Yet another OB prototype

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JohnR

Yet another OB prototype
« on: 13 Dec 2010, 09:24 pm »



(Evolution from the first prototype.)

richardcooper2k

Re: Yet another OB prototype
« Reply #1 on: 13 Dec 2010, 11:56 pm »
if they're lacking response in the lower frequencies you'd loose less by having the bass drivers lower in the baffle.

unless there's a better reason for having them as high as they are ?


i like the suspended tweeters - no vibration from the other drivers will move them around

JohnR

Re: Yet another OB prototype
« Reply #2 on: 14 Dec 2010, 12:16 am »
if they're lacking response in the lower frequencies you'd loose less by having the bass drivers lower in the baffle.

unless there's a better reason for having them as high as they are ?

Yes indeed :) There will be a separate set of subs.

Quote
i like the suspended tweeters - no vibration from the other drivers will move them around

I had envisioned some kind of network of wires cross-crossing suspending them... but this will have to do for now!

ttan98

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Re: Yet another OB prototype
« Reply #3 on: 14 Dec 2010, 12:40 am »
Hi John,

Looks good you may like to tell us the details of your design, e.g. drivers used, x-over point etc.

This combo should sound good when you have completed with them.

Cheers and enjoy.

studiotech

Re: Yet another OB prototype
« Reply #4 on: 14 Dec 2010, 12:41 am »
Those look like the original, Nick McKinney made Dipole 15s.....When he was running the business in Orlando, his shop was right down the street from my apartment.  Hung out there a few times.  Very passionate, intense speaker guy.

Greg

studiotech

Re: Yet another OB prototype
« Reply #5 on: 14 Dec 2010, 12:44 am »
OT:  Ttan98

I sent you 2 PMs.  Never heard back.  Not sure if you read them.  Just curious if I could help you out....

Greg

JohnR

Re: Yet another OB prototype
« Reply #6 on: 14 Dec 2010, 01:25 am »
Well spotted, Greg :)

ttan98, yep I'm working on it ;) Mid is a B&C 6PEV13, tweeter is the same neo3 PDR I used before (but not in a baffle this time)

ttan98

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Re: Yet another OB prototype
« Reply #7 on: 14 Dec 2010, 05:26 am »
OT:  Ttan98

I sent you 2 PMs.  Never heard back.  Not sure if you read them.  Just curious if I could help you out....

Greg

sorry I have changed my email address. please send to this one yttean98@hotmail.com.

JohnR

Re: Yet another OB prototype
« Reply #8 on: 15 Dec 2010, 12:45 pm »
I feel like I'm getting in the middle of something.

Anyway, it seems to be working very well so far, with the miniDSP doing its thing. There's a good way to go yet but considering the cheap/flimsy baffle and the poor room (temporary), so far things are pretty much on track.

studiotech

Re: Yet another OB prototype
« Reply #9 on: 15 Dec 2010, 03:59 pm »
I feel like I'm getting in the middle of something.

Anyway, it seems to be working very well so far, with the miniDSP doing its thing. There's a good way to go yet but considering the cheap/flimsy baffle and the poor room (temporary), so far things are pretty much on track.

Sorry, didn't mean to sidetrack your thread.

How is the minidsp software working out?  Is it stable and simple to use so far?  I am using the digimoda dsp/amp modules and the hardware is excellent, but man, the software can be very glitchy.  Really gets frustrating sometimes when I want to make quick changes to compare settings and communication with the amp breaks or values that I did not enter show up.

Hebrew Hammer

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Re: Yet another OB prototype
« Reply #10 on: 15 Dec 2010, 10:18 pm »
if they're lacking response in the lower frequencies you'd loose less by having the bass drivers lower in the baffle.

unless there's a better reason for having them as high as they are ?


i like the suspended tweeters - no vibration from the other drivers will move them around

this won't be an issue with using the minidsp.. if low end response is lacking, all John would have to do is to create a parametric band using a low shelf and adjust both gain and Q to what works best in his room..

ttan98

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Re: Yet another OB prototype
« Reply #11 on: 16 Dec 2010, 12:09 am »
John,

I don't mean to hijack your thread.

Two observations here,
1. I suppose your baffle is only for testing, I think the rigidity of baffle needs to be improved.
2. The x-over between the mid and tweeter can be passive(mine is), this combo is better, thereby
    reducing the no. of amps and usage of Minidsp.

Anyway when you finish with these speakers they should sound good.

Hebrew Hammer

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Re: Yet another OB prototype
« Reply #12 on: 16 Dec 2010, 12:14 am »
John,

I don't mean to hijack your thread.

Two observations here,
2. The x-over between the mid and tweeter can be passive(mine is), this combo is better, thereby
    reducing the no. of amps and usage of Minidsp.

Anyway when you finish with these speakers they should sound good.

there isn't any magic a passive provides that can't be emulated actively.. and the flexibility an active system provides trumps it 1000 fold IMO

I'll give you the less channels or less cable argument..

ttan98

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Re: Yet another OB prototype
« Reply #13 on: 16 Dec 2010, 01:58 am »
there isn't any magic a passive provides that can't be emulated actively.. and the flexibility an active system provides trumps it 1000 fold IMO

I'll give you the less channels or less cable argument..

Not necessary, I have a DCX2496, at one stage I use active throughout and now use passive between mid and tweeter and active between woofer and mid. This combo works much better IMO.

JohnR

Re: Yet another OB prototype
« Reply #14 on: 16 Dec 2010, 03:07 am »
Hi ttan98

1. I suppose your baffle is only for testing,

Yep! This is far from the final one, I expect there will be another one or two prototypes before then. The purpose of this one is to measure the drivers and refine baffle shape and crossover points. Also to confirm driver choice.

Quote
2. The x-over between the mid and tweeter can be passive(mine is), this combo is better, thereby
    reducing the no. of amps and usage of Minidsp.

Number of amps is not a problem ;) I did have a passive for a time in the first prototype. I'd have to find something specifically wrong to switch back now - not expecting too :)

PS. What order xover are you using between your mid and tweet?

JohnR

Re: Yet another OB prototype
« Reply #15 on: 16 Dec 2010, 03:21 am »
How is the minidsp software working out?  Is it stable and simple to use so far?

It works great. Everything now and then it doesn't sync the very first time- I haven't figured out how to reproduce it but I wonder if it's because the OS is sill loading something and it times out (the miniDSP uses Adobe Air on the Mac). But then it stays synced (unless you disconnect it). The only inconvenience is that you can only talk to one of them at time.

JohnR

Re: Yet another OB prototype
« Reply #16 on: 26 Dec 2010, 04:54 am »
Hi, I've written up the first part of this for Hifi Zine, in what looks like being the first of three (!) articles on it:

  http://www.hifizine.com/2010/12/prototyping-4-way-open-baffle-speaker-with-the-minidsp-2x4/

Any comments or feedback would be appreciated (either here or there).


Badwater

Re: Yet another OB prototype
« Reply #17 on: 26 Dec 2010, 03:49 pm »
It will be take some time to digest, but this is just what I was looking for as I plan on implementing a active 3-way system using MiniDSP. 

Thank you so much sharing.

Bill

richidoo

Re: Yet another OB prototype
« Reply #18 on: 26 Dec 2010, 04:31 pm »
Looks great John! I had not heard about miniDSP, that looks cool too. Nice job on the article. Three thumbs up...   :thumb: :thumb: :thumb:



JohnR

Re: Yet another OB prototype
« Reply #19 on: 28 Dec 2010, 01:04 am »
Hi Bill, you're welcome, thanks for the feedback :) Rich, I read that you're using a Rane Unit? Interesting looking UI, I'd certainly be interested to hear how you go with it.