The "Elsinore Project" Thread

[Joe Rasmussen]

Originally posted by tktran303


They correlate very well with Zaph's, which is always reassuring.

The 810921 sure looks like a winner, across the board.

Although the low end of the XT25 leaves a little to be desired, above 3Khz it looks cleaner than the DX25. The limited dispersion can be an advantage, or disadvantage, depending on your design goals.

Have you run similar comparisons with the Peerless midwoofers?

Correlation is quite good, indeed.

You are right, if you had a 3KHz LR4 hi-pass, then use XT25, but the Elsinores are initially 1st order and then just under 1500 Hertz dive into 4-5th order, then DX25 has an advantage.

Because tweeters are closed backs they are a lot easier to do these tests, but woofers and especially midwoofers are a greater challenge. You are now measuring the box as well as some of the internal energy wants to break back through the cone. This is why computer modeling should always be done in the intended (actual) box. I have seen 1dB added midrange output.

But I have a 42L box that is fairly well damped and midrange breakthrough is low. I don't have any PPB drivers here but I have measured the Nomex that I now prefer over PPB, the extra dB is now a plus with Nomex that was not so good with XT & DX.

Peerless 6.5" Nomex 830875:



Joe R.

[Joe Rasmussen]

Originally posted by augerpro
Joe R. I was wondering if you could share a bit of info on your test setup. Things like mic distance, baffle qualities, room treatment (if any). I've started doing my own HD measurements and I'm trying to develop a good method and environment so i trust my results.

I use ClioWin V7.03 and gated Sinusoidal. The mic distance is 125mm on axis. The weakness in the measurement is that this is not an IEC baffle but rather smaller rectangular. Does not bother me much as we are not looking closely at frequency response but HD much lower than that. It's easy to do/set up and the results speak for themselves.

Besides, 125mm is probably the optimum distance to do this type of measurement, whereas it certainly is not for frequency response, so why be bothered too much?

Environment is not a problem as the gating is set to 1.5ms, but the auto-delay feature of ClioWin adjust this to less than 1ms. Make sure that you have no near reflective surfaces.

Joe R.

[Joe Rasmussen]

Just add to that last reply: The setup is calibrated to give 90dB @ 1 Metre for 1 Watt (2.83V). But if you note that on the dBSPL scale on the left of graphs, I adjust output to 100dB, that means the mic is actually seeing (hearing) 100dB, and so would you if you put your ear in the same position as the mic. It is LOUD and thus environmental noise is not just reduced by gating but also by sheer SPL.

Joe R.

[augerpro]

Thanks Joe that was very helpful! I can't gate sweeps with SE so right now I'm trying to get rid of reflections. But I'm confident I can get solid measurements eventually.

[Joe Rasmussen]

Originally posted by augerpro
Thanks Joe that was very helpful! I can't gate sweeps with SE so right now I'm trying to get rid of reflections. But I'm confident I can get solid measurements eventually.

I have SE but don't use the acquisition part of it (no sound card used) and use ClioWin for that as it is a specific tool for that purpose. I use SE for modeling though.

Whatever method you use you will still need a quiet environment and attempt to exploit it - make best use of it - and come up with a method that does the job.

BTW, Zaph also uses SE, so it is doable. Is there anything on his website that describes how he did it. I seem to recall there is an article there 'I use SE' or somesuch.

This is it: http://www.zaphaudio.com/setup.html

Joe R.

[augerpro]

Zaph doesn't have anything specific about his setup or method. Although he did write a little bit about his baffle in his last blog. I've posted questions concerning setup before at htguide and the SE user group hoping he'd answer, but no luck. In fact I get very little info from other SE users at the user group so it's kind of tough for someone new to loudspeaker design and the SE software to make progress. So, again, thanks Joe for your help!

Edit: I was refering to setup and method for distortion and other nonlinear testing above, not regular FR.

[soongsc]

Originally posted by augerpro
Zaph doesn't have anything specific about his setup or method. Although he did write a little bit about his baffle in his last blog. I've posted questions concerning setup before at htguide and the SE user group hoping he'd answer, but no luck. In fact I get very little info from other SE users at the user group so it's kind of tough for someone new to loudspeaker design and the SE software to make progress. So, again, thanks Joe for your help!

Edit: I was refering to setup and method for distortion and other nonlinear testing above, not regular FR.

How long ago did you post at the SE user group?

[augerpro]

I've been posting there since last fall. You are probably the most active user there and for that I thank you! But if you don't answer or don't know the answer I haven't had as much help as I would have expected. I don't mean to bash Bohdan or anyone else. Maybe my questions were dumb. But it's a bit of a letdown nontheless.

Anyway enough that. I don't want to hijack this thread

[soongsc]

Originally posted by augerpro
Zaph doesn't have anything specific about his setup or method. Although he did write a little bit about his baffle in his last blog. I've posted questions concerning setup before at htguide and the SE user group hoping he'd answer, but no luck. In fact I get very little info from other SE users at the user group so it's kind of tough for someone new to loudspeaker design and the SE software to make progress. So, again, thanks Joe for your help!

Edit: I was refering to setup and method for distortion and other nonlinear testing above, not regular FR.

I think that issue was answered a few weeks ago, and there seemed to be some error in Zaph's setup for a certain portion of that part of the data, but I can't recall which right now. You just need to unplug the ref input channel. Otherwise same as normal FR. The new distortion tools are very useful for many purposes. If you have any other questions about this just post in the SE user group again.

[PoorSound]

I want to bring this back!
I'm ALMOST ready to give these a listen to. I have the components, the boxes, and the crossover i just need to assemble.

i have a quick question...my port is almost half the size of the original design...how will this affect the sound? i don't have the tools to make the hole bigger...will the sound suffer?

thanks!