The "Elsinore Project" Thread

That crease is in an unfortunate location, i expect that it will affect the suspension.

dave

Thanks for your help Dave. I'll try to find a replacement then.

Hey 32yo, more pics?
Looks like a coating issue not a crease from that pic.

I thought about that too, but I think the picture just makes it look like that. I don't think it's a coating issue, especially because the crease is visible at the back too. I've attached some more pictures.
 

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32y0,

That "crease" looks like a fracture in the paper - possibly happened at the time of manufacturing when handling the cone? Does the area look/feel slightly weaker vs rest of the cone?

My guess is a little bit of binding material applied around that area should be able to make the driver usable.
 
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Just some quick comments:

Any further updates on the Hamlet?

Computer modeling set for next week.

I have been slowly gathering all the parts for my build. Looking at the woofers today I discovered one of them has an imperfection to it. It might be a bit hard to see on the picture, but it looks a bit like a paper fold in real life. What do you guys think, is it still usable or should I try find a replacement?

Probably happened during handling when packing it? Best to get a replacement.

But, if you are stuck with using that driver, make it the one at the bottom of the array, nearest the floor. The bottom two drivers works mostly under 400-500Hz and hence within their piston range, which is to say that the cone moves as a whole together without flexing, which it does above the 'knee' related to its diameter.

My choice other than the DT300 is the D2608/91300 as they already have been proven by Joe that they work fine (in the Elsinores) with the SB17MFC35 which I will use.

The DT300 was what I used in an earlier design before I designed our own waveguide - I simply used what interesting waveguide was available off-the-shelf at that time. It served me well because it was a part of exploring waveguides and then determining the need to design one for ourselves using the D2608/91300, which despite it price is a great tweeter when used the right way - indeed better than a lot of higher priced tweeters. With a good waveguide and careful crossover, the distortion is very low indeed. Many use waveguides to lower the crossover frequency, I do not. I use the waveguide to do two things 1) lower distortion and 2) increase power handling. I could add 3) that it also gives you a useful "offset" which is another way of saying that mounting the driver further into the box also makes the time alignment much easier than flush mounting.
 
Just some quick comments:
.....
The DT300 was what I used in an earlier design before I designed our own waveguide - I simply used what interesting waveguide was available off-the-shelf at that time. It served me well because it was a part of exploring waveguides and then determining the need to design one for ourselves using the D2608/91300, which despite it price is a great tweeter when used the right way - indeed better than a lot of higher priced tweeters. With a good waveguide and careful crossover, the distortion is very low indeed. Many use waveguides to lower the crossover frequency, I do not. I use the waveguide to do two things 1) lower distortion and 2) increase power handling. I could add 3) that it also gives you a useful "offset" which is another way of saying that mounting the driver further into the box also makes the time alignment much easier than flush mounting.

Thanks Joe,
As i have the wg since ordering quite a few while building my Elsinores it might as well be that full combination. Except for that it will be a two way with only one SB17MFC. Xo somewhere just above 2 kHz. Baffle width 230 mm, leaning 3 cm on the 30 cm where the drivers are mounted.

Are there any measurements of the D2608/91300 together with the WG but without xo?
 
The Hamlet boxes, the drivers have been burned-in before testing. Next step will be testing and that has to be done outdoors, the reason is that I do the modeling based on acoustic measurements done at 2 metres and not the usual 1 metre. Later in-room confirmation measurements with RTA (1/6th octave pink noise) will be done at 2.5 metres, being close to what most people will listen.

So we are now down to weather and opportunity, but not far away. I likely have all the parts required to finish the crossovers, so we are getting there.
 
Hi Scott

So-called dBSPL measurements are norotiously difficult and even arguing how it should be measured. When I set up the fairfield measurement before the computer modelling, I use a Vifa XT25 Tweeter as my reference. How accurate it is, what frequency would you select and so on. Because I know that the XT25 Tweeter is extremely flat response (the flattest I have measured) and I set it up at 0.5M, mic right on axis, then I I look at the response between 2-4KHz and aim for 96dBSPL - this is 6dB more than if the same measurement was at one meter and the Tweeter is rated at 91dBSPL at one Meter.

I actually do all my measurements at 2 Metres rather than one, so I increase the output by +6dB, so the respoonse I get is 2 Metres, but the scale in dBSPL is one Meter.

The modelling sums all responses and the final frequency response is what you see:

EL-6_Traces.gif


If I was looking for an avereage from 100 Hertz to 10KHz, I would say 92dBSPL easily and maybe slightly more. What do you think?

I could justify dBSPL = 92.5dB ? :D

Cheers, Joe

.

This is from post 1942. I have spent like 15 hours (800 posts) looking for any measures on the tweeter with the wave guide.

Is this it or are there others that might be of interest? (1189 also contain a SPL graph)

As a base line for further investigation of using D2608+WG in another design.
 
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Waveguide_Responses.gif


Red is straight 'On' axis. The 3KHz peak disappears even slightly off axis.

Green is 15 degrees off axis. Clearly the smoothest.

Blue is 30 degrees off axis.

With a series 1.8uF capacitor, the responses flatten out and down approx -6dB @ 3KHz. The flattest summed response will be Green and 15 degrees off axis, hence this is close to the recommended listening angle of the Elsinores. Depending on room brightness, this can be fine-tuned, turned closer to the listener makes it slightly brighter and turned away slightly less brighter.
 
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The Hamlet boxes, the drivers have been burned-in before testing. Next step will be testing and that has to be done outdoors, the reason is that I do the modeling based on acoustic measurements done at 2 metres and not the usual 1 metre. Later in-room confirmation measurements with RTA (1/6th octave pink noise) will be done at 2.5 metres, being close to what most people will listen.

So we are now down to weather and opportunity, but not far away. I likely have all the parts required to finish the crossovers, so we are getting there.

Joe:

Thanks for the update!

Regards,
Scott
 
A note to all Canadian Elsinore Project DIY'ers.

I have eight - (8) - new SB Acoustics SB17NRXC35-8 drivers available for sale
if anyone is interested. Thought I would get to build the Elsinores, but have now retired
to an apartment building and it looks as though my construction days are over.

These were bought at Solen in Montreal 4 - 5 months before they were discontinued.

I will only ship these to a Canadian location. For more details you can check my ad
on Canuck Audio Mart.

Good luck with your Elsinore builds, and thank you Mr. Joe Rasmussen for designing and
providing plans for such an interesting and high performance speaker.
 
Construction

Have had some nice weather and making good progress on the construction. Spent the day cutting the speaker cutouts. :)

Noticed something strange with the tweeter sizing. I did the recommended 5mm flush mounting on the sub-front panel but it seems the screws provided with the waveguide may be too long. Should I just get a drill bit larger than the nuts on the screws and create some holes where the screws are? Did anyone else have this issue? Pics below.
 

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