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hmmmm
08-19-2005, 04:24 AM
I just wanted to thank Kex for talking me into making AR.com's for surrounds to match the front. I ended up building a sealed box design because they had to squeeze into a small space and hang on the wall. The guys at Madisound did a great job at helping with the box size. It ended up being 12" x 7 3/4" x 5 1/2". I could barely fit the drivers and the crossover in. I used deflex panels because the box was so small. I haven't tested them with my spl meter or anything but they sound awesome and match much better with the fronts. They are crossed over at 80hz with the sub.
I'll try to post a photo later. Thanks!

kexodusc
08-19-2005, 04:54 AM
Hey great stuff, glad you're happy. Just to be sure, did you use the same parts? Or a different woofer? I remember you thinking of a 4" or 5.25"? I can imagine a 6.5" woofer being a tight fit.

I'm working on and MTM'ing a set of mine for a friend. Getting too many speakers in my house and I'm having to make room. I think I'll keep a pair of the AR.com's and build something new for the home theater. Not sure yet.

hmmmm
08-19-2005, 06:23 AM
Hey great stuff, glad you're happy. Just to be sure, did you use the same parts? Or a different woofer? I remember you thinking of a 4" or 5.25"? I can imagine a 6.5" woofer being a tight fit.

I'm working on and MTM'ing a set of mine for a friend. Getting too many speakers in my house and I'm having to make room. I think I'll keep a pair of the AR.com's and build something new for the home theater. Not sure yet.

I actually ended up using the exact same drivers, etc... and that's why they recommended the deflex pads (drivers are really close to the panels). Madisound said they would drop about 3 decibels at 80hz which I thought would be fine for the surrounds but also mentioned the bass would be stronger since I would be mounting them on the wall. I took one of the ported AR's off the speaker stand and listened to some familiar music and watched a movie and really couldn't hear much of a difference if any. One test for me is listening to the "Flight Test" on Flaming Lips "Yoshima Battles the Robots"...when the drum moves around the room it now finally sounds very smooth. Before, it changed tones from the front to the back speakers. I actually like listening in 7 channel stereo now that they all sound the same. Before, the rear speakers annoyed me a bit because they sounded too bright. I might sink these speakers into the wall to make them look even smaller. Only about 2 inches would show. Any problems with that?

kexodusc
08-19-2005, 07:11 AM
Theoretically there can be a problem with sinking the speaker in..you're kind of increasing the effective baffle size (the wall becomes the new front baffle), so you're adding back the baffle step loss (lower frequencies). The crossover slopes take take baffle step loss into consideration in this speaker.

This is why you get more bass with close placement to a wall. The closer to the wall you get, the higher the frequency in which volume is added back. For example, the upper bass region, close to the midrange will also regain some of that lost volume.

In real life though, how different it will sound might not be very noticeable.
Whether or not you can distinguish the difference and would find it unpleasant is hard to tell. Place them against the wall. If they sound fine, I don't think a few more inches is going to change that much. Won't know until you try.

The narrower cabinets you have start to experience baffle step loss at around 1700 Hz. The frequency response of these starts to rize around this point to compensate.

If you find they start to sound a bit boomy, or nasally, you can probably overcome most of this effect just by changing the value of the padding resistor that runs in series right before the tweeter. A quick 1 dollar fix. I think the standard value was 2 ohms. Not sure what you use. But going to 1 ohm or even 0.5 ohm would bring the output of the tweeter back up a bit up a dB or so. Might have to experiment with the exact value, but resistor are super cheap. 0 ohms might work too, but then you might have to solder the tweeter circuit to the terminal, as removing the 2 ohm resistor probably breaks the circuit on the madisound crossovers board...

Make sense?

hmmmm
08-19-2005, 07:28 AM
I have a 4 ohm resister at the tweeter (not the board). I found the 2 ohm a bit bright for me, but it sounds perfect now. I'll keep what you mentioned in mind. I'm trying to keep the wife happy with the looks of the room:) Now I just need to find a nice tan speaker grill fabric so they blend with the wall better.

kexodusc
08-19-2005, 07:58 AM
Maybe in your case then, going to a 3 or 2 ohm resistor from the 4 ohm resistor would bring them back to balance. I'm guessing it's not even going to be worth the bother for you, but if it is, at leats it's a quick, easy, cheap fix.

Parts express sells a brownish color grill fabric....not sure I'd call it tan...might have to hit up a fabric store.
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=260-339

I know some people double up pantyhose....acoustically transparent, and all sorts of colors.