After some false starts, I have finally settled on a design and am getting towards something that looks like a speaker.
There are about a million hours of work still to go on this, mainly sanding - the more I sand any curve, the better it looks.
Drivers:
12-SB34NRX75-6 (to be delayed / crossed via mini DSP)
SN4-60F (unless I find something better*)
Ideas that didn't make it:
Taller version with 2 bass drivers**
Similar horn, but asymmetric (oval mouth)
Similar horn, but longer throat section
Inspirations:
Azura / Oris type horns
This thread - http://www.diyaudio.com/forums/full-range/259293-prv-5mr450-ndy-fast-applications.html
hearing some >$20,000 speakers, and being impressed by many aspects - but not by how vocals sounded.
* the Tang Band W5-2143 seems pretty tempting.
** just too heavy and unwieldy. I can console myself with the knowledge that putting the spare drivers in their own enclosures (distributed bass) is a technically better idea.
There are about a million hours of work still to go on this, mainly sanding - the more I sand any curve, the better it looks.
Drivers:
12-SB34NRX75-6 (to be delayed / crossed via mini DSP)
SN4-60F (unless I find something better*)
Ideas that didn't make it:
Taller version with 2 bass drivers**
Similar horn, but asymmetric (oval mouth)
Similar horn, but longer throat section
Inspirations:
Azura / Oris type horns
This thread - http://www.diyaudio.com/forums/full-range/259293-prv-5mr450-ndy-fast-applications.html
hearing some >$20,000 speakers, and being impressed by many aspects - but not by how vocals sounded.
* the Tang Band W5-2143 seems pretty tempting.
** just too heavy and unwieldy. I can console myself with the knowledge that putting the spare drivers in their own enclosures (distributed bass) is a technically better idea.
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Horn FAST in Timber
Very nice looking job. I think the design is great and it should work well too. I would love to see step-by-step construction pictures or at least a description of how you made the horn/waveguide integrated with the front baffle. How do you intend to finish the timber? I am about to embark on a similar project and your design takes care of aligning acoustic centres of the two drivers while providing some extra loading to the fullrange driver. Is the horn/waveguide a simple conical or some other curve?
Are you leaving the back of the FR open as an OB or is it a closed-back driver?
I would be tempted to make the horn part on a lathe, then attach it to the front baffle and then use a roundover bit on a router to match it to the front baffle surface, but then I don't enjoy sanding as much as you ;-)
Any info would be appreciated.
Kind Regards
OZZIOZZI
Very nice looking job. I think the design is great and it should work well too. I would love to see step-by-step construction pictures or at least a description of how you made the horn/waveguide integrated with the front baffle. How do you intend to finish the timber? I am about to embark on a similar project and your design takes care of aligning acoustic centres of the two drivers while providing some extra loading to the fullrange driver. Is the horn/waveguide a simple conical or some other curve?
Are you leaving the back of the FR open as an OB or is it a closed-back driver?
I would be tempted to make the horn part on a lathe, then attach it to the front baffle and then use a roundover bit on a router to match it to the front baffle surface, but then I don't enjoy sanding as much as you ;-)
Any info would be appreciated.
Kind Regards
OZZIOZZI
XRK, if you use sharp lathe tools there is very little need for sanding. I turned a horn for a 60W compression driver that is intended for a 2- or 3-way design. compression driver crosses over around 3kHz., sorry pic is upside down, bl@@dy iPad file management. BTW my horn is approx 6" or 150mm diameter at the mouth. I still need to do some work with filling and sanding of the throat as 19mm plywood tends to pull out grain when turned. I needed plywood to attach driver as it is bolt-on type. Re FAST design, I think up to 12" (30cm) horn mouth is doable on most home lathes, but I am interested in how Hollowboy actually made his horn.
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ozziozzi: look up "SEKIN Serving bowl, birch" and the rest explains itself, I think. Note that Hornresp allows you to calculate the dimensions of petal horns, so you can build something aesthetically similar in any size / angle. The Sekin happened to be almost perfect for a 4" driver, which saved me some time.
I'll put a heavily stuffed tube on the back of the FR (aperiodic). I did this in a more conventional FAST (4" + 2 rear-mounted 6.5") last year, and was pleased with the result.
X: tried it today, unfinished - no back, just draped and stuffed, so like a U-frame open baffle. It gets down to 60Hz, which is surprisingly satisfying. The bass does have an odd quality to it, but overall it is a thoroughly pleasing sound.
Would you mind pointing me to a simple guide to the impulse and other features of REW? I've just messed with the basics (SPL, distortion) so far.
I'll put a heavily stuffed tube on the back of the FR (aperiodic). I did this in a more conventional FAST (4" + 2 rear-mounted 6.5") last year, and was pleased with the result.
X: tried it today, unfinished - no back, just draped and stuffed, so like a U-frame open baffle. It gets down to 60Hz, which is surprisingly satisfying. The bass does have an odd quality to it, but overall it is a thoroughly pleasing sound.
Would you mind pointing me to a simple guide to the impulse and other features of REW? I've just messed with the basics (SPL, distortion) so far.
I have found Sevin serving bowl, but picture doesn't explain how you integrated it to the front baffle. I was thinking of doing something like the Econowave design as I have 2 nice 15" EV 15L and compression drivers, but FAST with OB or horn mid/tweet is a good FR alternative. I have a small collection of 4" fullrange drivers that would work well in your design. BTW have you read reviews of Yamamoto speakers. They have an open back, so essentially U frame sub, but sides are as deep as the front baffle. I read a review which criticised this design because of strange resonances. I have read MJKs H and U frame designs wher he stresses that sides should not be too deep to avoid cavity resonances. That could explain the "odd quality" that you mention. I guess that you plan to put back on boxes, will they be sealed or vented?
I have attached pic of what I had in mind for my horns. It is not too hard to flatten the front of horn and roundover connection to front baffle, but I really liked the way yours seamlessly flowed from horn to baffle. PS Did you attempt to time align the two drivers physically or are you doing that in the miniDSP?
I have attached pic of what I had in mind for my horns. It is not too hard to flatten the front of horn and roundover connection to front baffle, but I really liked the way yours seamlessly flowed from horn to baffle. PS Did you attempt to time align the two drivers physically or are you doing that in the miniDSP?
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How to get a similar baffle / mouth
- make a sandboard by gluing strips to a tabletop or similar
- use that to grind the top of the SEKIN flat
- cut a (slightly smaller) hole in the speaker baffle
- chamfer that hole with a router
- glue the Sekin to the back of the baffle (use lots of glue and weights)
- laminate a 2nd layer of timber to the baffle (offset the joins; use lots of glue / weight / clamps)
- re-do the cutout in this 2nd layer
- finish with file and sandpaper and swearing
This last step is the biggest time-eater for me, because of failures to plan & measure properly, and because I cannot chamfer the entire 19mm thickness of the timber I'm using, with my current equipment.
I'm glad you like how it "seamlessly flowed from horn to baffle". It is not really seamless, as there is a sharp transition in grain orientation between horn and baffle.
With patience, a lathe and other good equipment, you could do better than I have, by making make a petal horn from thick timber, lathing that smooth, then cutting / mounting it as pictured.
"...avoid cavity resonances"
I think the odd bass I heard may be from this, and also because the box sides (19mm timber laminated onto 5mm of high density fibreboard) are as yet unbraced.
"will they be sealed or vented?"
The plan was to simply seal the back, but I'll also experiment with aperiodic. I've only heard a few ported boxes that sounded right.
"Did you attempt to time align the two drivers physically"
Nope: the horn has to be deeper than the woofer, because I wanted the horn to go fairly low. The 4" is therefore about 10cm behind the bass driver.
I'm using the DSP for:
-crossover
-delay
-to attenuate the low end of the 4"
-a notch (4.3kHz)
These could all be achieved with passive components / different design choices, but the DSP makes it all so easy.
"I have a small collection of 4" fullrange drivers that would work well in your design."
Sweet - what have you got? I'd be keen to find something better. They all seem to have their faults.
- make a sandboard by gluing strips to a tabletop or similar
- use that to grind the top of the SEKIN flat
- cut a (slightly smaller) hole in the speaker baffle
- chamfer that hole with a router
- glue the Sekin to the back of the baffle (use lots of glue and weights)
- laminate a 2nd layer of timber to the baffle (offset the joins; use lots of glue / weight / clamps)
- re-do the cutout in this 2nd layer
- finish with file and sandpaper and swearing
This last step is the biggest time-eater for me, because of failures to plan & measure properly, and because I cannot chamfer the entire 19mm thickness of the timber I'm using, with my current equipment.
I'm glad you like how it "seamlessly flowed from horn to baffle". It is not really seamless, as there is a sharp transition in grain orientation between horn and baffle.
With patience, a lathe and other good equipment, you could do better than I have, by making make a petal horn from thick timber, lathing that smooth, then cutting / mounting it as pictured.
"...avoid cavity resonances"
I think the odd bass I heard may be from this, and also because the box sides (19mm timber laminated onto 5mm of high density fibreboard) are as yet unbraced.
"will they be sealed or vented?"
The plan was to simply seal the back, but I'll also experiment with aperiodic. I've only heard a few ported boxes that sounded right.
"Did you attempt to time align the two drivers physically"
Nope: the horn has to be deeper than the woofer, because I wanted the horn to go fairly low. The 4" is therefore about 10cm behind the bass driver.
I'm using the DSP for:
-crossover
-delay
-to attenuate the low end of the 4"
-a notch (4.3kHz)
These could all be achieved with passive components / different design choices, but the DSP makes it all so easy.
"I have a small collection of 4" fullrange drivers that would work well in your design."
Sweet - what have you got? I'd be keen to find something better. They all seem to have their faults.
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Fullrange Drivers
Because you asked for it...THe Fostex FE103 lookalikes are older FosteR fullrange drivers from a short column church PA, probably from the late 60s or early 70s, the Korean drivers are from some cheapo boxes I picked up from a recycling centre for $5/pr and the slightly larger, maybe 5", but smaller cone are from Infinity RS7b. Strictly speaking the last are mid-woofers as some infinity models have just them and the EMIT tweeter in a shoebox size enclosure. BTW I hated the sound of the sealed Infinity RS7s, but kept the 5" and the EMITs. All Infinity drivers are 4 ohm. They needed heaps of power to drive and the bass always sounded congested and light. manufacturer recommends up to 200w amp for the three-way sealed boxes. The XO use a lot of padding resistors on the mid and tweeter.
Sorry, but I could not upload pics from iPad, probably something to do with image size although I tried to crop them. I could resize and reduce quality on computer, but I do not have time now.
You probably know what most of them look like anyway. I suspect the Fosters and the Korean driver are the best candidates for a FAST. I listened to the Korean ones in maybe 3 litre sealed boxes and they sounded very nice down to about 150-200 Hz. Oh BTW I also have some Harmon Kardon 2" extracted from old iMac. They run pretty flat from 200 up and might be nice paired with the Infinity or some 5" 50W bass drivers for a mini-FAST. Desktop system.
I have future plans for most of the drivers apart from the SONYs which are from a stereo R-R recorder, probably early 70s. They have a cult following, but mainly in Japan! I am thinking the Infinitys would make nice transition from sub to horn in a 3-way, while the others would be good for FAST like yours. I moved from Canberra to Brisbane and need to move tools from garage and spare room out to my new workshop before starting speaker building. My main priorities are a compact computer speaker and a large efficient floor stander.
One question: what DSP are you using and where did you get it? My only concern is whether it would work with my iMacs. Does it require a PC program to set up?
BTW My nearest IKEA store is about two hours drive away on the other side of Brisbane.:-(, do they deliver?
Because you asked for it...THe Fostex FE103 lookalikes are older FosteR fullrange drivers from a short column church PA, probably from the late 60s or early 70s, the Korean drivers are from some cheapo boxes I picked up from a recycling centre for $5/pr and the slightly larger, maybe 5", but smaller cone are from Infinity RS7b. Strictly speaking the last are mid-woofers as some infinity models have just them and the EMIT tweeter in a shoebox size enclosure. BTW I hated the sound of the sealed Infinity RS7s, but kept the 5" and the EMITs. All Infinity drivers are 4 ohm. They needed heaps of power to drive and the bass always sounded congested and light. manufacturer recommends up to 200w amp for the three-way sealed boxes. The XO use a lot of padding resistors on the mid and tweeter.
Sorry, but I could not upload pics from iPad, probably something to do with image size although I tried to crop them. I could resize and reduce quality on computer, but I do not have time now.
You probably know what most of them look like anyway. I suspect the Fosters and the Korean driver are the best candidates for a FAST. I listened to the Korean ones in maybe 3 litre sealed boxes and they sounded very nice down to about 150-200 Hz. Oh BTW I also have some Harmon Kardon 2" extracted from old iMac. They run pretty flat from 200 up and might be nice paired with the Infinity or some 5" 50W bass drivers for a mini-FAST. Desktop system.
I have future plans for most of the drivers apart from the SONYs which are from a stereo R-R recorder, probably early 70s. They have a cult following, but mainly in Japan! I am thinking the Infinitys would make nice transition from sub to horn in a 3-way, while the others would be good for FAST like yours. I moved from Canberra to Brisbane and need to move tools from garage and spare room out to my new workshop before starting speaker building. My main priorities are a compact computer speaker and a large efficient floor stander.
One question: what DSP are you using and where did you get it? My only concern is whether it would work with my iMacs. Does it require a PC program to set up?
BTW My nearest IKEA store is about two hours drive away on the other side of Brisbane.:-(, do they deliver?
I'd guess the Foster drivers are what I'd go with. I've tested 10-15 salvage / boombox drivers. Some were quite good, but all were worse in a least one important, measurable way (efficiency, smoothness or extension) than the couple of drivers I tried which cost $50-$80 a unit.
"what DSP are you using and where did you get it?"
mini DSP - I got the basic DSP box and a calibrated mic from the same company for ~$100 each. They are good. They also sell plate amps with the DSP integrated, which I haven't bought - but they seem like good value.
Note: If you're allergic to digital, you could use the DSP just for the bass.
"My only concern is whether it would work with my iMacs. Does it require a PC program to set up?"
I don't recall what it is compatible with, check their website.
Note: once set up, the mini DSP doesn't need to be connected to a computer.
Maybe you could get a 2nd hand Toughbook as dukebox for the workshop + to run any Windows stuff?
- old ones are available ~$300 (they cost $3-7K new)
- rugged vs impact & spills, impervious to dust = good in a workshop
- no iTunes
- generally awesome. Like a tablet, if tablets had ports, better keypads, and were literally bulletproof
"they sounded very nice down to about 150-200 Hz"
If you are just guessing, buy or borrow a mic
"BTW My nearest IKEA store is about two hours drive away on the other side of Brisbane.:-(, do they deliver?"
In Melbourne, nope, not for small stuff.
"what DSP are you using and where did you get it?"
mini DSP - I got the basic DSP box and a calibrated mic from the same company for ~$100 each. They are good. They also sell plate amps with the DSP integrated, which I haven't bought - but they seem like good value.
Note: If you're allergic to digital, you could use the DSP just for the bass.
"My only concern is whether it would work with my iMacs. Does it require a PC program to set up?"
I don't recall what it is compatible with, check their website.
Note: once set up, the mini DSP doesn't need to be connected to a computer.
Maybe you could get a 2nd hand Toughbook as dukebox for the workshop + to run any Windows stuff?
- old ones are available ~$300 (they cost $3-7K new)
- rugged vs impact & spills, impervious to dust = good in a workshop
- no iTunes
- generally awesome. Like a tablet, if tablets had ports, better keypads, and were literally bulletproof
"they sounded very nice down to about 150-200 Hz"
If you are just guessing, buy or borrow a mic
"BTW My nearest IKEA store is about two hours drive away on the other side of Brisbane.:-(, do they deliver?"
In Melbourne, nope, not for small stuff.
MiniDSP?
I think that I will use analog active XO between sub/bass driver at ~ 200 Hz and then passive XO if I need one mid/FR to tweeter. I have Mac measurement software called Fuzzmeasure that should do the job to check overall response. It can also be used to show other parameters like impedance etc, but as long as the speaker sounds OK to me I don't get hung up on graphs. I believe in the KISS principle.
"Buy a Toughbook"
Life is too short to mess around with Windows computers and I already have enough hobbies
:-D
I speak from experience after working with PCs for over 25 years including hardware repairs and software installs/updates, installing larger HDs in old laptops and re-installing software etc. I am not fanatical about Apple products and they have their faults, but their user interface is a delight to use after Windows and software installation is a breeze.
thanks for pointing me at IKEA SEVIN bowls and your techniques for modifying them. One way not to worry about blending in horn is to use a contrasting colour wood, but that's a style choice rather than technical issue.
Cheers
Ian
I think that I will use analog active XO between sub/bass driver at ~ 200 Hz and then passive XO if I need one mid/FR to tweeter. I have Mac measurement software called Fuzzmeasure that should do the job to check overall response. It can also be used to show other parameters like impedance etc, but as long as the speaker sounds OK to me I don't get hung up on graphs. I believe in the KISS principle.
"Buy a Toughbook"
Life is too short to mess around with Windows computers and I already have enough hobbies
:-D
I speak from experience after working with PCs for over 25 years including hardware repairs and software installs/updates, installing larger HDs in old laptops and re-installing software etc. I am not fanatical about Apple products and they have their faults, but their user interface is a delight to use after Windows and software installation is a breeze.
thanks for pointing me at IKEA SEVIN bowls and your techniques for modifying them. One way not to worry about blending in horn is to use a contrasting colour wood, but that's a style choice rather than technical issue.
Cheers
Ian
PC for miniDSP
Hi Hollowboy, I had a mind fade there for a while. Just realised that I CAN run Windows program's on a Mac using Bootcamp. For full Windows functions I would need an emulator and maybe I would need a bit more memory to be able to hot-key swap from OSX to Windows. I imagine that miniDSP controller is not too demanding on resources. I will investigate. Rather than buy another computer I would rather upgrade my Macs, external DAC or other audio gear. I will look into miniDSP when I get the chance. Thanks for the suggestion.
Hi Hollowboy, I had a mind fade there for a while. Just realised that I CAN run Windows program's on a Mac using Bootcamp. For full Windows functions I would need an emulator and maybe I would need a bit more memory to be able to hot-key swap from OSX to Windows. I imagine that miniDSP controller is not too demanding on resources. I will investigate. Rather than buy another computer I would rather upgrade my Macs, external DAC or other audio gear. I will look into miniDSP when I get the chance. Thanks for the suggestion.
Ian, Fuzzmeasure should work well. I have had it since day 1. I used to use it for measuring T/S but have since switched to Smith + Larson Woofer Tester 2. I run that in XP under bootcamp on my MacPro. The UI sucks, but it is probably the best measurer short of the tools the factories use.
At some point i will take the time to switch to Win 7 (i have a copy) in Parallels or VMWare as that would be much more convenient.
dave
PS: AFAIK there is an OS X client for miniDSP.
Dave, thanks for your comments. I haven't used fuzzmeasure for awhile, but I remember it was good for checking overall frequency response just using the inbuilt imac mic and, with a few components, impedance etc. I mainly want it to fine tune levels and XO point sub to FR in FAST system or sub to bass mid with active XO then passive for (super) tweeter if required.
Hollowboy Please excuse me for going OT with a Fuzzmeasure question while Dave is on the line.
Dave
1. If I have a few good quality mics that are not "measurement mics" per se, can I use fuzzmeasure to calibrate what mics I have?
2. I have early version of FM on G4 iMac, a Core2 duo Mac mini as music server. What do you think of the quality of iMac or MacBook AD converters on line in? Is it good enough for ripping vinyl. Not ultimate audiophile quality, just good enough. I have phono preamp, TT and cartridge already.
Ian
Any suggestions or advice would be appreciated.
Hollowboy Please excuse me for going OT with a Fuzzmeasure question while Dave is on the line.
Dave
1. If I have a few good quality mics that are not "measurement mics" per se, can I use fuzzmeasure to calibrate what mics I have?
2. I have early version of FM on G4 iMac, a Core2 duo Mac mini as music server. What do you think of the quality of iMac or MacBook AD converters on line in? Is it good enough for ripping vinyl. Not ultimate audiophile quality, just good enough. I have phono preamp, TT and cartridge already.
Ian
Any suggestions or advice would be appreciated.
No problem going OT. Usually anything > 5 posts has an OT component!
Fuzzmeasure looks sharp and comprehensive.
"MiniDSP?
I think that I will use analog active XO between sub/bass driver at ~ 200 Hz and then passive XO if I need one mid/FR to tweeter."
Have you already got a good analog active XO? I've only ever owned a bad one
I had a basic pro unit*, about 10 years ago. It was 3-way, with adjustable levels and X-points. I stopped using it because it reduced intelligibility.
If you did decide to give a miniDSP a go:
A) you could try using the DSP only for < 200Hz, and different/analogue XO above, e.g. passive line level XO for >200Hz. This would be less $ than the cheapest analogue XO, but have more flexibility (miniDSP lets you add delay, notch out any bass peaks, try different slopes).
B) if you hated the DSP, you could onsell it. If you ordered it now and didn't fancy it, I'd be happy to pay $100 AUD for it. I'm sure I could find a use for another.
"thanks for pointing me at IKEA SEVIN bowls and your techniques for modifying them. One way not to worry about blending in horn is to use a contrasting colour wood, but that's a style choice rather than technical issue."
Spelling (for anyone doing a web search) - the bowl is Sekin with a k
My GF went to IKEA yesterday & I asked her to pick up some more of these. Therefore, if you'd rather pay for postage than do the >2 hour drive to your "local" IKEA, I could mail a pair of them to Brisvegas ($26 for the bowls + whatever postage comes to).
* my analogue XO was this brand, but I don't recall which model. CX-153 - McLELLAND
The unit worked just as you'd expect, it was fun to experiment with ...but the sound was oddly wrong. For quiet speech, it was much harder to understand what was being said, when the signal went through the active crossover.
Fuzzmeasure looks sharp and comprehensive.
"MiniDSP?
I think that I will use analog active XO between sub/bass driver at ~ 200 Hz and then passive XO if I need one mid/FR to tweeter."
Have you already got a good analog active XO? I've only ever owned a bad one
I had a basic pro unit*, about 10 years ago. It was 3-way, with adjustable levels and X-points. I stopped using it because it reduced intelligibility.
If you did decide to give a miniDSP a go:
A) you could try using the DSP only for < 200Hz, and different/analogue XO above, e.g. passive line level XO for >200Hz. This would be less $ than the cheapest analogue XO, but have more flexibility (miniDSP lets you add delay, notch out any bass peaks, try different slopes).
B) if you hated the DSP, you could onsell it. If you ordered it now and didn't fancy it, I'd be happy to pay $100 AUD for it. I'm sure I could find a use for another.
"thanks for pointing me at IKEA SEVIN bowls and your techniques for modifying them. One way not to worry about blending in horn is to use a contrasting colour wood, but that's a style choice rather than technical issue."
Spelling (for anyone doing a web search) - the bowl is Sekin with a k
My GF went to IKEA yesterday & I asked her to pick up some more of these. Therefore, if you'd rather pay for postage than do the >2 hour drive to your "local" IKEA, I could mail a pair of them to Brisvegas ($26 for the bowls + whatever postage comes to).
* my analogue XO was this brand, but I don't recall which model. CX-153 - McLELLAND
The unit worked just as you'd expect, it was fun to experiment with ...but the sound was oddly wrong. For quiet speech, it was much harder to understand what was being said, when the signal went through the active crossover.
Hollowboy, thank you for your kind offers of seKin bowls and offer to buy any DSP I decide to buy. My mis-spelling was a typo as I ffound the bowl on the IKEA site.
Mini-DSP Don't think I will go down that path? I respect Linkwitz designs and similar highly developed electronic solutions, but I don't really want to go that way. I aim for well matched drivers and first-order electrical XO if possible.
The active XO I have has good frequency response and distortion figures eg THD 0.002% AND variable Lo- and hi-pass turnover points from 50-5kHz so I can experiment with asymmetrical XO. This seems to be required by MJK and other experienced people messing with OB FR drivers and subwoofer or bass driver. Once I have established XO points I can investigate other XO options including PLLXO if Active one sounds "oddly wrong". My reference for SQ is a pair of over ear AKG headphones. IF speakers sound as good or better than those I will be happy.
Re: Sekin bowls thanks for you kind offer, but you are talking to a wood turner;-) I can turn up to 300mm diameter wooden bowl / waveguide including hole for driver throat. BTW how do throat and slope of walls of your bowl/waveguide match to the cone of the driver ie: diameter of cone vs diameter of throat? I guess they are basically conical waveguides. The bottom of the IKEA bowl looks flat-bottomed. Are you worried about that? I can achieve a taper to the exact throat diameter needed. Not sure how important that is for a waveguide, but examples I have seen try to make the transition from driver to horn/waveguide as smooth as possible to avoid frequency anomalies or distortion. See example of waveguide for compression driver that I turned. Throat needs to be smoothed as 19mm ply tends to pull out grain from the different layers unless tool is very sharp. Keep up the excellent looking speakers you are building. Let me know how they sound when completed. I think you are heading in the right direction.
Just looked at the specs of your XO, I am surprised that it sounded so oddly wrong. Did it just lose definition or top frequencies? It could have been a mismatch in levels, impedance etc, or something similar. many pro audio components are designed for high level inputs and outputs compared with "domestic" equipment.
Cheers
Ian
Mini-DSP Don't think I will go down that path? I respect Linkwitz designs and similar highly developed electronic solutions, but I don't really want to go that way. I aim for well matched drivers and first-order electrical XO if possible.
The active XO I have has good frequency response and distortion figures eg THD 0.002% AND variable Lo- and hi-pass turnover points from 50-5kHz so I can experiment with asymmetrical XO. This seems to be required by MJK and other experienced people messing with OB FR drivers and subwoofer or bass driver. Once I have established XO points I can investigate other XO options including PLLXO if Active one sounds "oddly wrong". My reference for SQ is a pair of over ear AKG headphones. IF speakers sound as good or better than those I will be happy.
Re: Sekin bowls thanks for you kind offer, but you are talking to a wood turner;-) I can turn up to 300mm diameter wooden bowl / waveguide including hole for driver throat. BTW how do throat and slope of walls of your bowl/waveguide match to the cone of the driver ie: diameter of cone vs diameter of throat? I guess they are basically conical waveguides. The bottom of the IKEA bowl looks flat-bottomed. Are you worried about that? I can achieve a taper to the exact throat diameter needed. Not sure how important that is for a waveguide, but examples I have seen try to make the transition from driver to horn/waveguide as smooth as possible to avoid frequency anomalies or distortion. See example of waveguide for compression driver that I turned. Throat needs to be smoothed as 19mm ply tends to pull out grain from the different layers unless tool is very sharp. Keep up the excellent looking speakers you are building. Let me know how they sound when completed. I think you are heading in the right direction.
Just looked at the specs of your XO, I am surprised that it sounded so oddly wrong. Did it just lose definition or top frequencies? It could have been a mismatch in levels, impedance etc, or something similar. many pro audio components are designed for high level inputs and outputs compared with "domestic" equipment.
Cheers
Ian
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You need at minimum a well calibrated mic to calibrate another. But even a panasonic capsule (or equivalent) is pretty flat 100-near 10k.
I've not used the line-in, but like the line-out DAC you can do better.
You can get reasonably priced semi-pro ADC/DAC units that hook up via USB (or Firewire).
dave
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