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Old 15th February 2008, 10:08 PM   #11
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all i remember is way back in the 80s when i listened to horn loaded klipsh heresays (la scalas?), i hated their sound, probably mostly due to the horn mids & tweeters. the FIRST real hi-fi sound that i heard was a friend's pair of $120 infinity acoustic suspension minimonotors on a B&O turntable through a 45wpc denon reciever.

that's when i realized all of the speakers in shops were overpriced, gimicky and bogus. aside from the amazing image those little 4.5" two ways threw with their grey styrofoam tweeters, i was stunned by how much tighter and clearer the bass was compared to bloated and sluggish ported and large woofer floor standers. back then, the only full range speakers i liked were bostons with 8" woofers. that's when they still made acoustic suspension before selling out to "duh... me want louder" idiots who want more volume in showrooms.

from that day on, i became hardcore acoustic suspension & the smaller the better. to me, ports & horns are gimicky & take away from pure sound. i've heard plenty of horn drivers in nightclubs and to me, they suck rotten eggs. the sound is sluggish and boomy. maybe part of it is 12-15" woofers & ports, but i just hate that blurred sound. betwen nightclubs & klipsh demos, i just associate horns with distortion the same way i do ports.

you can argue that quality varies between designs, but the bottom line for me is that good designs are less distorted than others while i've never heard acoustic suspension sound bad outside of department store no-fi junk.

acoustic suspension has that quick snap i like without any of those unforgivable resonances designed to increase efficiency. the only way i'd veer away from acoustic suspension is or planars which are even quicker.

i'm all for quality over quantity, but want as much quantity as i can get without sacrificing speed and detail. as far as i'm concerned, there are only two speaker makers left... NHT & magnepan.

i thought the literature for those AMP-50s sounded suspect too. i know A/B amplifiers are closer to 50% efficient and only class A gets down to 20% or lower. still, i need more power than 10-15 watts and don't seem to have ANY options other than battery draining class A/B. i like the sound of class D anyways. it, too, is quick and detailed. i love my panasonic reciever and hated my NAD.

there's a total market niche out there waiting to be exploited. everty day i see more and more street party bikes. someone should make realistic modules for those or high end DIY boom boxes.
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Old 16th February 2008, 01:09 AM   #12
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The fact of the matter is that if you want more than 10-15 watts you either need relatively low impedance or a DC-DC converter to obtain higher voltages. You can't change Ohms law here, it is was it is.

I think your best bet would be to get a kit from 41hz.com. There's pretty much a kit to cover any need. I know you want a completed module, but you're going to have to compromise somewhere. I'm sure if you ask nicely you could persuade someone into assembling one for you.
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Old 16th February 2008, 05:17 PM   #13
joemana is offline joemana  United States
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Hi,
I have 8 channel 41Hz Amp5 with (1000Vac) 2 500Vac trafo, no case yet. I'm selling it for $480 just to cover my expenses. This is 60W @8 ohms and 100W@4.
The board has built in supply, all you need is transformer.
I can sell (2 channel) 1 board for $90.00.
If you are interested, Please PM me.

Joe
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Old 20th February 2008, 12:59 AM   #14
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yes, 41Hz i think is the place that had a kit that was close to what i needed, but after reading a review for the charlize (or one of the other 10 watters) online, i was totally put off building a class D module because the builder started talking about something like impedence mismatches & needing a voltmeter etc. to fix it. THAT'S getting over my head. if i set my mind to it, i could build a speaker crossover from schematics, but solid state is different eg. you can't do resistors backwards.

as the "ohm's law" thing, 50w is DEFINATELY doable with 1.5 batteries. JVC's kaboom box has 50w for the subs PLUS something like 4wpc for the mains and that's a class A/B unit. i would have thought that class D would be even easier on batteries.

now, i'm just starting to think that the best thing would be to just quit trying to get 50w on my bike and build a 12v car battery trailer. i could easily do 4 x 8 inchers for subs with no cabinet volume issues and run as many watts as i want to. it's a bigger undertaking, but it has a few other upsides:
no more bike tipping with the slightest lean
i could use a car deck & changer with a remote on my handlebars
i could build a better looking cabinet without fear of dings & scratches
&
i could add SFX lighting

thanks a bunch for all of your input. so there really aren't any quality RTR 50w class D modules like i though there would be. oh well.

just for kicks though, i think i'll try a $30 40wpc car amp and see if it works with 15v in the short term. if it does, i'll get a pair of 93dB pyle outdoor speakers too.
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Old 22nd February 2008, 06:56 PM   #15
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Default Re: are there any prebuilt 30w-50w modules to be found?

Quote:
Originally posted by budget minded
i'm looking to upgrade my bicycle system this summer.

Bicycle system?!?! Nobody in all those posts called him on this? Has my reading comprehension completely gone or are you using a small set of bookshelf speakers on your bicycle?!

Could I interest you in a set of these: http://www.etymotic.com/


I know you said you only want completed modules, but if you get desperate enough, you can get a variety of power levels from the kits at 41Hz.


Sheldon
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Old 22nd February 2008, 09:29 PM   #16
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Quote:
Originally posted by budget minded
....you can't do resistors backwards....


Quote:
Originally posted by budget minded
JVC's kaboom box has 50w for the subs PLUS something like 4wpc for the mains and that's a class A/B unit. i would have thought that class D would be even easier on batteries.
I had a kaboom box about 8 years ago when they first came out. I can tell you with certainty is was nowhere near 50w RMS. When it ran on the batteries it had even less output power due to an automatic power reduction to lengthen the battery life. Strangely you could bypass the power saver mode by just plugging the AC cord into the back of the unit but leave it unplugged from the wall.
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Old 28th February 2008, 10:24 PM   #17
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yes... bicycle system! here's my V1.0
http://takatomon2000.googlepages.com...eet_party_bike

you've never seen a street party bike? some of them are sick with megawatts. check out some of them i posted in this old DIYaudio thread
Street party bikes

recently, i've seen a realy twisted setup that has a ton of speakers all over. i found it on a search engine, but don't have the URL. the owner claimed it cost $4,000, but it looked like alot of cheap gear.

as to my upgrade plans for the bike at my website, i've found what i need by accident. for a minute i was resigned to mounting motorcycle batteries above my crank & using car amps, but i just found two nice class D amps that aren't killowatters

Alpine PDX-2.150
http://www.sonicelectronix.com/item_...PDX-2.150.html

Blaupunkt THA275 PnP
http://www.sonicelectronix.com/item_...HA275PnP-.html

that blaupunkt is PERFECT and as small as it is, i could mount it inside my frame over a 12 motorcycle battery instead of a more power hungry A/B unit.

BTW i'm also planning on getting lighter pyle outdoor 2 ways with 6 1/2" woofers that's rated at 93dB.
http://www.partsexpress.com/pe/showd...number=310-218

stay tuned. i'll update my website when i get v 2.0 built and 3.0 will be a tricked out 12v trailer with lighting effects etc., but that's probably next year
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Old 2nd March 2008, 12:24 AM   #18
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i've found the bike i was talking about again, here it is
http://flickr.com/photos/fat_tony/2073333789/
http://flickr.com/photos/fat_tony/2073333779/

and here's ANOTHER example
http://flickr.com/photos/biketourist/145219621/

and another by a SERIOUS DIY customizer
http://flickr.com/photos/8374950@N06/506535745/

and another from the "soul bike" "fossil fool" crowd who sell off the shelf pre-made gear
http://flickr.com/photos/brettlider/136727461/

people who own gass guzzling pollution machines aren't the only ones who like taking their music on the go. it's amazing just how surprised people are to hear of, or see, bikes pumping tunes. it's not THAT radical an idea like, say, putting a swamp boat propeller on the back of a bike. now THAT'S radical.
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Old 29th August 2008, 02:02 AM   #19
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not that i need it now, i found a 2X20w class D amp that can be bridged to 40w mono at ramsey electronics when thumbing through nuts & volts magazine.

if anyone needs a 40w class D monoblock, they can be found here...
http://www.ramseyelectronics.com/cgi...ction&key=UAM4

right now i'm building a 560w bike trailer system with power acoustik plasmasphere amps, my NHT super zeroes as mains and a goldwood 10" acostic suspension sub but i thought i'd stop by and share my knowledge of the ramsey modules for anyone else looking for efficient & portable amps.
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Old 29th August 2008, 03:03 AM   #20
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Looks like it uses the MAX9708 "Filterless Class-D".

The two stereo outputs are already in a BTL configuration; they can only be paralleled, not bridged, for use with ~4 ohm loads.

Running this board off of a 12v battery won't net you any more power than a sonic impact or equivalent, plus there are no output filters so I'm sure the radiated EMI is lovely.
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