AudioCircle
Audio/Video Gear and Systems => Single Driver, Wide-Bandwidth Speakers => Topic started by: FullRangeMan on 18 Nov 2011, 07:53 pm
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This thread is about keep Full Range drivers cross-over-less to listen its best sound possible, its Harmonic Integrity and spatial 3D sound-stage, that is the best feature a FR can delivery to the music lover.
If you are a famous brands lover or buy speakers for the good looks you may not like this topic, this is a thread for DIYers and for those who want modify their current expensive enclusure for a better performance.
Some Full Ranges drivers has strong mid-treble response, to keep it cross over less is need some passive treatment to smother the high frequencies.
Of course passive here, is not a passive crossover or any of its electronic parts, as inductor, capacitor, etc but apply in the internal box various suited materials as explained below
1) First: round all the box corners, even the small ones, with a triangular or L shape profile of wood or MDF. Alternatively can be used that soft massa/dough of caulk, avoid plastic or metal parts here.
2) Second: Paint matte black or dyeing with black dye all walls inside the box, even the Baffle, it will decrease the hi freq., its a procedure used in automotive subs with success.
3) Stuffing all the fullrange magnet with 30 to 50mm black foam or dark blue or brown. Pressed wool 20-30mm also is good. You will need some glue. Please note that foam begins to crumble/mill after some 10 years, so use a new quality sample of medium density. Avoid 10mm carpet or non shaggy rug.
4) Stuffing inside the box as recommended by the driver manufacturer or even more. If the box is BassReflex, stuffing the duct also, with dark foam, not the inside of the duct/flute of course, but the outside of the duct. If you want up the bass you must use 10/15mm car hood brown blanket at the back wall of the box.
5) Foam will raise the bass freq response too few or nothing varing according the driver TS pars, but the car hood blanket will up the bass much more at a low cost and will last a century, I have this material inside a speaker about 30 years and it look just like new.
6) Toe-in cost no money and will reduce the treble and beef-up image and will decrease lateral reflections on the walls.
7) Just adding this imaging to this old thread, this is a blanket used in car hoods and is very useful to up the bass freq, if used in excess it will down the hi freq too, that may be a useful tool to peaky full range drivers.
Use the 15mm version, image show thinner 5mm brown blanket.
(http://www.audiocircle.com/image.php?id=102638)
Please Note: Foam and wool blanket use space in the internal volume of the box, the white Polyester blanket will not occupy space in the box litrage.
Update 2023: Very recommend to use this car hood blanket in the 15mm or 20mm thickness, the 5mm has minimal or none effect in increase the bass.
If you had a suggestion or a new trick, please fill free to post here to us.
Cheers
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This thread is about keep FullRange drivers crossoverless to listen its Harmonic Integrity, that is the best feature a FR can delivery to the music lover.
If you are a CrossOver lover you may be frustated here.
Some Full Ranges drivers had strong mid-treble response, to keep it crossoverless, is need some passive treatment to smother the high frequencies.
Of course passive, is a non electronic part, as inductor, capacitor, DSP etc.
1) First: around all the box corners, even the small ones, with a triangular or L shape profile of wood or MDF. Alternatively can be used that soft massa/dough of caulk, avoid plastic or metal parts.
2) Second: Paint matte black all walls inside the box, even the Baffle, it is not difficult with a spray can.
3) Stuffing all the fullrange magnet with 30 to 50mm black foam or dark blue or brown. Pressed wool 20-30mm also is good. You will need some glue. Please note, that foam begins to crumble/mill after some 10 years, so use a new quality sample of medium density. Avoid 10mm carpet or non shaggy rug.
4) Stuffing inside the box as recommended by the driver manufacturer or even more. If the box is BassReflex, stuffing the duct also, with dark foam, not the inside of the duct/flute of course, but the outside of the duct.
5) Foam will raise the bass response too, that is great, as I am a bass fan.
Please Note: Foam and wool blanket use space in the internal volume of the box, the white Polyester blanket will not occupy space in the box litrage.
If you had a suggestion or a new trick, please fill free to post here to us.
Cheers
After what I read, it appears that you are treating the enclosure and not the driver. If a raw driver has problems then the driver needs treatment too.
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After what I read, it appears that you are treating the enclosure and not the driver. If a raw driver has problems then the driver needs treatment too.
Yes, Iam treat the enclousure(I will no listen the raw driver), it can be BassReflex or Sealed, obviously for horns or OB this treatment not work.
Iam unknow any raw driver treatment, unless the magnet stuffing(item 3). Do you would inform which you are referring??
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Yes, Iam treat the enclousure(I will no listen the raw driver), it can be BassReflex or Sealed, obviously for horns or OB this treatment not work.
Iam unknow any raw driver treatment, unless the magnet stuffing(item 3). Do you would inform which you are referring??
Ever hear of EnABL?
Sometimes cone problems can be treated with a coat of damping material. Something brushed on or sprayed on. Dammar (varnish) was all the rage a few years ago.
Baskets that are stamped or that ring can be damped too. Use modeling clay or self adhesive peel and stick type of damping sheets.
Wedging, bracing the entire motor assembly (back of the magnet) to the inside rear wall of the enclosure has benefits too. Shown to improve transients.
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Wouldn't a notch filter be less of a compromise than a handful of passive tweaks that may each have their own side effects?
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Wouldn't a notch filter be less of a compromise than a handful of passive tweaks that may each have their own side effects?
The word "capacitor" frightens a lot of "Full Rangers!"
I actually saw before and after frequency response graphs of an inexpensive paper cone driver treated with Dammar. Took the points off, muted all the sharp peaks, be it ever so slightly.
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Ever hear of EnABL?
Sometimes cone problems can be treated with a coat of damping material. Something brushed on or sprayed on. Dammar (varnish) was all the rage a few years ago.
Baskets that are stamped or that ring can be damped too. Use modeling clay or self adhesive peel and stick type of damping sheets.
Wedging, bracing the entire motor assembly (back of the magnet) to the inside rear wall of the enclosure has benefits too. Shown to improve transients.
Thanks for informing. I suspect brace the magnet motor as used on Yamamoto OB lower the Fs.
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Another trick, Use different thicknesses of wood for less enclousure resonance:
BAFFLE = 30mm
BACK = 10 to 15mm
SIDES = 20mm
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Hi,
I am new here. Guess I will jump in, and try to make some friends, share what experience I have, and learn from others.
I have built two pairs of speakers so far. Both were Full Range Drivers. The upper-end was always the thing I wanted to "properly" tame.
My first pair was Voigt Pipes with Fostex FE166E drivers. Getting the line length right was my first (and biggest) improvement. I had originally made them to tall. Once I shortened them by putting a flat piece of wood inside at the top, my bass increased! The next thing was fiberglass insulation. Cutting the wizzer cone out, and adding a wooden phase plug I made (by use to two tiny magnets) was also a worthwhile improvement.
I did make a baffle step circuit, and would not have wanted to be without it for MANY moons. Someone told me at takes about 3 years for those drivers to fully break in. That seemed to be true. Eventually, I removed the baffle step circuits, moved to speakers closer to the corners of my room, and got better sound.
By second pair of speakers was a BIB (folded horn) with a Fostex F208 sigma and T90A super tweeter. Hanging a banner shaped piece of masonite (with the pointed end toward the floor) into to second chamber, helped.
Eventually, I did put a 0.25mH coil in series with the 208's. I later added a little more wire to the coil to hopefully bring it to about 0.3mH. I knew I lost some definition in the bass, etc., but I didn't care. It took the edge off, and I could listen and enjoy them much longer.
Once I added the inductance, I could either listen on axis more than before, or position the speakers further from the corners. Here is my current dilemma. I have a spot somewhat out into the room where I get the very fastest, most natural (but slightly anemic) bass, as well as overall dynamics and resolution, from top to bottom, and depth of image. Or, I put them back tight into the corners, and loose some of what I have described (and gain much more power, but a slight bloating) in the bass. But mostly, tight in the corners, is where the vocals sound the very most natural. Not piercing. It is like having two different pairs of speakers in one, depending on how I position them.
I am glad this subject has come up. I do plan to keep these speakers a long time, if I ever replace them. I hope someone can benefit from my experiences. I am excited to study all that everyone else has experienced. I have not tried Bud's EnAble process on a driver. I was afraid I might screw up. Guess I should try it on a driver I don't care about first. Bud did once invite me to hear two identical speakers. One EnAbled and one not. I live several hours away, and haven't done it, though.
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Another trick, Use different thicknesses of wood for less enclousure resonance:
BAFFLE = 30mm
BACK = 10 to 15mm
SIDES = 20mm
If you really want to attenuate enclosure wall resonances, double or triple the layers.
Constrained layers are best, but you end up with a very heavy back breaking enclosure.
(http://www.audiocircle.com/image.php?id=53936)
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If you really want to attenuate enclosure wall resonances, double or triple the layers.
Constrained layers are best, but you end up with a very heavy back breaking enclosure.
This is great to a strong, firm enclousure. If the walls are all same thickness the resonance are greater than, if the walls are variable thickness.
Same walls thickness = more resonances.
Variable wall thickness = less resonances.
This happen why the vibrations run inside the wood like a loop.
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This is great to a strong, firm enclousure. If the walls are all same thickness the resonance are greater than, if the walls are variable thickness.
Same walls thickness = more resonances.
Variable wall thickness = less resonances.
Fail.
Different wall thicknesses = Different wall resonance. No guarantee of "less" resonance only a change in frequency.
Not something you can guess. The only way you'll know for sure is to use an accelerometer attached to the enclosure walls.
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Fail.
Different wall thicknesses = Different wall resonance. No guarantee of "less" resonance only a change in frequency.
Not something you can guess. The only way you'll know for sure is to use an accelerometer attached to the enclosure walls.
Interesting point of view, thanks.
A great speaker that use different wall thickness with success are some Avalon models.
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Chladni plate/patterns.
http://www.youtube.com/watch?v=Sz1AuS-qA1c&feature=related
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Chladni plate/patterns.
http://www.youtube.com/watch?v=Sz1AuS-qA1c&feature=related
Hey this is a tweeter burn machine. What is Chladni ??
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Hey this is a tweeter burn machine. What is Chladni ??
http://www.absoluteastronomy.com/topics/Ernst_Chladni
(http://upload.wikimedia.org/wikipedia/commons/3/31/Chladni_guitar.svg)
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http://www.absoluteastronomy.com/topics/Ernst_Chladni
(http://upload.wikimedia.org/wikipedia/commons/3/31/Chladni_guitar.svg)
OK, Thanks for your help.
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Another economic tip: Use 3 feet(not 4) to support the enclousure on the floor or stand.
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A great tip from ERIKB1971: Make random craters inside the enclosure as the image below.
(http://www.audiocircle.com/image.php?id=53993)
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A great tip from ERIKB1971: Make random craters inside the enclosure as the image below.
A lot of hard work . . . .
An even easier way would be to install acoustical ceiling tile inside the enclosure.
(http://www.audiocircle.com/image.php?id=53998)
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If it's ok to think "outside the box" and still respect the intent of this post, three things that come to mind are placement, toe-in, and speaker cable. 1) Positioning the speakers closer to a corner will emphasize the bass frequencies and subjectively reduce the relative loudness of any treble peaks. This is a compromise because some of the "magic" of a single driver's soundstage may be lost in the process. 2) Spacing the enclosures as far apart as possible without losing the center image, and pointing them straight ahead with no toe-in, will increase the listening angle and reduce the treble intensity at the listening position. 3) SET amps are especially sensitive to speaker impedance, and many single driver enthusiasts use very small gauge speaker cable and internal wiring to increase the total resistance, which also increases the "Q" of the speaker and the bass amplitude at the driver's resonant frequency.
Also, most of the peakiness of low Q, high sensitivity drivers is generated by the cone itself, but some peakiness can also come from the back wave reflected off the back of the enclosure and through the cone, especially in shallow enclosures that don't have dense stuffing. I've found that a piece of Armstrong 420 contractor series fiberglass ceiling panel glued to the rear wall behind the driver will absorb more high frequency reflections than convoluted foam, loosely stuffed pillow stuffing, or even fiberglass ceiling insulation. This material is about 3/4" thick, and the piece needn't be much larger than the driver itself.
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If it's ok to think "outside the box" and still respect the intent of this post, three things that come to mind are placement, toe-in, and speaker cable. 1) Positioning the speakers closer to a corner will emphasize the bass frequencies and subjectively reduce the relative loudness of any treble peaks. This is a compromise because some of the "magic" of a single driver's soundstage may be lost in the process. 2) Spacing the enclosures as far apart as possible without losing the center image, and pointing them straight ahead with no toe-in, will increase the listening angle and reduce the treble intensity at the listening position. 3) SET amps are especially sensitive to speaker impedance, and many single driver enthusiasts use very small gauge speaker cable and internal wiring to increase the total resistance, which also increases the "Q" of the speaker and the bass amplitude at the driver's resonant frequency.
Also, most of the peakiness of low Q, high sensitivity drivers is generated by the cone itself, but some peakiness can also come from the back wave reflected off the back of the enclosure and through the cone, especially in shallow enclosures that don't have dense stuffing. I've found that a piece of Armstrong 420 contractor series fiberglass ceiling panel glued to the rear wall behind the driver will absorb more high frequency reflections than convoluted foam, loosely stuffed pillow stuffing, or even fiberglass ceiling insulation. This material is about 3/4" thick, and the piece needn't be much larger than the driver itself.
Thanks for your detailed report.
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One more tip for peaky FR drivers: Add 5mm felt layer outside the baffle, of course it will hide the beautiful mahogany vaneer you pay hi for;
http://www.audiocircle.com/index.php?topic=100846.msg1018154#new
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Just adding this imaging to this old thread, this is a blanket used in car hoods and is very useful to up the bass freq, if used in excess it will down the hi freq too, that may be a useful tool to peaky full range drivers.
Use the 10mm version, image show thinner 5mm.
(http://www.audiocircle.com/image.php?id=102638)
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Shoutiness and peakiness are tamed by using a current source amplifier.
More info:
https://www.current-drive.info/
http://www.firstwatt.com/pdf/art_cs_amps.pdf
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Pretty much want Fred said (Hi, Fred).
Full-rangers have a rising response on axis. Don't listen on axis! Most full-rangers are pretty much flat 15* off-axis.
Boxiness is almost always due to reflection off of the back wall coming through the cone. Armstrong 420 works. It is actually 5/8" thick, and at least out here in the sticks only available in 12-packs. I am using a Owens-Corning 703 knock-off that can be had in single panels, but is cheaper in a 6-pack(!).
Bottom end with low Q drivers is always a problem. Use a driver with a Qts above 0.3 -- preferably closer to 0.5. Makes cabinet design so much easier. You can still use SE tubes, but you will get real bass.
BSC does not "take the life out of the music". It give a balanced FR. We have been conditioned from birth to like a smiley faced EQ. A flat FR sounds, well, flat! OK. maybe you do want to have your speakers pointing directly at you. That sparkle and "detail" is fake and characteristic of a rising response.
If your drivers have a crappy FR, screwing them onto a two watt SE amp with thin silver wires is not going to give you audio nirvana (that's lower case letters -- don't get me started). You have to get the FR straightened out first. Then go for the audiophile tweaks.
EQ is your friend, and if you go digital rather than passive, you can still have nothing but wire between your amp and the speakers. Win-win.
Bob
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Thanks Bob for your experiencied tips in passive treatment :thumb:
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Thanks Bob for giving your expert opinion in the matter. I am glad to hear that you are still active in the forums.
:thumb:
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Bob is one of my audio heroes. I commissioned him to build my speakers (last called M18-F200) 13 years ago. They are floor-standing single driver transmission lines using the "mighty" (now discontinued :cry:) Fostex F200A AlNiCo driver that last retailed for $575 each (rated 30-20,000Hz, 89 dB/w/m, 8 ohms, no stinking whizzer cone). I had Bud Purvine EnABL the drivers (Bud invented the idea/process). As Bob mentioned I've run cable directly from my mono-blocks to the drivers for years (does make auditioning speaker cable all but impossible) and replaced BSC with DSP (currently DSPeaker Anti-Mode 2.0 Dual Core).
And thanks to Duke LeJeune added Late Ceiling Splash tweeters (Dayton Audio 1.125 inch soft dome) on the floor behind speaker to alleviate the high frequency beaming (boost treble response a bit and greatly expanding the soundstage). This pretty much my destination speaker (at age 61 I'd better have arrived :)).
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Gave up on tiny amps when I couldn't find satisfactory loudspeakers to mate to them. Currently run Supra Classic 1.6 speaker cable between my Bob Brines babies and 70 watt Temple Audio mono-blocks.