[Zero the Hero]

Hi everyone, I'm really glad I found this site! I haven't been into audio for that long, and only started thinking about DIY in the last month or so. I picked up Ray Alden's Speaker Building 201 and read that, and have been trying to make up my mind on my first project. I thought about starting small with some Parts Express package, but I dont need to build speakers that im not going to use. I started off with AVSforum, started browsing the usual DIY sites like HTGuide, Zaphaudio, DIYaudio, etc. I am really intrigued by the AV-0's though, and would really like to build them. My question is; it is possible to get any more bass extension out of them? I don't want to go any taller, so thats out. If I made it 8 x 8 with 1/2" MDF (braced really well), that would almost double the internal volume, and I should get closer to 40 hz f3. Would the 8 x 8 baffle kill the dispersion? What if I used a 3/4" roundover?
Thanks for any assistance

Kevin

[Hank]

Welcome, Kevin!  That would be a great speaker for you to start with.  Please don't use 1/2" MDF - stay with 3/4".  Have you run the driver params through a program that showed the lower extension?  If so, what did the curve look like?  If you just applied a book formula, then you might have a problem.  If you do determine you want to increase volume, I always recomend staying with the designer's baffle width and add volume by increasing cabinet depth.  Also, I almost always use 3/4" roundover baffle vertical edges.  The degree of diffraction effects are debated, but I also do it because I like to wrap a single piece of veneer around the sides and baffle of cabinets - I like the look.  Good luck and enjoy!

[Zero the Hero]

Thanks for the reply Hank. I ran it through WinISD, the only program I've learned so far. The problem with the AV-0 is, that the baffle is really on top, so I can't increase cab depth without changing the baffle. Well, I could make a pyramid, but since this is my first foray into woodworking I don't think there's enough MDF on the east coast for me to try that experiment...
I'm guessing it's the small 7 x 7 baffle that enables the woofer the work correctly facing the ceiling, and changing that will alter the sound. But, the plans don't show the top baffle rounded over, so I was hoping increasing the size could be countered with the roundover. But, I suppose 1/2 MDF isn't such a good idea, even with good bracing? If I stayed with 3/4", that would put the top at 8 1/2 x 8 1/2; probably too big.
I guess I could just use a sub...

[klh]

Another option would be to build the O-3 instead of the AV-0. Not much more difficult plus it's a better sounding speaker and it doubles the number of woofers (thus increasing low end output). You may or may not need a sub depending on your listening habits. The O-3 also has user adjustability in how you use the second woofer, so it would increase your understanding of crossover design. Just a thought.

[klh]

BTW, the pyramid thing is probably the best way to increase the volume of the AV-O, and it would look pretty cool, too. But, having angles like that certainly adds complexity to fabricating the enclosure.

[Zero the Hero]

I thought about the O-3, but I'm on a budget right now, and I don't need the extra woofer or sensitivity for the intended application.

[Danny Richie]

Thanks for stopping in and posting. Also thanks for your interest in that speaker.

It is a great sounding speaker and easily beats up on its brother (the A/V-1) that uses the same drivers. It fact it easily out performs it in every way.

-3db is mid 50's and it really can't be pushed any lower without putting it in a well tuned transmission line.

klh's suggestion of the O-3 is a good one. It takes the performance up a notch across the board and does add a little low bass extension. You can even add the new M-130X woofer in the rear woofer location to get a little more low end response and power handling in the lower ranges. It's pretty easy to build too.

Yes it is a little more expensive but the sensitivity is still about the same. The rear woofer shares the low end duty and lowers the load and distortion. It doesn't increase the sensitivity.

[Zero the Hero]

Thanks for the reply and for clarifying that Danny. I guess I can't turn gold into platinum, huh?
It's a tough call, I think I will stick with the stock AV-0's for my first set. Who knows, maybe after xmas I'll move them to the back and build the O-3s.

[HT cOz]

Is it possible to work a Dennis Murphy Plop in the Box but use the AV-0 cabinet?

http://murphyblaster.com/content.php?f=newplop.html

[Danny Richie]

Is it possible to work a Dennis Murphy Plop in the Box but use the AV-0 cabinet?

Not a chance. The network design has to be completely different.

[soewhatman]

Hey Zero.  I completed a pair of Danny's AV-0's recently to be the rear speakers in my 4.1 surround setup (no center, as of yet).  While I was veneering and finishing the front speakers (AV-3's) I was using the AV-0's as my primary speakers for about 10 days.  I don't have a golden ear or anything, but at no point in those 10 days was I disappointed with the way the AV-0's sound.  I made sure to give them plenty of room from the walls, which I think they need, and they sounded great.  I feel kinda guilty relegating these neat speakers to rear surround duty, where they don't get the attention they deserve.  I don't think you will be disappointed if you go ahead with them.  Construction wise, they were nice and easy to build.  The only tricky part would be if you wanted to round-over all of the vertical corners.  Given the nature of this speaker, you would want to round all four corners and that makes veneering tricky since you are wrapping one sheet all the way around.  That's what I did, and as a newbie to veneering, it was quite an experience.  I got it done though.

Good luck.

Rick.

[Zero the Hero]

Thanks Rick,

That sounds like quite a chore - care to post pics? I actually placed the order last night for them; I can't wait to try them out! I guess I can start cutting the body out before the driversget here. I was considering going with some "furniture grade" plywood I saw at Lowe's maybe? Or was it Home Depot, I don't remember... instead of MDF/veneer. Who knows, I'll experiment a bit. If I don't like it, I can always start over.

[soewhatman]

I think many guys like to build their speakers out of baltic birch plywood if you go that route.  My understanding is that it tends to be more consistent in density, as well as having a nice solid core without any chips to vibrate, as compared to other types of plywood.  There is lots of information about this in this forum, as well as on the diyaudio.com site.  I built mine with MDF, however, and think it's fine to my non-golden-ear.  I played around with damping some when I was building my speakers, and it made a very notable difference in the sound.  I bet more noticeable than the wood you use.  I used Danny's no-rez quite happily.  It's a bit expensive, but one sheet will do both av-0's and I think it's worth it.  I'll try to get some pics up when I find my camera.   

Rick.

[TomS]

I have to second the idea of using No-Rez.  I used it even on my small AV1-RS's and the stuff really works. 

In terms of cabinet volume, if your woodworking skills were really good (mine are NOT), you could always try building the sides non-parallel such that the base is larger than the top.  This still retains the AV-0 dimension (pyramid with flattened top).  Before going to that much trouble with weird cut angles, I'd still look at the O-3's

Good luck!

Tom

[soewhatman]

I posted some pictures of my av speakers in the audiocircle gallery for you Zero.  Just follow the link in my signature.  The veneer on them is ribbon cut mahogany, with tung oil and a gel varnish finish.

Rick.

[Zero the Hero]

Wow Rick, those look great! Nice job. I can't tell you the last time I saw an antenna on a TV, that really brought me back

[soewhatman]

Hehe.  I don't watch very much TV so I can't justify paying a bunch of money for cable.  I'd rather spend my dough on speakers and A/V equipment.  I watch lots of DVD movies.  The rabbit ears do add a certain character to be sure.   

Rick.