Detaché
Hi all,
Nice idea the tweeter one, I will add this to my design, I have neopreno sheets available. What I need to change is the plywood cover thickness (I don't have a router, so for flush mounting the drivers I need to put this).
I'm attaching the cad file for the enclosure, any suggestion is welcome, more than welcome.
Now the crossover is starting to be designed, and again I need your opinions. I'd like to get the wider dispersion available, is one of the project targets, so I think there are two things to consider: For one side the bass driver is 125mm: That means 2744Hz to unsurpass. For the other side the distance of the drivers centers is 126mm, that means 2722Hz. So I think that for avoid lobing and maintain dispersion wide I shouldn't cross higher than 2722Hz, am I right?
The problem now is the tweeter: The manufacturer states that 2k 12db is the minimum (the resonance is at 1050Hz). I'd like to keep it 1st order, but this way despite the higher frequency it reaches clearly the 1050Hz... The speaker is planned to be 90dB, so wich one is the maximum db could I apply to the tweeter 1050Hz without hearing the resonance?
Now I'm using as crossover simulator Speaker Pro 6 from visaton (I introduced manually the data of both drivers, yes it was boring...), but I like this software.
The compromise here, seems to me, it's this one:
Should I keep the 2722 and go to LR 4th order? Should I go higher and cross 2722 with 1st order? The drivers are reasonably flat and the final adding results with all the cases reasonably flat, and the final power management is not an issue (maybe they will be driven with 10WZenV4, I don't know yet...) I don't know wich change will be more audible. I'm afraid I will have to hear them and compare (I know this will be your answer, too)
This boy has already got a name!!!!: DETACHE.
Bye
Hi all,
Nice idea the tweeter one, I will add this to my design, I have neopreno sheets available. What I need to change is the plywood cover thickness (I don't have a router, so for flush mounting the drivers I need to put this).
I'm attaching the cad file for the enclosure, any suggestion is welcome, more than welcome.
Now the crossover is starting to be designed, and again I need your opinions. I'd like to get the wider dispersion available, is one of the project targets, so I think there are two things to consider: For one side the bass driver is 125mm: That means 2744Hz to unsurpass. For the other side the distance of the drivers centers is 126mm, that means 2722Hz. So I think that for avoid lobing and maintain dispersion wide I shouldn't cross higher than 2722Hz, am I right?
The problem now is the tweeter: The manufacturer states that 2k 12db is the minimum (the resonance is at 1050Hz). I'd like to keep it 1st order, but this way despite the higher frequency it reaches clearly the 1050Hz... The speaker is planned to be 90dB, so wich one is the maximum db could I apply to the tweeter 1050Hz without hearing the resonance?
Now I'm using as crossover simulator Speaker Pro 6 from visaton (I introduced manually the data of both drivers, yes it was boring...), but I like this software.
The compromise here, seems to me, it's this one:
Should I keep the 2722 and go to LR 4th order? Should I go higher and cross 2722 with 1st order? The drivers are reasonably flat and the final adding results with all the cases reasonably flat, and the final power management is not an issue (maybe they will be driven with 10WZenV4, I don't know yet...) I don't know wich change will be more audible. I'm afraid I will have to hear them and compare (I know this will be your answer, too)
This boy has already got a name!!!!: DETACHE.
Bye
tweeter slope
Hi,
Making some simulations I found that the 24-LR at 2750Hz will give me the more I like. This way the signal to the tweeter is >30dB down, so I hope this will be good enough. So I will follow this way. I started thinking to cross higher but following linkwitz's advice I will keep this last one. I'm expecting great mid-band looking at the graph.
Agur,
Hi,
Making some simulations I found that the 24-LR at 2750Hz will give me the more I like. This way the signal to the tweeter is >30dB down, so I hope this will be good enough. So I will follow this way. I started thinking to cross higher but following linkwitz's advice I will keep this last one. I'm expecting great mid-band looking at the graph.
Agur,
Raka:
The signal to the tweeter is greater than 30 dB down at which frequency?
The next issue is the matter of tweeter placement as regards the distance between the centers of the woofers and tweeter.
There is some indication that placing the centers one crossover wavelength apart gives positive reinforcement-perhaps 6 dB-at the crossover frequency.
If this phenomenon exists, it must be compensated for in the crossover, or else you have a 6 dB lump at the crossover frequency.
Planning to conduct tests on that this weekend, to settle the matter once and for all. I'll get back to you on this.
The signal to the tweeter is greater than 30 dB down at which frequency?
The next issue is the matter of tweeter placement as regards the distance between the centers of the woofers and tweeter.
There is some indication that placing the centers one crossover wavelength apart gives positive reinforcement-perhaps 6 dB-at the crossover frequency.
If this phenomenon exists, it must be compensated for in the crossover, or else you have a 6 dB lump at the crossover frequency.
Planning to conduct tests on that this weekend, to settle the matter once and for all. I'll get back to you on this.
Tweeter position
Hi Keltic,
I put the data in my Speaker Pro to simulate the crossover, and with the 4 LR the signal to the tweeter at the resonance frequency is 30dB down, that I suppose is low enough to get any "ringing" sound. With the 3rd order I get an acceptable result, but doesn't sound to me to invert the polarity of the tweeter...
I didn't know that point about the reinforcement because of the drivers' distance, and I suppose it's of main importance to include it in the xo. If this is so, maybe I can solve the problem crossing only the tweet a little higher and let only the woofer to play at the xo frequency. BTW, the LR is 6dB at the crossover frequency instead of the 3db of the butterworths, is this Ok?
Thank you very much for your assistance, is greatly apreciated.
Hi Keltic,
I put the data in my Speaker Pro to simulate the crossover, and with the 4 LR the signal to the tweeter at the resonance frequency is 30dB down, that I suppose is low enough to get any "ringing" sound. With the 3rd order I get an acceptable result, but doesn't sound to me to invert the polarity of the tweeter...
I didn't know that point about the reinforcement because of the drivers' distance, and I suppose it's of main importance to include it in the xo. If this is so, maybe I can solve the problem crossing only the tweet a little higher and let only the woofer to play at the xo frequency. BTW, the LR is 6dB at the crossover frequency instead of the 3db of the butterworths, is this Ok?
Thank you very much for your assistance, is greatly apreciated.
LR Cross
Hi navin,
Thank you very much for your suggestion. My doubt is how much attenuation is good enough at the tweeter resonance. Besides, once I'm deep in the hole, and being 1st order imposible(?), why not jump to the 4th order?
Now I'm thinking about the time delay of the woofer, this a good point...
Hi navin,
Thank you very much for your suggestion. My doubt is how much attenuation is good enough at the tweeter resonance. Besides, once I'm deep in the hole, and being 1st order imposible(?), why not jump to the 4th order?
Now I'm thinking about the time delay of the woofer, this a good point...
from my experience (I have blown a pair of Morel MDT33s) is that it is not thermal wattage that kills tweeters as much as it is excursion.
however for normal uses most tweeters (Vifa, Morel, SS etc.) can withstand 100 W @ 12db at 2.5k. Focal for one prefers a higher XO 3.5k /18db or so.
again I am being vague as these are rules of thumb. I use a 9db/oct XO with my SS 9900 and have not blown them yet (I use a 40kg, 300W rms amp with a 1200VA transformer and 60,000uf or caps per side).
I have no notch filter either so there is an idea.
regards
navin
however for normal uses most tweeters (Vifa, Morel, SS etc.) can withstand 100 W @ 12db at 2.5k. Focal for one prefers a higher XO 3.5k /18db or so.
again I am being vague as these are rules of thumb. I use a 9db/oct XO with my SS 9900 and have not blown them yet (I use a 40kg, 300W rms amp with a 1200VA transformer and 60,000uf or caps per side).
I have no notch filter either so there is an idea.
regards
navin
Project follow up
Hi all,
I'm back to tell you how is my project. I have spent too much time studying the aleph projects, that my "Detaché" was left apart.
Now it is back!!
Well, now the boxes are done. This was a lot of work because I don't have router, so flush fitting the drivers was kind of eternal. The tweeter is in a separate enclosure and sealed with silicone, the woofer is also sealed with silicone. The walls are covered with foam and no stuffing inside (didn't like the results with felt or fiberglass).
I ran in the drivers with a 1st order net at 3000Hz or more. Didn't calculate accurately, and applied low volume with the music, noise and low frequency waves.
At this stage, the sound was very, very nice. The midbas was very good. Maybe the sound was incisive, but the detail was amazing. Note that my system "reference" is an Advance Acoustic (480EURO tower design-2ways-6.5"+Peerles 811815). Well, now I can't stand to switch back to them, my 120EURO "detachés" are obviously better.
Particularly, the classical music was clearly better, now all the notes are heard, and bass is not as lower, but better than the now to me Boooomy sound of the AA.
OK, then I started to measure things with my workshop:
-The woofer is well behaved, better than the specs, but I'm afraid that the bass response is a little peaky around 90Hz. The resonance freq. is 65Hz (100Hz in cabinet) . There is a little but wide valley as expected (as shown in kelticwizard graph), that maybe sustract some sweetness, but this was a known compromise. Maybe in the future I should tune the box more accurately.
- The surprise was in the tweeter. Resonance was lower than in specs:950 vs 1050Hz. That is suposed to be good. The bad news are that it showed a big peak around 1000Hz. This was something that had to be studied in the XO. The best solution given by SW was 3rd order that reduced the peak to good limits.
So I choose to XO a 3rd Butter at 2740 with impedance compensation for the woofer. I considered the actual impedance of each driver instead of the rated 8 ohm, i believe this is of capital importance. I built it and the measurements was something to be proud of: Almost flat responses with freq. and with impedance (6 ohm down to 150 Hz)
The sound? Well, compared to the 1st order now has more efficiency. Is this normal? Shouldn't the coils burn some energy?
The first order sound is maybe crisper, but softer, but I believe that this has more to do with the xo freq than with the order.
Soundstaging is something like that: WoooooaaaaaaaaaoooooooWWWWW.
As soon as I can I will post some pictures of the speaker, and also of the measurements.
This is a simple project, and this follow up is intended to be as help to newbies like me, but the main point is that sounds fantastic for classical music and it gave/gives me a lot of pleasure.
Hi all,
I'm back to tell you how is my project. I have spent too much time studying the aleph projects, that my "Detaché" was left apart.
Now it is back!!
Well, now the boxes are done. This was a lot of work because I don't have router, so flush fitting the drivers was kind of eternal. The tweeter is in a separate enclosure and sealed with silicone, the woofer is also sealed with silicone. The walls are covered with foam and no stuffing inside (didn't like the results with felt or fiberglass).
I ran in the drivers with a 1st order net at 3000Hz or more. Didn't calculate accurately, and applied low volume with the music, noise and low frequency waves.
At this stage, the sound was very, very nice. The midbas was very good. Maybe the sound was incisive, but the detail was amazing. Note that my system "reference" is an Advance Acoustic (480EURO tower design-2ways-6.5"+Peerles 811815). Well, now I can't stand to switch back to them, my 120EURO "detachés" are obviously better.
Particularly, the classical music was clearly better, now all the notes are heard, and bass is not as lower, but better than the now to me Boooomy sound of the AA.
OK, then I started to measure things with my workshop:
-The woofer is well behaved, better than the specs, but I'm afraid that the bass response is a little peaky around 90Hz. The resonance freq. is 65Hz (100Hz in cabinet) . There is a little but wide valley as expected (as shown in kelticwizard graph), that maybe sustract some sweetness, but this was a known compromise. Maybe in the future I should tune the box more accurately.
- The surprise was in the tweeter. Resonance was lower than in specs:950 vs 1050Hz. That is suposed to be good. The bad news are that it showed a big peak around 1000Hz. This was something that had to be studied in the XO. The best solution given by SW was 3rd order that reduced the peak to good limits.
So I choose to XO a 3rd Butter at 2740 with impedance compensation for the woofer. I considered the actual impedance of each driver instead of the rated 8 ohm, i believe this is of capital importance. I built it and the measurements was something to be proud of: Almost flat responses with freq. and with impedance (6 ohm down to 150 Hz)
The sound? Well, compared to the 1st order now has more efficiency. Is this normal? Shouldn't the coils burn some energy?
The first order sound is maybe crisper, but softer, but I believe that this has more to do with the xo freq than with the order.
Soundstaging is something like that: WoooooaaaaaaaaaoooooooWWWWW.
As soon as I can I will post some pictures of the speaker, and also of the measurements.
This is a simple project, and this follow up is intended to be as help to newbies like me, but the main point is that sounds fantastic for classical music and it gave/gives me a lot of pleasure.
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