1) If you use two rear chambers, that is, the drivers are not sharing a common box, then VRC is divided by 2.
2) Huh?
3)Yes.
4) Yes, four ports APT /4 .
Not all is fine.
ehh I see the throat dimensions for the woofer get 448 cc for nice graph, but woofer is 448 cm2, that is a lot more and destroy that nice graph, I mean then VRC.
Is VRC in cc the port itselfs? then it is not difficult, atc is in cm2 is atc the space between cone and baffle,? if not then is that vrc and yes not very good.
There are a lot of akabak scrips, but when using a cloed back chamber I can work fine with hornresp right? it is also mucho more easy.
I get with the phillips nice graph, I do need two way system, I go use a wideband speaker in stead of a CD, these can go lower, even a coaxial
looks nice bet get the woofer couple to the horn is more difficult, (ports to long).
just put a eye on the picture, do you see something what is not possible?.
thanks
kees
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1) I don't recall, but it says in the Hornresp instructions.
2) I don't understand your question.
3) Looks like a response curve that should be achievable if you can build a cabinet which is reasonably close to the simulation.
Hi weltersys
I mean I am somewhat confused, because the speaker itself is 448 cm2, and hornresp speaks about cc for that, you now then this will not work well, I have read somewhere in
the past if I remember that the VTC is the port itselfs, and the ATC the space between cone and baffle, if this is right then I can proberly build it, this was also the question about it, David say that I need to fill up the space between cone and baffle but this is not wo simple in a synergy horn.
so little confused about synergy, but the rest I understand like tapped horns and such.
regards
kees
I mean I am somewhat confused, because the speaker itself is 448 cm2, and hornresp speaks about cc for that, you now then this will not work well, I have read somewhere in
the past if I remember that the VTC is the port itselfs, and the ATC the space between cone and baffle, if this is right then I can proberly build it, this was also the question about it, David say that I need to fill up the space between cone and baffle but this is not wo simple in a synergy horn.
so little confused about synergy, but the rest I understand like tapped horns and such.
regards
kees
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Kees,
You have an AkAbak model which has no ambiguity because every element is placed there by the user. I am no HR expert but I think the terms you are asking about are the driver front chamber volume is Vtc, and Atc is the chamber cross sectional area. Making Atc smaller implies a longer driver front chamber. If you just stick with the model in AkAbak you should be good. I don't see why you are jumping between the two. AkAbak is the more comprehensive software that can model multiple injection ports and combinations of different drivers at different locations in the horn - exactly what is needed to model a synergy.
You have an AkAbak model which has no ambiguity because every element is placed there by the user. I am no HR expert but I think the terms you are asking about are the driver front chamber volume is Vtc, and Atc is the chamber cross sectional area. Making Atc smaller implies a longer driver front chamber. If you just stick with the model in AkAbak you should be good. I don't see why you are jumping between the two. AkAbak is the more comprehensive software that can model multiple injection ports and combinations of different drivers at different locations in the horn - exactly what is needed to model a synergy.
A synergy who have a tractrix yes, but hr can do conic synergy because I have try it and compare in akabak.
that I jump is because I try to learn and play with both, I was confused because I did not now how witg VTC and ATC, this because the woofer has also his own 0.448 liter x 2 space in his cone itselfs, there is where I go wrong, fill up that place is not easy or impossible. I do play with yours also and have remove the subbass section of it to see more clearly what it does, and it looks very nice, I do not let it for what it is I go shure play with it first try how to drawn that tractrix box, you have a smaller one who was even better a 6.5 inch woofer is maybe a nice way there.
Oke, for the others, I have try in akabak the two phillips woofers, she do work with a nice bandwidth but run out of Xmax quick around 80 hz where afcourse hornloading is no more present, with a basreflex port things are better. this is the last question I have now enough stuff to go practice a lot with that speaker thingie.
regards
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I just completed the tractrix fullrange synergy. More info here:
http://www.diyaudio.com/forums/full-range/261427-40-full-range-synergy.html
http://www.diyaudio.com/forums/full-range/261427-40-full-range-synergy.html
The sheet for calc a synergy horn is nice stuff, when I calc a horn 400 Hz then I get this with the two phillips woofers.
A compression driver is needed, do not now what a tweeter does, have to measure this when it is that far.
I did a EQ for the front chamber peak of the woofers, (woofer chamber filled half each for smaller VTC).
Also I need a bassreflex port for woofers to limit Xmax considerly. And the eq for the peak is easely done with analog filter, adjusting with sweep signal measuring output.
regards
kees
A compression driver is needed, do not now what a tweeter does, have to measure this when it is that far.
I did a EQ for the front chamber peak of the woofers, (woofer chamber filled half each for smaller VTC).
Also I need a bassreflex port for woofers to limit Xmax considerly. And the eq for the peak is easely done with analog filter, adjusting with sweep signal measuring output.
regards
kees
Attachments
Kees,
You might try a Helmholtz resonator stub to control that peak passively without electronics or filters as you say you are not using DSP. A 4.5 inch long stub filled with wadding may control that quite nicely. Very easy to simulate in AkAbak prior to build.
I am surprised you say a BR is needed to control excursion. I usually find a small sealed chamber more effective although bass extension won't be as low.
You might try a Helmholtz resonator stub to control that peak passively without electronics or filters as you say you are not using DSP. A 4.5 inch long stub filled with wadding may control that quite nicely. Very easy to simulate in AkAbak prior to build.
I am surprised you say a BR is needed to control excursion. I usually find a small sealed chamber more effective although bass extension won't be as low.
Sealed chamber do work, but I did simulate that it has to much excursion when go above 110 dB, you are proberly right about that this is quite loud, and the phillips has not much Xmax peaking easely above that when watch movies for example, so a BR do help here.
I go for the conic synergy as a start, and so try everything when it gets winter here.
that Pipe I do hear some of it long ago, however you now I am still a akabak nert, a filter with a scap/inductor in serie who have some Q do work fine, Q set makes it set bandwidth, this sit between speaker terminals, more I do not need.
regards
kees
regards
kees
Oke I did use the hornresp filter capacity to let see how easy it is.
Q of coil/cap is make low be resistor after the low pass.
Afcourse it is simmed, so in real world it is harder, but a adjustable coil and resistor will do I hope
regards
kees
regards
kees
Attachments
I seen this oddball over at ebay (Speaker Addict's Store):
Eminence 8" 8 Ohm Sealed Closed Back Beta 8CXCB 2 Way Coax Midrange Custom Made
Search it, I have no luck with copy/paste links that got tracking info embedded in them.
No idea what might be the sealed back TS, cause he's
listed wrong set of specs from the normal Beta8cx.
Eminence 8" 8 Ohm Sealed Closed Back Beta 8CXCB 2 Way Coax Midrange Custom Made
Search it, I have no luck with copy/paste links that got tracking info embedded in them.
No idea what might be the sealed back TS, cause he's
listed wrong set of specs from the normal Beta8cx.
Promising, but the transition from the compression driver to the mounting manifold won't be optimal (in theory) because of the volume enclosed by the cone driver (and possibly intermodulation effects). Might not be too much of an issue, in practice however.
I cant remember who I chatted with about other BC CD's but does anyone have any experience using the DE500 in a SH?
I have been looking at using the DE550 for my application. I will also have a pair of DE250's. I like the 550's lower usable XO and for me I cant beat the price compared to any other CD. BMS, Faital and others are all much more expensive. I know the 250 extends higher but that about the only advantage for me that I can see. I am building this for PA and think 16/17khz will be just fine.
Thanks in advance.
I have been looking at using the DE550 for my application. I will also have a pair of DE250's. I like the 550's lower usable XO and for me I cant beat the price compared to any other CD. BMS, Faital and others are all much more expensive. I know the 250 extends higher but that about the only advantage for me that I can see. I am building this for PA and think 16/17khz will be just fine.
Thanks in advance.
According to BC they recommend a XO of 1200hz, 1500hz and 1600hz on the DE550, DE500 and DE250 respectively. So that is why I was leaning towards the 550. I will own a pair of 250's soon and the 550 is the same price as the 500.
So with the specs on the BC site as of now the 550 wins in all the categories except high frequency roll off. Which I would have suspected anyways with the highest Le of the 3.(.14 vs .11mH)
So with the specs on the BC site as of now the 550 wins in all the categories except high frequency roll off. Which I would have suspected anyways with the highest Le of the 3.(.14 vs .11mH)