaps). Adjust to infinity 🙂 ?
Or an open baffle coax/rear wave cancellation trap hybrid, like the portable mic booth idea....but a bit more elegant. Again, fiddle forever !
I must admit the simplicity of the latter appeals and could be the start of a permanent enclosure design if successful (useful).
As there is so much information and experience on it, a large waveguide/horn may be what I end up doing, I'd rather work on something with a smaller footprint as it gives me more options on placement. I am still only considering 300-500hz in/on its own structure, at low spl and will deal with bass placement once I find a decent solution for the rest.
Nissep "And a test enclosure with variable enclosure depth to fine tune the of axis cancelation would be a fun project. A time consuming one but interesting and fun."
The penny's dropped. Small baffled enclosure for a coaxial, leaky (perforated) side-walls, rockwool stuffing - plenty, adjustable back-wall depth (mechanism similar to a flower press or vice perhaps). Adjust to infinity 🙂 ?
Or an open baffle coax/rear wave cancellation trap hybrid, like the portable mic booth idea....but a bit more elegant. Again, fiddle forever !
I must admit the simplicity of the latter appeals and could be the start of a permanent enclosure design if successful (useful).
I'm going to try my pair of un-baffled 12" coaxials on a dining room table and see what kind of response I can get. The table is against a wall on one side so there should be plenty of interference to simulate a real world setup.
Will post an update tomorrow.
Will post an update tomorrow.
The flower press it is!
But then I realized that the stuffing is a key part of it too.
If one only had to dial in the rear wall 1/2 wave length distance for acoustic cancelation it would work with that idea, but the stuffing will compress and change its parameters to.
The coax from Sica looks really good that’s all, plenty of headroom for near field.
But then I realized that the stuffing is a key part of it too.
If one only had to dial in the rear wall 1/2 wave length distance for acoustic cancelation it would work with that idea, but the stuffing will compress and change its parameters to.
The coax from Sica looks really good that’s all, plenty of headroom for near field.
I'm working on something similar with:
Faital pro 8pr200
Faital pro sth100 horn
Peerless dfm-2535r00-08
£340 the lot. Chuck in a minidsp for £100 and the rest on amps.
I'm listening at 2 metres with the comp driver on h9800 horn atm but will be switching to the sth100 soon.
If that isnt acceptable to my requirements I will look at monacor dt-300 in waveguide £60 a pair inc wg) or seas dxt tweeters (£120) both in either narrow bevelled or circular large roundovered baffles above mid woofer box.
Faital pro 8pr200
Faital pro sth100 horn
Peerless dfm-2535r00-08
£340 the lot. Chuck in a minidsp for £100 and the rest on amps.
I'm listening at 2 metres with the comp driver on h9800 horn atm but will be switching to the sth100 soon.
If that isnt acceptable to my requirements I will look at monacor dt-300 in waveguide £60 a pair inc wg) or seas dxt tweeters (£120) both in either narrow bevelled or circular large roundovered baffles above mid woofer box.
OK, let's shelve the flower press idea.
Won't having mids in a traditional enclosure leave me in the same position; wide dispersion and room colouration?
It strikes me that horns are fundamentally designed to increase spl over a distance ie. controlled directivity over distance leading to wide coverage eg. a crowd at a gig. Not suitable for nearfield listening at all. And assuming a clever cardioid effect is tricky (and expensive) to achieve, wouldn't one want instead to dampen sound directly around the source to achieve controlled directivity nearfield? Much in the same way that headphones do.... And BTW I'm not planning to wear headphones every day for the rest of my working life!! But some kind of compromise shouldn't have to cost me £15k.
Won't having mids in a traditional enclosure leave me in the same position; wide dispersion and room colouration?
It strikes me that horns are fundamentally designed to increase spl over a distance ie. controlled directivity over distance leading to wide coverage eg. a crowd at a gig. Not suitable for nearfield listening at all. And assuming a clever cardioid effect is tricky (and expensive) to achieve, wouldn't one want instead to dampen sound directly around the source to achieve controlled directivity nearfield? Much in the same way that headphones do.... And BTW I'm not planning to wear headphones every day for the rest of my working life!! But some kind of compromise shouldn't have to cost me £15k.
https://www.magiclx521.com/epages/17940394.sf/en_GB/?ObjectPath=/Shops/17940394/Products/LXsirius
Doesn't have to be too complicated to gain an improvement over typical boxes. Doesn't have to be perfect either...a lot of the early attempts in the linked thread by the D&D founder look perfectly usable.
Doesn't have to be too complicated to gain an improvement over typical boxes. Doesn't have to be perfect either...a lot of the early attempts in the linked thread by the D&D founder look perfectly usable.
Yep, you're right Ernie. So, if I were to attempt to measure the half-wave cancellation effect, would I be right in assuming that two equally opposed mics routed through oscilloscope plugins, playing a sine wave, would show me visually when I reach that point? 5 or 6" coax, small baffle, deep enclosure, open sides, mounted on threaded bolt rods (which I have) to the back. This could take a looong time.
Smallish monitor
I have so many projects in the pipeline, but if i were starting fresh, I think i would take a very long look at the Helios project designed by the late Jeff Bagby.
Cardioid DIY builds that are well documented are rare, unfortunately.
The Helios is NOT the most efficient of the controlled directivity designs out there, seemingly sacrificing efficiency for low end extension. But it does use a clever passive radiator to combine the best of sealed and ported box designs. Passive radiators seem to be gaining in popularity lately.
The tweeter is new, but combines a beryllium dome with a waveguide. No trouble with top end extension like some claim with the popular 1" compression drivers (B&C DE250 etc.)
The first CD design I heard was the Jazz Module by Audiokinesis. They are spectacular.
The CD design I own is the Earl Geddes 10" 'Nathan', which relies on multiple subs for the true under 80Hz work.
These designs help mitigate the speaker/room interaction and from my personal experience sound good near field.
I have so many projects in the pipeline, but if i were starting fresh, I think i would take a very long look at the Helios project designed by the late Jeff Bagby.
Cardioid DIY builds that are well documented are rare, unfortunately.
The Helios is NOT the most efficient of the controlled directivity designs out there, seemingly sacrificing efficiency for low end extension. But it does use a clever passive radiator to combine the best of sealed and ported box designs. Passive radiators seem to be gaining in popularity lately.
The tweeter is new, but combines a beryllium dome with a waveguide. No trouble with top end extension like some claim with the popular 1" compression drivers (B&C DE250 etc.)
The first CD design I heard was the Jazz Module by Audiokinesis. They are spectacular.
The CD design I own is the Earl Geddes 10" 'Nathan', which relies on multiple subs for the true under 80Hz work.
These designs help mitigate the speaker/room interaction and from my personal experience sound good near field.