well a sketchup of my idea...
asthertically similar to the Linkwitz Orion (which I think is quite nice to look at).
No other changes. (except perhaps a change to the Hemp Acoustic FR4.5c from the FE127, which in modified form is excellent. Dave, your thoughts?)...
Baltic Birch Ply, or hardwood IKEA counter top for the baffles themselves.
asthertically similar to the Linkwitz Orion (which I think is quite nice to look at).
No other changes. (except perhaps a change to the Hemp Acoustic FR4.5c from the FE127, which in modified form is excellent. Dave, your thoughts?)...
Baltic Birch Ply, or hardwood IKEA counter top for the baffles themselves.
Attachments
FYI, there is at least one other set of these in progress. I was telling a friend about them, he asked how much it would cost. This is his first diy audio project, and I was thrilled when he didn't flinch at the price. Parts should be here tomorrow, and the cnc router is cutting the baffles right now. 😎
I will let you all know how he likes them.
best regards,
psz.
I will let you all know how he likes them.
best regards,
psz.
Nope it's a Caterham. I have a Caterham Superlight, but not the one in the picture. Mine has a raw aluminum body with carbon fiber nose and fenders. Any Super Seven variant is fine with me, locosts included. FUN cars.
Sorry for going OT.
best regards,
psz.
Sorry for going OT.
best regards,
psz.
I just turned BRG with envy. Used to own two Lotuses and a Caterham or similar is on the dream car list. The ONLY thing I've ever driven that has the same sort of tactile feel of a good bike. Until then 1000cc of V twin goodness will have to suffice.PSz. said:Nope it's a Caterham. I have a Caterham Superlight, but not the one in the picture. Mine has a raw aluminum body with carbon fiber nose and fenders. Any Super Seven variant is fine with me, locosts included. FUN cars.
Sorry for going OT.
best regards,
psz.
BHD said:
Here the 8 ohm driver is going to be your friend. Put 2 in parallel for 4 ohms. You have just gained 6dB at the same voltage. That helps a LOT. Not only that, now your (passive) low pass filter will need an inductor of only 1/2 the size the 8 ohm woofer(s) would. That's also a big help.
Don't worry about making the design of a crossover to an eight ohm full range easier, it isn't easier. In fact it will be more expensive, because of the larger inductors needed. It's a trick that works well, the 4 ohm woofer, or 2 8s in parallel.
With 2 15" 8 Ohm drivers you will gain 6dB of bass over a single driver. Those 6 dB will bring you much closer to your mid/high driver. That's a good thing.
MJK said:
Hehehe...you could say that you suffered from listening fatigue, so building nice OB's was the only cure....
😀Re: Re: Re: sreten...and MJK too
Hi,.
Here is another FE126E plot for cross referencing :
It agrees well with the previous plot so we can assume the shown
FE103E response is representative, unfortunately its not very good.
The 2KHz ~ 12dB dip of the FE103E you could regard as unworkable
or simply ignore it. It does seem fairly flat above this point, i.e. will
not need an upper midrange filter, but there is not much you can
do about the dip.
Genuine 90 dB 8 ohm small drivers are pretty rare, this $10
Pioneer driver from PE (special) seems on paper more workable :
http://www.partsexpress.com/pdf/290-010g.pdf
This would need a supertweeter IMO .......
🙂/sreten.
planet10 said:
Hi,.
Here is another FE126E plot for cross referencing :
It agrees well with the previous plot so we can assume the shown
FE103E response is representative, unfortunately its not very good.
The 2KHz ~ 12dB dip of the FE103E you could regard as unworkable
or simply ignore it. It does seem fairly flat above this point, i.e. will
not need an upper midrange filter, but there is not much you can
do about the dip.
Genuine 90 dB 8 ohm small drivers are pretty rare, this $10
Pioneer driver from PE (special) seems on paper more workable :
http://www.partsexpress.com/pdf/290-010g.pdf
This would need a supertweeter IMO .......
🙂/sreten.
I'm pretty much a tube guy, so I'd be matching the impedance with a transformer, so I'd only get 3db.
FE103's were on my desk chair this morning... buying wood and a plunge router tonight.
Mwahahahahahahaaaa...
Re: Re: Re: Re: sreten...and MJK too
The dip may not be nearly as bad as mark measures. The unsmoothed measurement you show has a ~5db trough in the 126 whereas mark has a dip of 9db.
Sean
sreten said:
The dip may not be nearly as bad as mark measures. The unsmoothed measurement you show has a ~5db trough in the 126 whereas mark has a dip of 9db.
Sean
Re: Re: Re: Re: Re: sreten...and MJK too
Hi,
or the measurement I show has a little smoothing .....
TBH I don't know but the FE103 does not look too promising to me on paper.
🙂/sreten.
seanzozo said:
Hi,
or the measurement I show has a little smoothing .....
TBH I don't know but the FE103 does not look too promising to me on paper.
🙂/sreten.
I have no idea what the FE103E sounds like, I selected the driver based strictly on price and a good feeling I got from the Fiostex spec sheet. I believe that either the FE103E, FE107E, or the FE108EZ will work in this design. But before we dismiss the FE103E based on one or two measurements lets wait and hear some feedback from the builders, it should come within a week or so.
If we look at the measured response traces I have posted for my Lowther DX drivers, I would never have concluded that they sound as good as they actually do in my systems. There are nasty dips and peaks clearly shown in the SPL response plots. But one of the interesting results was how well they measured and sounded off axis. It could be that at some slightly off axis position the peaks and dips in the FE103E response plot above might clear up significantly. I know that dispite some not so nice looking measurements that the Lowthers are by far the best full range driver I have heard. At this point, I am not too concerned about the FE103E driver.
While I am definitely a stong believer in doing the math and making the measurements, I have not found a way of looking at a response plot measured on axis at 1 m and concluding how a driver will sound in my room at some greater distance. The FE103E may be a good driver or it may be an average driver (hopefully not worse than average), only time will tell. Worst case the builder could substitute a FE108EZ into the design which I have heard and know sounds great.
If we look at the measured response traces I have posted for my Lowther DX drivers, I would never have concluded that they sound as good as they actually do in my systems. There are nasty dips and peaks clearly shown in the SPL response plots. But one of the interesting results was how well they measured and sounded off axis. It could be that at some slightly off axis position the peaks and dips in the FE103E response plot above might clear up significantly. I know that dispite some not so nice looking measurements that the Lowthers are by far the best full range driver I have heard. At this point, I am not too concerned about the FE103E driver.
While I am definitely a stong believer in doing the math and making the measurements, I have not found a way of looking at a response plot measured on axis at 1 m and concluding how a driver will sound in my room at some greater distance. The FE103E may be a good driver or it may be an average driver (hopefully not worse than average), only time will tell. Worst case the builder could substitute a FE108EZ into the design which I have heard and know sounds great.
"what's the BUZ, tell me what's a happenin'..."
Kinda ages me a little doesn't it?
Our rsident FR guru, Dave could comment? He's had quite a bit of experience with the Fostex drivers...
I have no experience with the FE103 either.
stew
Kinda ages me a little doesn't it?
Our rsident FR guru, Dave could comment? He's had quite a bit of experience with the Fostex drivers...
I have no experience with the FE103 either.
stew
hi ob friends
i came to this thread late, just want to ad few of my observations, since I have been living with all sorts of permutations of open baffle systems for about 15 years
i have tried many versions, closed box woofer with ob full range, complete woofer and full range ob, one amplifier/passive crossover, active crossover/biamplification and so on, each with its advantages and disadvantages
i have arrived at the following arrangement giving me the best sound: signal from source (no preamp, no active or passive crossover) goes to low power tube amp (run fullrange), output of which goes to fullrange on open baffle thrue high quality capacitor, value of which depends on crossover frequency and speaker resistance, the same signal from tube amp (before cap) goes to big power solid state amp (no need for resistor if high efficiency full range is used, the level is too small to overload the input of ss amp, but a low pass active or passive can be used), output of ss amp goes to woofer thrue inductor, volume of solid state amp is carefully adjusted to match efficiencies between woofer and fullrange, volume pot on tube amp is master volume
this arrangement sounded better than active crossover with biamplification, maybe because midrange was slightly messed up by a number of op-amps in active crossover and it helps to remove it
other advantages are authority of ss amp driving woofer, easy to eliminate efficiency mismatch, easy to reach high spl, and so on...
ed
i came to this thread late, just want to ad few of my observations, since I have been living with all sorts of permutations of open baffle systems for about 15 years
i have tried many versions, closed box woofer with ob full range, complete woofer and full range ob, one amplifier/passive crossover, active crossover/biamplification and so on, each with its advantages and disadvantages
i have arrived at the following arrangement giving me the best sound: signal from source (no preamp, no active or passive crossover) goes to low power tube amp (run fullrange), output of which goes to fullrange on open baffle thrue high quality capacitor, value of which depends on crossover frequency and speaker resistance, the same signal from tube amp (before cap) goes to big power solid state amp (no need for resistor if high efficiency full range is used, the level is too small to overload the input of ss amp, but a low pass active or passive can be used), output of ss amp goes to woofer thrue inductor, volume of solid state amp is carefully adjusted to match efficiencies between woofer and fullrange, volume pot on tube amp is master volume
this arrangement sounded better than active crossover with biamplification, maybe because midrange was slightly messed up by a number of op-amps in active crossover and it helps to remove it
other advantages are authority of ss amp driving woofer, easy to eliminate efficiency mismatch, easy to reach high spl, and so on...
ed
It's mentioned as a possible replacement in Martin's article, but I think he focused on the FE103 because he wanted to keep the costs down. I thought about that driver too...
MJK said:
I've not had a chance to play with the current 103... many of the older ones are exemplary.
The FE108eS is hard to beat in the midrange (i have a set set aside for an OB application) -- it too has a significant measured dip (at 1k?) that is MIA in actual use.
dave
Re: FX120
Or the F120A if you can find (& afford) a pair. Any vintage FE103 alnico family member -- particularily the Holey Basket Coral or even rarer Atomix -- would also be potential candidates.
And someone on a real budget could use RS40-1197.
dave
jimmyd53 said:
Or the F120A if you can find (& afford) a pair. Any vintage FE103 alnico family member -- particularily the Holey Basket Coral or even rarer Atomix -- would also be potential candidates.
And someone on a real budget could use RS40-1197.
dave
adason said:
Hi,
If I understand correctly, you are using first order passive x-overs with dual amplification. One thing is not clear: output of a tube amp goes through a capacitor? Please forgive my ignorance, but I thought that most tube amps are connected to a speaker via transformer, not a capacitor. Anyway, I don't want to discuss that here; I got your point.
Could you please tell us what speakers are you using at the moment? What is the crossover frequency?
Regards,
Vix
Edit: ok, I got it, too late: a capacitor is after the transformer, is it?
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