Hi,
According to you is the climbing curve of this driver good for a natural bafle step nulling on a 14" width bafle plan ?
12NCX750H
horn is 70°x50° which is quite good imo for a home environment controlled dirictivity ?
What could be the XO point for the tweeter if you were using this driver ? 1500 Hz for having a dip between the 1000-2000 Hz for a casual BBC sound while still having dynamic (compression driver + 12" OB)??
I know a nude 12" is able with a little help of around 300 - 1000 Hz , even less with EQ boost (maybe 180/200 Hz)...Low enough for a Ripole in bass area at the bottom ???
Sorry, 3 questions in one : but open thread, feel free for a testimonial if you already went with OB coax design expériences 🙂
cheers, Eldam
According to you is the climbing curve of this driver good for a natural bafle step nulling on a 14" width bafle plan ?
12NCX750H
horn is 70°x50° which is quite good imo for a home environment controlled dirictivity ?
What could be the XO point for the tweeter if you were using this driver ? 1500 Hz for having a dip between the 1000-2000 Hz for a casual BBC sound while still having dynamic (compression driver + 12" OB)??
I know a nude 12" is able with a little help of around 300 - 1000 Hz , even less with EQ boost (maybe 180/200 Hz)...Low enough for a Ripole in bass area at the bottom ???
Sorry, 3 questions in one : but open thread, feel free for a testimonial if you already went with OB coax design expériences 🙂
cheers, Eldam
Last edited:
I use a Ciare NDCX12-1.4 nude on pa stands. They drop off quickly below 300hz and I wouldn't recommend trying to eq below that if you ever need volume out of them. I cross around 1500hz acoustically using a semi-linear phase Harsch like crossover. On the low end there is overlap with 2x18's between 2-300hz. Has pretty smooth coverage with a narrowing upper octave.
I would be wary of using coax's with front horns like that. Seems like a recipe for a lot of nasty midrange diffraction effects. Never heard them though so I can't say for sure.
I use these in a 32m x 15m x 6m garage. You will need at least back wall treatment if placed anywhere near the wall.
DSP with multiple amps seems almost mandatory for best results. I can't see spending months on passives when you can get the same or better performance in one afternoon and change if necessary.
This system has served me well and still impresses today. If I were to start over I would be tempted to try a synergy horn, large cinema horns, 18 Sound XT1464 with their latest drivers or bookshelf synergy, and last but not least a huge line array of SB65WBAC25 full range drivers.
I would be wary of using coax's with front horns like that. Seems like a recipe for a lot of nasty midrange diffraction effects. Never heard them though so I can't say for sure.
I use these in a 32m x 15m x 6m garage. You will need at least back wall treatment if placed anywhere near the wall.
DSP with multiple amps seems almost mandatory for best results. I can't see spending months on passives when you can get the same or better performance in one afternoon and change if necessary.
This system has served me well and still impresses today. If I were to start over I would be tempted to try a synergy horn, large cinema horns, 18 Sound XT1464 with their latest drivers or bookshelf synergy, and last but not least a huge line array of SB65WBAC25 full range drivers.
Last edited:
Thanks, good & usefull inputt.
I would like to try the last design of Bwsalo, but I'm worried about my skill with drilling holes and tweak the horn with the plastic glue to make the shape to fix the mid-woof ! I already gave up a horn foam by lack of hand-skill 😱. But have to say I like a lot the elegant not invasive box Bwaslo designed ! It has "roman" shape and looks good with white fabric and the natural plywood color... It can be also very good to look at with blue Fabric à la JBL... Not worry about the sound with Bawslo skill as well !
That's why the coax despite time alignement is not exacte is attracting me ! Although I understand the utility of MiniDSP but want not listen to it for everyday but the setuping of the XO... I understand the need of FIR, at least for time/phase correction though !
Well seems the PA coax on an OB or nude is not as easy I believe ! Thanks fellow to testimonial about that. Usefull.
cheers
I would like to try the last design of Bwsalo, but I'm worried about my skill with drilling holes and tweak the horn with the plastic glue to make the shape to fix the mid-woof ! I already gave up a horn foam by lack of hand-skill 😱. But have to say I like a lot the elegant not invasive box Bwaslo designed ! It has "roman" shape and looks good with white fabric and the natural plywood color... It can be also very good to look at with blue Fabric à la JBL... Not worry about the sound with Bawslo skill as well !
That's why the coax despite time alignement is not exacte is attracting me ! Although I understand the utility of MiniDSP but want not listen to it for everyday but the setuping of the XO... I understand the need of FIR, at least for time/phase correction though !
Well seems the PA coax on an OB or nude is not as easy I believe ! Thanks fellow to testimonial about that. Usefull.
cheers
Last edited:
Happy to share.
The reason I wanted a try at coaxials was because of the single point source ideology. Took more work than I thought to unlock their potential but I have achieved very nice measurements similar to Danley's own creations by using a DCX. The downside is that the DCX isn't super transparent. Planning an upgrade to pc based crossover in the future.
Complicated fabrication doesn't appeal to me so I understand your dilemma. Martin's CDD line looks awfully tempting.
The reason I wanted a try at coaxials was because of the single point source ideology. Took more work than I thought to unlock their potential but I have achieved very nice measurements similar to Danley's own creations by using a DCX. The downside is that the DCX isn't super transparent. Planning an upgrade to pc based crossover in the future.
Complicated fabrication doesn't appeal to me so I understand your dilemma. Martin's CDD line looks awfully tempting.
You can't hear a Danley's synergy in France, I let you imagine about Martin's speaker !🙁 ! I even didn't suceed to find the synergy speaker Tom Danley designed for this canadian PA speaker brand !
Not sure if I understand, but it seems that you are saying that the "climbing curve" of the driver would be cancelled out or partially offset by the OB's response??? The answer to that is no. When you put a driver in an OB you get (being very general here) the same kind of "climbing" curve, that is the bass level is much lower than the midbass level, etc. So the curves will not cancel or compensate for each other. If I misunderstood what you meant, please disregard.
Yes, that's what I wanted to say (sorry for the grammar/vocabulary).
Thanks for the answer and to rephrase it acuratly. Indeed I believed the progressiv loss made by a bafle step around 300/400 to around 1000 on the driver could be a sort of reversed Linkwitz transform and the addition of both curves (with the raising one of this particular driver in the same area) will make a flat one (I remember reading that the bafle step of a cabinet is approximatly in this area, so my naive question).
But as I understand from your answer this is more the pass length between the front and the bottom of the driver which dictates the whole midbass curve for a driver on a simple open bafle (natural -6 dB loss in the bass till the Fs.)!
ok, 12" or 15" coax on a narrow open bafle is a bad idea with passive filter.
Thanks for the answer and to rephrase it acuratly. Indeed I believed the progressiv loss made by a bafle step around 300/400 to around 1000 on the driver could be a sort of reversed Linkwitz transform and the addition of both curves (with the raising one of this particular driver in the same area) will make a flat one (I remember reading that the bafle step of a cabinet is approximatly in this area, so my naive question).
But as I understand from your answer this is more the pass length between the front and the bottom of the driver which dictates the whole midbass curve for a driver on a simple open bafle (natural -6 dB loss in the bass till the Fs.)!
ok, 12" or 15" coax on a narrow open bafle is a bad idea with passive filter.
I 'm just understanding than to offset the bafle step of a bafle, the raw curve of the driver should naturally fall from around 300 Hz (for a 12") to around 1 000 Hz... because the bafle step is getting a progressive boost towards the higher frequencies !
My question had no sense, I understand better the answer from Charlie now !
yes the 0.4 Qts of this driver even if it is for upper bass-mid area is too much optimistic (at least without boost and high Xmax)
But a low Qts for a better control of the cone in the frequency area discussed is a temptation, despite the OB design ! (but yes forget it with passive filter) !
So I forgett the coax in OB ( an Altec 604 in a vented box à la Hiraga is working good, but this is difficult yet because the cabinet construction !
OB is appealing because the (relativ) simplicity
My question had no sense, I understand better the answer from Charlie now !
yes the 0.4 Qts of this driver even if it is for upper bass-mid area is too much optimistic (at least without boost and high Xmax)
But a low Qts for a better control of the cone in the frequency area discussed is a temptation, despite the OB design ! (but yes forget it with passive filter) !
So I forgett the coax in OB ( an Altec 604 in a vented box à la Hiraga is working good, but this is difficult yet because the cabinet construction !
OB is appealing because the (relativ) simplicity
Well, yes, it's is easier to build a nice baffle than a nice box. But the crossover isn't as easy. Crossovers for OB are different. There is much more EQ built into them than normal box crossovers. That can be very simple, but you have to know what it is, to do it properly. Many people do not.
I've worked with 2 rather different OB rigs that used an Altec 15" coax with a helper woofer. In one case an 18" woofer, in the other I recall it was a 15". Both worked well, both were large baffles. There was a good bit of crossover tweaking, but results were very satisfactory in both.
- Status
- Not open for further replies.