[wasifazim]

This guy I know put this together:

http://members.rogers.com/exquisitea...topiaclone.htm

Still can't believe he got as far as he did..370 lbs. per speaker

 

[Dusty Chalk]

That's pretty insane.

Let me know if he ever does a Shahinian/Nearfield Acoustics Pipedream hybrid...

 

[setmenu]

Wonderfull!
I love it when people are motivated to go this far,
it reminds me of the insane project complexity 'model' engineers
can go to!

 

[Nezer]

This is pretty complex but I don't find it as impressive and insane as Dr. Meier's power amp with all those LM6171 op-amps.

For more info look here. Scroll down to the bottom. 88 op-amps total. Jan tole me he runs two of these bi-amped for a total of 172 op-amps total!!! He says the sound is excellent. It better be for what this must have cost!

This is a definate project for those that get off on solder fumes.

 

[setmenu]

I looked at THAT amp a while back,I had forgotten,
Interesting...extreme.
I would love to hear it.

Setmenu

 

[Budgie]

Not exactly a copy of the Nearfield Pipedreams, but my speakers are similar.


http://spiritone.com/~bdg/

(look at the line source pictures)

 

[aos]

Meier's amp is not that expensive, you get a nice price break when you buy 100 opamps - $275 Canadian for 100. It is however probably a major pain to build, with PCB being the absolutely worst if you have to design and build it yourself (and you do as Jan didn't publish PCB layout). Just imagine drilling thousands of holes... Even with Dremel it's not fun. Soldering takes a while but it's all DIP and that's easy to solder.

I'm more impressed with these speakers. Likely because I don't have the required skills to build them, and lot of hard physical labour is involved...

 

[Dusty Chalk]

Quote:

Originally posted by Budgie Not exactly a copy of the Nearfield Pipedreams, but my speakers are similar.

Yup, they shore do look like Pipedreams...but I was being ironic -- Shahinians are a completely different beast. Not mutually exclusive with a line source, so not impossible, but...would be freaky looking. Maybe if I said Wilson Benesch Bishop/Shahinian/Nearfield Acoustics Pipedreams, my frankensteinian suggestion might have been a little bit more obvious. The mental image I get is a large cylindrical ball that "eats" drivers, sort of like that thing at the beginning of Hellraiser III: Hell On Earth.

So anyway, I got distracted -- what sort of performance do you get out of them? Do you like them?

 

[Nezer]

Quote:

Originally posted by aos Meier's amp is not that expensive, you get a nice price break when you buy 100 opamps - $275 Canadian for 100. It is however probably a major pain to build, with PCB being the absolutely worst if you have to design and build it yourself (and you do as Jan didn't publish PCB layout). Just imagine drilling thousands of holes... Even with Dremel it's not fun. Soldering takes a while but it's all DIP and that's easy to solder. I'm more impressed with these speakers. Likely because I don't have the required skills to build them, and lot of hard physical labour is involved...

I dunno, aos, maybe *your* time is free but mine sure isnt!

I agree that the actual costs of the thing will probably be somewhere under $500 USD give or take but it would take a *LOT* of time to finish that project off. I think this is why Dr. Meier doesn't sell the thing. He would prpobably have to charge $3000 just to make it worth his time. Probably not that much, but still...

 

[Budgie]

I am very happy with them. My Maggies went back in the box and haven't come out since. Very efficent at around 98 db/watt so single ended is easy, but can also soak up tons of power if neccesary. The drivers don't have to work much at all individually, so the distortion stays low. Very dynamic sound. I just finally found the crossover caps that will be the permanent ones in the design so I can finish the crossovers, which are outboard of the towers.
The bottom end goes to about 45 hz, so i am also experimenting with subwoofers to fill in the bottom octave, but getting it right is kinda frustrating and time consuming.

 

[ringtheorist]

Have any of you considered a dual d'Appolito in a single enclosure? I was thinking of maybe MTMWMTM, although the configuration on the actual speaker may vary.

I was looking at an ubercheap 84dB/1W/1m mid. If you wired them in parallel/series pairs, then you'd get about 90dB/1W/1m from those because of the quadrupling in radiating area but keeping impedence constant. You could pick up some 4 ohm tweets and wire them in series, and get a nicely efficient sub like a 98dB 12" or something.

You could build it line-array stylee with an arc in your front baffle so as to minimize delay distortion, since the speaker would have to be mighty tall if you build them in exactly the MTMWMTM order.

b

 

[Dusty Chalk]

Quote:

Originally posted by ringtheorist Have any of you considered a dual d'Appolito in a single enclosure? I was thinking of maybe MTMWMTM...

That's scary, I actually understood that (whereas two years ago, I would not have).

Sounds like a good idea, worth investigating. Have you seen the WEGG3's? wegg3.com

PS Where were you during the avatar contest? I've always liked that one (yours).

 

[skippy]

i think i'd prefer to keep the tweeter at ear level though.

 

[Budgie]

You need to keep the tweeters as close together as possible or the delay caused by the distance between them will cause weird effects from comb filtering. Something like WMTMW. Take a look at Dunlavy designs as an example.

http://www.dunlavyaudio.com/prim_lvl/products.html

 

[ringtheorist]

Avatar contest? I probably wasn't registered then.

I built an MTM out of some PVC tubing but it was exceptionally bright. I decided to replace it with a tall PVC transmission line with two full range drivers in each. Once I can find more of the 40-1041 5" full range Radioshack drivers, I'll probably upgrade the design to four in each enclosure. The nice thing about the PVC joints I'm using is that it is very easy to cement them at an angle, so the speaker can be arced in a circular pattern. That way no crazy delay distortion/comb effects as abovementioned will occur.
ta ta,
b