True, that's why I looked into the radius backside mount solution. Did you compare the plots on that German site? There is less of a difference in the on axis / off axis plots with the back side mount plus radius compared to the flush mounted driver. The part that needs EQ is the slight boost the horn/waveguide shape gives.
That little 6mm waveguide gives a 3dB boost to the top end. This actually would change the op amp based analog EQ circuit that Bob Richards and I worked on but would not be an issue with the DSP that you plan to use. Ever since I got the miniDSP, I am not sure if I would ever go the analog circuit route anymore. I wonder if the phase changes that the EQ intrduces in the DSP implementation is better or worse than the analog implementation - or is it necessarily the same given the exact two same curves?
Not sure I am competent enough to answer that (yet). That's one of the reasons I am working on two paths. One is with the Behringer DEQ as base, with upgraded analog input section and a proper DAC and the other path is using the PC as EQ from within JRiver Media Player.
That last option can use plugin EQ programs and has the advantage to play with minimum phase parametric EQ and phase linear EQ if the plugin is setup for that.
A plugin like PLParEQ comes to mind as well as other solutions like Audiolense and Acourate.
The advantage of both these solutions compared to the analog EQ circuit Bob and you worked on is the separate left/right EQ available to tailor the in room response (up to a point of coarse).
As no room is the same you would have to have some leverage left to tailor the response to the room. It will never be a one size fits all kind of solution I guess.
That last option can use plugin EQ programs and has the advantage to play with minimum phase parametric EQ and phase linear EQ if the plugin is setup for that.
A plugin like PLParEQ comes to mind as well as other solutions like Audiolense and Acourate.
The advantage of both these solutions compared to the analog EQ circuit Bob and you worked on is the separate left/right EQ available to tailor the in room response (up to a point of coarse).
As no room is the same you would have to have some leverage left to tailor the response to the room. It will never be a one size fits all kind of solution I guess.
The miniDSP has an option for a digital input via a USB to I2C daughter board. I wonder if keeping the signal all digital and applying EQ in digital domain removes the whole phase issue? Seems like it would because the EQ is a simple linear-phase 'chop off the bits' that don't fit prior to the DAC.
I might have to look into the USB-I2C option... hmmm...
I might have to look into the USB-I2C option... hmmm...
That was my understanding as well. However a solution like PLParEQ does provide a phase linear phase EQ solution, right?
I read about that plugin on StigErik's long and impressive thread on his OB setup...
The Behringer solution would be minimum phase, but my PC solution could be either one depending on the processing. Fir filters or a product like PLParEQ etc. do provide that linear phase option or so it seems.
PLParEQ websitePLParEQ website: said:
I read about that plugin on StigErik's long and impressive thread on his OB setup...
The Behringer solution would be minimum phase, but my PC solution could be either one depending on the processing. Fir filters or a product like PLParEQ etc. do provide that linear phase option or so it seems.
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Hi,
Personally going with USB > miniSharc > DAC setup, so as I get more experience I can try out different PEQ, FIR filters etc... Note, USB > miniDSP via I2S, the playback sample rate would be set to that of the DSP unit [48 or 96KHz]... it's recommended to connect the USB boards via S/PDIF to the miniDigi first.
Paul
Personally going with USB > miniSharc > DAC setup, so as I get more experience I can try out different PEQ, FIR filters etc... Note, USB > miniDSP via I2S, the playback sample rate would be set to that of the DSP unit [48 or 96KHz]... it's recommended to connect the USB boards via S/PDIF to the miniDigi first.
Paul
You are assuming that the filters are minimum phase. There's no reason for this to be true (Eg. see Linkwitz's ASP crossover)
There's a whole bunch of discussion on this in the thread over here
Wesayso - thank you for the inspiration, my interest i SLA have peaked!
Estethically speaking LA look extremely nice and apparently they do not lack fidelity... I have spent the better part of this weekend reading myself up on LA and it is starting to sink in
So my idea is similar to yours, vifa TC9's, in a single line array. Undecided about power tapering and such but realise EQ is in order. Probably wont do 25 per side so wont have floor-ceiling coverage but that rely on supply/cost of drivers. Vifa TC9will cost me about 25$ per speaker due to shipping cost and import/VAT rules. (Norway is expensive)...
Main application will be front speakers in my home theatre and the array itself be of same height as the screen (160cm). From what I've read SLA fair well in HT-applications.
My idea of construction in physically similar to yours except I intend to create a XPS-foam &plywood sandwich structure with MDF front baffle. Speakers might be rear mounted and MDF routed to form wave guide. Curved exteriors like you created are simply sexy
Haldor,
Norway
Estethically speaking LA look extremely nice and apparently they do not lack fidelity... I have spent the better part of this weekend reading myself up on LA and it is starting to sink in
So my idea is similar to yours, vifa TC9's, in a single line array. Undecided about power tapering and such but realise EQ is in order. Probably wont do 25 per side so wont have floor-ceiling coverage but that rely on supply/cost of drivers. Vifa TC9will cost me about 25$ per speaker due to shipping cost and import/VAT rules. (Norway is expensive)...
Main application will be front speakers in my home theatre and the array itself be of same height as the screen (160cm). From what I've read SLA fair well in HT-applications.
My idea of construction in physically similar to yours except I intend to create a XPS-foam &plywood sandwich structure with MDF front baffle. Speakers might be rear mounted and MDF routed to form wave guide. Curved exteriors like you created are simply sexy
Haldor,
Norway
Hello Haldor,
Don't give up on the floor to ceiling extension just yet! Couldn't you import from Germany? I did! I wrote to several firms in Germany, the Netherlands and the US to get attractive pricing, you should be able to do better than that price.
A search for Vifa 9bn 119/8 should give more hits, also Peerless FR35/8. Those names are more commonly used in Europe. I bought the Peerless FR35/8 and when I received them they had a sticker on the back reading: TC9FD18-08. Buying them in numbers (50+) should effect pricing as well.
If you do go shorter than ~ 70% of floor-ceiling power tapering should be considered.
Seeing you are building them for HT makes me assume the lower spectrum is going to be separate from the arrays. At least that's what I would do for HT.
Are you going to cover the XPS-foam and ply sandwich? What do you have in mind exactly?
Don't give up on the floor to ceiling extension just yet! Couldn't you import from Germany? I did! I wrote to several firms in Germany, the Netherlands and the US to get attractive pricing, you should be able to do better than that price.
A search for Vifa 9bn 119/8 should give more hits, also Peerless FR35/8. Those names are more commonly used in Europe. I bought the Peerless FR35/8 and when I received them they had a sticker on the back reading: TC9FD18-08
. Buying them in numbers (50+) should effect pricing as well.If you do go shorter than ~ 70% of floor-ceiling power tapering should be considered.
Seeing you are building them for HT makes me assume the lower spectrum is going to be separate from the arrays. At least that's what I would do for HT.
Are you going to cover the XPS-foam and ply sandwich? What do you have in mind exactly?
wesayso - thanks for the reply
I have asked for a quote from Madisound and with shipping and VAT price will equal about 18$ (€12) per speaker - if I go for 50 units. I will source Germany or other EU-sided options aswell to see if I can find them any cheaper over there.
My use will be mainly HT but I properly enjoy listening to music also so they need to fit both uses. The overall ceiling height in my HT is 210cm but I also have a 40cm deep, 20cm high soffit running the full circumference of the room. That mean I have 190cm floor-soffit height available while the room itself is 210. With a 160cm high array I have about 75% coverage, but if I go for 50units adding the extra height is a trivial addition. With 190cm arrays I will achieve 90% coverage = 20 speakers per side.
Pic of the room before it was completed:
(B&W 603's replaced with B&W DM604 which I use today, screen size is 270x160cm and viewing/listening distance is 3-3,2m )
I do intend to add subs to cover the lower spectrum but that will take a while, an DIY array is a lot of work already
As far as the sandwich construction goes I plan on the following sequence, from outside to inside:
Outer finish Laquer or staining / Veneer / XPS / Epoxy & Fiberglass or veneer. Front baffle MDF. The veneer will add a stiff outer surface providing some ding resistance plus texture. I have quite a lot of experience with this construction method from my RC-planes background. The horisontal layer of stained wood on yours look exceptionally great, I would consider something similar for mine if I can source suitable veneer. If horisontal layers are available I will need an extra layer (epoxy & cloth) under the veneer to control vertical stress of the array. Still absorbing as much info about arrays as possible, things might change during this process but as far as I can tell this could work well
I have asked for a quote from Madisound and with shipping and VAT price will equal about 18$ (€12) per speaker - if I go for 50 units. I will source Germany or other EU-sided options aswell to see if I can find them any cheaper over there.
My use will be mainly HT but I properly enjoy listening to music also so they need to fit both uses. The overall ceiling height in my HT is 210cm but I also have a 40cm deep, 20cm high soffit running the full circumference of the room. That mean I have 190cm floor-soffit height available while the room itself is 210. With a 160cm high array I have about 75% coverage, but if I go for 50units adding the extra height is a trivial addition. With 190cm arrays I will achieve 90% coverage = 20 speakers per side.
Pic of the room before it was completed:
(B&W 603's replaced with B&W DM604 which I use today, screen size is 270x160cm and viewing/listening distance is 3-3,2m )
I do intend to add subs to cover the lower spectrum but that will take a while, an DIY array is a lot of work already
As far as the sandwich construction goes I plan on the following sequence, from outside to inside:
Outer finish Laquer or staining / Veneer / XPS / Epoxy & Fiberglass or veneer. Front baffle MDF. The veneer will add a stiff outer surface providing some ding resistance plus texture. I have quite a lot of experience with this construction method from my RC-planes background. The horisontal layer of stained wood on yours look exceptionally great, I would consider something similar for mine if I can source suitable veneer. If horisontal layers are available I will need an extra layer (epoxy & cloth) under the veneer to control vertical stress of the array. Still absorbing as much info about arrays as possible, things might change during this process but as far as I can tell this could work well
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That figure is way better than the first number you put up. Too bad Parts Express has high shipping costs as well. But I'm quite sure you can find some good deals in Germany too. In the end for me, the prices importing from the US and buying in Germany were quite close, all costs included. I opted for Germany to save me some hassle.
I would like to encourage you to build them as large as you can, that option with 20 speakers should work well enough and you could play a bit with the wiring in series parallel to work out the total impedance.
Your construction method is one I had considered too. Too bad I didn't do that. Now I have the troubles with expansion/contraction in my stacks.
I figured the extra weight of my full plywood build would have enough extra benefits to be worth it. But in hindsight I should have added in some stress relieving layers in the construction. I do hope when the time comes to build you'll start a thread about it!
If I may ask, what is the reason of the asymmetrical placed screen? Just wondering if that will influence the left/right reflections you will get that way.
I would like to encourage you to build them as large as you can, that option with 20 speakers should work well enough and you could play a bit with the wiring in series parallel to work out the total impedance.
Your construction method is one I had considered too
. Too bad I didn't do that. Now I have the troubles with expansion/contraction in my stacks.I figured the extra weight of my full plywood build would have enough extra benefits to be worth it. But in hindsight I should have added in some stress relieving layers in the construction. I do hope when the time comes to build you'll start a thread about it!
If I may ask, what is the reason of the asymmetrical placed screen? Just wondering if that will influence the left/right reflections you will get that way.
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The extra cost of adding the few added drivers dont ad up much, +45 units increase the discount aswell. So it apper to me that two arrays with 20 units each is ideal.. How much cabinet volume did you use per driver, I seem to recall 2liters?
Yeah, a real bummer with your array splitting apart Problem with plywood is that we do not have control of the glue/bond between the individual layers that for the plywood sheet. That and wood is alive.. That is the main reason I am thinking composites. Weigth will be lower but i recon the weight will still add up
I had originally intended to place the screen on the short right wall in the photo but that would mean you'd enter the room from behind the viewing seat and my wife veto'ed that option. Flipping the arrangement 180deg would leave me with a max width = 310cm for screen and speakers. So I placed it on the long side and offset. Wall2wall distance is 4 m and width of the room is 5. I havent been bothered with offset reflectiions yet though they are present, I intend to acousticly treat the room in a little while. ( mainly 1st reflection with absorbents and diffuse the rear wall
Yeah, a real bummer with your array splitting apart
Problem with plywood is that we do not have control of the glue/bond between the individual layers that for the plywood sheet. That and wood is alive.. That is the main reason I am thinking composites. Weigth will be lower but i recon the weight will still add up I had originally intended to place the screen on the short right wall in the photo but that would mean you'd enter the room from behind the viewing seat and my wife veto'ed that option. Flipping the arrangement 180deg would leave me with a max width = 310cm for screen and speakers. So I placed it on the long side and offset. Wall2wall distance is 4 m and width of the room is 5. I havent been bothered with offset reflectiions yet though they are present, I intend to acousticly treat the room in a little while. ( mainly 1st reflection with absorbents and diffuse the rear wall
You need those extra drivers to get floor to ceiling coverage of array - that is what makes it all work. It is too short for a 96 in tall ceiling without it. Also needs to be a square number so you can wire series parallel to get nominal 8 ohms. With 20 you can wire to 10 ohms or 5 ohms which may be ok depending on your amp.
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xrk - thanks for your input. I think I wrote poorly on the previous post as I meant the extra cost of the extra few drivers were small and I should just as well go for the full monthy
Main amp is an Emotiva UPA-5 (5x125W 8ohm) which is used to bi-amp the current B&W DM604's. The Emotiva should handle 5ohm well.
However, my gross ceiling height is 83" and the soffits covering the circumferance lower that an additional 8". I could run the arrays all the way up to the soffits but this would still not be considered a full ceiling-floor coverange. Removing the soffit on the screen wall is doable but not desireable, nor is pulling the SLA's 16" out from the wall
The floor-soffit height of 75" would accept 21,7drivers so an even 20 units can be utilized. Should it prove difficult to shoehorn 20units in under these soffits I need to bump each array down to 18.
Still, 45 units will be ordered and the final cost will be $17-18 per unit all included. Madisound deliver by the crate and with 45units per crate.
Main amp is an Emotiva UPA-5 (5x125W 8ohm) which is used to bi-amp the current B&W DM604's. The Emotiva should handle 5ohm well.
However, my gross ceiling height is 83" and the soffits covering the circumferance lower that an additional 8". I could run the arrays all the way up to the soffits but this would still not be considered a full ceiling-floor coverange. Removing the soffit on the screen wall is doable but not desireable, nor is pulling the SLA's 16" out from the wall
The floor-soffit height of 75" would accept 21,7drivers so an even 20 units can be utilized. Should it prove difficult to shoehorn 20units in under these soffits I need to bump each array down to 18.
Still, 45 units will be ordered and the final cost will be $17-18 per unit all included. Madisound deliver by the crate and with 45units per crate.
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You can get those drivers from Strassacker (https://www.lautsprechershop.de/index_hifi_en.htm). their webpages are.. well.. old fashioned, to be polite.
They use different naming, Vifa 9 BN 119/8, 15 euros/each.
They use different naming, Vifa 9 BN 119/8, 15 euros/each.
I appreciate the links & PM - I will check these out for sure 
Madisound US quoted me 120USD for shipment of 45pcs and for that quantity they also give a 15% discount. (25% VAT in Norway)
I plan to wait the final purchase of speaker elements but will start with building the cabinets shortly. Have another quick DIY in progress, my first BTW, which I will need to finish first (Cornu Spirals)
Most of the work will be planning/manufacturing the cabinets and I have 4 Vifa's on the way (should arrive this week) already so I can check dimensions etc for the build - so having them all on hand before building start isnt required. The units are easy accessible so I can wait a little longer.
Madisound US quoted me 120USD for shipment of 45pcs and for that quantity they also give a 15% discount. (25% VAT in Norway)
I plan to wait the final purchase of speaker elements but will start with building the cabinets shortly. Have another quick DIY in progress, my first BTW, which I will need to finish first
(Cornu Spirals)Most of the work will be planning/manufacturing the cabinets and I have 4 Vifa's on the way (should arrive this week) already so I can check dimensions etc for the build - so having them all on hand before building start isnt required. The units are easy accessible so I can wait a little longer.
It's very pretty, complex and interesting...
...would like to see the measured results.
But, I'd likely not build a line source this way.
I prefer a wider baffle face for assorted reasons.
If there was a CNC outfit to chunk out the sections quickly and cheaply, I guess this is a way to go. Hand cut? WHEW! <sweat pouring down> and lots and lots of MDF dust.
Folks, wear really GOOD breathing apparatus when making MDF dust!
As it is currently configured, I think the internal box area is going to have a significant effect on the frequency response, and waterfall... I'd do it differently.
But it's one heck of an effort.
One last thought.
It's floor to ceiling?
How are you going to get it to stand up in the room??
...would like to see the measured results.
But, I'd likely not build a line source this way.
I prefer a wider baffle face for assorted reasons.
If there was a CNC outfit to chunk out the sections quickly and cheaply, I guess this is a way to go. Hand cut? WHEW! <sweat pouring down> and lots and lots of MDF dust.
Folks, wear really GOOD breathing apparatus when making MDF dust!
As it is currently configured, I think the internal box area is going to have a significant effect on the frequency response, and waterfall... I'd do it differently.
But it's one heck of an effort.
One last thought.
It's floor to ceiling?
How are you going to get it to stand up in the room??