You might try the SB19s, the 'stress' issue with a 3/4" dome in a 2-way will not bother with the very steep filters you can implement with DSP. The 19s are as good within their limits as anything, and their off-axis response is great as you move about the room. But don't look down on the 2905s for being 'old'. You love the P13s, and they are no spring chickens design-wise. When the phone is answered at one of our local banks with "Welcome to America's most exciting bank!" I say "that's not good, I want a bank I don't notice, but that doesn't do anything wrong".
At risk of sounding like Steve...
2mL of ferrofluid should go a long way.
I have a little £5 0.5mL syringe which is apparently enough for 5X 19mm tweeters. Like my current ancient SEAS 19TAF/G metal types.
http://www.bluearan.co.uk/index.php?id=SONFF05&browsemode=manufacturer
If level is down by 5db, that does suggest voicecoil rubbing. Or dried out ferrofluid which sets to a thick "Vegemite" or "Marmite" iron oxide gunge after 20 years when the oil or kerosene has evaporated. We all know that ferrofluid wicks heat away to the metal magnet too.
Apparently ferrofluid works wonders in centreing the voicecoil which sits in a relatively narrow magnet gap. There might be some mileage in in trying a 90 or 120 degree different alignment if something is askew.
Did I mention that this type of tweeter in an MTM really appeals to my sense of symettry and dispersion?
That plus an 18dB/octave Butterworth filter, which was Joe D'Appolito's original whizz MTM idea.
Enjoying this project.
2mL of ferrofluid should go a long way.
I have a little £5 0.5mL syringe which is apparently enough for 5X 19mm tweeters. Like my current ancient SEAS 19TAF/G metal types.
http://www.bluearan.co.uk/index.php?id=SONFF05&browsemode=manufacturer
If level is down by 5db, that does suggest voicecoil rubbing. Or dried out ferrofluid which sets to a thick "Vegemite" or "Marmite" iron oxide gunge after 20 years when the oil or kerosene has evaporated. We all know that ferrofluid wicks heat away to the metal magnet too.
Apparently ferrofluid works wonders in centreing the voicecoil which sits in a relatively narrow magnet gap. There might be some mileage in in trying a 90 or 120 degree different alignment if something is askew.
Did I mention that this type of tweeter in an MTM really appeals to my sense of symettry and dispersion?
That plus an 18dB/octave Butterworth filter, which was Joe D'Appolito's original whizz MTM idea.
Enjoying this project.
Now you're onto something, Steve. I reckon if I remove the ferrofluid and substitute Vegemite, they'd be completely flat to 30+KHz
At least playing men at work...
I'm very tempted to try a ribbon, and agree regarding the nice dispersion match between a short ribbon and MTM woofers. I quite like the EMIT ribbons in my infinitys. Getting one to fit without major surgery is another matter.
At least playing men at work...
I'm very tempted to try a ribbon, and agree regarding the nice dispersion match between a short ribbon and MTM woofers. I quite like the EMIT ribbons in my infinitys. Getting one to fit without major surgery is another matter.
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Suzy - just a suggestion but have a quick listen with no ferofluid in the tweeters. I've built quite a few Proac clones which use the Scanspeak D2010 & in my opinion the top end definately improved after the removal of the ferofluid from the tweeters. Troels Gravesen was the one who suggested it.
DIY Loudspeaker Projects Troels Gravesen
The resonance of the tweeter will go up but that should not be a problem with your high slope active crossovers. I just found that once the ferofluid was removed the tweeter seem to open up with more resolution & detail.
Excellent build by the way!
DIY Loudspeaker Projects Troels Gravesen
The resonance of the tweeter will go up but that should not be a problem with your high slope active crossovers. I just found that once the ferofluid was removed the tweeter seem to open up with more resolution & detail.
Excellent build by the way!
Suzy,
Now your "Ariels" are up and running, may I ask how you find them in comparison with Graham's Linkwitz OB Orions that you mentioned hearing a while back?
My reason for asking is the following: I made an OB out of my Spendor BC1s and discovered that there is a whole new world of un-coloured sound without the boxes. The speakers completely disappear and the stereo image takes on new dimensions of clarity and spaciousness. Of course 44 year old speakers have their faults so I was wondering whether a decent TL design with highly rigid case might not achieve similarly uncoloured results. The last recording I was involved in used PMC LB1 TL speakers for monitoring the sound. That brought me to consider the Ariel design. Back to the Ariel??
Now your "Ariels" are up and running, may I ask how you find them in comparison with Graham's Linkwitz OB Orions that you mentioned hearing a while back?
My reason for asking is the following: I made an OB out of my Spendor BC1s and discovered that there is a whole new world of un-coloured sound without the boxes. The speakers completely disappear and the stereo image takes on new dimensions of clarity and spaciousness. Of course 44 year old speakers have their faults so I was wondering whether a decent TL design with highly rigid case might not achieve similarly uncoloured results. The last recording I was involved in used PMC LB1 TL speakers for monitoring the sound. That brought me to consider the Ariel design. Back to the Ariel??
I really can't compare. Graham's Linkwitz sound really fantastic with great imaging and heaps of detail, but the Ariels also have great imaging and heaps of detail. I listened to the Linkwitz speakers for a couple of hours in Grahams garage, while I've listened to the Ariels for much more time in my own lounge room.
They really are diametrically opposed speakers that achieve a similar result.
They really are diametrically opposed speakers that achieve a similar result.
What is the experience by Ariel owners with the P13WH over time? My 4 drivers had an Fs averaging about 68Hz in 1999. Las year the same four drivers measured around 112 Hz. The Qt did not increase by the same ratio since the Rms increased dramatically over the period. This was measured using the same CLIO 4 setup. The surrounds feel pretty stiff. I don't think the drivers are much good anymore except maybe as dedicated midranges.
I've built a prototype active crossover, and put that in on one speaker. Sounds fairly good - tweeter delay will need a little tweaking and tweeter level is a tad high, but showing promise.
So I had the brilliant idea of running one channel through DSP and the other through the opamp crossover. Despite setting the levels carefully it was absolutely awful. Sounded like garbage. I think the DSP introduces heaps of delay. The DSP speaker was like it was coming from the next room.
Currently running the opamp crossover via the DSP with everything bypassed, and it sounds pretty good. Still got the low level DSP mumbles, but otherwise quite reasonable.
So I had the brilliant idea of running one channel through DSP and the other through the opamp crossover. Despite setting the levels carefully it was absolutely awful. Sounded like garbage. I think the DSP introduces heaps of delay. The DSP speaker was like it was coming from the next room.
Currently running the opamp crossover via the DSP with everything bypassed, and it sounds pretty good. Still got the low level DSP mumbles, but otherwise quite reasonable.
A couple of quick plots from the opamp crossover so far. Tweeter gain is close but not quite. Impulse response is good.
I'm getting weird 360 degree jumps in phase from REW, despite choosing "generate minimum phase". I really don't understand this program enough to be confident my phase plots are valid.
Before I get the relative gains dialled in I really need to sort the gains of my amps. I'm using two generations of amps - newer ones with 24dB (x16) gain for the tweeters and one I built about 12 years ago with (I think) 29dB (x28) gain.
I'm getting weird 360 degree jumps in phase from REW, despite choosing "generate minimum phase". I really don't understand this program enough to be confident my phase plots are valid.
Before I get the relative gains dialled in I really need to sort the gains of my amps. I'm using two generations of amps - newer ones with 24dB (x16) gain for the tweeters and one I built about 12 years ago with (I think) 29dB (x28) gain.
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