AudioCircle
Industry Circles => GR Research => Topic started by: soewhatman on 31 Aug 2007, 05:32 pm
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Hi there. I'm about ready to bite the bullet and order a pair of A/V-3's to build as the front left and right. I've never built speakers before, but I have a garage full of woodworking tools and I like projects that keep me busy. In addition, I like the lots of bang for your buck aspect, as these seem like extremely well liked speakers. I've gone through a number of setups with commercially available satellite/sub sets over the years, and have never really been happy with the little speakers for listening to music.
In any case, I want to make sure to order everything I need for the speakers. Do I need any additional packing material for the inside of the boxes, other than the No-Rez which I will order along with the speaker kits?
When I build the boxes, it is well within my ability to laminate a couple of layers of MDF to make for thicker surfaces with more mass. I am thinking of only doing this for the front plate (baffle), but should I consider doing this for the rest of the sides as well? One reason I like the A/V-3's is the relatively modest footprint. They will fit well in my room, and be pleasant on the eye. I am reluctant to make them larger in every direction, but would consider it if it adds enough to the sound of the speakers.
Also, though I will do this project a bit at a time, I am trying to map out the system as a whole. For a center speaker, it seems the preferred choice is an an A/V-3S. I will be building the main A/V-3 speakers to be front ported so they can be nearer to the wall. Is there any reason I can't build a third A/V-3 front ported and use this as a center speaker? Is there a disadvantage to a vertical speaker alignment for the center? Every center I see is horizontally aligned. It will sit below a wall hung flat panel TV, so in my application vertical is just fine.
If this is a viable option, can I get just one A/V-3 kit? The web store only lists them in pairs.
Finally, I am planning on the A/V-O as the rears. My sitting area is about 15' wide x 13' deep, but is open on the back and one side to the rest of the "common room." I can't really put rears on the walls, as there are no walls to put them on. The entire room is about 20' x 30'. The A/V-O's as rears would sit basically in the middle of the room. Is this a reasonable application for these, or would a more directional speaker like the A/V-1 on a stand be better?
Thanks for your input. This will be the first set I've owned that wasn't Sony/Bose/Yamaha etc. I really looking forward to gettting at least the fronts and working my way through these.
Rick.
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If you want to do an all-out construction of the cabinets, try this. For the front baffle laminate 3/4" MDF, then 1/8" mass-loaded vinyl, then 3/4" marine grade ply or void-free baltic birch ply. With the mass-loaded vinyl sandwiched in-between it's what we call a constrained layer damping technique, and really helps keep those driver inertial forces from transfering into the rest of the cabinet materials. Since the front baffle will be thick, make sure and chamfer out the inside of the driver holes so they can breathe.
For the rear wall do a 3/4" MDF and 3/4" ply laminate. But for the side walls if you make them 1 1/2" thick it'll change the front baffle width, which will affect diffraction and the final frequency response of the speakers ... best to stick with the same width unless you have proper acoustic measurement gear.
And yes, there's no problem with a vertical center ... it's better actually. The reason you see center channels as a horizontal layout is simply because most people can't use a vertical center.
I'm sure Danny will sell you 3 A/V3 kits. I'd definately go for the NoRez and Sonicap upgrades too, at least for the left and right speakers.
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I'll try to take your questions in the order that you posted them.
Do I need any additional packing material for the inside of the boxes, other than the No-Rez which I will order along with the speaker kits?
Yes, there are provisions in the plans for additional poly fill or fiberglass insolation. You can view it now by downloading the cabinet plans from the link at the bottom of the page.
When I build the boxes, it is well within my ability to laminate a couple of layers of MDF to make for thicker surfaces with more mass. I am thinking of only doing this for the front plate (baffle), but should I consider doing this for the rest of the sides as well?
You can laminate a couple of layers if you like. If it were me I might be inclined to do the front baffle 1" thick or something, but making the rest of the cabinet thicker is really not necessary with this model. It is really well braced and once lined with the No Rez it is pretty solid.
I will be building the main A/V-3 speakers to be front ported so they can be nearer to the wall. Is there any reason I can't build a third A/V-3 front ported and use this as a center speaker?
The main speakers are actually transmission line loaded, and you can flip flop the plans to allow the end of the transmission line to exit out the front. No problem there. The center can be ported if you like and I can provide you with ports, but you will need to double the volume of the box. For a lot of people that can be a problem. Most want them as small as possible.
Is there a disadvantage to a vertical speaker alignment for the center?
No disadvantages at all, but there is an advantage. You will have a wider and more even off axis response in the horizontal plane by keeping it upright. The reason most people lay them over on the side is due to space limitations.
If this is a viable option, can I get just one A/V-3 kit? The web store only lists them in pairs.
No problem. The A/V-3 and A/V-3S are the same kits. The only differences are that the single A/V-3S kit is fully shielded and the A/V-3 kit (pair of floor standing speaker kits) comes with floor spikes. Other than those two things the difference is the box design, how the woofers are loaded and the low end extension.
The A/V-O's as rears would sit basically in the middle of the room. Is this a reasonable application for these, or would a more directional speaker like the A/V-1 on a stand be better?
This is ideal for the A/V-O. The A/V-O blows away the A/V-1. It is a great sounding speaker and sounds less like a boxed speaker than any of the other A/V series kits. It also sounds much bigger than it really is. You'll love them.
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Thank you much for answering my questions. I went ahead and ordered a kit for the A/V-3's and will start with those. I like projects, and I like to learn new things, so this should fit both bills. I'm looking forward to working on these.
I don't understand the difference between ported and transmission line loaded, but I'll do a bit of research and figure it out. In any case, I will build the boxes with the opening towards the front, as I have noticed a few folks have done here in the forums. If you've designed these to be transmission line loaded, then transmission line loaded they'll be. :wink:
Rick.
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Thanks for the order. They'll go out on Monday unless UPS isn't running tomorrow because of Labor Day.
You'll have fun with these. They have been a personal favorite for a long time.
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Ok, so I did a bit of research on transmission lines. In layman's terms, to my understanding, it is a technique to mitigate the sound waves being generated by the back side of the speaker cone, which are undesirable sounds. Does that sound about right?
Does it allow the woofer speakers to play lower frequencies than, by comparison, playing in a sealed box because the woofers won't be operating against the air pressure contained in the box?
Also, I'm still mapping out how I'm going to put this all together as a 5.1 system and I've got one more question, regarding a sub unit. Aesthetics are very important to me for this setup, and I don't really have a place for a sub box anywhere. I will, however, be building a nice large, square coffee table for this room. I already have a 2" thick solid mahogany top that I will adapt for this table, so it will be nice and solid. I am considering purchasing one of your sub unit kits and essentially building the box, to your specifications, into the table. In theory, the sounds from a sub should be non-directional if the sub is only playing the lower end frequencies, but is there any issue with having it placed close and center to the primary listening position?
When I listen to music, I prefer pure simple stereo and I won't even use the sub if the AV-3's live up to expectations, which I'm sure they will. For music I prefer really crisp bass, in general. The sub will be solely for movies, and I'm willing to sacrifice the "best" location in order to conceal it into my room nicely. Is this a terrible idea for any reason, or should it work out ok? Is there a best direction to orient the sub unit in the table?
I'm looking forward to the AV-3 kits, by the way. One significant factor in my deciding to purchase these is the excellent service you provide your customers through your forums here. You are running a top notch business, at least to my expectations.
Rick.
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Rick, Danny's new TL version does go a bit lower than his orginal design. They are a favorite of mine too and I assure you, you won't be disappointed. For quite a bit of music you won't need a sub - depends on your main musical tastes. If you do your sub as planned, I'd recommend you don't physically couple it to your coffee table - just "hide" it with the table - and, place it so the driver faces away from your seating position.
There are a couple of pics of the pair of A/V-3's that I built and veneered in rosewood on page 3 of my crude website: http://www.geocities.com/hankbond1/index
Have fun building and listening :thumb:
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The A/V 3's go down low enough for most music. And the bass they do, they do really well. TL bass is really nice.
Despite having built Danny's sub as well, I often times did my listening without it when I ran the A/V 3's.
Cheers
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In layman's terms, to my understanding, it is a technique to mitigate the sound waves being generated by the back side of the speaker cone, which are undesirable sounds. Does that sound about right?
Actually that is what the damping material does.
A properly designed transmission line times the pressure of the box and output of the transmission line opening (port) to the woofer output to increase low end output levels beyond what you can get with a sealed or ported design.
Think of it as the woofers move out and they create a negative air pressure behind them in the box. This begins to pull air trough the transmission line, but by the time a negative air pressure is created at the opening to outside air, the woofers have already moved all the way in creating a negative air pressure in front of the woofers as well.
Then when the woofer move in it creates a positive air pressure in the box. This positive air pressure then moves through the transmission line and out the opening to outside air, but by the time this positive pressure exits the opening the woofers have already reached the maximum forward exertion again. So it created positive air pressure on both sides of the box.
This effectively allows the surface area of the woofers to be increased as we are now taking advantage of movement in both directions and effectively doubling it minus the losses of velocity from the transmission line itself.
Now if you tune the output of the transmission line to the 6db down point we effectively increase its output bringing the level up and creating a new -3db level that is 5Hz or so lower than before. You can get more increase than this but the size of the transmission line gets fairly large.
This also raises the impedance in a lower frequency range and helps power handling, loading on the woofer at a lower range, and over all low end control. The larger air space also puts less load on the woofers in upper ranges allowing it to preform more as if in free air as frequency increases. This allows for a cleaner mid-range.
Make sense?
The A/V-3's will work fine for you for most music without a sub. It has always been one of my favorites as well.
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This is ideal for the A/V-O. The A/V-O blows away the A/V-1. It is a great sounding speaker and sounds less like a boxed speaker than any of the other A/V series kits. It also sounds much bigger than it really is. You'll love them.
Danny, I'm considering the A/V-3's also but the A/V-O looks interesting too. Here you made a comment about the A/V-O relative to the A/V-1. What's your opinion of the A/V-O compared to the A/V-3?
Doug
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Wow. Your description makes perfect sense. Thanks for taking the time to describe that.
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Here you made a comment about the A/V-O relative to the A/V-1. What's your opinion of the A/V-O compared to the A/V-3?
The A/V-3 has it beat on power handling and output levels, but the A/V-O has the ability to sound more transparent and more realistic in sound stage, imaging, and 3 dimensionality. The A/V-O can sound much like an open baffle type speaker. They do need to be more out into a room though. They can't be too close to a boundary wall or it will color the sound.
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Thanks Danny
That helps, and I think it clinches the A/V-3 as the better choice for me (between these two) as the speakers will need to be fairly close to the rear wall. I'm still looking around but the A/V-3 is definitely on my short list.
Doug
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Received the kit on Friday, and started cutting up MDF today. Fun opening up a box of nice looking speaker drivers. No grill is going to cover these up. I'm going to make the front panel 1 1/2" thick just for kicks by laminating two layers of 3/4" material together. I'm assuming I will then need to make the side panels 3/4" wider to maintain the same internal box volume?
Edit: I realize now this isn't necessary the way the box is designed. Scratch that question.
Also, in regards to the sub, I'm glad it sounds like the AV/3 doesn't need a sub for music listening. I much prefer music without a sub. The sub will be used solely for movies. At present I have a little 150 watt yamaha sub, but I doubt it will be adequate once I get the AV-3's going. I'm not sure if a sub, or center/rear speakers will be my next project, but I fear this might get addictive. At least I can put my garage full of tools to work.
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I'm assuming I will then need to make the side panels 3/4" wider to maintain the same internal box volume?
Making the front baffle thinker will not take away internal volume. Make it thicker to the outside and not the inside. Maintain all the same internal dimensions. Don't make the front baffle any wider or it effect the surface reflections in an adverse way.
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Also, in regards to the sub, I'm glad it sounds like the AV/3 doesn't need a sub for music listening. I much prefer music without a sub. The sub will be used solely for movies. At present I have a little 150 watt yamaha sub, but I doubt it will be adequate once I get the AV-3's going. I'm not sure if a sub, or center/rear speakers will be my next project, but I fear this might get addictive. At least I can put my garage full of tools to work.
This sounds almost like me when I was building my AV/3! Then after I finished them I was a bit bored so I decided to order Danny's sub kit. After I completed the sub, plugged it in my system, I said, from now on I will never listen to music without a sub! :icon_lol:
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Well, I've got the boxes constructed and I'm putting in foam before I glue on the face. I ordered the no-rez upgrade with these, so I have one sheet of it. I'm about 2/3 of the way complete with one box and I realize one sheet is nowhere enough to add dampening material to all surfaces as the plans denote. Should I only be using the no-rez on some of the surfaces, and something else on the others?
The options as I see them:
1. Order another sheet of no-rez to do both boxes complete with it.
2. Only use no-rez in the most critical areas, which I am guessing are the areas immediately around the two larger drivers, and use something else at the other locations. I'm not sure what "something else" might be, though. I do have a bunch of leftover vinyl composite tile (benefits of running my own remdoel business, I've got lots of odds and ends lying about) and it seems pretty similar to the backing pad on the no-rez. This is actually what I used to create my 1 1/2" thick sandwich for my front panel. If I used this as a base, what would be the best type of foam to use and where might I go about purchasing it?
Thanks for your help.
Rick.
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You could solve your problem and go with option number 1.
You can also go with option number two and use the No Rez in the most critical areas. These would be in the upper part of the cabinet and behind the drivers.
Keep in mind that the No Rez serves two functions. Firstly it dampens the walls and takes away the resonance of the panel. It also absorbs standing waves with its foam layer.
You can use your floor tiles to dampen the walls. It is not quite as effective as no Rez but not bad either. The strongly braced area in the transmission line itself will not be as prone to resonant.
You can then use a layer of open cell foam on top of the floor tiles to absorb standing waves and minimize an cavity resonance that might set up in the transmission line itself. Even a thin layer of foam on the side walls of the transmission line won't hurt.
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With the Master's endorsement I'll go with option #2. :wink:
It will be a bit cheaper for me. That no-rez is nifty stuff, but I'm already well above the $400 front speaker budget I established with the significant other.
Thanks for taking the time Danny.
Rick.
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Also, in regards to the sub, I'm glad it sounds like the AV/3 doesn't need a sub for music listening. I much prefer music without a sub. The sub will be used solely for movies. At present I have a little 150 watt yamaha sub, but I doubt it will be adequate once I get the AV-3's going. I'm not sure if a sub, or center/rear speakers will be my next project, but I fear this might get addictive. At least I can put my garage full of tools to work.
Sounds cool! I built a pair of AV-3s this summer and they turned out great. I finished them on the tops with black paint and lacquer (this took lots of sanding) and the bottom section I wrapped 24 gauge stainless steel. The steel worked like a thick veneer and looks great. I'll try to find a pic.
For dampening I used peel and stick floor tiles, doubled them up a few times and glued them to the walls where the dampening goes. I then covered all of that in 1" open foam I picked up at Hobby Lobby. It made the box dead, although (as mentioned countless times before) it probably isn't as effective as No-Rez. Either way it sounds great. I upgraded to Sonocaps too.
As for the subwoofers... yeah. The Av-3s have bass response, and it is nice, but it (to me) sounds a bit dry and thin. Most subwoofers sound this way to me, so it isn't really a knock on the AV-3. However, I built an Infinite Baffle subwoofer into the wall space behind my mains (2 x 18") and that thing is something else. Obviously you gain another dimension, even if you don't think your music needs it. Trust me, a sub will help. These aren't the LS-9s or anything.... :D
Show us how it turns out!
EDIT: Here's mine:
(http://farm2.static.flickr.com/1157/993223868_984029279e.jpg)
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Sounds cool! I built a pair of AV-3s this summer and they turned out great. I finished them on the tops with black paint and lacquer (this took lots of sanding) and the bottom section I wrapped 24 gauge stainless steel. The steel worked like a thick veneer and looks great. I'll try to find a pic.
For dampening I used peel and stick floor tiles, doubled them up a few times and glued them to the walls where the dampening goes. I then covered all of that in 1" open foam I picked up at Hobby Lobby. It made the box dead, although (as mentioned countless times before) it probably isn't as effective as No-Rez. Either way it sounds great. I upgraded to Sonocaps too.
As for the subwoofers... yeah. The Av-3s have bass response, and it is nice, but it (to me) sounds a bit dry and thin. Most subwoofers sound this way to me, so it isn't really a knock on the AV-3. However, I built an Infinite Baffle subwoofer into the wall space behind my mains (2 x 18") and that thing is something else. Obviously you gain another dimension, even if you don't think your music needs it. Trust me, a sub will help. These aren't the LS-9s or anything.... :D
Show us how it turns out!
EDIT: Here's mine:
(http://farm2.static.flickr.com/1157/993223868_984029279e.jpg)
Those look really nice. Nice job finishing those. I really like the combination of metal/paint. They look very professional. Is that sub-woofer built into yhour wall? It looks that way.
I finished constructing mine yesterday and installed all the hardware in the boxes. I have been using a pair of Bose 201 bookshelf speakers for quiet some time and I used to think they were pretty nice. Ummm.....well. I'm not sure I'll ever be able to purchase speakers at a big box electronics store again after listening to the A/V-3's. I am very pleased with the way these sound, and I'm glad I could get them at the price I did, with a bit of work of course. Compared to the Bose speakers, which are my only reference point, there is a very substantial increase in both the definition and fullness of the sound. I'm quite happy with the amount of low end these produce for only using 5 1/2" drivers. They sound very good with most music.
I did a few things in the construction of my boxes:
1. I made the front panel almost 1 1/2" thick. Even without dampening material attached it was pretty "dead" sounding.
2. Since I only had one sheet of no-rez, I used it for dampening immediately surrounding the drivers. Everywhere else I used a combination of Vinyl Composite Tile, about 1/8" thick, and 1" open cell foam. I found the foam at a craft store.
3. I built the boxes 48" tall. The floor for the speaker portion is at 42", per the plans, and I constructed another small box at the bottom with the additional 6". This small box is filled with sand. I did not want to have a base extending past the footprint of the speaker box, so I was trying to bias the weight towards the bottom. Each speaker took almost 1/2 of a 50 lb. bag of playground sand, so there is an additional 20-22 lb. weight right at the bottom. It worked out pretty well. I wouldn't trust them if I was in an active house with kids, but since it's just me, my fiance, and our dogs they will be fine. You really have to work to push them over, but once they pass a certain point there's no stopping them. They look really slick, just nice narrow boxes coming right up out of the floor.
Right now they are set up in my bedroom, waiting for me to complete my front room renovation so they can be moved to their new home. I'll wait until I"m done with that in order to veneer them. I am planning on a mahogany veneer to match some other furniture that will be in the room. I will most definitely put up some pics once they are finished and in their final home.
One last question on these...the open cell foam I used in the box was from a craft store, and I think is used for seat cushions. I have also noticed there are "acoustic foams" available in various sorts that are much less expensive that no-rez. Are these acoustic foams appreciably different from the commonly available open cell foam? If so, I may consider swapping out the foam when I pull the speakers back apart for final finishing.
Thanks much, in particular to you Danny for designing such great kits and making them available at a reasonable price.
Rick.
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Ok, I received the veneer I ordered and I'm ready to put a finish on these AV-3's. I got a nice set of matched sheets of striped mahogony from veneersupplies.com so I have enough to do my av-0's and av-3's and have them look the same.
I'll pull all the hardware out of the boxes now and before I veneer I need to decide if I'll round-over the front corners of the boxes. In some poking around I've done, it seems there is a sonic difference if the front corners are rounded, especially with a narrow baffle. I've seen av-3's built both ways. Is there a way that is considered "better" for these speakers? For pure asthetics I would probably leave them square on the corner, but I'm not set on that. Thanks.
Rick.