tinitus,
In a normal sized room you can surely get plenty of bass from a good 10" speaker in the right box. No it isn't going to be equal to an 18" speaker but at the level that most people listen it can do more than adequate for the majority of listeners. If you are only using the device for low frequencies they can do a very good job with sufficient Xmax and not using them for the midrange where they would be muddy. Low 30hz frequencies are easy to do. Now if you are going for max impact and loud home theater perhaps you may need something bigger, but to say they can't do it is just plain wrong.
I would add that many bass horns would have a hard time getting down to 30hz and they will be much bigger to even get close.
In a normal sized room you can surely get plenty of bass from a good 10" speaker in the right box. No it isn't going to be equal to an 18" speaker but at the level that most people listen it can do more than adequate for the majority of listeners. If you are only using the device for low frequencies they can do a very good job with sufficient Xmax and not using them for the midrange where they would be muddy. Low 30hz frequencies are easy to do. Now if you are going for max impact and loud home theater perhaps you may need something bigger, but to say they can't do it is just plain wrong.
I would add that many bass horns would have a hard time getting down to 30hz and they will be much bigger to even get close.
yes, ofcourse
and I never said anything else
I just thought there are plenty of small 10" hifi woofers already
but good big woofers with low Fs are more rare
One thing that should be considered is slot loading- one can make a waveguide of sorts to act as a mild bandpass filter, if desired. The airmass can push the Fs down. Nelson Pass leverages this in his slot loaded dipole
The Slot Loaded Open Baffle Project Article By Nelson Pass
The Slot Loaded Open Baffle Project Article By Nelson Pass
tinitus,
That we both can agree on. Most 15" speakers for pro use are not much good for low bass, they just aren't intended for real low bass. I have some very old now Altec speakers that have a 15" air suspension speaker that does do the job, that type of speaker is fairly rare though.
That we both can agree on. Most 15" speakers for pro use are not much good for low bass, they just aren't intended for real low bass. I have some very old now Altec speakers that have a 15" air suspension speaker that does do the job, that type of speaker is fairly rare though.
One problem that may creep up when you add enough mass to make a real change in the resonant frequency and Qts - suspension sag.
You definitely do not want the driver facing the floor (or up) because gravity will displace the cone away from the rest position. Even if you position the driver so it is facing the "normal" way (excursion axis parallel to the floor) the suspension can still sag under the effect of the extra mass, and this can eventually cause the voice coil to contact and rub on the magnet structure. Avoid!
-Charlie
You definitely do not want the driver facing the floor (or up) because gravity will displace the cone away from the rest position. Even if you position the driver so it is facing the "normal" way (excursion axis parallel to the floor) the suspension can still sag under the effect of the extra mass, and this can eventually cause the voice coil to contact and rub on the magnet structure. Avoid!
-Charlie
even if it doesn't happen, just a small voicecoil 'wobble' might lead to distortion, which in the low bass means blurred bass
on the other hand, just a small amount of added mass might actually calm down the voice coil wobble, and give less distortion
Thanks guys
All helpful 🙂 Pass's slot design is a particularly interesting idea - extra mass with no damage to warranty combined with AMT improvement in efficiency - need not be a slot I guess if aim is simply to increase the mass.
Rod
All helpful 🙂 Pass's slot design is a particularly interesting idea - extra mass with no damage to warranty combined with AMT improvement in efficiency - need not be a slot I guess if aim is simply to increase the mass.
Rod
no, ported/BR is much more effective in that respect 😉
but the slot is more effective summing multiple drivers to get more coherent output
or more precisely- bandpass. The efficiency boost trades off with bandwidth in a bandpass, just as in a manifold design. It's really just two different extremes of the same delicious bass cookie.
reminds me...there are two very good threads on that subject
he might find them interesting
but I can't remember the thread titles
I've glued a ring of solid-core solder around the dust cap. There was an article in Speaker Builder many years ago about somebody doing that for these exact same reasons, trying to use a small ported box to go very low, you still end up with narrow bandwidth and low efficiency.
There is a general old-timer's procedure called 'cone doping' and some assembly lines even sprayed cones until they achieved some specific wet weight, more for consistency than anything else. In the early days speakers often had paper cones and paper surrounds, so we would put stiff strong model airplane dope engineered to reinforce onto the cone and rubber contact cement on the convoluted surround, just to establish and reinforce which was which by making one stiffer and the other "bendy".
You can do OK if you decide to use a LOT of power and EQ and don't have to power-match with other sections via a passive crossover. I painted the paper cones of some expensive 18" drivers with Envirotex brand clear epoxy, thinned with Klenk's tub & tile epoxy thinner (no longer available, mostly alcohol, toluol and zylene I think). Most of it soaked into the paper cones. It was perfect...not too brittle and not too soft, it ended up with characteristics somewhere between a paper cone and a poly cone. Those particular original paper cones were known for collapsing along their ring ribs like an accordion when they hit Xmax limited by the surround, so the additional cone strength helped (kind of...tore the cheaper replaceable surround instead) and the embossed rings prevented flutter breakup modes nicely, especially when doped. These things had more motor than they could usually use. Then I mounted them in clamshelled isobaric pairs so the sealed cabinet was half-size but had the characteristics of one twice the size. Q was still a steep hump, and I used about 7200 watts for 4 clamshelled pairs (8 drivers); the EQ required to flatten that hump increased the power requirement considerably and the isobaric doubled thre requirement (and the amount they would handle safely). Of course, that still had 2 18" cones exposed to the room on each of 2 stereo channels...so the 8 isobaric drivers sounded like 4 in larger boxes. But they were relatively small stacked-cube boxes that went very low. Definitely didn't go very high. I used them in a 5-way system with active crossovers. In a little more space I could have made something 1000 times more efficient. I don't know how that would scale down. Often whatever you can achieve via adding weights or even via isobaric might be achievable by shopping for drivers instead. You might do well making a smaller model with modern large-displacement drivers and switching-mode amps.
Try looking for unused space instead. Under a sofa, behind a sofa, commandeer a closet or attic or crawlspace. Very tall speakers can have a very small floor footprint. You can engineer something to place right against a wall from floor to ceiling. Paint speakers the same color as the walls. Or make something like Danley's flat folded tapped horns and place them against the back wall or use them as a platform along the wall, kind of a stage for all the home theater stuff to sit upon. Or make speakers on stands, and design the stand as either box volume or as the port. Maybe she won't notice if the room is suddenly 6 inches shorter...that gives you an incredible volume to work with.
Good luck. Keep in mind that any expense may be less than trading in the spouse.
There is a general old-timer's procedure called 'cone doping' and some assembly lines even sprayed cones until they achieved some specific wet weight, more for consistency than anything else. In the early days speakers often had paper cones and paper surrounds, so we would put stiff strong model airplane dope engineered to reinforce onto the cone and rubber contact cement on the convoluted surround, just to establish and reinforce which was which by making one stiffer and the other "bendy".
You can do OK if you decide to use a LOT of power and EQ and don't have to power-match with other sections via a passive crossover. I painted the paper cones of some expensive 18" drivers with Envirotex brand clear epoxy, thinned with Klenk's tub & tile epoxy thinner (no longer available, mostly alcohol, toluol and zylene I think). Most of it soaked into the paper cones. It was perfect...not too brittle and not too soft, it ended up with characteristics somewhere between a paper cone and a poly cone. Those particular original paper cones were known for collapsing along their ring ribs like an accordion when they hit Xmax limited by the surround, so the additional cone strength helped (kind of...tore the cheaper replaceable surround instead) and the embossed rings prevented flutter breakup modes nicely, especially when doped. These things had more motor than they could usually use. Then I mounted them in clamshelled isobaric pairs so the sealed cabinet was half-size but had the characteristics of one twice the size. Q was still a steep hump, and I used about 7200 watts for 4 clamshelled pairs (8 drivers); the EQ required to flatten that hump increased the power requirement considerably and the isobaric doubled thre requirement (and the amount they would handle safely). Of course, that still had 2 18" cones exposed to the room on each of 2 stereo channels...so the 8 isobaric drivers sounded like 4 in larger boxes. But they were relatively small stacked-cube boxes that went very low. Definitely didn't go very high. I used them in a 5-way system with active crossovers. In a little more space I could have made something 1000 times more efficient. I don't know how that would scale down. Often whatever you can achieve via adding weights or even via isobaric might be achievable by shopping for drivers instead. You might do well making a smaller model with modern large-displacement drivers and switching-mode amps.
Try looking for unused space instead. Under a sofa, behind a sofa, commandeer a closet or attic or crawlspace. Very tall speakers can have a very small floor footprint. You can engineer something to place right against a wall from floor to ceiling. Paint speakers the same color as the walls. Or make something like Danley's flat folded tapped horns and place them against the back wall or use them as a platform along the wall, kind of a stage for all the home theater stuff to sit upon. Or make speakers on stands, and design the stand as either box volume or as the port. Maybe she won't notice if the room is suddenly 6 inches shorter...that gives you an incredible volume to work with.
Good luck. Keep in mind that any expense may be less than trading in the spouse.
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Cal,
Mine are in a pair of vintage perfect condition Barcelona enclosures. Still have the original surrounds and no signs of decay. I was real surprised when I got those and thought that they would have the same bass speaker as in the A7, but they had these real light, small magnet air suspension speaker that sounded better than an A7 ever would in the low range. Been sitting in the same location is a very large room for 40 years now. I know I could make changes to the cabinets and make them better but I don't want to ruin the originality of them! 511 horn on top.
Mine are in a pair of vintage perfect condition Barcelona enclosures. Still have the original surrounds and no signs of decay. I was real surprised when I got those and thought that they would have the same bass speaker as in the A7, but they had these real light, small magnet air suspension speaker that sounded better than an A7 ever would in the low range. Been sitting in the same location is a very large room for 40 years now. I know I could make changes to the cabinets and make them better but I don't want to ruin the originality of them! 511 horn on top.
The 411 8A -LF is underated. Very low Fs, 4" coil and not that small of a motor. The woofers do weigh over 20 lbs. One of the few Altecs that could reach down low. That's part of the reason they fetch such a pretty penny.
What do you mean by air suspension woofer - half roll surround?
Oh, and I wouldn't change a thing with the cabinets, regardless of their shortcomings. But I think you already know that 😉
What do you mean by air suspension woofer - half roll surround?
Oh, and I wouldn't change a thing with the cabinets, regardless of their shortcomings. But I think you already know that 😉
Cal,
Now you make me want to pull out the driver which I haven't done in over 20 years I think. Yes they had a half roll foam surround and I sure don't remember the speaker weighing over 20 pounds but maybe I have just forgotten? I haven't even taken the grills of in a long time, they are held on with velcro and aren't that easy to pull out. The only thing I should do is oil the wood and leave them alone, they still have the original diaphragms in compression drivers which I think were the symbiotic surround designs at the time.
ps. The Barcelona was a sealed enclosure, no ports.
Now you make me want to pull out the driver which I haven't done in over 20 years I think. Yes they had a half roll foam surround and I sure don't remember the speaker weighing over 20 pounds but maybe I have just forgotten? I haven't even taken the grills of in a long time, they are held on with velcro and aren't that easy to pull out. The only thing I should do is oil the wood and leave them alone, they still have the original diaphragms in compression drivers which I think were the symbiotic surround designs at the time.
ps. The Barcelona was a sealed enclosure, no ports.
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AFAIK, Barcelona came in two types, The biamp and the passive. I believe the woofer remained the same but the tweeter went from the 802 to the 808 or the other way round. The horn stayed the same and I think the XO did too, not quite sure.
Pull the grills and look either side if the horn, tell me what you see 🙂
Pull the grills and look either side if the horn, tell me what you see 🙂
I think I just discovered something. I always thought the openings on either side of the horn were ports.
Old dog, new tricks. 🙂
Old dog, new tricks. 🙂
Cal,
Yes the Barcelona is a sealed enclosure without any ports. There is space around the horn only because the bass cabinet is wider than the horn itself, not ports on any of the models. Mine have the passive not active cabinets. Was Mac powered for a long time, now I have to decide what I am going to power them with. I will have to remove the back cover to look at which compression driver they used. Crossovers are nothing to speak of but I don't want to mess with the originality of them. I otherwise would have changed the capacitors a long time ago. I guess I could make a new set of x-overs and just take the originals out of the loop and put them back if I ever decided to sell the pair. They are rather crude to say the least, have an adjustable high frequency output and that is about it. Time alignment and a better match may help, but the room is definitely not ideal anyway,
Yes the Barcelona is a sealed enclosure without any ports. There is space around the horn only because the bass cabinet is wider than the horn itself, not ports on any of the models. Mine have the passive not active cabinets. Was Mac powered for a long time, now I have to decide what I am going to power them with. I will have to remove the back cover to look at which compression driver they used. Crossovers are nothing to speak of but I don't want to mess with the originality of them. I otherwise would have changed the capacitors a long time ago. I guess I could make a new set of x-overs and just take the originals out of the loop and put them back if I ever decided to sell the pair. They are rather crude to say the least, have an adjustable high frequency output and that is about it. Time alignment and a better match may help, but the room is definitely not ideal anyway,
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