I need a few Guinea Pigs

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Kevin Haskins

I need a few Guinea Pigs
« on: 15 Jun 2010, 03:23 am »
I know it doesn't sound appealing but I need a couple brave souls who might be interested in being involved in helping me to prototype some active speakers.    I have a good part of the design done on the first couple models so it would be a fairly quick  commitment.   

What do you get out of it?   You get to help me develop documentation, give me feedback & input on voicing and in the end for all your hard work.... you get a set of speakers at the cost of parts (my cost).    It should be fun but you have to be ready to lend a hand and give me feedback in a timely manner.    It is probably a $600 commitment in funds for a pair of active speakers that will be fairly full-bandwidth (about 35Hz is the low-end).   The electronics are all in small monoblocks... machined from aluminum so they are cute little guys.   The first model is designed around the PE 0.5 cubic foot cabinet so it will not look like a Frankenstein prototype speaker and in the end... you will have a very nice set of speakers with amplification.   

Qualifications:    You need to have some DIY skills.... soldering and comfort with populating a PCB, bolting together parts, wiring a power supply etc....    You need to have some ears..... and some practical time spent in critical listening.     You also need to be able to lend some feedback and help on writing documentation.   

Just drop me a PM if interested.   I know it is a lot to ask but for the right person... it could be a gratifying experience.   ;-) 

Best,
Kevin Haskins

 

FullRangeMan

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Re: I need a few Guinea Pigs
« Reply #1 on: 15 Jun 2010, 04:07 am »
Gulp!!  Iam out of area(Brazil).

Kevin Haskins

Re: I need a few Guinea Pigs
« Reply #2 on: 15 Jun 2010, 03:46 pm »
Gulp!!  Iam out of area(Brazil).

Yea... that would be a problem.    The cabinets have to ship along with about 40lbs worth of transducers and parts.   We better limit this to those in the USA and possibly Canada.   


Kevin

drew54

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Re: I need a few Guinea Pigs
« Reply #3 on: 15 Jun 2010, 05:01 pm »
Hi

35Hz is pretty low.

How do you get 35Hz out of a 0.5cu ft cabinet?  What size is the woofer?  Active EQ?

If you do get 35Hz, is that f3, f6?  at what spl?

Are these supposed to be studio monitors, computer spkrs or far field?

Regards,
Drew.

Kevin Haskins

Re: I need a few Guinea Pigs
« Reply #4 on: 15 Jun 2010, 07:23 pm »
Hi

35Hz is pretty low.

How do you get 35Hz out of a 0.5cu ft cabinet?  What size is the woofer?  Active EQ?

If you do get 35Hz, is that f3, f6?  at what spl?

Are these supposed to be studio monitors, computer spkrs or far field?

Regards,
Drew.

The 2-way in the half cubic foot box is a monitor.   It could be used in any of those applications although I don't optimize around near-field measurements.   I optimize most of the filter design around >1.5M.    It would fit a number of applications.... home theater, 2-channel or as a studio monitor.   I don't differentiate how I design any of those categories except for something like a center channel or a specialty surround that might have a different physical footprint.   

Bass is set by the transducer/box and I'm using very little or no boost at this point.    I do have a high-pass filter set at 30Hz to protect the driver and lower bass distortion under the port tuning frequency.    I'll play with it a little in the final design phase but it won't deviate much from this.

   

That is a free-field simulation of the low-end in the appropriate box with the high-pass filter in place.   The 3dB down is about 33-34Hz in that simulation and you would obviously get more bandwidth in-room with boundary gain.   This is with 100W and you start to get near the voltage rails so I'd call this near maximum output before something starts to audibly complain.    One speaker.... anechoic is about 96dB @ 1M so a pair of them in-room would net you a fair amount more.     You are still below the excursion limits of the driver and the HP filter helps keep it out of trouble under the port tuning frequency.   

Woofer is my Anarchy which is a 6.5" format unit.   The tweeter is currently a small Vifa in a custom machined horn/waveguide.  I'm still playing around with the horn design but I have enough measurements to confirm that I'm happy with it.   







tg3

Re: I need a few Guinea Pigs
« Reply #5 on: 18 Jun 2010, 05:02 am »
PM sent.   :eyebrows:

Kevin Haskins

Re: I need a few Guinea Pigs
« Reply #6 on: 18 Jun 2010, 05:53 am »
PM sent.   :eyebrows:

PM received!  ;-) 

mbolek

Re: I need a few Guinea Pigs
« Reply #7 on: 6 Jul 2010, 09:44 pm »
PM sent...

HT cOz

Re: I need a few Guinea Pigs
« Reply #8 on: 6 Jul 2010, 10:57 pm »
A little OT, but why is DIY Cable an Archived Manufacturer Circle?

Kevin Haskins

Re: I need a few Guinea Pigs
« Reply #9 on: 6 Jul 2010, 11:04 pm »
A little OT, but why is DIY Cable an Archived Manufacturer Circle?

Ohh.... I'm making some changes and just don't have time to monitor forums.    I'll be doing a blog at some point that will follow the things I'm designing but I'm seriously cutting back forum participation.   

The forum here at AC gets used very little so I just didn't see a reason to keep it live.   It is another one of those things that steals 5-10 minutes of my life every day and I'm trying to reclaim as many of those minutes as possible.    :lol: