I am thinking about using full range driver as midrange driver in 3 way system.
One of considering driver is Fostex FF125WK.
The Madisound Speaker Store
In my experience,
when using midwoofer of 5~6.5 inches for midrange, the high frequency response is sometimes not good enought to match with tweeter,
when using midwoofer of 4 inches or less for midrange, the sound pressure is sometimes not enought to match with woofer,
when using midrange driver for midrange, because of the early roll off at the low frequencies, it is hard to lower the xover frequency of woofer.
So, I thought full range driver of 5~6.5 inches may be a good alternative.
It has very flat response from low to high and has enough sound pressure.
The power handling is not problem because it doesn't handle bass.
But, I'm curious why this type of speaker can hardly be seen around.
Are there any problems or cons, or do you have any experiences ?
One of considering driver is Fostex FF125WK.
The Madisound Speaker Store
In my experience,
when using midwoofer of 5~6.5 inches for midrange, the high frequency response is sometimes not good enought to match with tweeter,
when using midwoofer of 4 inches or less for midrange, the sound pressure is sometimes not enought to match with woofer,
when using midrange driver for midrange, because of the early roll off at the low frequencies, it is hard to lower the xover frequency of woofer.
So, I thought full range driver of 5~6.5 inches may be a good alternative.
It has very flat response from low to high and has enough sound pressure.
The power handling is not problem because it doesn't handle bass.
But, I'm curious why this type of speaker can hardly be seen around.
Are there any problems or cons, or do you have any experiences ?
Plenty of them around, though they may be disguised (more or less).
Be that as it may, for reference, the 125 is a 4 1/2in unit, so smaller than the nominal 5 - 6 1/2in you specify. You'll probably need to do some work in the filter to kill some of its modes around 7KHz or so. With that done, it should do a reasonable job.
Be that as it may, for reference, the 125 is a 4 1/2in unit, so smaller than the nominal 5 - 6 1/2in you specify. You'll probably need to do some work in the filter to kill some of its modes around 7KHz or so. With that done, it should do a reasonable job.
If 93dB suites your purpose, Fostex fe126e is a great little driver. I measured it in january last year in one of their BLH cabinets that can be found in pdf on their site. It looks like this:
On axis and off axis 30 and 45 deg if i remember:
Measured in this cabinet at distance of approx 1m:
Usable from 500 to about 3KHz in a three way. The guy that listens them now asked me to help him with his loudspeakers. He liked them too much to be able to separate from them so i suggested two way by adding 15" woofer (Beyma SM115/K) and keeping little fostex xovered at arround 300Hz. I added a notch filter to cope with 7KHz peak. I didn't touch 14KHz peak because that would influence the highs too much. Fostex is in open baffle and woofer is in BR box. He listened them in back loaded horns from pic above but he lacked bass so we made a two way for him
An externally hosted image should be here but it was not working when we last tested it.
On axis and off axis 30 and 45 deg if i remember:
An externally hosted image should be here but it was not working when we last tested it.
Measured in this cabinet at distance of approx 1m:
An externally hosted image should be here but it was not working when we last tested it.
Usable from 500 to about 3KHz in a three way. The guy that listens them now asked me to help him with his loudspeakers. He liked them too much to be able to separate from them so i suggested two way by adding 15" woofer (Beyma SM115/K) and keeping little fostex xovered at arround 300Hz. I added a notch filter to cope with 7KHz peak. I didn't touch 14KHz peak because that would influence the highs too much. Fostex is in open baffle and woofer is in BR box. He listened them in back loaded horns from pic above but he lacked bass so we made a two way for him
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I use the Alpiar 7.3 in OB with a 15" in a H baffle. Sounds fantastic.
I guess the problems with using a full range is that the driver has to balance so many things that it will struggle to match a dedicated midrange driver in the midrange. Not saying it can't be made to work well, but....
A driver designed only to work from say 300 to 5k won't need as large a surround or spider to handle the bass or a heavy/stiff cone, so it can be made more sensitive and smooth.
It can also have a smooth roll off at the top end so its easier to cross with the tweeter and won't need notch filters = more detrimental xover parts = also cheaper.
Three ways aren't easy to do properly, but starting with drivers that are mechanically / accousticly designed to do one part well and hand over to the next driver easily makes things so much easier its not funny.
Having said all that, you just never know what might work ;P
I guess the problems with using a full range is that the driver has to balance so many things that it will struggle to match a dedicated midrange driver in the midrange. Not saying it can't be made to work well, but....
A driver designed only to work from say 300 to 5k won't need as large a surround or spider to handle the bass or a heavy/stiff cone, so it can be made more sensitive and smooth.
It can also have a smooth roll off at the top end so its easier to cross with the tweeter and won't need notch filters = more detrimental xover parts = also cheaper.
Three ways aren't easy to do properly, but starting with drivers that are mechanically / accousticly designed to do one part well and hand over to the next driver easily makes things so much easier its not funny.
Having said all that, you just never know what might work ;P
I built a pair of three ways with the old FF125K as a midrange. I'm not sure why more people don't use a FR as a mid, as in many ways it makes the best possible 3 way. The wide bandwidth makes 'perfect' first order crossovers practical, though of course there will still be some lobing issues.
There were two main challenges. First, as you mention, the mid can easily run out of excursion while the woofer is just cruising. I ended up crossing to the 10" woofer at 700Hz, first order. If you use 2nd or higher order, obviously this can be lower. Secondly, the highs from the FF dustcap tended to conflict with the tweeter. One solution was to simply run it up high, to 10 or 12kHz, and use a horn supertweeter. I ended up gluing a thin disk of felt over the aluminum, and crossing it first order (acoustically) to a modified Focal tweeter at 3500.
One more issue is the impedance peak of the mid and its effect on the lowpass. I ended up using an aperiodic sub chamber, and a simple high pass cap sufficed. A short stuffed TL would also work. With a sealed chamber, you would need a full LCR trap to flatten the Z.
There were two main challenges. First, as you mention, the mid can easily run out of excursion while the woofer is just cruising. I ended up crossing to the 10" woofer at 700Hz, first order. If you use 2nd or higher order, obviously this can be lower. Secondly, the highs from the FF dustcap tended to conflict with the tweeter. One solution was to simply run it up high, to 10 or 12kHz, and use a horn supertweeter. I ended up gluing a thin disk of felt over the aluminum, and crossing it first order (acoustically) to a modified Focal tweeter at 3500.
One more issue is the impedance peak of the mid and its effect on the lowpass. I ended up using an aperiodic sub chamber, and a simple high pass cap sufficed. A short stuffed TL would also work. With a sealed chamber, you would need a full LCR trap to flatten the Z.
No xover parts are detrimental if they make the loudspeaker sound better and that series notch filter did
Making bad xovers on the other hand can kill the sound.
If 93dB suites your purpose, Fostex fe126e is a great little driver. I measured it in january last year in one of their BLH cabinets that can be found in pdf on their site. It looks like this:
Usable from 500 to about 3KHz in a three way. The guy that listens them now asked me to help him with his loudspeakers. He liked them too much to be able to separate from them so i suggested two way by adding 15" woofer (Beyma SM115/K) and keeping little fostex xovered at arround 300Hz. I added a notch filter to cope with 7KHz peak. I didn't touch 14KHz peak because that would influence the highs too much. Fostex is in open baffle and woofer is in BR box. He listened them in back loaded horns from pic above but he lacked bass so we made a two way for him
which do you prefer? how do the compare to the Sonido econowave?
Huh... Both have their own set of compromises.
Sonido econowave with SCW300 will never have that kind of bass. Midrange from fostex is surgically precise and defined. Beyma 15K200 (marked as SM115/K in new catalog) can be bought in Serbia new for 260 euros a pair is one hell of a bass. It needs 120 liters cabinet and sound incredibly well. I compared it with JBL 2235 and TAD 1601 and i ended up with Beyma. It is very simple to make and xover is 12dB/o for Beyma and 6dB/o for Fostex. All in all a good loudspeaker.
Sonido Econowave on the other hand has waveguide that sounds great and with DE250 things just get better. Fostex FE126E sounds pretty good but does not have that much precise high end. Sonido SCW300 has very good midrange too. It can be easilly xovered even lower then 1.5KHz without loss of clarity. Down side of it is sensitivity. Mr Varga declared it 94.5 dB (my pair was declared like that) but it has a 3-4dB peak at say 2KHz where it gets to that sensitivity. The usable range of it is 90-91dB and then peaks at 2KHz. Measurements made by Mr Varga that are given on the website are not of any use for us because it is not gated and in his measuring conditions cover most of the problems. I made xovers and later on i realised that i have to notch that peak down. My xover point was at arround 1.5KHz and i used series notch filter in parallel with SCW300 to flatten that peak. When i did that the sound was amazing.
Econowave with Sonido was a bit more complicated to make. First i didn't count on the notch filter on midbass, other thing is that when i bought PT WG and B&C DE250 - wg is thread-on and DE250 is bolt-on, so adapter was needed. I bought plastic adapter and then filed it until i got smooth transition from adapter to waveguide. The result of that was smooth response in opposed to unfiled adapter that is responsible for 10KHz dip. But when i finished it the sound was great.
Then, after some time i sold it and started to experiment with large format waveguides and 15" woofers and i still am
So the advice would be - if you don't mind the highs from full range, make a two way with Fostex in OB. If you want and love the sound of waveguide, make econowave. Sonido is made in your homeland so that is no problem.
But i must say that when i bought SCW300 its price was 95 euros a piece. Knowing that now the price is gone up to 145 euro a piece - for that money i would buy Deltalite II 2512. It is crafted much better than SCW300.
Sonido econowave with SCW300 will never have that kind of bass. Midrange from fostex is surgically precise and defined. Beyma 15K200 (marked as SM115/K in new catalog) can be bought in Serbia new for 260 euros a pair is one hell of a bass. It needs 120 liters cabinet and sound incredibly well. I compared it with JBL 2235 and TAD 1601 and i ended up with Beyma. It is very simple to make and xover is 12dB/o for Beyma and 6dB/o for Fostex. All in all a good loudspeaker.
Sonido Econowave on the other hand has waveguide that sounds great and with DE250 things just get better. Fostex FE126E sounds pretty good but does not have that much precise high end. Sonido SCW300 has very good midrange too. It can be easilly xovered even lower then 1.5KHz without loss of clarity. Down side of it is sensitivity. Mr Varga declared it 94.5 dB (my pair was declared like that) but it has a 3-4dB peak at say 2KHz where it gets to that sensitivity. The usable range of it is 90-91dB and then peaks at 2KHz. Measurements made by Mr Varga that are given on the website are not of any use for us because it is not gated and in his measuring conditions cover most of the problems. I made xovers and later on i realised that i have to notch that peak down. My xover point was at arround 1.5KHz and i used series notch filter in parallel with SCW300 to flatten that peak. When i did that the sound was amazing.
Econowave with Sonido was a bit more complicated to make. First i didn't count on the notch filter on midbass, other thing is that when i bought PT WG and B&C DE250 - wg is thread-on and DE250 is bolt-on, so adapter was needed. I bought plastic adapter and then filed it until i got smooth transition from adapter to waveguide. The result of that was smooth response in opposed to unfiled adapter that is responsible for 10KHz dip. But when i finished it the sound was great.
Then, after some time i sold it and started to experiment with large format waveguides and 15" woofers and i still am
So the advice would be - if you don't mind the highs from full range, make a two way with Fostex in OB. If you want and love the sound of waveguide, make econowave. Sonido is made in your homeland so that is no problem.
But i must say that when i bought SCW300 its price was 95 euros a piece. Knowing that now the price is gone up to 145 euro a piece - for that money i would buy Deltalite II 2512. It is crafted much better than SCW300.
My friend made something similar to 3Pi with SCW300 instead Eminence Delta. You can find it in Waynes forum. I didn't like the sound of that H290 horn. Even selenium d220ti in pt wg sounded better than DE250 in H290 to my ears. Good thing is that it measures flat and can be xovered with just a few components - unlike pt wg that needs a notch filter.
I'm am experimenting with 15" woofers xovered at 1000Hz and higher and the more of them i test, the more i realise that only few of them can work that high without compromises. Look for the woofers with Mms <75gr and Le as low as possible. That is conclusions i have made so far.
I woud use that JBL in some three way or with 2" compression driver crossed over at 600Hz or lower if possible.
Or you can make a two way with full range in OB like i did for my friend. Here is the pic in test cabinets made out of chipboard:
This is measurement with Beyma SM115/K. Dip at 200 Hz is a floor bounce and the measurement was done before notching down that 7KHz peak but even with that it sounded good.
I'm am experimenting with 15" woofers xovered at 1000Hz and higher and the more of them i test, the more i realise that only few of them can work that high without compromises. Look for the woofers with Mms <75gr and Le as low as possible. That is conclusions i have made so far.
I woud use that JBL in some three way or with 2" compression driver crossed over at 600Hz or lower if possible.
Or you can make a two way with full range in OB like i did for my friend. Here is the pic in test cabinets made out of chipboard:
An externally hosted image should be here but it was not working when we last tested it.
This is measurement with Beyma SM115/K. Dip at 200 Hz is a floor bounce and the measurement was done before notching down that 7KHz peak but even with that it sounded good.
An externally hosted image should be here but it was not working when we last tested it.
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Von Schweikert Audio UniField 3
Fostex FX120 midrange
dave
An externally hosted image should be here but it was not working when we last tested it.
Fostex FX120 midrange
dave
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