Hi,
More meat to the bone?
You find them lacking in which range?
What crossover do you use and does it involve/ take into consideration bsc?
What ( playback) source do you use? If by chance it involve a computer ( pc or mac) there is way to try to identify what freq correction could be needed.
Bsc: baffle step compensation:
True Audio TechTopics: Diffraction Loss
More meat to the bone?
You find them lacking in which range?
What crossover do you use and does it involve/ take into consideration bsc?
What ( playback) source do you use? If by chance it involve a computer ( pc or mac) there is way to try to identify what freq correction could be needed.
Bsc: baffle step compensation:
True Audio TechTopics: Diffraction Loss
Last edited:
Thank you for your reply.
I guess I want them to sound fuller. And there's something lacking in the midrange. It's kind of thin and the higher freguencies are a bit harsh.
I'm sorry, I'm really not knowledgable about the tech-talk in loudspeakers
Here's an example: when I listen to Agnes Obel her voice is almost OK. But when I listen to Leonard Cohen his voice is very recessed.
At the moment I'm using a streamer into a Quad Vena II. It's a class A/B amplifier. I'm waiting on a tube amp to maybe get more body.
I use a crossover from the shop who also sold me the drivers. I don't know if it takes BSC into account.
I think I may have been in too much of a hurry when I damped the cabinet. So maybe I should do more? And I have added no bracing.
I can use a computer instead of my streamer if that would help me locate the problem?
Kind regards
Mads
I guess I want them to sound fuller. And there's something lacking in the midrange. It's kind of thin and the higher freguencies are a bit harsh.
I'm sorry, I'm really not knowledgable about the tech-talk in loudspeakers
Here's an example: when I listen to Agnes Obel her voice is almost OK. But when I listen to Leonard Cohen his voice is very recessed.
At the moment I'm using a streamer into a Quad Vena II. It's a class A/B amplifier. I'm waiting on a tube amp to maybe get more body.
I use a crossover from the shop who also sold me the drivers. I don't know if it takes BSC into account.
I think I may have been in too much of a hurry when I damped the cabinet. So maybe I should do more? And I have added no bracing.
I can use a computer instead of my streamer if that would help me locate the problem?
Kind regards
Mads
Hi,
Malm, your description and the fact you use a non optimised filter scream no bsc to me.
Being green in a field is a chance as there is things to discover!
If you read the link i gave you'll soon undrrstand the shop who sold you the filter can't have implemented it as... it is box dependent ( box width dependent more accuretly).
So could you give the dimension of your box please? It'll help to determine the frequency at which it ( bsc) happen and then implement a 'counter curve' to bring 'back' some low midrange/low end.
I bet your loudspeakers are in the 50cm width range and from this i can tell everything above 250hz is 'boosted' ( so Leonard Cohen's voice's lack body, but not Agnes Obel...).
A Streamer as source. Ok. I hoped you had a pc as you could have used an eq plug-in to try different eq corrections to evaluate what is needed.
There is way to achieve the same thing though if you can play a digital wav file ( through usb stick?). And if you have headphone you know availlable?
But first the dimension of your box please.
Malm, your description and the fact you use a non optimised filter scream no bsc to me.
Being green in a field is a chance as there is things to discover!
If you read the link i gave you'll soon undrrstand the shop who sold you the filter can't have implemented it as... it is box dependent ( box width dependent more accuretly).
So could you give the dimension of your box please? It'll help to determine the frequency at which it ( bsc) happen and then implement a 'counter curve' to bring 'back' some low midrange/low end.
I bet your loudspeakers are in the 50cm width range and from this i can tell everything above 250hz is 'boosted' ( so Leonard Cohen's voice's lack body, but not Agnes Obel...).
A Streamer as source. Ok. I hoped you had a pc as you could have used an eq plug-in to try different eq corrections to evaluate what is needed.
There is way to achieve the same thing though if you can play a digital wav file ( through usb stick?). And if you have headphone you know availlable?
But first the dimension of your box please.
The non-DIY option
For those who aspire to DIY but that should not be let near any dangerous power tools, and even the soldering iron only under supervision, there are some (relatively) affordable options. The Yorkville Unity U15 is sadly out of production, but in the ~$2000 (pair) range new, it was perhaps the Poor Man's Synergy*. About 2015 I lucked onto a used pair about $700 delivered; crossovers were shot but intended to run them active anyway. After some minor modifications, they are easily the best sounding speakers I've ever owned. I can't say how they compare to true DSL Synergy or good diy efforts but they are good enough for me. The point of this long-winded comment is that buying a used pair might be a good option for the less skilled amongst us. They must still be in demand; I've checked on Ebay and they're > $2000.
*As I understand it, the Synergy is "just" a minor improvement over the Unity (crossover and port differences). Danley used a modified SPL TD-1 (Unity) as his Synergy prototype; it's all there in the official patent.
For those who aspire to DIY but that should not be let near any dangerous power tools, and even the soldering iron only under supervision,
there are some (relatively) affordable options. The Yorkville Unity U15 is sadly out of production, but in the ~$2000 (pair) range new, it was perhaps the Poor Man's Synergy*. About 2015 I lucked onto a used pair about $700 delivered; crossovers were shot but intended to run them active anyway. After some minor modifications, they are easily the best sounding speakers I've ever owned. I can't say how they compare to true DSL Synergy or good diy efforts but they are good enough for me. The point of this long-winded comment is that buying a used pair might be a good option for the less skilled amongst us. They must still be in demand; I've checked on Ebay and they're > $2000.*As I understand it, the Synergy is "just" a minor improvement over the Unity (crossover and port differences). Danley used a modified SPL TD-1 (Unity) as his Synergy prototype; it's all there in the official patent.
A&D deserves attention as not expensive .alternative.HTH AD-Audio Übersichtsliste
Look at 15",12", and 10" coax drivers.
A&D Audio Datenblatt
Look at 15",12", and 10" coax drivers.
A&D Audio Datenblatt
Are they actually available? The 2005 looking website inspires little confidence, as does the lack of published FR and Z curves.
Thank you for all your answers and sorry for the late reply.
Fabricadetabaco: You're right, I'm burning them in still. I think we're getting close to the 50 hour mark of loud playing. Can't say I've noticed a big improvement. But maybe that'll come.
Krivium: The crossover is developed specifically for the driver, also by B&C. I've tried to make the cabinet the same size as Tannoy Arden, but deeper. The dimensions are (WHD) 62, 92, 50.
I wanted to make a kind of Tannoy Arden copy, but with a cheaper driver. I think I might want to develop this speaker a bit.
Is it feasible, maybe even advisable, to add a big 15" or 18" woofer? I'm going to make new cabinets anyway. Maybe as a three-way the coaxial driver will be better off not having to do anything below, say, 200Hz?
Kind regards
Mads
Fabricadetabaco: You're right, I'm burning them in still. I think we're getting close to the 50 hour mark of loud playing. Can't say I've noticed a big improvement. But maybe that'll come.
Krivium: The crossover is developed specifically for the driver, also by B&C. I've tried to make the cabinet the same size as Tannoy Arden, but deeper. The dimensions are (WHD) 62, 92, 50.
I wanted to make a kind of Tannoy Arden copy, but with a cheaper driver. I think I might want to develop this speaker a bit.
Is it feasible, maybe even advisable, to add a big 15" or 18" woofer? I'm going to make new cabinets anyway. Maybe as a three-way the coaxial driver will be better off not having to do anything below, say, 200Hz?
Kind regards
Mads
Hi,
Ok so with 60cm width bsc freq should be located around 190hz ( 193hz).
If you want to try if it does 'fix' the issue you have now i repeat i can help you evaluate this. What do you use as playback source, at least you have a cd player or maybe a computer?
Bringing a dedicated low (sub)woofer will help for sure. It'll limit displacement of the now mid membrane so overall the sound will be cleaner ( less movement of membrane= less distortion ( even more so if it's in a sealed box stuffed) and less modulation of the highs too).
The freq at which you xover should be in the 200/300hz vicinity yes. I've setled on 250hz with my 8" coax, but it could be even higher ( i've choosen 250hz because of center to center distance of drivers/box i use).
With simulation you'll clearly see the gain beforehand.
Ok so with 60cm width bsc freq should be located around 190hz ( 193hz).
If you want to try if it does 'fix' the issue you have now i repeat i can help you evaluate this. What do you use as playback source, at least you have a cd player or maybe a computer?
Bringing a dedicated low (sub)woofer will help for sure. It'll limit displacement of the now mid membrane so overall the sound will be cleaner ( less movement of membrane= less distortion ( even more so if it's in a sealed box stuffed) and less modulation of the highs too).
The freq at which you xover should be in the 200/300hz vicinity yes. I've setled on 250hz with my 8" coax, but it could be even higher ( i've choosen 250hz because of center to center distance of drivers/box i use).
With simulation you'll clearly see the gain beforehand.
I find no 15CXB in the B&C datasheets.
There are neodium magnet models 15HCX76 and 15CXN76 with fs~38, Qt .28 VAS 246 dm
There are ferrite magnet models 15FCX76 and 15FHX65 with FS 40 Qt . 44 an VAS 186 dm
Which do you have? the ferrite models will have a big slug glued to the back, maybe 3 cm thick by 12 cm diameter?
The neodyum models will have a ring of little magnet slugs 2 cm dia 3 cm long? glued to the back of the driver.
The ferrite models are cheaper; I suspect you have those. Better, because the Qt .28 models are unsuited to a sealed box. The Qt .44 models are.
With box 62x92x50 and 2 cm MDF the inside dimension is 58x88x46 or 235 dm. Ratio bv/vas=1.26 qclosedbox=
sqrt(vas/vb+1)*Qt=.59
system resonance=Qcb*Fs or .59*40hz or 23.6 hz This is pretty extreme. The Qcb of .5 bass response curve droops pretty badly.
At least according to David B. Weems Designing Building Testing your Own Speaker System.
So if you have the B&C ferrite driver with Qt .44 VAS 186 dm Fs 40 hz your box is too large. Limit your watts in, large wattage may exceed Xlim or the mechanical damage limit of your driver.
You could fill the bottom of the box with bricks covered by foam, or cut the bottom off, I would recommend lining the walls with foam anyway or 2 cm jute pads which is more traditional. That cuts the volume in a way that reduces internal reflections.
If you want to experiment with frequency contouring, I find analog graphic equalizers about $50 because they are obsolete. If you have a cell phone to program a dsp that is the way to go, but the graphic equalizer has numbers next to the slider controls that tells one directly what he is listening to and want to emulate in a inductor+capacitor crossover at a later date (and more >$$). you put the graphic equalizer between your digital source and the power amp. Use the 30 hz slider of a graphic equalizer turned down, you don't want the driver making huge excursions.
All the above are a lot cheaper than a subwoofer in another box with a separate amplifier appliance. An electronic crossover is then required to separate the lows from the mids+highs, a $50-80 used device. Unless you buy a new 3 channel amp with that feature built in.
A cheap tip for better bass, put your box about 1/3 m from a hard wall like brick, or in an apartment, drywall. Your bass radiates out the back and is lost if you are sitting in front of the speaker box. If you live in an apartment with drywall, I'd put a 2 cm sheet of MDF against the wall behind the speaker to increase reflection. Secure or prob up securely, you don't want that falling on you or any occupant.
I have 2.5 cm thick plaster walls installed in 1936. A beautiful concert hall in an old bungalo. main room is 4.3 m w 11 m long 3.5 m high, perfect shape. I have bookshelves all over the sidewalls to cut standing waves, carpet and acoustic tile ceiling.
Happy listening & maybe adjusting.
There are neodium magnet models 15HCX76 and 15CXN76 with fs~38, Qt .28 VAS 246 dm
There are ferrite magnet models 15FCX76 and 15FHX65 with FS 40 Qt . 44 an VAS 186 dm
Which do you have? the ferrite models will have a big slug glued to the back, maybe 3 cm thick by 12 cm diameter?
The neodyum models will have a ring of little magnet slugs 2 cm dia 3 cm long? glued to the back of the driver.
The ferrite models are cheaper; I suspect you have those. Better, because the Qt .28 models are unsuited to a sealed box. The Qt .44 models are.
With box 62x92x50 and 2 cm MDF the inside dimension is 58x88x46 or 235 dm. Ratio bv/vas=1.26 qclosedbox=
sqrt(vas/vb+1)*Qt=.59
system resonance=Qcb*Fs or .59*40hz or 23.6 hz This is pretty extreme. The Qcb of .5 bass response curve droops pretty badly.
At least according to David B. Weems Designing Building Testing your Own Speaker System.
So if you have the B&C ferrite driver with Qt .44 VAS 186 dm Fs 40 hz your box is too large. Limit your watts in, large wattage may exceed Xlim or the mechanical damage limit of your driver.
You could fill the bottom of the box with bricks covered by foam, or cut the bottom off, I would recommend lining the walls with foam anyway or 2 cm jute pads which is more traditional. That cuts the volume in a way that reduces internal reflections.
If you want to experiment with frequency contouring, I find analog graphic equalizers about $50 because they are obsolete. If you have a cell phone to program a dsp that is the way to go, but the graphic equalizer has numbers next to the slider controls that tells one directly what he is listening to and want to emulate in a inductor+capacitor crossover at a later date (and more >$$). you put the graphic equalizer between your digital source and the power amp. Use the 30 hz slider of a graphic equalizer turned down, you don't want the driver making huge excursions.
All the above are a lot cheaper than a subwoofer in another box with a separate amplifier appliance. An electronic crossover is then required to separate the lows from the mids+highs, a $50-80 used device. Unless you buy a new 3 channel amp with that feature built in.
A cheap tip for better bass, put your box about 1/3 m from a hard wall like brick, or in an apartment, drywall. Your bass radiates out the back and is lost if you are sitting in front of the speaker box. If you live in an apartment with drywall, I'd put a 2 cm sheet of MDF against the wall behind the speaker to increase reflection. Secure or prob up securely, you don't want that falling on you or any occupant.
I have 2.5 cm thick plaster walls installed in 1936. A beautiful concert hall in an old bungalo. main room is 4.3 m w 11 m long 3.5 m high, perfect shape. I have bookshelves all over the sidewalls to cut standing waves, carpet and acoustic tile ceiling.
Happy listening & maybe adjusting.
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Okay B&C 15CXB is old stock. Not in the archives section of their current "all drivers" zip file.
Fs 47 hz, Qt .30 VAS 139.7 dm Rather different than the Ferrite models above. Suitable only for vented cabinet according to Mr. Weems & Eminence.
Mr Weems suggests proper box size Vb=volume factor * Vas. His chart shows volume factor for Qt .3 is .47 or in your case .47*139.7=65.7 dm . About a fourth the size of your 235 dm box. He says you can go a little larger for more bass. As far as resonant frequency for a 65.7 dm box, Mr Weems suggests tuning factor for Qt .3 is 1.2 . Fs*tuning factor is box resonant frequency or 1.2*47 is 78 hz.
You get F3 bass 3db down frequency by multiplying a factor * Fbx. F3 factor for Vbx/Vas .47 is 1.5 so f3 is 117 hz.
Doesn't sound too useful, does it? The new niobium 15's 15CXN76 with a Vas of 246 dm probably gave you better bass in a bigger box.
Mr Weems suggest port size should be 1/7 cone area 830 cm^2 or 118 cm^2 . port diameter is 2*sqrt(118/pi) or 12.6 cm about what I see on commercial 15" woofer speakers I have bought. Mr Weems suggests a port 10 cm diameter can tune a 60 l box dm to 50 hz with a tube 5.3 cm long.
That is about the length of the ports on my SP2(2004) Peaveys.
If I had built a 235 dm box already, I would be tempted to buy a 15" woofer with a VAS more like that. Living 40 miles from the Eminence factory, I am familiar with the Delta-Pro15A with VAS 243.5 dm and Qt .4 . It cost me $259 +7% tax with free freight. It would go either way sealed or vented. Their coax model KL3015CX-8 has Vas 219.7 l Qt .44 (sealed) and was $270 +tax today without the high-frequency driver.
Fs 47 hz, Qt .30 VAS 139.7 dm Rather different than the Ferrite models above. Suitable only for vented cabinet according to Mr. Weems & Eminence.
Mr Weems suggests proper box size Vb=volume factor * Vas. His chart shows volume factor for Qt .3 is .47 or in your case .47*139.7=65.7 dm . About a fourth the size of your 235 dm box. He says you can go a little larger for more bass. As far as resonant frequency for a 65.7 dm box, Mr Weems suggests tuning factor for Qt .3 is 1.2 . Fs*tuning factor is box resonant frequency or 1.2*47 is 78 hz.
You get F3 bass 3db down frequency by multiplying a factor * Fbx. F3 factor for Vbx/Vas .47 is 1.5 so f3 is 117 hz.
Doesn't sound too useful, does it? The new niobium 15's 15CXN76 with a Vas of 246 dm probably gave you better bass in a bigger box.
Mr Weems suggest port size should be 1/7 cone area 830 cm^2 or 118 cm^2 . port diameter is 2*sqrt(118/pi) or 12.6 cm about what I see on commercial 15" woofer speakers I have bought. Mr Weems suggests a port 10 cm diameter can tune a 60 l box dm to 50 hz with a tube 5.3 cm long.
That is about the length of the ports on my SP2(2004) Peaveys.
If I had built a 235 dm box already, I would be tempted to buy a 15" woofer with a VAS more like that. Living 40 miles from the Eminence factory, I am familiar with the Delta-Pro15A with VAS 243.5 dm and Qt .4 . It cost me $259 +7% tax with free freight. It would go either way sealed or vented. Their coax model KL3015CX-8 has Vas 219.7 l Qt .44 (sealed) and was $270 +tax today without the high-frequency driver.
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