Dimensions of opening for the tweeter
Joe and all,
I'm almost done with my enclosures (just not glued yet) and will be cutting the fronts shortly. I'm making it from nice oak boards and would like to keep the board in one piece, i.e. not cut it like the official design shows in a separate top and bottom. Instead I would like to cut a rectangular opening with the opening height as in the design, but with 50 mm of wood on each side, that would frame the tweeter and the felt.
The question: Is there something about the design that requires that the top and bottom front boards be completely separate? It seems to me that the felt damping would be sufficient as long as it covers the area around the tweeter by a few cm in each direction.
Thanks,
Francois
Joe and all,
I'm almost done with my enclosures (just not glued yet) and will be cutting the fronts shortly. I'm making it from nice oak boards and would like to keep the board in one piece, i.e. not cut it like the official design shows in a separate top and bottom. Instead I would like to cut a rectangular opening with the opening height as in the design, but with 50 mm of wood on each side, that would frame the tweeter and the felt.
The question: Is there something about the design that requires that the top and bottom front boards be completely separate? It seems to me that the felt damping would be sufficient as long as it covers the area around the tweeter by a few cm in each direction.
Thanks,
Francois
Joe and all, Hello! I have a question on the trap filter. I am sure there are some who may hear the difference with & without the trap on the tweeter? I haven't ordered the components yet and wanted feed-back on this part before I include. Also there are two differing values to the inpedance network for the tweeter, 68microf. and the other at 300microf. It shows 300 on the early post and back to 68 on the latest. can you explain?
kingfisher
PS. most interesting sight!
kingfisher
PS. most interesting sight!
Hello all, Hello Joe;
There is several weeks than the Joe's Elsinore tempts me ... I did not find this achievement on French forums.
I fell on the Joe realization, seeking my inspiration on the net... What a job! It's an impressive achievement that makes me get into the DIY with enthousiasm.
Thank Joe!
With this project, are always few questions for a newbie like me who throws himself into his first DIY!
I already plan a list of components on website Europe-Audio, prices are very competitive (I think)
-For resistors, I think Wirewound resistor 5W 5%
For inductors:
L1-Tritec Ferrobar coil with ferrite core 9mH 0.430Ohm
L2-Visaton coil with air core and tinned wire ends 1mH 0,5 Ohm (5014) or Air core coil 1.0mH 0.28Ohm 1.4mm
L3-Monacor air core coil 0.47mH 0.45Ohm 0.85mm
L4-Monacor air core coil 0.82mH 0.35Ohm 1.2mm or Air core coil 0.82mH 0.26Ohm 1.4mm
L5-Air core coil LUT 55/30 1.80 mH R 0.79 CU 1.00 AL 40
-For capacitors:
C1-AUDYN-CAP KP-SN tinfoil capacitor 3.3uF 160V 24 x 38mm
C2-AUDYN-CAP KP-SN tinfoil capacitor 4.7uF 160V 24.5 x 38mm
C3-AUDYN-CAP KP-QS foil capacitor 68uF 400V 50 x 66mm
C4-AUDYN-CAP KP-QS foil capacitor 10uF 400V 28 x 36mm
So my questions are these: Joe, in the crossover, indicates the values 0R5 max for L2, L3, L4 and 1R max for L5.
If I understand correctly, for L3 and L5, we can adjust the values of resistors in series to compensate for low resistance of the coil .. but what about the values of L2 and L4? is it better to be close to 0R5 or lower values would be better?
Also, is that my choices in the capacitors are ok?
Feel free to point me to other products (R/L/C) if you think it useful.
I will wire the speakers with UL1213, Alpha-Wire in AWG-16 (silver plated copper wire covered with Teflon)
Thank you for helping me and excuse me for my deplorable English..
Jerome
There is several weeks than the Joe's Elsinore tempts me ... I did not find this achievement on French forums.
I fell on the Joe realization, seeking my inspiration on the net... What a job! It's an impressive achievement that makes me get into the DIY with enthousiasm.
Thank Joe!
With this project, are always few questions for a newbie like me who throws himself into his first DIY!
I already plan a list of components on website Europe-Audio, prices are very competitive (I think)
-For resistors, I think Wirewound resistor 5W 5%
For inductors:
L1-Tritec Ferrobar coil with ferrite core 9mH 0.430Ohm
L2-Visaton coil with air core and tinned wire ends 1mH 0,5 Ohm (5014) or Air core coil 1.0mH 0.28Ohm 1.4mm
L3-Monacor air core coil 0.47mH 0.45Ohm 0.85mm
L4-Monacor air core coil 0.82mH 0.35Ohm 1.2mm or Air core coil 0.82mH 0.26Ohm 1.4mm
L5-Air core coil LUT 55/30 1.80 mH R 0.79 CU 1.00 AL 40
-For capacitors:
C1-AUDYN-CAP KP-SN tinfoil capacitor 3.3uF 160V 24 x 38mm
C2-AUDYN-CAP KP-SN tinfoil capacitor 4.7uF 160V 24.5 x 38mm
C3-AUDYN-CAP KP-QS foil capacitor 68uF 400V 50 x 66mm
C4-AUDYN-CAP KP-QS foil capacitor 10uF 400V 28 x 36mm
So my questions are these: Joe, in the crossover, indicates the values 0R5 max for L2, L3, L4 and 1R max for L5.
If I understand correctly, for L3 and L5, we can adjust the values of resistors in series to compensate for low resistance of the coil .. but what about the values of L2 and L4? is it better to be close to 0R5 or lower values would be better?
Also, is that my choices in the capacitors are ok?
Feel free to point me to other products (R/L/C) if you think it useful.
I will wire the speakers with UL1213, Alpha-Wire in AWG-16 (silver plated copper wire covered with Teflon)
Thank you for helping me and excuse me for my deplorable English..
Jerome
Hi Jerome
Yes, your choices seem fine. Re resistances in the inductor, the Elsinores can tolerate higher resistances than far the most of speakers around. Each wing of the crossover is virtually 16 Ohm nominally, so it can tolerate four times the resistance compared to that of 4 Ohm design. For example, even as high as 1 Ohm DC resistance at 16 Ohm is virtually the same as 0.25 Ohm at 4 Ohm.
So there is no problem with what you have listed, the DC resistances are more than adequate.
Cheers, Joe
The LC trap is L = 0.82mH and 68uF and keep DC resistance of L as low as possible.
300uF and other L value was for Vifa XT Tweeter as used in Mark 1 - we are now Mark 3 and the Tweeter was changed to Peerless HDS 810921 - which is now Scan-Speak D2608 Discovery Tweeter.
This LC trap - a null filter actually - is critical in lowering distortion from the Tweeter and improving power handling etc. It should not be omitted unless you desire a significant loss in performance. Surely not?
Cheers, Joe
Hey guys, does someone have an answer or opinion for me? Am I missing something important in the requirement for having two separate boards?
Francois
Hey Rob, any news on the Hamlet boxes front?
Cheers, Joe
Joe,
Do you think you will try a 2.5 way crossover for the hamlet as well?
Been wanting to build the Elsinore in a more compact form to make a matching lcr set with subs and the Hamlets seems like the ticket. I am guessing that a 2.5 way might have wider off axis response? And Higher efficiency?
Thanks for all the hard work
John
Cheers, Joe
Joe,
Do you think you will try a 2.5 way crossover for the hamlet as well?
Been wanting to build the Elsinore in a more compact form to make a matching lcr set with subs and the Hamlets seems like the ticket. I am guessing that a 2.5 way might have wider off axis response? And Higher efficiency?
Thanks for all the hard work
John
Yes. If you move the tweeter forward/backward relative to the woofers it changes the time alignment and phase alignment (two separate but related issues).
Critofur, I appreciate for your reply. But I'm asking a diffrent question than the question you (and apparently everyone else) thought I asked. I will try to ask and explain better. (Sorry to be long winded - if I could draw this it would be much more understandable)
Joe's design has the tweeter mounted on a "sub-front" which has openings for the woofer magnets. Then there are two front pieces for each speaker, an upper and lower front. The upper front has one whole for one woofer and the lower has three.
I'I would like to use a single front in nice 19mm oak with a rectangular opening the same height as the original space between upper and lower fronts, still mounting the tweeter on the sub-front 19 mm behind the woofers, but keep the upper and lower fronts together by making the opening 50 mm narrower on each side. My proposed single front has the woofer wholes as before plus a rectangular opening that fits over the tweeter.
The question is really is: "Does it matter if the recessed area does not go all the way across the front (everything is the same, except framing the opening by 50mm wood on each side. It also means the felt is as before, except it stops 50mm short against the "frame" compared to the standard design.
Joe's design has the tweeter mounted on a "sub-front" which has openings for the woofer magnets. Then there are two front pieces for each speaker, an upper and lower front. The upper front has one whole for one woofer and the lower has three.
I'I would like to use a single front in nice 19mm oak with a rectangular opening the same height as the original space between upper and lower fronts, still mounting the tweeter on the sub-front 19 mm behind the woofers, but keep the upper and lower fronts together by making the opening 50 mm narrower on each side. My proposed single front has the woofer wholes as before plus a rectangular opening that fits over the tweeter.
The question is really is: "Does it matter if the recessed area does not go all the way across the front (everything is the same, except framing the opening by 50mm wood on each side. It also means the felt is as before, except it stops 50mm short against the "frame" compared to the standard design.
The idea was to make the boxes as easy to construct as possible. But if you made it one piece it would require good skills to cut out the Tweeter cavitity that many would not have or not have the equipment to do it neatly as it is highly visible.
But if you were to make the width smaller and the felt less wide, it should work provided you don't reduce the width of the cavity too much, maybe a max of 15mm either side (which will reduce cavity width by 30mm). We don't want to create diffraction effects that has not been compensated for, espescially in the crossover.
Cheers, Joe
You are welcome.
Doing 2.5 way was not the idea and there is no reason to expect higher efficiency. What would be explored is parallel versus series connection of Nomex drivers. Parallel will certainly increase the voltage sensitivity but also become nominal 4 Ohm and hence double the current relative to 8 Ohm. So the actual efficiency is the same, only voltage sensitivity goes up. The same goes for 2.5 way as below a certain frequency (diffraction loss determines that frequency) the overall the system impedance will be 4 Ohm and there is no gain or loss relatively speaking.
But doing it MTM will mean the Hamlets will be symmetrical both laterally and vertically a la John Dunlavy preached. This makes it virtually a true point source speaker if you get all the other things right like the phase etc.
I better explain this idea of Dunlavy. The Tweeter will be in the dead centre of the front panel or baffle. The baffle above and below the Tweeter to be mirror image pairs (vertical symmetry) and the baffle either side of the Tweeter also mirror image pairs (lateral symmetry). Needless to say, vertical symmetry includes drivers both above and below the Tweeter. Of course all drivers need to be vertically aligned. Now such a speaker, and look at the Hamlet boxes, with the drivers "time" aligned correctly on the front panel (baffle) can have both point source and also symmetrical response both laterally and vertically.
While the Elsinores are only point source from roughly 400 Hertz up (but not truly symmetrical), the Hamlets will be proper point source in true Dunlavy terms. What I am trying to say is that the Hamlets have to be a compliment to the Elsinores and share as many characteristics as possible as multi-channel systems will need both Elsinores and Hamlets. This will also mean the sound fields they generate will be similar and sonically compatible. That was always what we wanted to do.
Cheers, Joe
I suppose that question is understandable. But what I suspect (and hope) is that the driver has not changed and they've only adjusted the figure. The real question is how do you measure dBSPL of a driver relative to 2.83V when the frequency is not flat? You cannot pick a discrete frequency but have to pick a band of frequencies where it averages such and such dBSPL.
But that is only the start of it. It is really difficult to set up "calibrated" dBSPL measurement to start with. What I do is use a reference Tweeter - the Vifa XT25 that has the flattest frequency response I have ever seen - and set the equipment up as the flat part of its response of the XT25 is my reference for 94dB @ 2.83V @ 0.71 Metre. That sets up my calibration so I can set if at any point calculated from my reference.
No two will have the exact same reference. Even my reference measurement I only use for that particular session. I have to go through the same setup procedure every next session/project. It will be close but never the exact same - but relative measurements during that session will match.
But back to the Tweeter, I expect only the measurement has changed and the Tweeter is the same.
Cheers, Joe
ATTENTION ELSINORE DIY CONSTRUCTORS Potential Crossover Upgrade Needs Road Testing:
The details are yet to come, but it requires six 33 Ohm resistors rated a minimum of 5 Watt - please use good quality grade, by that I suppose I mean by audiophile standards. They don't need to be ultra-low inductance type, but good ones usually are.
These resistors are added to the existing crossover - no existing values are removed or changed.
I will explain further how exactly to fit those resistors and why.
Do I have any takers?
Cheers, Joe
Yes, that would be good. Whether we end up with six times 33R will depend as six 47R could also be tried - feedback from different users would be welcome. The value of all the resistor need to be the same, three places in the crossover and the max value 100R as above that the difference is small.
I am listening to 33R at the moment and more than just liking it - with the amp I am using it really works well. Probably more gains if tubes are used and less, but maybe still important, with solid state amps.
Cheers, Joe