OB Project Design Started, Help Requested.

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Note that I never measure at listening distance.

I'm a bit puzzled by this... why not?

It's at the listening position we hear what we hear, dont you agree? I never measure anywhere else... (except when I check the polar response).

I also set my (as few as possible) EQ's based on 1/3 oct smoothed measurements in the listening position that includes a full room response, but I do compare them to anechoic measurements to check if I'm totally off.
 
RD50

They don't appear to shake, I have some isolation ideas, but for the moment the speaker development is on hold until I get a couple of other projects out of the way, still some more prototyping to do on these.

thanks for the input.
Too bad the BG RD50 are so expensive and you never see them for sale used. You could stick a couple of those on top of your cabs to compare very easily.
 
I'm a bit puzzled by this... why not?

It's at the listening position we hear what we hear, dont you agree? I never measure anywhere else... (except when I check the polar response).

I also set my (as few as possible) EQ's based on 1/3 oct smoothed measurements in the listening position that includes a full room response, but I do compare them to anechoic measurements to check if I'm totally off.

Im with you, do it in the back yard to see your on track & get some pretty graphs, then do where you listen, to see the truth.

I started off applying masses of EQ, got a pretty good graph & they sounded crappy, then removed most of the EQ, got a less than perfect graph & they sounded much better, your ears are the final arbitrator.
 
Lighting May Strike Me Down

I'm thinking about trying a passive crossover on the new speakers :) It's the only way I will know if all this active stuff is worthwhile & will make life easier in a lot of respects.

My problem is, I know nothing about designing passive crossovers :D, wouldn't be a challenge if I new what I was doing.

So my question is; can you recommend the best approach to take.
 
I take a long-winded approach that does end up with a good-sounding (maybe great) speaker. I listen with the most basic ramshackle 1st or 2nd order crossover, measure with and without the crossover - each driver and the total response from about 50cm-1m, just one speaker, in-room. Then I take it from there altering slopes and values and measuring and listening repeatedly. The listening matters more but I find the measuring gets the good results much faster, and then fine-tuning can only be done by ear as your program material and tastes dictate the final desired outcome more than a flat axial response.

That said I do have a preferred slope, which sounds good to me. It's a tilted down curve that's maybe 4-5dB louder at the bottom than at the top.
 
I take a long-winded approach that does end up with a good-sounding (maybe great) speaker. I listen with the most basic ramshackle 1st or 2nd order crossover, measure with and without the crossover - each driver and the total response from about 50cm-1m, just one speaker, in-room. Then I take it from there altering slopes and values and measuring and listening repeatedly. The listening matters more but I find the measuring gets the good results much faster, and then fine-tuning can only be done by ear as your program material and tastes dictate the final desired outcome more than a flat axial response.

That said I do have a preferred slope, which sounds good to me. It's a tilted down curve that's maybe 4-5dB louder at the bottom than at the top.

Thanks thats a starting point. Does anyone know if there is simple/basic/good, how to, on the web somewhere
 
Parts Express

Thanks thats a starting point. Does anyone know if there is simple/basic/good, how to, on the web somewhere
Ask on Parts express. They are the most active speaker building forum. Many of the guys there buy close out speakers just to spend hours fine tuning another passive crossover for fun. They keep parts bins full of passive componants on hand. Tons of experience in other words. They will recommend using "Passive Crossover Designer" for PC which is free ware.
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Tech Talk Forum - Techtalk Speaker Building, Audio, Video, and Electronics Customer Discussion Forum From Parts-Express.com
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Thanks guy's, I will research your suggestions. I have previously paid for the MathCad Computer Models but had so much trouble with the whole MathCad thing I gave up in frustration. Shame there written for such a seemingly inaccessible program. I don't have the money to spend on that sort of software.
 
Don't have money for Excel or for Mathcad? If by small chance you mean Excel, you should know there's a free open source alternative: OpenOffice.org - The Free and Open Productivity Suite

I meant MathCad, doesn't everybody have Excel:). I did download the MathCad Explorer but had nothing but trouble with it. Also the MathCad worksheets that are available don't seem to suit my 3 way H frame setup. I'm also using the Neo 10 & 3 which also don't seem to have the same parameters as cone drivers, of course I could be talking sh?t as I know so little.
 
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Hi david,

After you mentioned that the sound isn't what you aspected did you manage to improve it some way. Are you more adapted to the sound of the new dipole.

203338d1293847069-ob-project-design-started-help-requested-01012011-001-.jpg
 
Hi david,

After you mentioned that the sound isn't what you aspected did you manage to improve it some way. Are you more adapted to the sound of the new dipole.

203338d1293847069-ob-project-design-started-help-requested-01012011-001-.jpg

Hi Helmut

Nice to hear from you, I hate to admit it but they are still in the unfinished state as per the photo. I got caught up building the Coldamp, then sold that & have been building a pair of 3 channel amps based on the Aussie Amp Mosfet modules. They have taken WAY longer than planned & are still not finished.

The speakers are good but my plans are to finish the amps & then go back to the speakers once I have finished a Sub & queen size bed for my daughter. So the speakers will have to wait till next year.

When I compare them to the Lukasz Frikus 17 speakers that I built (as seen in the background of the above photo), which have very simple passive crossovers & 50 year old drivers, & can be driven successfully with a 20watt Kingrex amp, in general the new ones are better overall but the P17 have something speacial about them which I think is in the midrange. Also the new speakers require six channels of amplification & an active crossover to make them work, basically I was hoping for better. I am using a MiniDSP active crossover which I have my doubts about. I have been toying with the idea of building an active analogue crossover & using a Buffulo DAC to do the conversion, but that will keep me busy till the year after next :)

David

Oh yer, the MiniDSP is know in a case.

11-10-21MiniDSP1_3.jpg


11-10-21MiniDSP1.jpg
 
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Hi Helmut

Nice to hear from you, I hate to admit it but they are still in the unfinished state as per the photo. I got caught up building the Coldamp, then sold that & have been building a pair of 3 channel amps based on the Aussie Amp Mosfet modules. They have taken WAY longer than planned & are still not finished.

The speakers are good but my plans are to finish the amps & then go back to the speakers once I have finished a Sub & queen size bed for my daughter. So the speakers will have to wait till next year.

When I compare them to the Lukasz Frikus 17 speakers that I built (as seen in the background of the above photo), which have very simple passive crossovers & 50 year old drivers, & can be driven successfully with a 20watt Kingrex amp, in general the new ones are better overall but the P17 have something speacial about them which I think is in the midrange. Also the new speakers require six channels of amplification & an active crossover to make them work, basically I was hoping for better. I am using a MiniDSP active crossover which I have my doubts about. I have been toying with the idea of building an active analogue crossover & using a Buffulo DAC to do the conversion, but that will keep me busy till the year after next :)

David

Oh yer, the MiniDSP is know in a case.

11-10-21MiniDSP1_3.jpg


11-10-21MiniDSP1.jpg
Hi david,

I have build a SE tube amp as you know. Because their are many people who say it is the best thing.
And I have to say my own amp sounds very special certainly a improvement on the good hypex class-D the spacious sound it produces is very nice.

So I would say keep the woofer on transistor and play with the mid and high on a SE tube amp. A active hybrid of transistor an SE tube amps it most work fine with the efficient BG ribbons. If you go for tube amp the transformer is a essential quality part.

The mini-dps case looks very good.
 
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