[tg3]

Looking for advice on a speaker kit.

I'm taking Physics 221 (engineering physics) this quarter in the PNW.  At the first lab session last week, I was surprised to learn we can pick most any project we want, as long as it has a physics angle. They call this "Problem Based Laboratories." Very cool.

I would like to build a monitor speaker set: one box with No Rez damping, and the other without. Then measure to see if there is any difference. I propose to test for enclosure resonance with accelerometers. We don't have adequate facilities for good frequency response measurements.

Requirements.
  * not too big, not too small. I think a sealed MTM with ~6" woofers would work.
  * would like to not spend more than $600 - 700.
  * must be able to use pre assembled cabinets. I can route holes for the drivers, but don't have time to build cabinets.

The A/V-2 is about what I had in mind.

All comments and suggestions appreciated.

[Captainhemo]

You could do a pair of either the AV3S's or a pair of the X CS Encores.
The AV3S might be more fun, you'd get to assemble the network from scratch , not sure if that would be of any benifit to your project. 
Or, you could go withthe  Encore CS's which  come with a pre-built network on a cirucit board ( you can always build your own P2P wired network  with these as well)
Either  speaker kit would benifit from the available  upgrades if you want to spend the extra $$.

Either pair would make a great sealed pair of  moitors when stood up.

You could  use the  PE  1 cu ft prefinished cabinets for  either I think
http://www.parts-express.com/dayton-audio-mtm-10bk-10-cu-ft-mtm-speaker-cabinet-gloss-black--302-750

I only suggest the Encores and the upgrades as I'm assuming you will put thiese to use  once the experiment is  over.   If you  just want them  stricly as the experiment, I'd go with the  CS Classic x 2
jay

[Hank]

What Jay said.  Those PE cabs are great - you save many hours and their finish is extremely difficult to duplicate in a home shop.

[Danny Richie]

Rich Hollis sent me an accelerometer and pre-amp that allows it to be used with my Clio system. The pre-amp gain area is very critical to getting good readings. The gain is way to high on this one that I have. I intended to come back to it at some point but haven't got around to it.

Before deciding on and building speakers to test I highly recommend that you establish repeatable testing procedures that will allow you to get meaningful results.

[sfox7076]

Rich Hollis sent me an accelerometer and pre-amp that allows it to be used with my Clio system. The pre-amp gain area is very critical to getting good readings. The gain is way to high on this one that I have. I intended to come back to it at some point but haven't got around to it.

Before deciding on and building speakers to test I highly recommend that you establish repeatable testing procedures that will allow you to get meaningful results.

I am sure that is what the class is about.

[tg3]

Thanks, Danny.

I'll need a cabinet to help define a methodology, but your point is well taken. Next lab we are introduced to some of the lab equipment.

What PE cabinet woild work for the A/V-2?

[Danny Richie]

Thanks, Danny.

I'll need a cabinet to help define a methodology, but your point is well taken. Next lab we are introduced to some of the lab equipment.

What PE cabinet woild work for the A/V-2?

I have not used any of their cabinets for that kits.

I have used their .38 cubic foot box for A/V-1 and N1 kits and their .5 cubic foot box for X-LS and N2X kits. I am not a fan of the brace and the reflections it can cause by the direction they ran it. Here is a thread I started on them: http://www.audiocircle.com/index.php?topic=54352.msg485002#msg485002

If you really want to see a lot of difference from the No Rez then use an un-braced box. Then you'll really see some big differences in the readings.

[lacro]

What Jay said.  Those PE cabs are great - you save many hours and their finish is extremely difficult to duplicate in a home shop.

Those PE cabinets do look pretty nice, but at $168 each They don't appear to be braced as well as the X-CS  cabinet design, so more or different bracing may be required. It might be better to pay someone to build the proper cabinets for the speakers you choose. With the PE cabinets, you still have to cut the driver holes, and you only get one shot at it being perfect. With raw MDF, a failure is no big deal, just make another one.

[jparkhur]

Set yourself up for success and make sure all your validity and reliability standards are set.  Don't try to go crazy, build something you can use and do it well.  No Rez is and interesting thing to test and would easily show significant differences in your tests.  Look at old tests and see if you can improve on them some way.

I did some double blind tests with student in the perception lab and they always come out really neat.  They hear what I think they will, but the why is more interesting too. 

Looks like fun..
JP

[Captainhemo]

What PE cabinet woild work for the A/V-2?

I believe the AV2 used roughly a .75 cu ft cabinet
http://www.parts-express.com/dayton-audio-mtm-075ch-075-cu-ft-mtm-speaker-cabinet-cherry--302-742

Like Danny says, the PE cabinets are not ideal but,  if you want a pre-finished cabinet, I don't know  where you can do better unless you  are willing to pay someone to build  them.  Many people who have used the PE cabinets  cut as much of the brace out as possible, round over what is left as best they can and  add  their own bracing if necessary  If someone has a link to a better pre-finsihed cabinet,  a link would be great, I'm sure there are  quite a few people who don't want to buod their own .

Also worth pointing out as it s on the AV page,  it is a 4 ohm  load, make sure your amp/receiver is ok with that. If not, either model   mentined earlier  in pairs shouldl work great  stading up as mains.

jay

[Hank]

I built a pair of Danny's best two-ways for a customer, using the PE cabs.  I cut out the center brace and replaced it with an oak dowel which was sufficient.  If you don't want to spend the money for the PE cab finish, find a local woodworker or cabinet maker who will make some bare MDF cabs for you, then you can paint or wood veneer them, or use the PE wood grain vinyl to cover them - I've used a few of them over the years:  cherry, ash, black oak, black, etc.