Hello all,
I'm planing to build a 2-way using the Seas CA26RFX:
http://www.seas.no/Prestige Basser PDF/CA26RFX-H1305-08.pdf
and, at first sight, the Seas 27TDFC:
http://www.seas.no/seas_line/tweeters/H1189.pdf
I know I'll have some difficulties to get a right mid-range; so I thought on placing the woofer 45° backward leaned on the top of the enclosure in the way to "naturally" smooth the CA26 bumps(at least at the listening point) and also because of the loading principle I will use; the filter will be a high slope acoustically at 1500hz, the lower I can go with this tweeter. Tweeter will be placed behind the woofer.
So guys, any suggestions about this project? Do you feel it is possible to get a good mid-range or will I have to choose another tweeter for a lower X-over point?
Thanks,
I'm planing to build a 2-way using the Seas CA26RFX:
http://www.seas.no/Prestige Basser PDF/CA26RFX-H1305-08.pdf
and, at first sight, the Seas 27TDFC:
http://www.seas.no/seas_line/tweeters/H1189.pdf
I know I'll have some difficulties to get a right mid-range; so I thought on placing the woofer 45° backward leaned on the top of the enclosure in the way to "naturally" smooth the CA26 bumps(at least at the listening point) and also because of the loading principle I will use; the filter will be a high slope acoustically at 1500hz, the lower I can go with this tweeter. Tweeter will be placed behind the woofer.
So guys, any suggestions about this project? Do you feel it is possible to get a good mid-range or will I have to choose another tweeter for a lower X-over point?
Thanks,
Hi Crazyhub,
CA26RFX has recomended frequency range 30 - 1000Hz and I think that people in Seas know what they write to datasheet. Maybe FR cuve of the driver goes to 3kHz, but there might be another problem above 1kHz, which you can not overcome. I'm not trying to say that it will be wrong driver for your purpose, but there might be some problem.
If you place the woofer to 45 degrees baffle, you might get smooth FR curve, but note that peaks in on axis FR will be reflected by your room right to your ears.
CA26RFX has recomended frequency range 30 - 1000Hz and I think that people in Seas know what they write to datasheet. Maybe FR cuve of the driver goes to 3kHz, but there might be another problem above 1kHz, which you can not overcome. I'm not trying to say that it will be wrong driver for your purpose, but there might be some problem.
If you place the woofer to 45 degrees baffle, you might get smooth FR curve, but note that peaks in on axis FR will be reflected by your room right to your ears.
DarkOne,
Thank you for your response.
I know there will be problems above approximately 1khz, certainly distortions issues (break-up of this 26cm probably does occur at 800-1000hz); leaning the woofer will not lower the bumps of-axis but help a bit on-axis regarding that my room is relatively high; but I agree this will not be enough, so I want to know if it does exist a tweeter which can support to go down to 1khz; somebody advised me to use the BR Neo8; I will make a new thread about this tweeter to know a little more about.
Thank you for your response.
I know there will be problems above approximately 1khz, certainly distortions issues (break-up of this 26cm probably does occur at 800-1000hz); leaning the woofer will not lower the bumps of-axis but help a bit on-axis regarding that my room is relatively high; but I agree this will not be enough, so I want to know if it does exist a tweeter which can support to go down to 1khz; somebody advised me to use the BR Neo8; I will make a new thread about this tweeter to know a little more about.
Any tweeter that can be called a hi-fi tweeter really shouldnt be crossed bellow 2kHz and even then only for low system power maybe 50watts per channel or even less. The tweeter will be mechanically and electrically stressed.
A steep crossover slope will really only mess up the crossover region
The truth is both drivers would be at their worst right in the frequency range where your hearing is most sensetive to sound quality
If you really want 10 inch drivers making the bass go for a 3 way system or a sub and satellites system.
If you seriously want to build a simple two way system you should consider the tried and true MTM set up.. two 6-1/2 inch drivers above and bellow the tweeter in each channel
Two 6.5 inch drivers can kick out almost as much bass as one 10 inch.
You can cross them higher so that the tweeter is only being driven with frequencies it can handle well.
Please consider
A steep crossover slope will really only mess up the crossover region
The truth is both drivers would be at their worst right in the frequency range where your hearing is most sensetive to sound quality
If you really want 10 inch drivers making the bass go for a 3 way system or a sub and satellites system.
If you seriously want to build a simple two way system you should consider the tried and true MTM set up.. two 6-1/2 inch drivers above and bellow the tweeter in each channel
Two 6.5 inch drivers can kick out almost as much bass as one 10 inch.
You can cross them higher so that the tweeter is only being driven with frequencies it can handle well.
Please consider
Yes Filgor,
I agree with your thoughts; With conventional tweeters, the main problem is with mechanical moving parts displacements at such low fr. However I don't want to use smaller woofer, even MTM. If I don't find the tweeter I'm looking for, I will go to a 8" woofer. BR Neo8 seams to be relatively hard to smooth from 1 to 20khz.
Another solution could be horn loading a conventional tweeter but this would need a large baffle.
I'm middle of the pond.
Thank you for your opinion.
I agree with your thoughts; With conventional tweeters, the main problem is with mechanical moving parts displacements at such low fr. However I don't want to use smaller woofer, even MTM. If I don't find the tweeter I'm looking for, I will go to a 8" woofer. BR Neo8 seams to be relatively hard to smooth from 1 to 20khz.
Another solution could be horn loading a conventional tweeter but this would need a large baffle.
I'm middle of the pond.
Thank you for your opinion.
3" midtweeters like vifa trius and hi-vi 3" does the mids and treble, and does them very well, better than many dedicated mids and tweeters. You can use a crossover point of 400-500hz with a 12" subwoofer. Unless you are planning to blast them super loud at parties, they should get decently loud.
Hi Folks,
Don't know whether this might be an alternative:
http://www.ejjordan.co.uk/drivers/jxr6.html
Cheers - Fez
Don't know whether this might be an alternative:
http://www.ejjordan.co.uk/drivers/jxr6.html
Cheers - Fez
A possibility would be to use a waveguide. It would allow you to cross a low Fs tweeter like the seas at around 1,2 khz i think. You should wait , zaph is actually testing the two PE waveguides, and i presume that he will test them with a tweeter very similar to yours
zaph used the 27tdfc with a linkwitz riley 4th order at 1.7khz with great success. But the only real way to go if you want to cross really lower is waveguiding this tweeter
zaph used the 27tdfc with a linkwitz riley 4th order at 1.7khz with great success. But the only real way to go if you want to cross really lower is waveguiding this tweeter
While I think that a 10" is pushing it a little too much I see no reason from a distortion standpoint that you couldn't push a tbfc/g to ~800 Hz with a waveguide. You would have to do this by experiment, but I think it could work.
The point is to do it and prove it works. Conventional wisdom can be set aside if you test and measure carfully.
The point is to do it and prove it works. Conventional wisdom can be set aside if you test and measure carfully.
ucla88 said:
I agree with this for sure.
A wave guide is a far more realistic solution than looking for some suped-up tweeter with an X-max of +/-1mm which is what you would need.
A good sized waveguide will inrease the Tweeter's loading at its lower end this means a huge reduction in mechanical and electrical stress once you have equalised the resultant hump down. This can be done with a 12dB crossover of very low Q.
It allows you to bring your 1 inch driver down to a lower frequency without stressing it to buggery!
But how about that 10" for mid range. With the tweeter in a wave guide it is a genuine possiblility but I would be using the 10" on axis and roll it off using a 12dB/octave.
Do a search for waveguide threads you will find heaps of stuff.
You will also notice that most people are still using smaller woofers for mids.
I second the idea of using a small full range like the HiVi 3" down to about 500hz or so. I did this with a tang band w3-871s and a cheap 12" i pulled out of another speaker. I used a first order XO on the woofer around 500hz. Due to a glitch in my amp that cause the protection circuit to shut down when I put a cap on the 3" i just let that driver roll off naturally. It didn't cause any noticable problems but I never measured it. It was quite a nice sounding speaker. It utterly destroyed some small missions someone left at my house and cost about $60. I cant guess how this would compare to the drivers your looking at since I've never heard them.
Not much to lose if you use the HiVi. Its only about $9. Check out www.zaphaudio.com if you want a design for that driver.
Not much to lose if you use the HiVi. Its only about $9. Check out www.zaphaudio.com if you want a design for that driver.
yeah, kifeinthesink idea is good too, as it would allow you to cross the 10" lower. I think a dome is better for the highs than a B3s. And i don't think that using a 10", if it is carefully chosen, is so detrimental to the mids, if you use it to 1khz .(damn , there are 6,5" that are used past 3khz), but yours is having little problems is this band so maybe the fullrange is a better solution
To get a 2-way to work with that 10", you will need to go the mid-tweeter approach. A number have been suggested -- the Jordan (i'm guessing) likely to be one of the best tweeters available (and good to a couple hundred hz. The Aura 3" ers and Tangbands worthy of a look for something way less costly. The Fostex FE8x, FE103, 107 & 108ES are also candidates.
dave
dave
At work I have the Genelec 1032A active monitors, they use a Seas tweet and 10" midbass. the tweet is in a waveguide and crossed over at about 1kHz, with a VERY steep slope. It is an active setup so I'm presuming 4th order electrical on top of the tweets acoustical roll off and that of the waveguide.
Personally I don't like the sound of that speaker, I fing the treble somewhat tizzy and overpowering/tiring, also worth noting is the tweets' response does deteriorate over time (we have 5 and after measuring their resopnse I would be hard pushed to pick a matched pair from them), I think due to it being worked so hard.
It can be done, its just if you feel it can be done well enough for you.
Personally I don't like the sound of that speaker, I fing the treble somewhat tizzy and overpowering/tiring, also worth noting is the tweets' response does deteriorate over time (we have 5 and after measuring their resopnse I would be hard pushed to pick a matched pair from them), I think due to it being worked so hard.
It can be done, its just if you feel it can be done well enough for you.
Hi again Crazyhub,
You seem to know about the limitaions of tweeters in terms of linear displacement so keep this in mind. When you push the lower frequency limits of any driver the linear displacement becomes as important as its response curve.
loading a 1" with a decent sized waveguide will roughly double its linear displacement depending of course on the angle of the flare. doubling linear displacement will buy you half an octave at the low end. A larger mid teeter as suggested by many will obviously have much greater low frequency capabilities at the potential sacrifice of HF performance.
As for the 10" mid... Logic suggests that if you can use a 6.5" to 3kHz then you would expect to be able to use a 10" to almost 2kHz assuming it is similarly optimised for mid range. IMO the CA26RFX you are opting for has a reasonably low Qms (2.14) which implies that the suspension provides a reasonable amount of damping to the cone. It should sound fine up to 1kHz maybe higher depending on your crossover.
I'm really interested to see what you end up opting for!
You seem to know about the limitaions of tweeters in terms of linear displacement so keep this in mind. When you push the lower frequency limits of any driver the linear displacement becomes as important as its response curve.
loading a 1" with a decent sized waveguide will roughly double its linear displacement depending of course on the angle of the flare. doubling linear displacement will buy you half an octave at the low end. A larger mid teeter as suggested by many will obviously have much greater low frequency capabilities at the potential sacrifice of HF performance.
As for the 10" mid... Logic suggests that if you can use a 6.5" to 3kHz then you would expect to be able to use a 10" to almost 2kHz assuming it is similarly optimised for mid range. IMO the CA26RFX you are opting for has a reasonably low Qms (2.14) which implies that the suspension provides a reasonable amount of damping to the cone. It should sound fine up to 1kHz maybe higher depending on your crossover.
I'm really interested to see what you end up opting for!
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