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Old 8th June 2009, 08:15 PM   #531
rob323 is offline rob323  Australia
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Quote:
Originally posted by BL4S7ER
[B]Rob, would that happen to be a center speaker by any chance?!
A pair of them to be exact .
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Old 9th June 2009, 01:04 PM   #532
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Hi Guys.

Just a few things...

1) I spoke to WES on Friday and they said they had 50 plus of the Nomex 830875 in stock and also 30 plus of the Tweeter 810921.

2) Rob is also going ahead with the Hamlet boxes and will deliver them here with drivers fitted and then leave the rest to me.

3) I will do my best to post a provisional crossover this week. I had a computer crash and needs to find files and also install modeling software. How close this will be to the final crossover is anybody guess.

4) Tyson emailed re using electronic crossover:

Hi Joe,

I've completed the construction of my Elsinores, at least the boxes and drivers are all installed. Next up is building the passive crossover.

In the meantime, I am running the Elsinores using my DCX active crossover and 3 amps. I'd like to mimic the passive crossover settings as closely as possible.

Can you tell me the crossover points and slopes for each set of drivers? I have the ability to choose almost any crossover slope and any point, as well as creating notch filters at specific points (for dealing with resonances and such). I also have 6db, 12db, 18db, 24db, and 48db per octave slopes available, using Linkwitz-Riley, Besel, or Butterworth. I can also do asymetric crossover slopes, ie, 6db on the tweeter, and 24db on the woofer, or any other combination.

Mainly I just need the crossover points and their slopes and the DCX should be flexible enough to let me program them in.

Thanks!


We want to make sure that the Elsinore speaker still follows the correct recipe' and not just another electronic crossover that misses the mark through standard slopes. There are certain characteristics that needs to come through in the final result. My reply to Tyson tries to address this:

Hi Tyson

The problem with the crossovers in the Elsinore is that they don't follow normal slopes.

1. The low-pass on the two series wired bass drivers is LESS than first order. While it uses a single choke there, the rising Z response prevents full 1st order slope and makes it more gradual. But if using 1st order you will need to try about 300 Hertz and tweak from there. Or you could attempt to model the slope, using the Z curve of the two drivers in series, and get DEQX to follow that? Or is DEQX stuck with fixed order slopes? If it is, try -3dB at 300Hz.

2. There is no lo-pass on the series wired mid-bass either. There is a flattening of the 4KHz peak inherent in the drivers, as represented by the LCR trap in the crossover, and there is the R/L that flattens the reponse and interacts with the choke action of the choke in the bass section. The levelling of the 4KHz peak does introduce a premature roll-off frequency but does NOT alter the actual final slope. You will need to replicate what the LCR trap is doing. BUT, there is no lo-pass. Ultimately you MUST aim to be -6dB at around 3KHz. This must be the combined response including the two bass drivers. But make sure this is at no less than 2 metres as there is an interaction caused by the difference in time and at 2 metres this comes in well above 3KHz. If you do it closer there could be problems due to this interaction. This time difference is discussed on the website.

3. The hi-pass on the Tweeter is 1st order, but only for an octave and a bit below the 3KHz crossover. Whatever you do, you must make sure that it is out of phase electrically speaking. The tweeter will invert its acoustic output provided you aim at it being -6dB at the 3KHz crossover. If you end up summing flat at -3dB, then something is wrong that cannot be sorted/solved out electronically, the ultimate power response that the Elsinore aims at in front of the baffle. BUT at 1300-1500 Hertz you will need to introduce an at least fourth order filter, so that the combined slope below this point is 5-6 order. This dramatically lowers the tweeter's distortion and is a key part of the design. So you can see that the hi-pass filter is multi-pole (or two-pole if you like).

You will need to get all the elements right to give a good summed response at the listening position and also a decent phase response. Make sure that the microphone is at the same height as the tweter and about 10 to 15 degrees off axis. Again I must point out how important it is to get the tweeter's phase right and being -6dB down at 3KHz and also to get it to show the phase response being good as well as the summed response at least 2 Metres slightly off axis.

Really, without hands on being there with the equipment, that is about the best I can do.

I may polish the above a bit and post it on the thread with your question, OK with you?

Cheers

Joe


Tyson's return reply:

Thanks for getting back to me, I really appreciate it. You can, of course post the information to the thread on diy.

I have a DCX, not a DEQX, and it is extremely flexible, I should be able to get the correct slope on the bottom woofers just fine. And I should be able to take care of the 4khz peak with a notch filter in the DCX as well. I also have the ability to invert phase on any driver "on the fly", in real time, so inverting the tweeters is no problem either.

I've been taking measurements of the Elsinores in my room and one thing I notice is that because of how I have them placed in the room, near the rear wall, and next to a pair of columns on each side, there is really no need for the 6db baffle step compensation. I have the ability to add or remove it at will with the DCX, and when it is added in, the bass is really overpowering. Removing it and simply running the woofers "flat" without the 6db gain, gives a much better response in my room.

But, now that I have the specific info on the slopes and crossover points, I'll re-work the crossover to mimic it exactly and then take some more measurements and do some more listening. Thanks again!

Tyson


--------------------------------------------------------------------

Hope that helps anybody going down that route.

Cheers.

Joe
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Old 9th June 2009, 08:17 PM   #533
rob323 is offline rob323  Australia
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Quote:
Originally posted by Joe Rasmussen
[B]Hi Guys.

Just a few things...

2) Rob is also going ahead with the Hamlet boxes and will deliver them here with drivers fitted and then leave the rest to me.
Hmm, I was going to send you a single empty box and hope you had some drivers lying around to throw in it .

Joe, do you want me to pull some "run in" drivers out of my Elsinores and put them in or just get brand new ones?
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Old 10th June 2009, 01:11 AM   #534
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Quote:
Originally posted by rob323


Hmm, I was going to send you a single empty box and hope you had some drivers lying around to throw in it .
Hmm, like they said in the movie "what we have here is lack of communication." I did have two 830875 but they went on the their merry way a few weeks back. I do have a pair of HDS tweeters.


Quote:
Originally posted by rob323

Joe, do you want me to pull some "run in" drivers out of my Elsinores and put them in or just get brand new ones?
Doesn't have to be run in, I do that anyway overnight before testing. But I wouldn't like to see your Elsinores out of action... ?

Joe R.
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Old 10th June 2009, 01:54 AM   #535
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Hi Rob

Just love Google Maps. Here is a pic of "The Home of the Elsinore Project" and that is my van you can see parked. When you get here you will know what to look for:

Click the image to open in full size.

Joe R.
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Old 10th June 2009, 07:56 AM   #536
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lol nice, i can beat that, i went to Elsinore 2 weeks ago in Denmark, went into the castle too. You can see Sweden across the sea. Amazing place. i think i deserve those HDS tweeters now for free right?? i can post pics when i get home from work. Damn denmark is one expensive country for a turo
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Old 10th June 2009, 09:08 AM   #537
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Hello, I have a simple way to get the elsinores working as intended with active crossover.

Joe give to Tyson your measurments of individual drivers mounted in the box, than he could use LSPCAD to model the crossover to match the measurment of passive crossover version. LSPCAD has the ability to simulate the active crossover, and also behringer dcx.
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Old 10th June 2009, 01:07 PM   #538
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Quote:
Originally posted by beauistheman
lol nice, i can beat that, i went to Elsinore 2 weeks ago in Denmark, went into the castle too. You can see Sweden across the sea. Amazing place. i think i deserve those HDS tweeters now for free right?? i can post pics when i get home from work. Damn denmark is one expensive country for a turo
Good on ya, but no, HDS tweeters don't come for free, only with a recent price increase.

That castle and fortification was of great strategic significance for many many centuries. It is only a few K's across, takes 15 minutes by ferry, but it is also THE gateway to the whole of the Baltic sea. Think of the importance to the Russians and their alternative capital St Petersburg. Think of all the seaside states of the Baltic, and they all had to ply their sea-going trade going past this fortification. Here was THE place to bring out effective blockades. Many battles were fought because of this location.

Maybe it's not as expensive as you think. They have some of the highest wages in the world. Here is an aerial view of the castle:

Click the image to open in full size.

Got any pics? Let's see some of them?

Joe R.
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Old 11th June 2009, 11:04 AM   #539
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Hi Guys

Here we go. It been coming for some time and I thank you for your patience. Not only for the requests made here but also more directly via emails.

PROVISIONAL HAMLET CROSSOVER

Click the image to open in full size.

The results here are based on modeling results from the Elsinores. I think that this provional crossover should be reasonably close to the final posted result. Compare both, the Elsinore and provisional Hamlet crossovers, and you will see that many of the component values are the same. You would expect the 4KHz LCR trap and the LC for the tweeter to be identical. The parallel LR was changed to cope with the different diffraction loss, the "step" that is not filled in by the addditional pair of bass drivers. This step/loss is based on the Elsinore box and since the width of the box is the same, we should be in a similar ball park. The unknown is the additional baffle area below the two MidBass that will be missing in the Hamlet. But since I see a loss of sensitivity, based on practical experience, I would say that -5dB should be pretty close and certainly within 1dB. Eventually when Rob comes up with the actual box to work with, all this will be revealed.

Let us look at the Frequency Response:

Click the image to open in full size.

This would indicate about or close to 87dB sensitivity. Considering that this is achieved with high Z like the BBC LS3/5A which was also 16 Ohm but 81dB sensitivity. This will be a speaker that is not current hungry. Let take a look at...

The Z (Impedance) Curve:

Click the image to open in full size.

Below 3KHz this comforms to a 16 Ohm speaker, above that it qualifies as 12 Ohm since the Z does not go below 8.5 Ohm (divide the nominal Z by 1.414 is the convention used).

Now that Z curve only tells a partial story, it needs to be looked at in the context of...

The Impedance Phase:

Click the image to open in full size.

Mildly negative. The lowest is around 85 Hertz and -50 degrees. But the Z plot shows it is 28 Ohm. This is no problem. The second lowest is 2.5KHz and -20 degrees. Yet the Z is a very high 12 Ohm. Above 6KHz the phase is positive.

One of the major features of the Elsinore is its phase response...

Minimum Phase:

Click the image to open in full size.

We can see then minimum phase extends from 20 Hertz to almost 20KHz. This is depite breaking the rule and wiring the tweeter in reverse phase based on The Renegade Tweeter Theory that states that a fast rising tweeter inverts the acoustic phase relative to the electrical phase below a specific frequency and input level. Yes, tweeters are Invertors.

I also looked at simulating that time response using a square wave:

Simulated Square Wave @ 750 Hertz:

Click the image to open in full size.

The spikes you see in this example show up beyond 17KHz as shown by the minimum phase plot.

Note the two last graphs are based on 4 Watts input, or 5.65V RMS. With lower levels the phase improves further and above comes down in frequency.

Coming back to those spikes, they largely disappear with actual measurement as opposed to simulation. The following example is the Elsinore:

Click the image to open in full size.

Notice how much the spikes are truncated, and as this is a real measurement rather than a simulated one, we can see that in the real world The Renegade Tweeter Theory works even better than one might think. Reality is better than even the theory indicates.

Conclusion: The Hamlet retains key features use in the Elsinore Project speaker. In addition to above it retains the use of series connection of the main drivers. In all honesty I have not seen this used in any commercial speaker and come to think of it, I can't recall any diy designs either. Normally we would connect the drivers in parallel and get a 3-4 Ohm speaker. Yes, the voltage sensitivity would likely match the Elsinore, but the current required would quadruple, so efficiency is not improved, just a heavier load on the amp. I make no excuses for being in a particular camp (a minority one I would say).

OK, over to you guys.

Cheers.

Joe R.
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Old 11th June 2009, 11:55 AM   #540
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well it is a very expensive country, one of the most expensive in the world. But i did state for a tourist. They have massive tax, but, like other European countries, they have free education and free uni, free health care etc etc. So its all there, for the people who live there.
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