Decor versus sound quality?
"...... I do still have 15" bass speakers and compression drivers in the house but that is more than rare these days, they are looked at as dinosaurs today by anyone who notices them.[/QUOTE]
I also have 15" bass drivers that are not sub woofers and compression drivers for mid and high, but I have to go to great lengths to placate my significant female other who doesn't have acute hearing or appreciates fine music as I do. I have put my rack gear in a closet and the speakers are built into a chimney. All the wires go under the house or in conduit in the walls. I realize most people can't build their own house around a hi-fi system. You need to take your wife on a tour of a recording studio. She will note that most have 15 inch bass drivers and hi freq compression drivers in their systems and most are built into the ceiling or wall.
I find that most of the female complaints emerge from sloppy wires going all over the floor and conflicts between speaker location and listening position. This is really aggravated by choice of planar electrostatics that beam to only one sweet spot. The physical size attendant of good efficient bass that is undistorted demands a large enclosure. It's just physics. Mine are 10 cubic feet transmission lines each with one 15 inch bass driver. The power amps are very near each speaker under the floor in a utility space with only about 3 feet of speaker cable. All the input cables are balanced from the rack in the closet in wall conduit or under the floor. If the wires are hidden then it's easier to clean the floor.
It seems little thought is placed on the amount of physical space is necessary for a 32 foot standing wave to emerge in a listening space. It's quite a conflict. I don't think it can be miniturized. Like most things there needs to be compromise. GRH
"...... I do still have 15" bass speakers and compression drivers in the house but that is more than rare these days, they are looked at as dinosaurs today by anyone who notices them.[/QUOTE]
I also have 15" bass drivers that are not sub woofers and compression drivers for mid and high, but I have to go to great lengths to placate my significant female other who doesn't have acute hearing or appreciates fine music as I do. I have put my rack gear in a closet and the speakers are built into a chimney. All the wires go under the house or in conduit in the walls. I realize most people can't build their own house around a hi-fi system. You need to take your wife on a tour of a recording studio. She will note that most have 15 inch bass drivers and hi freq compression drivers in their systems and most are built into the ceiling or wall.
I find that most of the female complaints emerge from sloppy wires going all over the floor and conflicts between speaker location and listening position. This is really aggravated by choice of planar electrostatics that beam to only one sweet spot. The physical size attendant of good efficient bass that is undistorted demands a large enclosure. It's just physics. Mine are 10 cubic feet transmission lines each with one 15 inch bass driver. The power amps are very near each speaker under the floor in a utility space with only about 3 feet of speaker cable. All the input cables are balanced from the rack in the closet in wall conduit or under the floor. If the wires are hidden then it's easier to clean the floor.
It seems little thought is placed on the amount of physical space is necessary for a 32 foot standing wave to emerge in a listening space. It's quite a conflict. I don't think it can be miniturized. Like most things there needs to be compromise. GRH
GRH,
The one thing that keeps those large speakers in the house are the fact that they are in very nice looking cabinets, Altec Barcelona's that happen to double as stands for flower arrangements and to hold up some art pieces. But I also am working on some new designs for those who wouldn't think to have a large enclosure or to build in the speakers and do what you have done. Most people don't seem to stay in one house long enough for that or would rather have an on wall or in-wall speaker so they blend in and aren't noticeable.
My ideas follow more of the Apple paradigm and are very modern looking in design so that they are acceptable by both sexes and don't take up much room. Because of this I am limited in driver size and have had to develop very long excursion linear motors and new cone materials to take advantage of that paradigm. I just need plenty of power to drive them to the level that I demand, not willing to settle for mediocre sound just because I can't make the cone area large.
The one thing that keeps those large speakers in the house are the fact that they are in very nice looking cabinets, Altec Barcelona's that happen to double as stands for flower arrangements and to hold up some art pieces. But I also am working on some new designs for those who wouldn't think to have a large enclosure or to build in the speakers and do what you have done. Most people don't seem to stay in one house long enough for that or would rather have an on wall or in-wall speaker so they blend in and aren't noticeable.
My ideas follow more of the Apple paradigm and are very modern looking in design so that they are acceptable by both sexes and don't take up much room. Because of this I am limited in driver size and have had to develop very long excursion linear motors and new cone materials to take advantage of that paradigm. I just need plenty of power to drive them to the level that I demand, not willing to settle for mediocre sound just because I can't make the cone area large.
I agree. I think most quality home speakers these days have efficiency of 83-90 dB SPL at 1 Meter at 2.83V (1W at 8 ohms). Note that, because it is spec'd these days at a voltage, many speakers achieve a higher stated efficiency by having lower impedance than 8 ohms, especially when the minimum impedance frequency is considered. Most of the efficiency issue is concerned with the woofer. It is not difficult usually to have much better efficiency with the midrange and tweeters. It is definitely not unusual to have the impedance dip to 3 ohms in some speakers. Now one is looking at quite a bit more power at the standard 2.83V. Maybe close to 3 watts.
Let's also keep in mind that the spec is at 1 meter; nobody listens at 1 meter; more like 3 meters. This costs you on the order of 10dB in a relatively dead room. Your 85dB speaker now produces 75dB at 3 meters at 3 watts. Unless I am mistaken, things get ugly fast. 95dB at the listaning position now takes 300 watts. But if we want 10dB headroom over that, we are at 3000 watts.
Of course, if things go our way and we are in stereo and the SPLs add rather than sound power, we get maybe a 6dB advantage on the average, which will cut the needed power in each channel by a factor of four. So now maybe we need each channel to produce 750 w into 4 ohms.
I must have made a mistake. I can't believe it is really THAT bad? Where have I gone wrong here. Maybe an average listening level of 95dB at the listening position is really loud. Guess I'll have to get out my trusty old Radio Shack SPL meter.
BTW, all of this makes a really good case for bi-amping or tri-amping with active crossovers.
Cheers,
Bob
Bob,
You are correct that bi-amp is the way to go. With a three way device then Tri-amp may be a good solution but as you said it is easier to get the efficiency up in those devices. The bass section is where the power is needed and required.
An interesting question is the impedance of the device. I have built my prototype speakers with both 4 ohm and 8 ohm voice coils and it was a wash actually. With the small area cone the added mass of the 8ohm voicecoil, wire size remaining the same, gave the same overall efficiency though the wire length basically doubled with the 8 ohm coil. The extra mass just countered the increase in B/L factor and then it is a question of which to choose? Leave the impedance higher for an easier load on the amplifier or use the 4 ohm load and use all the available current that is possible. The lowest impedance that I actually see is about 3.86 ohms and it never drops below this value with a very slight rise as the frequency rises due to the use of a Faraday sleeve in the motor assembly. A conjugate network will keep the impedance flat over the entire range of frequency which is a useable 35hz to 2.5khz on the top before handing off to a dome tweeter.
You are correct that bi-amp is the way to go. With a three way device then Tri-amp may be a good solution but as you said it is easier to get the efficiency up in those devices. The bass section is where the power is needed and required.
An interesting question is the impedance of the device. I have built my prototype speakers with both 4 ohm and 8 ohm voice coils and it was a wash actually. With the small area cone the added mass of the 8ohm voicecoil, wire size remaining the same, gave the same overall efficiency though the wire length basically doubled with the 8 ohm coil. The extra mass just countered the increase in B/L factor and then it is a question of which to choose? Leave the impedance higher for an easier load on the amplifier or use the 4 ohm load and use all the available current that is possible. The lowest impedance that I actually see is about 3.86 ohms and it never drops below this value with a very slight rise as the frequency rises due to the use of a Faraday sleeve in the motor assembly. A conjugate network will keep the impedance flat over the entire range of frequency which is a useable 35hz to 2.5khz on the top before handing off to a dome tweeter.
Hello Bob ,
I maked an excel to help us with the calculation .It calculates the minimum power needed to drive a given SPL speaker to a given distance with a given headroom and by placement.Also it calculates the listener level with a given amplifier,distance,headroom,placement ...etc .
I maked an excel to help us with the calculation .It calculates the minimum power needed to drive a given SPL speaker to a given distance with a given headroom and by placement.Also it calculates the listener level with a given amplifier,distance,headroom,placement ...etc .
Bob, I am not sure about this. In a real room, we have reflections and reverberations. The sound at the listening position is composed of the direct sound from the source and the reverberant sound that is more or less uniformly distributed in the room. Only the direct sound pressure level decreases inversely to distance. Direct sound pressure will equal the reverberant sound pressure at a distance of about 1m. At 3m, reverberant sound definitely dominates (in a 'typical' listening room).
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Hi Guys
95dB as an AVERAGE listening level? You must be deaf already - and if not not now then you will be soon.
I measured my living space with real music of all types. I can't stand to be in the room if it is 90dB at my listening spot. The more usual level is in the mid 70dBs - into the low 80s for louder that can be tolerated for a long period of time. Room gain and the fact of running stereo contribute to a higher effective efficiency for most systems.
I am obviously not in the group of listeners who want "live" levels in my home. Those levels are beyond human scale and unrealistic to try to reproduce., You can certainly get the same sonic experience as most live shows just by putting the volume control to '10' and let everything become unintelligible.
If you want to build high-power amps just for the sake of it then do so. But do not try to justify it as being required by most people in most environments. That reasoning follows in the footprints of maintaining a common ignorance. The public lacks education with respect to SPLs and how to protect their hearing. OSHA has only made tiny steps towards safeguarding the public and workers alike, yet their guidelines are far to permissive to assure true hearing protection. They are constrained by many economic considerations.
It does not actually take a large sub to create low-distortion low bass. My subs go down to 13Hz and are built as a symmetric labyrinth that is in total 4' x 4' x 8" deep. They sit against the wall and load into the corners of the room. The satellites are in front of them - this is what I call a 2.2 system as the satellites are more or less full-range and there are two subs as there should be. Efficiency is 90dB/1W@1m for everything. My clip LEDs calibrated for 1W/ch never light. My listening space is about 20x10'.
Have fun
Kevin O'Connor
95dB as an AVERAGE listening level? You must be deaf already - and if not not now then you will be soon.
I measured my living space with real music of all types. I can't stand to be in the room if it is 90dB at my listening spot. The more usual level is in the mid 70dBs - into the low 80s for louder that can be tolerated for a long period of time. Room gain and the fact of running stereo contribute to a higher effective efficiency for most systems.
I am obviously not in the group of listeners who want "live" levels in my home. Those levels are beyond human scale and unrealistic to try to reproduce., You can certainly get the same sonic experience as most live shows just by putting the volume control to '10' and let everything become unintelligible.
If you want to build high-power amps just for the sake of it then do so. But do not try to justify it as being required by most people in most environments. That reasoning follows in the footprints of maintaining a common ignorance. The public lacks education with respect to SPLs and how to protect their hearing. OSHA has only made tiny steps towards safeguarding the public and workers alike, yet their guidelines are far to permissive to assure true hearing protection. They are constrained by many economic considerations.
It does not actually take a large sub to create low-distortion low bass. My subs go down to 13Hz and are built as a symmetric labyrinth that is in total 4' x 4' x 8" deep. They sit against the wall and load into the corners of the room. The satellites are in front of them - this is what I call a 2.2 system as the satellites are more or less full-range and there are two subs as there should be. Efficiency is 90dB/1W@1m for everything. My clip LEDs calibrated for 1W/ch never light. My listening space is about 20x10'.
Have fun
Kevin O'Connor
Absolutely.
May-i add dome toughs, in connection with women approval ? (I was married too ;-)
Several little subs are better than a big one. It excites less room modes. 3 or 4 of them is a nice solution . Here, we can use little diameters, high power speakers, and power them with class D amps, witch are perfect for the job. Can be hidden in the room.
Now, it is not difficult to build a 2way column for stereo low medium and treble. It can look thin and use all the hight for the volume,( this kind of stuf is stupid) with enough efficiency and beatiful enough for any women can like-it and even consider-it as a part of the room's decoration. Bi amped with CFA amps, or, at least CFA for the mediums-trebles ?
Kindorman, you can consider JMLC horn integrated in the column and use imagination to make a beautiful design. With a high WAF.
With a 1" driver, you can reproduce the 1500 to 20 000Hz range, flat, with impressive levels and dynamic, and real treble, not this kind of "psss psss" soft domes produce, and get the same emissive surface than your cone driver at the cross frequency (important) while avoiding-it from fractioning. And keep the beloved high efficiency (sensitivity ?).
Struth , in order to reproduce nicely a simple piano at realistic level in your living room, you'll need very high level peaks.
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Live levels are necessary, and possible, to get convincing reproduction. With a recent system, on replay of solo piano works, there was a volume setting just 4 clicks down from maximum which correlated - very nicely on most recordings - to the sound level that a real piano would produce when played with matching vigour. So, a softly played note would sound just right, not disappear into background noise.
This volume setting for a modern pop recording would be deafening, the system would go into thermal overload - it's horses for courses ...
Are you are referring to B&W 802s?
AFAIK, they have quite well behaved impedance. Is this something you've experienced personally?
Bob, I've done a lot of this.
In the 'average' modern domestic living room, the 1m anechoic sensitivity is very similar to the spl you'd expect at your listening position in stereo with decorrelated pink noise.
Of course there are large variations due to the actual room and this was UK. Yus Yanks probably have larger and deader rooms too. 🙂
It was measured by Stereophile , hence my comments after looking on the imp phase/mag...
As to speaker sensitivity, i think we need to define what is high/med/low when in discussion, for me high is above 90db/2.83v/m , very sensitive above 94/2.83v/m.
Speakers with high to very high sensitivity tend to have unbalanced dynamics , unless large amount of drivers are used to increase sensitivity. High sensitivity horn speakers suffer alot from this "shout" as well as increased coloration and as some have stated, i do agree there is no substitute for size..
There is some room gain and it differs from room to room, the 6 db drop/doubling is for academic discussion and simplification. Personally i measure at center frequency , instead of using pink noise..
Sorry, a.Wayne, but this makes no sens for me.
The dynamic behavior is affected by the temperature of the coil. Means efficient speakers suffer from less 'compression' as power increase.
And if you are talking about flatness of the response curve, (good) horns can be a lot better than conventional speakers (membrane is more damped).
The bad reputation of horns is due to old bad designed PA horns, with a lot of resonances. My system, using spherical waves wooden horn suffer of no 'Donald Duck' sound, and is very analytic, *transparent*, with no fatigue.
I had a lot of occasions, in my studio, to compare live and recording, and it is quite difficult to make the difference.
I know no conventional speakers able to even approach this.
Try, one day, to listen to some good horn speakers, like JMLC or similar.
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The shout I'm talking about has nothing to do with VC temp and i have heard many horns over the decades , a lot since 1972, big ones , small , even large ones with bass horns, the last one cost a 100k. They have their advantages, especially for PA, i'm not sold on their domestic advantages. Lack of coherency, coloration( all speakers have this, some more offensive and listener tolerance ) and there dynamic shout is very obvious to me ...
I would love to see the Zimp/mag/phase on your speakers could you post up a graph..
I would love to see the Zimp/mag/phase on your speakers could you post up a graph..
Agree with SS AMPS 200-300 @8ohm seem to do the trick , while 50/100watts/ch for tooobs see more than enuff ,
thoughts ..?
Sorry, a.wayne, but this is too far from the subject of this topic.
Just try a translation of this: MHP (la Maison du Haut-Parleur) : concepteur français de kits d'enceintes pour la HI-FI et le Home Cinéma...
Specially the listening impressions: they report the exact opposite of your critics.
Just have a look at this thread: http://www.diyaudio.com/forums/multi-way/140190-jean-michel-lecleach-horns.html: the occasion to change your mind and abandon what i consider as wrong preconceptions ?
BTW, i don't know what can be "dynamic shout". Did-you mean high Q response curve accidents ? My horn is incredibly flat (+-1dB and has a very flat group delay, with a (little) help of my modified DCX2496.
Just try a translation of this: MHP (la Maison du Haut-Parleur) : concepteur français de kits d'enceintes pour la HI-FI et le Home Cinéma...
Specially the listening impressions: they report the exact opposite of your critics.
Just have a look at this thread: http://www.diyaudio.com/forums/multi-way/140190-jean-michel-lecleach-horns.html: the occasion to change your mind and abandon what i consider as wrong preconceptions ?
BTW, i don't know what can be "dynamic shout". Did-you mean high Q response curve accidents ? My horn is incredibly flat (+-1dB and has a very flat group delay, with a (little) help of my modified DCX2496.