Thanks, that's really interesting when you look at it when speakers cross in front whereas I go for crossing behind. The centre listener gets to hear the speakers around 15° off axis in both cases (adjustable of course. Would the Elsinores work crossed in front? Well, I don't mind if is tried. The point about the imaging, crossing behind and sitting in the middle, many are slightly surprised that I have the speakers wider than what they usually do and I also get comments about just how rock steady the centre image is. If you get that, then it augurs well that the overall imaging is going to be right up there. I have been to people's places and suggested changes if they are possible. Go maybe a bit wider, adjust toe-in. Watch for lateral reflections from side walls. Get the room not too live, not too dead. Maybe I should consider the possibility that crossing in front in rooms that have narrow side walls (put absorption [live room] or maybe diffuser [dead room] there). That actually might work for them. So thanks for putting that option into my head.
Thanks Allen for butchering my graphic... actually well done. BTW, my reference to PM by Geddes was not against the rules as I have asked for his permission, not only to refer to it, but he has even allowed me to post it. But that is another topic.
Lynn said disguise? This may need clarifying. One has to assume that EQ has been managed and is deliberate. No amount of EQ can change the directivity. Therefore this issue shouldn't come up, and the only way to address the underlying problem is acoustically, as it can't be done electrically.
You have PM.
May not not have been exact word he used. This was in context of the inductance of the driver. Drivers that look worse are often the better ones. The look worse because of the low inductance, High inductance drivers, not so good, can roll off the response and look flatter and better. But using external inductance is the better solution. I have often said, high internal inductance is bad, high external inductance (within reason) is good.
There is the view that neither is bad and it's all about how you use them. Certainly, looking at a response measurement will tell you little about breakup. You need to look at polars to learn what to do with it.
Since the inductance of the driver affects only its EQ, it has no effect on breakup. Lynn may have been alluding to a compensation effect for those who haven't already applied solutions to the problem.
I thought this discussion seemed familiar, you brought it back for me- posts around 138.
Used to toe in like AllenB's diagram in #5880, regardless of the speaker's directivity.
10 years later and deafer, I toe them in to the center of the couch and sit there
Art
It's not a question of cone breakup. Inductance may make things look better, but in fact is worse. Contact Lyn directly and ask him yourself. One 100% clarity as to what was meant.
Been awhile since chiming on this massive thread. I built a pair of MFC Elsinores back a few years ago, which I have enjoyed (and impressed others) using a number of tube amplifiers that I have built (KT66 Williamsons, KT88/6550 Williamsons, EL34 Eico HF-60 clone, and most recently, a 25W 211 Class A2 SET amp of my own design that is a perfect match for the Elsinores by all who have heard the combination. Anyway, the Elsinores have had a little competition recently from a pair of Nestorovics 5AS MkV I picked up from a friend who was upgrading to a pair of Tidal Contriva speakers. So have been listening to both, but keep coming back to the Elsinores for a more holistic and emotionally involving sound over the more detailed, revealing and slightly larger presentation of the Nesties (uses dome midrange and ribbon tweeters). The Nesties are definitely a more difficult load, and really want to see a bigger amp (the KT88 Williamson works fine, but not the others). Sometimes it is nice to have a tool that lets you hear everything in your system, but other times you just want to sit back and enjoy the music.
Anyway, I decided to take the leap on constructing a pair of the “ULD” Elsinores, since from what I have been reading, I believe these will be a discernable improvement in the areas where the Nesties prevail, but still retain what I really like about Elsinores, including the ability to be driven by all of my amplifiers In use. I already ordered the Purify drivers, tweeters and waveguides, and starting to plan the new build. I am taking a no compromise approach on the build, using higher grade cabinet materials (I regretably used low grade MDF from Home Depot in my original build).
So to my real reason for posting. I am trying to understand what equivalent acoustic insulation to use that is available in the US. On my first build, I used higher density Dacron batting used for cushions, but have no Idea what is the equivalent to the recommended R3.0 or R3.5 Polyester insulation batting available in Australia but unfortunately not in the US (probably a fire code thing). Most of the acoustic poly damping available for speaker building is loose fill, and not sheet batting. So a question for all the US builders on what you have found works best.
Sorry for the long post. I am excited to be building again though, and already have someone wanting my “MFC” Elsinores when I am done with the new build.
David McGown
Anyway, I decided to take the leap on constructing a pair of the “ULD” Elsinores, since from what I have been reading, I believe these will be a discernable improvement in the areas where the Nesties prevail, but still retain what I really like about Elsinores, including the ability to be driven by all of my amplifiers In use. I already ordered the Purify drivers, tweeters and waveguides, and starting to plan the new build. I am taking a no compromise approach on the build, using higher grade cabinet materials (I regretably used low grade MDF from Home Depot in my original build).
So to my real reason for posting. I am trying to understand what equivalent acoustic insulation to use that is available in the US. On my first build, I used higher density Dacron batting used for cushions, but have no Idea what is the equivalent to the recommended R3.0 or R3.5 Polyester insulation batting available in Australia but unfortunately not in the US (probably a fire code thing). Most of the acoustic poly damping available for speaker building is loose fill, and not sheet batting. So a question for all the US builders on what you have found works best.
Sorry for the long post. I am excited to be building again though, and already have someone wanting my “MFC” Elsinores when I am done with the new build.
David McGown
Hi David
I shall try to get some volume/weight/density figures to you shortly. I think I may or may not have posted them earlier?
With my own system improvements lately, I have come to appreciate the ULD version more. But it does need the best source and amp to show it's better than the MFC version, which is really still the way to go for most people. The cost difference is not justified otherwise.
Get back to you re poly fill.
I shall try to get some volume/weight/density figures to you shortly. I think I may or may not have posted them earlier?
With my own system improvements lately, I have come to appreciate the ULD version more. But it does need the best source and amp to show it's better than the MFC version, which is really still the way to go for most people. The cost difference is not justified otherwise.
Get back to you re poly fill.
David, Joe,
Something like this will work? This is wool and polyester mix and in the form of "batting".
https://www.amazon.com/Quilters-Dream-Batting-108in-Queen/dp/B00FFFR7E2
Dacron batting:
https://www.amazon.com/BayTrim-Densified-Bonded-Upholstery-Batting/dp/B0C9RNW66Q?th=1
Something like this will work? This is wool and polyester mix and in the form of "batting".
https://www.amazon.com/Quilters-Dream-Batting-108in-Queen/dp/B00FFFR7E2
Dacron batting:
https://www.amazon.com/BayTrim-Densified-Bonded-Upholstery-Batting/dp/B0C9RNW66Q?th=1
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I'd defer to Joe's fill recommendations, but I've usually used unfaced fiberglass batts, using string to staple it in place away from speaker cones.
Wear a mask and gloves.
After finding out that 1" fiberglass (hard to find anywhere now) has an R value of about 3.5, learned that there is a huge difference between U.S.A and metric R values - common R-19 insulation, about 6.5" thick is ~equal to metric R3.5 (about 175mm).
Priceline, Australia's Biggest Online Insulation Store:
Dropped to 64 degrees in the office, time to get under some insulation...
Art
Attachments
I have a piece here that occupies about 20 Litres in space and weighs a little bit under 300gr. It is 42cm x 27cm and being R3.5 is 18cm thick = 20 Litres of volume.
So the density per Litre is around 15gr. So this is not high density.
Yes, the polyester bats I have here is R.3.5 and is about 180m thick.
So the density per Litre is around 15gr. So this is not high density.
Yes, the polyester bats I have here is R.3.5 and is about 180m thick.
Joe,
The weight and dimensions of the polyester batting you measured is extremely helpful. It is a bit confusing when comparing with the density standard for upholstery and quilting batting, which is based on the weight (in oz.) per square foot (929 cm^2), not volume. But the thickness (loft) is specified along with the weight, so one can get an idea of the actual density in comparison. A standard loft dimension, for instance, is 1 inch (2.5cm).
For the benefit of the metrically challenged, 1 Liter = 61 cu in., which equates (given a 1" thickness) to 0.424 sq ft.
15 grams = 0.53 oz.
Therefore, the equivalent density is 0.53/0.424 = 1.25 oz./sq ft.
Standard density 1" thick Dacron upholstery batting is 1 oz. Extra dense 1" thick is 1.5 oz. So falling right in between, but using a little more (compressing) the 1 oz would work, although suspect either would do. The "Densified" Bonded Dacron that Zman points to on Amazon (3oz/1.75 in) ends up being maybe too dense, 1.7 oz per 1" loft in comparison. I think I used the extra dense (1.5 oz) batting in my original build, so it looks like is was not too off the mark.
So this really clears up the uncertainty I had.
I was thinking of weltersys suggestion of using 1" fiberglass. I wonder if wrapping the fiberglass with a thin layer of quilt batting might help in keeping the glass fibers contained.
Again, thanks to all.
David
The weight and dimensions of the polyester batting you measured is extremely helpful. It is a bit confusing when comparing with the density standard for upholstery and quilting batting, which is based on the weight (in oz.) per square foot (929 cm^2), not volume. But the thickness (loft) is specified along with the weight, so one can get an idea of the actual density in comparison. A standard loft dimension, for instance, is 1 inch (2.5cm).
For the benefit of the metrically challenged, 1 Liter = 61 cu in., which equates (given a 1" thickness) to 0.424 sq ft.
15 grams = 0.53 oz.
Therefore, the equivalent density is 0.53/0.424 = 1.25 oz./sq ft.
Standard density 1" thick Dacron upholstery batting is 1 oz. Extra dense 1" thick is 1.5 oz. So falling right in between, but using a little more (compressing) the 1 oz would work, although suspect either would do. The "Densified" Bonded Dacron that Zman points to on Amazon (3oz/1.75 in) ends up being maybe too dense, 1.7 oz per 1" loft in comparison. I think I used the extra dense (1.5 oz) batting in my original build, so it looks like is was not too off the mark.
So this really clears up the uncertainty I had.
I was thinking of weltersys suggestion of using 1" fiberglass. I wonder if wrapping the fiberglass with a thin layer of quilt batting might help in keeping the glass fibers contained.
Again, thanks to all.
David
Here's a link for a 1.25 ounce Dacron batting item:
https://www.amazon.com/FoamFit-Polyester-1-25-Ounce-Upholstery/dp/B09KWNWBTT
https://www.amazon.com/FoamFit-Polyester-1-25-Ounce-Upholstery/dp/B09KWNWBTT
I didn't suggest using 1" fiberglass, I wrote R-19 insulation (common in the USA), about 6.5" thick is ~equal to metric R3.5 (about 175mm).
Never noticed a problem with fiberglass containment when using string to staple it in place.
If the fiberglass was escaping, would have seen residue in bass reflex ports, which back in the bad old days before using high pass filters would often blow like a fan
.That said, I've used loose scraps of fiberglass batting covered with cotton T-shirt material in some small cabinets.
Sorry for my misunderstanding about using 1" fiberglass. Good to know about the equivalence of metric R3.5 to US R-19. I would rather not bother with trying to cut up R-19 into the sizes needed for the Elsinore enclosure, it seems to me it would be a real mess to do. Dacron batting, is much safer to work with.
weltersys:
Well, I'm left a little curious: on his website, Joe recommends 1" and 3" thicknesses of low density damping material (and specifically recommends Bradford polymax, which seems to be unavailable in my corner of the world). If one were to use R-19 insulation, would it be necessary to cut the material into 3" thick sheets, or is the R-19 insulation (as is) roughly equivalent to 3" of low density damping material?
As an aside, it's interesting how difficult finding suitable damping material has become in the past few years. I used 2" UltraTouch, manufactured from recycled denim (sourced from Home Depot) and 1" Dacron batting (sourced from Meniscus Audio, now sadly out of business) in my Elsinore project 5.5 years ago, and those materials (and many alternatives) were inexpensive and readily available.
Regards,
Scott
Well, I'm left a little curious: on his website, Joe recommends 1" and 3" thicknesses of low density damping material (and specifically recommends Bradford polymax, which seems to be unavailable in my corner of the world). If one were to use R-19 insulation, would it be necessary to cut the material into 3" thick sheets, or is the R-19 insulation (as is) roughly equivalent to 3" of low density damping material?
As an aside, it's interesting how difficult finding suitable damping material has become in the past few years. I used 2" UltraTouch, manufactured from recycled denim (sourced from Home Depot) and 1" Dacron batting (sourced from Meniscus Audio, now sadly out of business) in my Elsinore project 5.5 years ago, and those materials (and many alternatives) were inexpensive and readily available.
Regards,
Scott
Over time I have increased the suggested fill percentage of the box somewhat by going from R3 to R3.5 and I have a steady supply R3.5. This means around 8-10L more fill. It is not a dramatic change and if you have 45L of fill versus 53L of fill, I would not fret. What if you could only get R3 (or equivalent), then by all means use it. So my preference has graduated to a slighter higher fill. But of course, this is based on Polymax being around 14-15g per Litre density. So that needs to be kept in mind to. I calculate the total fill in the last box that I did was around 750 gram per box, that is 3/4Kg and two boxes 1.5Kg is needed. So be guided by that as well.
This is a good thing to be talking about, it is slightly tricky, but if you have made Elsinores in the past, please realise that this is not an exact science. Not in this instance. Normal vented box has a QL rating that is typically around 7 for a lined box (3-15 is a normal rage, the lower means more damping). We have some that is more filled than lined and a QL that is somewhere lower that 3 and maybe around 2 (high box damping). If we can get that down into that ballpark figure, you will get the kind of bass that I have in mind. It will work. So I don't want anybody to be too nervous about it.
I know Allen is reading this, maybe he can add any comments/wise words about the QL of a vented/ported box? All I know is what kind of bass I am getting doing what I am doing. I get a bass that sounds less vented and something I hear in transmission line speakers. I hear the bass coming out of the box in a more natural way. I have some theories about why, but I will leave that for another time.
This is a good thing to be talking about, it is slightly tricky, but if you have made Elsinores in the past, please realise that this is not an exact science. Not in this instance. Normal vented box has a QL rating that is typically around 7 for a lined box (3-15 is a normal rage, the lower means more damping). We have some that is more filled than lined and a QL that is somewhere lower that 3 and maybe around 2 (high box damping). If we can get that down into that ballpark figure, you will get the kind of bass that I have in mind. It will work. So I don't want anybody to be too nervous about it.
I know Allen is reading this, maybe he can add any comments/wise words about the QL of a vented/ported box? All I know is what kind of bass I am getting doing what I am doing. I get a bass that sounds less vented and something I hear in transmission line speakers. I hear the bass coming out of the box in a more natural way. I have some theories about why, but I will leave that for another time.
The uncertainty is justified in my opinion. A vented enclosure is best tuned by looking at the impedance. Centring the dip, seeing the peaks are where they should be, seeing they're at the right heights.
It's not as though you can't live with some variations, but mistuning what you have can sometimes be problematic. You'll get peace of mind.
Perhaps Joe could share a reasonable impedance example.. uncompensated of course
It's not as though you can't live with some variations, but mistuning what you have can sometimes be problematic. You'll get peace of mind.
Perhaps Joe could share a reasonable impedance example.. uncompensated of course
I could do that, give me a little time and I can show the before and after in SoundEasy, which on the electrical is much more precise than on the acoustic side. The modeled result and final measured result has never failed to be the same - so I will use that as suitable and it will show the 'hidden' Fb box tuning.