You might want air core inductors - aren't the Erse super Q's iron core - and that is meant for woofer duties rather than full range duties? I am not sure on this but never heard of an iron core inductor used on a full range BSC.
Make sure you set the XO for the sub no lower than 300 Hz if you want smooth integration. Also you will need some high pass filtering on the FE103EN to limit excursion at low end - don't run it full range. -12dB at 250 to 300 Hz is good.
Here is the impulse response - you should get very clean dynamics with this speaker. Looking forward to seeing the Dagger in action - maybe another Youtube vid?
Good luck!
Make sure you set the XO for the sub no lower than 300 Hz if you want smooth integration. Also you will need some high pass filtering on the FE103EN to limit excursion at low end - don't run it full range. -12dB at 250 to 300 Hz is good.
Here is the impulse response - you should get very clean dynamics with this speaker. Looking forward to seeing the Dagger in action - maybe another Youtube vid?
Good luck!
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Right now the sub is set at 80 and I have a 68uf cap on the + line heading to the fostex to protect it from LF signals . Not sure I like the sound of adding components to the signal... they don't usually improve the sound, Yes feel free to call me crazy. I'm picturing stuffing in the dagger, were you also? I always do a vid for prosperity.
We'll see what I can come up with.
okay I went over to Martins place and played with the baffle step correction spreadsheet. I also read up on baffle step correction to make sure I get the jist of it. so let me just run this by you one last time to make sure I've got everything right. Create a dagger that is 35" long with a baffle that is 5" wide and 8 inches tall, make sure it is sealed tight, do not add stuffing, add a .9 mh inductor paralleled with a 6 ohm resistor (I'm assuming a regular white cement 10w one will do?) then put my 68 uf cap in the + line after the BSC components. and it should sound awesome. Correct?
BTW my Dayton 12" sub crossover only goes up to 200hz... I think.
BTW my Dayton 12" sub crossover only goes up to 200hz... I think.
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You have it right except use stuffing. Put stuffing starting at the tail and pack it tight and gradually loosen the stuffing as you go towards the driver and go 2/3rds full length with stuffing so that 1/3rd in driver end is not stuffed. However cover the exposed flat walls immediately near driver with felt (if you have it) or open cell foam or other acoustical absorption liner. Also, I checked the response and 200 Hz should still work as a sub XO point as the FE103 is down only 2 to 3 dB at that point. What is the high pass freq of the 68uF cap? If 200 Hz then good.
No, not at all! I almost always use Erse Super Q's for full range BSC filters. Usually, you want absolute minimum DCR for the BSC inductor which pretty much dictates iron core. The Super Q's are rated at 500w, I'm running them at maybe 5w. Hysteresis and saturation are myths at this power level. But then, once the signal frequency has increased past the baffle step, the signal isn't going through the inductor anyway. The full signal is passing through the resistor. So, if SQ is the major factor, you want the best quality resistor and whatever inductor works.
Bob
Thanks for clearing up the air core for BSC myth Bob! Now that frees me to use some pretty compact and low cost inductors. There may be some compact shielded ferrite core PCB mounted varieties that can handle 4 amps that I want to try. I might have to put 4 of them in series to get enough Henries though.
I have some nice dense foam that I'll cut a triangle out of and put in the last 2" of tail then stuff the rest with polyfil. Not sure what you mean by high pass freq of the 68uf cap? I use it to stop LF from going to the fostex. Looks to be around 300. I had to go use a calculator. Also ordered air cores and resistors from PE last night. (I went with the dayton audio grade resistors)
Guess I'll go with Bobs recomendation since I got plenty of Super Q's laying around. If this works out I Might do 8 of them and space them 1 foot apart all the way across my viewing wall.
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They'll stab you in the back when you least expect it.
Yes I don't notice any frequencys suffering from the setup. they all seem to be close enough in spl that I don't notice. Actually the sub is set at 80 on the crossover, 200 is too much to my ears. it's a very clean sounding system.
Yes I don't notice any frequencys suffering from the setup. they all seem to be close enough in spl that I don't notice. Actually the sub is set at 80 on the crossover, 200 is too much to my ears. it's a very clean sounding system.
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So you have tried out this combo already in your quad-driver OB I assume? Half the battle is already won then. I am quite certain that the Dagger will give you a transparent "OB-like" sound without the reflected back wave ambiance. With such a skinny 5 in baffle the imaging on a pair of Dagger point sources should be phenomenal.
Looking forward to seeing the build and hearing your listening impressions and videos.
I was thinking that two stainless wires could be used to suspend the Daggers from the ceiling so they float in space unconstricted by a stand for the best imaging and sound stage possible. Might be kind of cool.
Yes, those are my settings as of right now. Not sure about hanging them as I don't want the wires blocking my view of the projector image on the wall, plus I will want to be able to move them around for best placement. I'm already thinking of cheating by tapering just one board and making a right angle with the other one.
I'm already thinking of cheating by tapering just one board and making a right angle with the other one.
or flip them and have them point upwards slightly, either way..
Yes but not big blocky ones maybe just some 1x4's on both sides running to the floor and then some kind of foot. that way I could tilt them up and down too. Still trying to figure out how I'm going to do the sides, the hole in the baffle for the speaker is 3 3/4 and I only have 5" to work 2 sides in.... I either have to go with less than 3/4" sides or expand the baffle wider.
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Today I built a PVC enclosure. 4" PVC pipe 12" long with a clean out cap on one end and a toilet flange on the other. I put a 2" thick piece of dense packing foam in the back end, then stuffed with poly for about another 3-4 inches. ( that left me about 100 cu,in, of space which is what I needed for a .7 Q on a sealed Cab for this driver) cut a piece of 1/2" ply that bolts to the toilet flange and put my 3 3/4 hole in it for the driver. It works Killer!!! No tube like sound, no box like sound no discoloration sound, just pure sweetness. It does still need the BSC components which should be here tomorrow. (It's a bit shouty and piercing) I rechecked it with the BSC calculator over on Martins site. It looks like the 6ohm resistors will still work but I have to go up to my 1.5 Mh inductors. that should give me somewhere between 4 and 5 db attenuation. will post up some pics and vids as soon as I get stuff worked out. I would like to do 8 of these and spread them all the way across the front wall. Not sure what it will do to my soundstage but it would probably be pretty cool with stereo effects and stuff flying by in movies.
One question though I wonder if I will have to do a cap and a BSC on each individual cabinet? I can't imaging I can just toss one cap and one BSC circuit in the line that is feeding 4 drivers.I also need to come up with a stand setup for all of them...
4" PVC pipe 12" long with a clean out cap on one end and a toilet flange on the other. I put a 2" thick piece of dense packing foam in the back end, then stuffed with poly for about another 3-4 inches. ( that left me about 100 cu,in, of space which is what I needed for a .7 Q on a sealed Cab for this driver) cut a piece of 1/2" ply that bolts to the toilet flange and put my 3 3/4 hole in it for the driver. It works Killer!!! No tube like sound, no box like sound no discoloration sound, just pure sweetness. It does still need the BSC components which should be here tomorrow. (It's a bit shouty and piercing) I rechecked it with the BSC calculator over on Martins site. It looks like the 6ohm resistors will still work but I have to go up to my 1.5 Mh inductors. that should give me somewhere between 4 and 5 db attenuation. will post up some pics and vids as soon as I get stuff worked out. I would like to do 8 of these and spread them all the way across the front wall. Not sure what it will do to my soundstage but it would probably be pretty cool with stereo effects and stuff flying by in movies.One question though I wonder if I will have to do a cap and a BSC on each individual cabinet? I can't imaging I can just toss one cap and one BSC circuit in the line that is feeding 4 drivers.I also need to come up with a stand setup for all of them...
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So you gave up on the Daggers? PVC pipe is good stuff but make sure you don't have a symmetric round baffle that is the same dia as the flange - that is the worst config from baffle diffraction standpoint and will put lots of ripple on the response. It looks like the foam may be doing its thing.
If you are running four in series parallel you only need 1 cap and 1 BSC circuit equivalent to a 8 ohm driver. So it should be same BSC. Note that putting a 68uF cap as a high pass filter in sores with a inductor and resistor makes an
RLC circuit with a different behavior than just cap and bare driver.
I think having 8 will ruin your point source sound stage and turn it into a Muzak like speaker system.
If you are running four in series parallel you only need 1 cap and 1 BSC circuit equivalent to a 8 ohm driver. So it should be same BSC. Note that putting a 68uF cap as a high pass filter in sores with a inductor and resistor makes an
RLC circuit with a different behavior than just cap and bare driver.
I think having 8 will ruin your point source sound stage and turn it into a Muzak like speaker system.
4 in PVC x 12 in long sealed speaker
Cradeldorf,
I think you may want to at least try building a Dagger to compare - it's just a few glue glued joints and a little bit of lumber. The performance difference between the Dagger and your PVC pipe speaker, according to the sims is substantial - there are a lot of back wave reflection issues. Here is the predicted performance of 4 in PVC pipe that is 12 in long with 0.5 Q with 0.9mH+6R BSC. The second plot is what happens when you add 68uF in series with BSC - not the smooth roll-off you want and not occuring at the 300 Hz you want.
4 in x 12 in PVC:
with 68 uF:
Compared to the Dagger tapered sealed TL design (without 68 uF):
Cradeldorf,
I think you may want to at least try building a Dagger to compare - it's just a few glue glued joints and a little bit of lumber. The performance difference between the Dagger and your PVC pipe speaker, according to the sims is substantial - there are a lot of back wave reflection issues. Here is the predicted performance of 4 in PVC pipe that is 12 in long with 0.5 Q with 0.9mH+6R BSC. The second plot is what happens when you add 68uF in series with BSC - not the smooth roll-off you want and not occuring at the 300 Hz you want.
4 in x 12 in PVC:
with 68 uF:
Compared to the Dagger tapered sealed TL design (without 68 uF):
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Nautaloss II is slightly different in that the "mouth" is taller to accommodate dual drivers but spiral length and overall exterior envelope is the same. You can run the Nautaloss full range and use a subwoofer XO at about 150 to 200 Hz. High passing the Nautaloss reduces cone excursion and makes it sound better but not necessary to use miniDSP.