OB Project Design Started, Help Requested.

[gainphile]

Hi David,

I just wrote a small article on measurements of dipole loudspeakers. Hopefully we can compare notes. Note that I never measure at listening distance.

Gainphile: Measuring Open Baffle loudspeakers

[Helmuth]

Originally Posted by gainphile

Hi David,
Hopefully we can compare notes. Note that I never measure at listening distance.

Note you hear what you receive(stereo) at your listening point. That is leading IMO.

Like I did here.

A backloaded horn low and horn midhigh.Project presentation Horn Almighty

[SimontY]

I also struggle with the concept of measuring only in free space away from boundaries etc. Isn't it best to do both, when possible?

[gainphile]

One can't correct deviations in time domain with amplitude adjustments.

Otherwise DSPs would have solved all of our 'problems' by now.

[John Busch]

Just finished reading Gainphile's "Measuring Open Baffle Loudspeakers" Interesting. Can't wait to read Gainphile's "Advanced" topics, especially "why passive dipoles won't work". Need to know how my well received passive OB designs manage to please so many? Hmmmm.....? Northern CA DIY, LSAF, RMAF......

[SimontY]

Originally Posted by gainphile

One can't correct deviations in time domain with amplitude adjustments.

Otherwise DSPs would have solved all of our 'problems' by now.

I'm not 100% sure that allowing for a listening space in the design parameters is the same as performing EQ (DSP). I use no EQ and have a good response, but I did measure my system in my room as a means to easily achieving the desired sound. I am something of a novice with speaker design however, always looking to learn more

[SimontY]

Originally Posted by John Bsuch

Can't wait to read Gainphile's "Advanced" topics, especially "why passive dipoles won't work".

I'd definitely like to read that too. It's very much news to me as my ears and measurements told me (my) passive open baffles can work, and if this is the sound of "not working" then sign me up for more!! Sure, there are trade-offs but "won't work" seems a bit strongly-worded. It also implies the author hasn't tried - yet??

[gainphile]

It is not my intention to offend anyone. I have reworded it to "Difficulties with passive dipole loudspeakers."

[DQ828]

I'm all for measuring outside for crossover purposes & to see how the crossover is working, but for me the final adjustments are made in the room.

I had the tweeter EQ'd within an inch of its life, showing a fairly impressive looking line, in the end I turned the tweeter specific EQ off & left the global high shelving on and liked the result better, even though the measurement didn't look so good.

My passive P17 clones sound pretty bloody good to me and may others, no audio nuts though. (they didn't measure well). I think the approach of keeping it simple, like the P17 crossover, can have benefits

David

[DQ828]

Since I reported "I think I'm happy for the moment" I was listening to some classical guitar & thought the highs where a bit lacking, so guess what, I had a fiddle, imagine that.

I changed the high shelf configuration a little & "I think I'm happy for the moment"

Or maybe not, we will see, they are sounding great though.

I was convinced to go active by the boys on the forum, "it'll be much easier they said" & they where right in one respect, it SO much easier to change the crossover & EQ 10mins & your done, with no dirty hands, I'm glad I did.

Its also lead to another project, six channel amp.

David

I should have said 2 extra projects, the active crossover of course.