Hi Anton, I'll try to respond to your two posts above. Sorry about the multi-quotes.
I checked the construction plans, it's a 6 inch baffle (15.2 cm). The wings are obstructing me from directly measuring them and I'm loathe to remove them just for one measurement.
I couldn't follow the geometry in the picture and what the colors mean. Anyway, we can move past that for now.
Yes, they are visible in that photo. I did attach them to both sides. This was supposed to be a temporary solution and it has stayed in place for a year or more. Mainly because I haven't had time to look into it. But it sounds pretty damn good.
The wings start near the edge of the driver and create a smooth transition to the wall. The projection screen creates a problem, but I guess I'll have to live with it. If I had to do it again, I would design a smoother interface from the driver to the wall. Even small differences in the flatness of the wall or cabinet creates an edge that can lead to reflections. Best to design for it.
I checked the construction plans, it's a 6 inch baffle (15.2 cm). The wings are obstructing me from directly measuring them and I'm loathe to remove them just for one measurement.
I couldn't follow the geometry in the picture and what the colors mean. Anyway, we can move past that for now.
Do you have photos of the cardboard? Did you add it to both sides? Making the baffle asymmetrical is almost always a good idea to reduce diffraction issues. Are they visible in this photo?
In that case you did something that strongly resembles my plan
Yes, they are visible in that photo. I did attach them to both sides. This was supposed to be a temporary solution and it has stayed in place for a year or more. Mainly because I haven't had time to look into it. But it sounds pretty damn good.
The wings start near the edge of the driver and create a smooth transition to the wall. The projection screen creates a problem, but I guess I'll have to live with it. If I had to do it again, I would design a smoother interface from the driver to the wall. Even small differences in the flatness of the wall or cabinet creates an edge that can lead to reflections. Best to design for it.
The addition of the cardboard waveguide essentially reduces the width of the baffle to ~76 mm. I made a simulation of that:
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It makes the first dip narrower and at a higher frequency, which should sound better. Moving the dip even higher in frequency is probably preferable if you want to listen on-axis. That might be possible to achieve by rear-mounting the drivers and adding a separate waveguide to each driver.
/Anton
Yes, that looks a lot better. I have wondered what a small slit-like opening would do to the response. Like the classic JBL horns with the vertical slit to improve horizontal polar response of 2 inch exit compression drivers up to 16 kHz. Maybe your simulation can tell. If your wings started from in front of the driver with maybe a 1 inch or 1/2 inch slit, what would happen to the response? You might get some resonances, but there might be benefits too.
A lot of people complain about harshness from horns that have slits in the throat (there's a name for them that is eluding me right now), but I have not had that problem and it makes me wonder if the complaint arises because the response is not correctly EQ-ed rather than a fundamental problem with the design.
Hi RA7,
Sorry to revisit an old topic, but given what you've seen with the various line array threads and your own experience, what do you think the right balance is of interior volume, managing the internal reflections, and getting the drivers as close to the corner as possible?
For my build, I can build volume into the walls themselves so that's less of an issue. But then I was getting caught up with the issue of not having enough room for fiberglass to damp the internal reflections and back wave problems. But of course, the larger the enclosure, the farther out from the corner the drivers need to be.
There's also the related issue of the interface of the baffle to the wall and it looks like your wings have addressed that reasonably well. But if you were me, what would you do? Thinner baffle to get the drivers closer to the corner to shift the frequency dip higher at the expense of potential back wave problems? Or perhaps just build in the wings from the beginning?
I'm even considering a hybrid baffle with a 5" wide, 1/4" thick aluminum baffle to mount the drivers but then have concave wings that would be asypmtotic to the wall. The aluminum would sit in a 1/2" wide rabbet in the wings which would be perhaps three layers of 1/4" MDF that would be kerfed and bent at a radius commensurate with the distance of the baffle to the corner.
On the other side of the spectrum, I might just build what's easiest.
Would love your perspective though.
Sorry to revisit an old topic, but given what you've seen with the various line array threads and your own experience, what do you think the right balance is of interior volume, managing the internal reflections, and getting the drivers as close to the corner as possible?
For my build, I can build volume into the walls themselves so that's less of an issue. But then I was getting caught up with the issue of not having enough room for fiberglass to damp the internal reflections and back wave problems. But of course, the larger the enclosure, the farther out from the corner the drivers need to be.
There's also the related issue of the interface of the baffle to the wall and it looks like your wings have addressed that reasonably well. But if you were me, what would you do? Thinner baffle to get the drivers closer to the corner to shift the frequency dip higher at the expense of potential back wave problems? Or perhaps just build in the wings from the beginning?
I'm even considering a hybrid baffle with a 5" wide, 1/4" thick aluminum baffle to mount the drivers but then have concave wings that would be asypmtotic to the wall. The aluminum would sit in a 1/2" wide rabbet in the wings which would be perhaps three layers of 1/4" MDF that would be kerfed and bent at a radius commensurate with the distance of the baffle to the corner.
On the other side of the spectrum, I might just build what's easiest.
Would love your perspective though.
Build what's easiest and what will get the job done acoustically. At least that is my approach
Internal waves depend on internal dimensions. For the line array, if you build something like Wesayso's cab, I would imagine 1-2 inch lining with fiberglass or denim insulation on all walls should do the job, plus insulation about 1/5th the thickness of the height near the middle of the cabinet to absorb the standing wave corresponding to the height.
See this marvelous post from speaker dave for the full scoop on how internal reflections/standing waves work:
http://www.diyaudio.com/forums/multi-way/215133-box-colourations-really-22.html#post3086482
I'm not sure why you say there will be back wave problems if you shift the drivers closer to the corners. If you shrink the cabinet, the amount of absorption needed will also shrink because the frequencies of standing waves will increase leading to the need for less insulation.
If I were in your shoes, my number one worry would be what would I do if I get bored or don't like the sound. But that's me. I would like to have the ability to tear it down without too much effort.
One question that might help guide you is whether you are planning to add subs for bottom end support. If your arrays are only going to be doing 80 Hz and up, your probably do not need to build a big cabinet. Even with my tiny cabinet, I can get to 80 Hz easily (with EQ).
Your hybrid baffle might be a good idea. Make your walls such that they can receive a baffle and the combination with the removable baffle makes a cabinet. Then you can mount your drivers on a thin baffle at first, but retain the ability to add width to the baffle and make the "cabinet" bigger.
Internal waves depend on internal dimensions. For the line array, if you build something like Wesayso's cab, I would imagine 1-2 inch lining with fiberglass or denim insulation on all walls should do the job, plus insulation about 1/5th the thickness of the height near the middle of the cabinet to absorb the standing wave corresponding to the height.
See this marvelous post from speaker dave for the full scoop on how internal reflections/standing waves work:
http://www.diyaudio.com/forums/multi-way/215133-box-colourations-really-22.html#post3086482
I'm not sure why you say there will be back wave problems if you shift the drivers closer to the corners. If you shrink the cabinet, the amount of absorption needed will also shrink because the frequencies of standing waves will increase leading to the need for less insulation.
If I were in your shoes, my number one worry would be what would I do if I get bored or don't like the sound. But that's me. I would like to have the ability to tear it down without too much effort.
One question that might help guide you is whether you are planning to add subs for bottom end support. If your arrays are only going to be doing 80 Hz and up, your probably do not need to build a big cabinet. Even with my tiny cabinet, I can get to 80 Hz easily (with EQ).
Your hybrid baffle might be a good idea. Make your walls such that they can receive a baffle and the combination with the removable baffle makes a cabinet. Then you can mount your drivers on a thin baffle at first, but retain the ability to add width to the baffle and make the "cabinet" bigger.
That is a great post! Super interesting. I am planning on infinite baffle subs but I also kind of want to have the flexibility to run it full range alone for music. And if it wasn't a huge deal to get lower, I could potentially forego the subs. But I'm thinking for movies, the subs will be a good thing to have regardless of how low the arrays go practically speaking. So yes, I'm less worried about the size. But to your point, tearing it down won't be difficult.
Thanks for the input as always!
Thanks for the input as always!
First Reviews Are In
I live in a relatively small town in the US, Seattle and Portland being the nearest "big" cities. I've lived here for several years without ever getting together with local audiophiles---I just didn't think there were any. There is no local club either. So, you can imagine my excitement when I found out there is not one but a whole gang of audio fiends who get together regularly to do the usual audiophile things. I joined them for a few listening sessions. These sessions were as much about gear as discovering new music, getting together with friends, drinking good alcohol, and just having some fun. I consider myself lucky to have found this group.
I heard a couple of great systems at their homes, mostly all tube, with Garrard 301s and Thornens TD124s driving Tannoy Westminsters and Altec VOTTs. Lots of tone and analog magic. It was great.
I invited them over to my home to listen to the line arrays and paper horn system. They really liked the system built around the paper horns. The woofers are JBL 2226, and I recently built cabinets for them per the JBL enclosure guide. I used 3/4 inch baltic birch for the first time. Really impressive plywood. It is so uniform and stable and strong. The front baffle is two layers of plywood separated by a thick rubber layer. The woofer is mounted on the front baffle, which is fastened to the enclosure baffle by threaded inserts and screws. Lined on the inside with denim insulation.
The line arrays were the main event and they did not disappoint. Here are some of the things that were said about the arrays:
- "With this system, you can basically tell Stereophile to go f*** themselves."
- "I've never heard this record sound better."
- "There is an electrostatic-like quality to the sound."
- "I've heard line arrays before, but this is something else. Superb."
- "This sounds better than any audio parlor in all of Portland." (One of the guys was visiting from Portland, OR).
All in all, positive reviews. Couple of the guys are reviewers for Positive Feedback and 6moons. This was a big relief for me because I've never had any other audiophiles listen to the arrays. I've heard Orions, and other diy well-designed systems, and had an idea what it should sound like, but to be validated by others is always a good sign.
With all the analog gear in their systems, I got the itch again and bought this beauty: Garrard Zero 100. Looking forward to getting it setup.
I live in a relatively small town in the US, Seattle and Portland being the nearest "big" cities. I've lived here for several years without ever getting together with local audiophiles---I just didn't think there were any. There is no local club either. So, you can imagine my excitement when I found out there is not one but a whole gang of audio fiends who get together regularly to do the usual audiophile things. I joined them for a few listening sessions. These sessions were as much about gear as discovering new music, getting together with friends, drinking good alcohol, and just having some fun. I consider myself lucky to have found this group.
I heard a couple of great systems at their homes, mostly all tube, with Garrard 301s and Thornens TD124s driving Tannoy Westminsters and Altec VOTTs. Lots of tone and analog magic. It was great.
I invited them over to my home to listen to the line arrays and paper horn system. They really liked the system built around the paper horns. The woofers are JBL 2226, and I recently built cabinets for them per the JBL enclosure guide. I used 3/4 inch baltic birch for the first time. Really impressive plywood. It is so uniform and stable and strong. The front baffle is two layers of plywood separated by a thick rubber layer. The woofer is mounted on the front baffle, which is fastened to the enclosure baffle by threaded inserts and screws. Lined on the inside with denim insulation.
The line arrays were the main event and they did not disappoint. Here are some of the things that were said about the arrays:
- "With this system, you can basically tell Stereophile to go f*** themselves."
- "I've never heard this record sound better."
- "There is an electrostatic-like quality to the sound."
- "I've heard line arrays before, but this is something else. Superb."
- "This sounds better than any audio parlor in all of Portland." (One of the guys was visiting from Portland, OR).
All in all, positive reviews. Couple of the guys are reviewers for Positive Feedback and 6moons. This was a big relief for me because I've never had any other audiophiles listen to the arrays. I've heard Orions, and other diy well-designed systems, and had an idea what it should sound like, but to be validated by others is always a good sign.
With all the analog gear in their systems, I got the itch again and bought this beauty: Garrard Zero 100. Looking forward to getting it setup.
Attachments
Good story! Must be fun to find a group of likeminded people to share a passion with!
Go figure, that TC9 driver can even impress the audiophiles.
I can imagine it was a bit scary to have people over to "judge" your system.
At least I felt like that each time I've had listeners over. That includes you and X, BYRTT.
Go figure, that TC9 driver can even impress the audiophiles.
I can imagine it was a bit scary to have people over to "judge" your system.
At least I felt like that each time I've had listeners over. That includes you and X, BYRTT
.
Year some positive comments there : )
Those review are very long way from other always insisting its TV application driver performer only.
...I can imagine it was a bit scary to have people over to "judge" your system.
At least I felt like that each time I've had listeners over. That includes you and X, BYRTT
In general don't be scared of me and especially not when you have so much order in their things.
Good story! Must be fun to find a group of likeminded people to share a passion with!
Go figure, that TC9 driver can even impress the audiophiles.
I can imagine it was a bit scary to have people over to "judge" your system.
At least I felt like that each time I've had listeners over. That includes you and X, BYRTT
Yeah, these are great people. Bound by the joy of listening to music and enjoying the company of friends. There is no bitching, grousing, complaining, or jealousy of any kind, which is very rare indeed in the world of multi-thousand dollar gear.
Yes, it is very scary to open yourself up for review. All these guys have highly evolved tastes and systems. All tube gear too. So, I really did not how it would go with my all diy system filled with Pass DIY stuff. Someone even asked me, "Are you sure there are no tubes in there?"
They were really impressed with the Pearl Phono II. The lowly Technics SL1200 with a DL103 also acquitted itself quite well. I heard this cartridge from Japan called the Sumile on one of the guys' systems. It was staggering what it could do relative to the 103, which was on another arm making rapid comparisons possible. The 103 is no slouch but the Sumile was stunning.
Coming back to the arrays, DRC is really a big improvement. Perhaps the most important "component" even though it is not a physical component.
Ra7,
Looks like you're having a good time! Great story, and keep on enjoying the music.
Thanks zman!
Yeah, when the driver does not help them make money and takes business away from other more expensive and poor performing drivers, the only thing to do is call it bad.
Also, would you be interested in testing out a waveguide like they are discussing here: Line array prototype (with waveguide and CBT shading)
Hi Chris,
I had a bunch of Neo8s that I sold two years ago. Yes, I thought about it, but you just can't push planars below 200 Hz and that's a bad place to crossover from an array. It is very hard to do a proper crossover in that region because it is hard to get measurements that correlate with what you hear in that region (at least, I haven't been successful). You really want to get down to 100 Hz or a little below for an easy cross to a sub. I thought of trying it though, which is why I had bought the Neo8s.
The waveguide design is interesting. Could be quite successful, if executed correctly. Mine are already in a corner, so, I get 90 degrees in the horizontal at least until the point they start beaming.
I had a bunch of Neo8s that I sold two years ago. Yes, I thought about it, but you just can't push planars below 200 Hz and that's a bad place to crossover from an array. It is very hard to do a proper crossover in that region because it is hard to get measurements that correlate with what you hear in that region (at least, I haven't been successful). You really want to get down to 100 Hz or a little below for an easy cross to a sub. I thought of trying it though, which is why I had bought the Neo8s.
The waveguide design is interesting. Could be quite successful, if executed correctly. Mine are already in a corner, so, I get 90 degrees in the horizontal at least until the point they start beaming.
I hope you played them something other than Led Zep. 
Maybe that singer you played for my on my horn system, don't remember her name, but one of your dad's favorites IIRC.