AR.com DIY crososver design

[kexodusc]

Anybody have any info on this? Like what frequency is it set at, etc...
Not much is said about it.

Anybody have a frequency response plot of this speaker with the newest crossover specs?

[poneal]

I priced the individual components and the price difference between the parts and having madisound build them was only $6 so I had them build mine (all 5). I belive the xover is around 2700

[dave_bullet]

Anybody have any info on this? Like what frequency is it set at, etc...
Not much is said about it.

Anybody have a frequency response plot of this speaker with the newest crossover specs?

I estimate the xover frequency to be 2,600Hz. I put the new xover (with 2Ohm resistor to pad down the tweeter a bit) into speakerworkshop out of interest. (The frequency plots are based on infinite baffle - I don't think I linked it to an enclosure so don't worry about it dropping away from 150Hz down....above 500Hz is indicative.)

Please note - these are estimations, modelled on Peerless' published frequency and impedance graphs (not measured). also - I don't know why but I had to invert the tweeter to avoid a null @ xover (as you'll see in the xover diagram) - not the case when you build one....

Cheers,
David.

[poneal]

Thats a large pad. Ed recommended between .5 and 10 I do believe. I was thinking of getting a 5 of the 2ohm as my boxes are almost complete. I sure do like that plot though. I am really anxious to get these boxes done LOL.

[kexodusc]

Yeah, that mid-bass dip is all but gone now...man, I've got to package all my stuff up in the next 2 days...I'm hoping unpacking goes rather quickly and that I can just jump right back into these. Got the house all bought...basement should be finished by the time I arrive. I should be able set up shop faily quickly in the garage. I've still got to finish the PeeCreek's, too (might buy the Usher tweets for those and swap them to see how they hold up to Ed's speakers).
Paul, can you recommend me a Plunge Router? Or were you the one cutting circles with a jig saw and dremel?

[poneal]

Get a good plunge router--one that will last you a life time. I recommend the brand I'm using which is a porter-cable (I think its 3.5hp) and an assortment of bits (straight, round over, cove, dovetail, etc.).

My boxes are looking good. I put the second coat of primer on yesterday and will sand tonight. I think I will have to put a 3rd coat on at least one of them as I can still see that I did not sand the glue line well enough on one box. Other than that, they are as smooth as a baby's ass. I may be able to apply the first coat of enamal in a few days.

That graph has me pumped up but I don't want to rush it. Well, your gonna be tired moving so I wish you good luck and take it easy. Easy as in don't hurt yourself moving heavy items, etc. You only got 1 back so take care of it. Later, Paul.

[kexodusc]

Me move? No way...my new employer is covering most of that so, I've boxed up the fragiles as best I can, and I'll let the movers handle the rest...
Porter Cable seems to be the most common one recommended...guess I'll have to grab one.
Sounds like you're soaring...how many of these are building again? What color (or colour now, I'm Canadian again).

Wonder if you'd have saved time veneering MDF like I'm doing? Maybe I'll try gloss black paint for Wayne J's speakers.

[Swerd]

can you recommend me a Plunge Router? Or were you the one cutting circles with a jig saw and dremel?

Hey kexodusc

Using a jig saw and a Dremel tool was very hard for me to cut circles in 3/4 inch MDF. I went through this about a year ago. Cutting out circles was a problem until I got a Jasper Jig. Parts Express had a special on them at the time. Other woodworking dealers sell them online as well. They make the whole job of cutting the circle and countersinking a speaker easy. Before choosing a plunge router, you should check out Jasper's instructions on which plunge routers fit their jig. (I'll try to attach the file) There are holes predrilled in the jig that fit these plunge routers:

Bosch 1613, 1615
Skil 1823, 1825
DeWalt 621, 625
Fein FT-1800
Elu 177
Porter Cable 7539, 7529, 690 series
All Sears, Ryobi, & Makita
Freud FT2000E
Hitachi M8V, TR12, M12V

Even if you don't want a Jasper jig now, you may change your mind later.
After reading too much about about plunge routers on the internet, and after some good advice from Dick Hertz on this forum, I bought a DeWalt 621. I like it and would recommend it. The Bosch plunge router is also well received. Here is one review of plunge routers that is worth reading http://www.taunton.com/finewoodworking/pages/w00047.asp

There are other newer models available now that may also fit the Jasper jig. You can email Jasper Audio to ask what fits their jigs.

[Swerd]

The attached file didn't appear. Go to

Jasper Audio
3612 Mangum Road Suite 108
Houston, Texas 77092
www.jasperaudio.com
jaspera@sbcglobal.net

I bought the Model 200 jig.

[dave_bullet]

.... got around to modelling the box with the 850122

I estimate the internal box volume is 10.58 litres. With a port @ 152mm (6") length and 2" ID, that would give a tuning frequency of approx 55Hz. Attached is the modelled response of the woofer in an arbitrary box (courtesy WinISD)

[poneal]

Dave, could you post the plot without the 2ohm resistor? Thanks, Paul.

[dave_bullet]

Sure Paul,

There doesn't appear to be much difference. As expected you get a lift of a dB from the tweeter so it's a hard call. I can see why he recommended quick connects so it is easy to switch out resistors to try.

(I was trying to link the enclosure to the graph so we could estimate the low end response but can't figure out in speakerworkshop how to do it.... )

Cheers,
David.

[poneal]

Thanks Dave, I'm going to try it without the resistor first and then if I think its a little bright add the 2ohm resistor. I ordered them just in case. It would be interesting to see where the lower end starts to drop off but madisound has the frequency response from 45hz-20khz +/- 2db which is pretty darn good for a monitor of this size. Thank you very much for the second graph. Paul.

[kexodusc]

Speaker city's response is the same, Wayne J's PeeCreeks which I'm also building (same 850122 woofer) have the cabinet tuned to just under 50 Hz, so I don't doubt the 45 is possible.

[poneal]

Here are some pics of my AR.Com. They actually shine much better than the photo shows but I guess the sun and angle were not right. I can actually see myself in them and inside they look spectacular. Notice that you can see the peerless tweeter from the rear port hole which I thought was kinda cool. Well, three are done and by the weekend I should have the other two finished. They sound great. Paul

[kexodusc]

helluva job, Paul...especially the grills...I haven't figured out how I'm gonna do the grills on mine.

[poneal]

Thanks, I'm going to take some more pictures inside this time and see if they come out better. The screws are actually brass which bring a look of elegance to the black.

[kexodusc]

Unpacking is taking alot longer than I hoped it would. I start my new job on Monday too, but I'm hopeful I'll get around to finishing mine up before October...at least starting up again.

Eventually I'm gonna do a head to head with the PeeCreek or U-Pee (depending which tweeter I decide to use) and my $800 Paradigm Studio 20's with some of my relatives, similar to Ed's comparison to the GR Research modified Ar.com. I'm hoping the results encourage people here to look into DIY more.

Whatcha using to polish those pretty things? Meguiar's? Mother's? Carnuba wax or synthetic?

[poneal]

Used a lacquer finish then a lot of sanding. Then used fine cut compound to get the 1500 grit scratches out. Then used finish restorer for polishing. It said to wait a month before applying wax to give the enamel and such time to cure. Not sure on waxes, but I'll probably go to the auto parts house and look up one of those you mentioned. The wax will probably make them look more mirror like and have a tougher protective coating. The only problem I have found so far is that you can see the dust settling on top of them very easily. The mirror finish seems to say "look I have dust on me".

I just got the MDF cut for my stereo sub cabinets (my next project). I have two 8" Peerless CC subwoofers ready to go. I decided on a ported cabinet of 4 cubic feet with 2 2x6 inch ports for a tuning of around 25hz. The fs is 25 on them so I will not hear anything below that anyway. These will double as my stands for the front AR.Coms. The overall height including feet, sub, and monitor comes out to 36". The tweeter around 33" which is at ear level while seated. I think the wife is gonna ***** at me for the hugh sub cabinets though :-). This project will go much quicker since I only have to cut a few holes and its only two cabinets. Of course there is more space to deal with on painting. I'm going to make them the same color and finish.

Well, gotta get back to work and quit messing around here. New jobs are usually stressfull in nature till you get your feet on the ground so take it easy and just take whatever comes come. Thanks, Paul.