RS100 pc speakers

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I bought a pair of the 4 ohm RS100's for my truck, and have been playing around with them. As many know they are really pretty amazing considering the cost and size. I'm thinking of buying another pair for my computer "desk" which is really a wardrobe. Not much room to work with and it's kind of like a cave. I was running these OB on some scrap 1/4" plywood I had laying around.

The dimensions I have to work with are 19" high, approx 9 inches wide and maybe 8 inches +/- deep.

Right now I have them mounted OB on a 6" wide redwood fence board that I cut up. The baffle is way narrow. They look nice, as expected the bass response is almost non existent. It's temping to use the redwood as the face for a sealed or ported box of some type.

Any ideas?

Eric

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I think I have a bass reflex enclosure worked out. It models good in winisd.

I have a question about 1st port resonance. When is it too high or too low? I understand that the port will radiate at the first port resonance, but the port also filters midrange frequencies.

Would a 1st port resonance in the neighborhood of 450 hz cause problems?

I've read this driver sounds good in a bass reflex enclosure designed for the FE103E. The RS100 models with a huge bump at 100hz, around +6db. I played around with the numbers and came up with this.

.108 cubic feet
74hz
3.75 square inch port cross area
15.5" port length
1st port resonance is 436hz. (this is the number that worries me)

I sketched up some plans that give an overall enclosure size of 12.25x6x6 with a rectangular port exiting at the bottom that folds up along the back of the inside of the enclusure.

If I'm headed in the wrong direction, someone please correct me. I have the day off and was hoping to build these.

Eric

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Here's a plot. Cone excursion and port velocity are also under control. Will attenuate sub 70 hz to control excursion at high volumes.

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I'm going to pick up some wood. I designed it to be built from 6" wide lumber. Probably use mahogany or walnut. Probably not the ideal material, but I only have a junk contractors type table saw and from previous experience it's nearly impossible to rip long lengths accurately with the tools at hand. OK for a painted MDF box, but I refuse to use MDF anymore.

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I found a piece of 1x10x 10 foot piece of maple with a tiger pattern at the local HD supply. It's too nice to make a bad box so I've been experimenting with cardboard and various containers to see if I'm on the right track.

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Built a sealed test enclusure at just over 2 liters. Just eyeballed the pieces when I cut them, so I'll have to get an exact measurement.

They sound decent. Bass drops off quickly starting around 200 hz, just like winisd says.


Using the frequency generator from winisd and my trusty Radio shack spl meter I've discovered a couple things.

First, I'm pretty much deaf above 14khz or so.

2nd, the driver has good response till 17khz when it tapers off. Over 10db down at 20khz according to my meter.

3rd, my left ear and right ear don't have the same response. I think I already knew this, I just have a better idea now of where the damage is.

I'm going to build a quickie bass reflex box with some more scrap wood, just to see if it's worthwhile proceeding as planned.

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Made a couple changes.

Upped the box volume to 4.4L.

Going to use 2 1" ports 4.75" long. At high listening levels port noise will be a problem, but these are PC speakers. Sitting in front of them with 7 watts going into them is uncomfortable. Port noise shouldn't be a problem until close to 20 watts.

I decided to keep the maple for some BIB's I'm planning for the living room.

Making these from poplar.

Also, for those without a circle cutting jig for your router, a 3" hole saw cuts the PERFECT circle for this driver.

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I'm not sure how useful these graphs are, but here it is anyways.

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Got one done. I have to say I'm very happy with the preliminary tests. Bass response is surprisingly good. 90hz is 6db down. From about 400hz up it's in the plus territory. Pretty much what I expected. It doesn't really follow the curve from WinISD, but the driver isn't broken in, and I don't have measurements from this driver. Response is virtually identical between the 2 though.

Anyways I'm really very pleased with the results. I'll have to experiment with stuffing a bit. Completely unstuffed now. A few minutes with Electri-Q should really clean it up.

[gurley123]

Sounds like your on the right track.

I'm glad someone has done something other than an OB with these.

Please post some pics if you get the chance.