DIY or Commercial Towers? (1 Viewer)

[Scott Sabin]

Man, this will be tough. The Kit 281s, the HE12 towers, the A/V-3 ported to the front, or even the SCH towers will all probably satisfy me - especially since these will be my first "real" speakers. Since I won't be comparing these to anything, I won't notice their inherent shortfalls.

Does anybody have an opinion on which of these 4 designs is easiest or take the least amount of time to build? Or are they all on the same order? My guess is that the AV-3 being a TL might make that cabinet assembly process a bit more involved.

Thanks for all the input.

 

[Scott Sabin]

By the way, Brian, regarding the AV3s and reversing the braces. Seems like this will be impossible since the top brace, which is on the back, cannot move to the front since that is where the lowest driver is mounted. I suppose I should start a new thread to get Danny's input on this.

 

[Hank Frankenberg]

Here's my humble input:
I've been building SCH kits for myself, family and customers for at least 5 years and can say they are the best value in speaker kits that I'm aware of. I still have my original towers and center channel and last year I built a modified cabinet version for a customer.

A/V-3's: 2 years ago I built Danny's original design for a couple and they were very pleased with them for a mainly music application. Recently I built a pair of Danny's new transmission line A/V-3's (veneered in rosewood of course). They are on the third page here:
http://www.geocities.com/hankbond1/Page3.html
They sound very, very good and are absolutely worth the money. Best combination HT/music speaker I've heard.
THE PORT: Not a problem - just keep them about a foot from the wall - you'd do that anyway probably. If you really must front port them, you certainly can. The way to do it is to eliminate the bottom "brace". Danny told me that the resulting shortening of the TL soundwave path will raise the F3 only a couple of Hz.

I hope that helps.

 

[Daniel Metcalf]

Hank, I was contemplating building some A/V-3's and an A/V-1 for the center(I don't like horizontal mtm's) both with Sonicaps. I currently have Madisound MDY-4's with the Esotec tweet that I built for my mains and NHT SZ's for my center and surrounds. The NHT's would go upstairs in the living room system and I was considering using the MDY-4's as surrounds with the A/V's, providing the A/V-3's sound "better" than my Dyn's. What do you think?

 

[Hank Frankenberg]

Daniel, I think you have a good plan. The A/V-3 cabinets are a bit labor intensive, but with patience, you'll have no problem.
I don't have the Sonicap upgrade and my A/V-3's have the GR T-1 tweeters. I'm about to order a pair of the new T-2 tweets and maybe the Sonicaps.

 

[Daniel Metcalf]

I think the A/V's will actually be easier than the MDY-4's, what with the sloped baffle and all, they'll just take longer. I was also going to double the baffle on the 3's to 1.5" and put as big of a chamfer as I could. That way they'll match my Madisounds. myweb.cableone.net/dnd2/test%20rt%20mainfull.jpg

 

[Dan Miller]

Hank,

I think you have done exactly what I wish to do. I spoke to Danny at GR and asked him a few questions about his new M-130-16 drivers. My question was how would they match up with his GR-T1 tweeter. He said just fine. Sounds like you are happy with this combination.

My goal is to make three AV-3 cabinets, using two M-130-16's and a GR-T1 in each for an 8 ohm impedence. Likely will build two structured the way you have, those being tall towers and wonder if I can come up with appropriate math, to create a laydown MTM configuration, for the center channel.

To save a few dollars, I was not going to use the upgraded capacitors or foil crossover coils. Is there a brand of reasonably price caps that you may recommend?


I manufacture electric armatures. This leads me to think that I can wind my own XO coils. Where would you suggest I go for information on the math involved in creating these coils?

From the information I have seen in various postings on this forum, I am certainly going for these drivers. The fact that Danny is so helpful has a great deal to do with this. When I spend my hard earned dollars, I like to think I am going to get good support. The numerous posts by Danny illustrate that.

Can I email you and get your reflections on where to cross these speakers over for HT use?

Thanks,

Dan Miller

 

[John Wes]

A question....I've not seen anything like a surround DIY speaker for the rear or sides in 6.1 or 7.1. Has anyone seen any such monster in a dipole?

Man, if Adaire or GR had such a thing using their own drivers..

The only reason I ask is because I've heard it's a better setup than using directional speakers for the sides in 6.1 or 7.1

 

[Hank Frankenberg]

Dan, feel free to e-mail me, but I suggesty you buy Danny's kit of parts. His standard caps are just fine. If you really have a burning desire to save a few bucks and wind your own coils you certainly can. Here's a link to a coil calculator:
http://www.colomar.com/Shavano/inductor_info.html
Plug in your desired indutance in mH, and it will generate a chart showing, by wire gauge, the DC resistanc, inductor height, radius, # of turns of wire, estimated wire length, etc.
My advice is to buy the kit and focus your efforts on cabinet construction and a nice veneer finish. I don't know what sub you have, so try crossovers between 80 and 60 Hz. BTW, Danny has just designed a smaller, sealed A/V-3, called the A/V-3S, so there's your center channel.
Have fun
John, Dolby labs recommends monopole speakers for 6.1 and 7.1. Danny is designing surrounds now.

 

[Scott Sabin]

Hank,
You did a wonderful job on those speaker cabinets! Thanks for the info on moving the TL opening to the front.

But now you have me thinking - 1 foot from the wall is feasible, but I've read elsewhere that you want about 4 feet. Are TL designs a bit more forgiving on "wall clearance" than rear vented designs? Now I'm thinking that perhaps I'd just stick with the AV-3 design as-is.

Last question. How stable is the AV-3 from being knocked over? With the cabinet being smaller than say the 281's, are they less stable? I suppose I could make the base plate a touch bigger without affecting any of the sonic characteristics, huh?

Thanks to all for your input!

 

[Hank Frankenberg]

Scott, thanks for the compliment. I've made several cabinets, some with rosewood veneer before, but these are my best qualiy finish yet. The rear port on the A/V-3's is quite large, so the air velocity is lower than if it were, say, a 2" port. I don't understand why 4 feet would be needed - you might consult with Danny just to be sure.
I haven't made bases for my A/V-3's yet. If you have small children or a big dog around, I strongly advise you make bases, and no, they won't affect the sound. You can go with a simple 3/4" MDF base 3 or 4 inches larger dimensions than the outside width and depth of the speaker cabinet.

 

[Joey Skinner]

I made the bases for my AV-3 speakers 14 x 15 in. and 1.5 in. thick. It would take a hard hit to knock them over.

 

[PaulDF]

I made my bases 11.5 x 15 inches. This seemed more proportionate than the recommended 14 x 15. The base makes the speaker very stable, and adds a very professional look, IMO.

Anybody able to estimate what the differences would be between front or rear ported? Is it mainly to allow placement closer to a wall, or will it also reinforce the bottom end? And if so in what way?

By the way, a suprising amount of air moves through that large opening!

 

[Hank Frankenberg]

Yes, it is a large amount of air, but fairly low velocity and it dissapates quickly, so I still believe that a foot or so away from the wall is okay. I'll try to get Danny to post here.

 

[Danny Richie]

With the base and the use of the floor spikes that come with the kit it is really solid. The size of the base can be adjusted as per your discretion as many here have added. One of the great things about building kits is having the flexibility of doing some things the way you want.

Thanks for the good questions.

 

[Dan Miller]

Danny or Hank,

If the AV-3 rolls off at about 45-50 and the AV-3S rolls off about 80, how much bass would I lose in a typical HT setup?

I do not know how much bass, ratio wise, is created by the two fronts vs the center channel, in what we will call, average 5.1 movie sound tracks.

My impression is that a pair of AV-3 towers and an AV-3S center will highly compliment one another for 95% of their ranges. I assume that dialogue and sound effects would be well reproduced with an AV-3 front array.

But would I notice a loss of bass with the AV-3S center channel rolling off at 80? Maybe I should ask, in a HT application, is there any center channel bass below 80hz, that I would even be aware of? Do movie sound tracks, in a 5.1 setup, even have center channel bass?

It is my plan to start out with the three fronts, using AV-3's and move back around the room from there. I just really want to nail the sound of the front array. Most probable that I will go with AV-1's for the rear corners.

After that, I am really going to be looking for a suggestion on what DIY sub to construct, that will fit in seamlessly with my GR group of various AV speakers .... but that question is for another thread.

Thanks guys,

Dan Miller

 

[Hank Frankenberg]

Dan, the towers will reproduce enough bass content and you won't notice the higher f3 of the center channel. It's main purpose in life is dialogue reproduction.
You'll get LOTS of info on subs from this forum. Enjoy.

 

[Danny Richie]

Hank is correct.

Also keep in mind that with a sealed box the low end roll off is very gradual compared to a ported box that plays flat longer but falls quickly.

 

[Scott Sabin]

Dan,

I think we share the same design goals in our applications. I too am trying to nail the front 3 speakers. If my room were high enough, I would go with 3 towers across the front, by due to my basement ceiling height at the location of the FP screen, I cannot fit a 42+ inch tower as a center. I could get away with a 30-35" tower for the center, but that's all.

My guess is that for movies, Hank is right - you'll never notice the lack of bass extension with the AV-3S. However, for multi-channel audio, I am less confident that the higher rolloff will go unnoticed. I suppose a bit more generic research and opinions from the multi-channel audio crowd would help me.

If I were into designing my own speakers (which at this point in my life, I am not), I suppose I could try to come up with a modified AV-3 design that gave up "a little bass extension" in order to save cabinet height. That would be my perfect center.

 

[Danny Richie]

You can have that too if you like.

The tall floor standing TL enclosure is 1.4 cubic feet.

The sealed box is .55 cubic feet.

Optimal ported is 1.1 cubic feet and as small as 1.0 cubic feet could be used.

Just change the dimensions of the box to suit you, keeping the same width and just changing the depth and height.

The smaller 1.1 cubic feet ported box will get you a -3db of about 47Hz.

Isn't DIY great?