New DIY speakers

bvbellomo

Member
2013-03-08 2:31 pm
I currently have an AV123/Onix Reference 1 / Reference 100 setup. I am running 7.1 with junk (< $50) speakers for the rear. I have a Sharp 52 LCD TV. I am very happy with the way this setup sounds, but am getting married to a girl who is not happy with the way this setup looks.

My initial response was to build an entertainment center that looks like whatever she wants it too. I have all the tools, like DIY, have the skills, a good lumberyard, and hate the cheap particle board furniture sold today. For some reason, this idea really freaked her out. She said it is not worth my time, as I need to redo the roof, kitchen, floors and finish my PhD. So I suggested we pay someone to build it custom, but again she didn't like this idea. Maybe she is worried it will look junky, but I don't understand how, using a professional woodworker and good cherry.

So we have been looking at entertainment centers for almost a year now. Everything made commercially is too small for 'real' speakers and has no good place to put a center. I am convinced no one who designs these things has seen a real home-theater system since 1990. Also, my speakers are rear ported, limiting placement options.

So I started thinking that if I can't build something better to hold my AV123's, maybe I can build something better than my AV123s. One option is to buy the same Vifa XT ring-radiator tweeter and 5.25" Atohm woofer in a new box, but if I am going to do a project, I want to upgrade. So here are my design issues:

1) Speakers need to be small as possible and sealed or front ported.
2) I have plenty of power (RX-A3000), have never listened at ridiculous (100db+) levels, and will mostly be listening at even lower levels as a married man (60db). So power and efficiency do not need to be anything special.
3) I like my current speakers, so anything new must be as detailed, and 'coloration' that is similar is appreciated. I am open to detailed drivers that have very different coloration however.
4) The TV is getting near the end of its useful life, but I have tons of ambient light in the room, so any replacement will likely be another LCD, meaning I cannot put a center behind the screen. I like having a center vs just sides, and am consider unconventional designs (2 centers, 1 above, 1 below, or 1 center with drivers above and below the screen).
5) I have a HSU subwoofer that is way overkill and my girl would probably want to get rid of, but she hasn't forced me to yet. So I am considering both full range speakers and bookshelves. Any full-range option would need full power (80+db) down to 15Hz like my HSU. I do realize this is in conflict with the size requirements, but it is still being considered.
6) Time and budget are not strictly limited, but the less of either, the more likely I can get this project by my girl 'under the radar'.
7) I understand physics, electronics and have the skills and tools to build almost anything, but am overwhelmed at the number of drivers to choose from, and have no knowledge of brands or models. I have limited listening experience with various designs (ribbons, metal domes, etc).

Advice on drivers, speaker dimensions and crossovers would be greatly appreciated.

I posted this on several other forums. Most of the advice I got was to get rid of the girl and keep the speakers. While that has already been strongly considered, the decision has been made, so please don't post that.
 

bvbellomo

Member
2013-03-08 2:31 pm
After a bit of reading, I am thinking of using the ZA5 in wall, but not actually building it into a wall, hanging it on or leaning it against the wall. Can this be done? I don't really understand the "in-wall" design. Does this mean there should ideally be 0 resonance behind the speaker? Or are they assuming a 15" wide, 8' high enclosure?
 
After a bit of reading, I am thinking of using the ZA5 in wall, but not actually building it into a wall, hanging it on or leaning it against the wall. Can this be done? I don't really understand the "in-wall" design. Does this mean there should ideally be 0 resonance behind the speaker? Or are they assuming a 15" wide, 8' high enclosure?

Below a certain frequency the sound begins to wrap around the speaker and travel in every direction like a continuously inflating bubble. In-wall speakers do not allow the sound to travel behind them obviously so all sound is projected forward. In simple terms an in-wall speaker is twice as powerful as a similar speaker placed in the middle of an open field because there's no loss of sound power to the rear.
Now, when regular speakers are placed some distance from the wall the backward-traveling sound will hit the wall and bounce back. When the reflected rear wave reaches the speaker again it will combine with the forward-traveling wave and will create constructive and destructive interference at certain frequencies.
By carefully selecting the distance of the speaker to rear wall one could successfully boost the frequency where the speakers begin to roll off. Speakers hanging on the wall generally don't sound correct because they boost the midrange where the ear is most sensitive.

The point I'm driving at is that it's very difficult to build something that is accurate as well as aesthetically pleasing. You need to examine your priorities and decide whether you want to spend years learning how do this right or just build/buy something that is acceptable.

DIY speaker building is great and it will be very rewarding if you have woodworking skills. My personal advice is to build a well-documented design from one of the many audio DIY web sites for the time being. Messing around with drivers and crossovers takes a lot of time to get right. A DIY design will give you a lot of satisfaction and a few years down the line you will have a much better idea what and how to upgrade.
 
IF some girl fixates on the apperance of some folish HT setup? this Really is an Ill omen for a marriasge situation. There are FAR more important issues to deal with/concern oneself with than some Dorky TV gear assembly.
IMO this is clear Warning of a poor choice for Marriage
 
Well she is allowed to be fixated if she is paying for it.
My advise to the OP is this - spend some time and make a collection of pictures of different HT setups. There are plenty of those on the Internet, especially HT forums. The idea is to pick very different designs even some you don't like. Then sit down with your woman and have her express her ideas about each one. It should be a good, positive relationship exercise. Once you have an idea of what she likes make a sketch together and start from there.
If she rejects all options without providing you with a sensible alternative then there's something wrong.
 

bvbellomo

Member
2013-03-08 2:31 pm
What people always fail to see on these forums is there is more to a marriage than liking the same speakers. I do have some things she doesn't like that I refuse to get rid of, but the speakers aren't one of them. If I have to design my own crossover to build a nice, small speaker, that is a fun project. If I can't do that and have to put a $3000 HT system in the garbage, well, it was nice well it lasted.