Sorry, but I didn't see any general agreement over this tweeter. FR is even worst than on the MDT29, and the CAT378 response supposedly includes the effect of its WG.
My bet is on the SB21 which I should get in a few weeks. FR and Fs seem a lot better
The WG is something that will take some time to try on the SBs.
Now that Wavecor looks promising, but it's 110m diameter.
My bet is on the SB21 which I should get in a few weeks. FR and Fs seem a lot better
The WG is something that will take some time to try on the SBs.
Now that Wavecor looks promising, but it's 110m diameter.
Last edited:
I am a man steeped in the traditions of the PERFECT SOUND! This means BBC.
I have my loudspeaker heroes. Troels Gravesen. Joachim Gerhard. Louis Corragio. Steen Duelund. Even Lynn Olson:
http://www.nutshellhifi.com/
My advice to you is to follow Alan Shaw of Harbeth:
Doubtless a Man with his finger on the Pulse.
I have my loudspeaker heroes. Troels Gravesen. Joachim Gerhard. Louis Corragio. Steen Duelund. Even Lynn Olson:
http://www.nutshellhifi.com/
My advice to you is to follow Alan Shaw of Harbeth:
Doubtless a Man with his finger on the Pulse.
I did suggest you post a picture of the crossover and drivers.
I am slightly puzzled why the Morel MDT29 is not working right.
It is an OK tweeter. I have some and used a 3kHz crossover with them.
I wonder if the polarity is wrong. Makes a hole in the response.
I am slightly puzzled why the Morel MDT29 is not working right.
It is an OK tweeter. I have some and used a 3kHz crossover with them.
I wonder if the polarity is wrong. Makes a hole in the response.
Last edited:
It won't be much use to show a picture of the speakers or crossover.
It would be bettern when I measure everything: the speaker, the drivers alone, with each separate crossover and all the stuff.
For that I need a preamp I bought from AE to feed my Sennheiser, AKG and Oktava capacitor mics into my computer, and see which mic works better. Will get here soon, more or less with the SB21.
The problem is the designer, who designed and built the 8" is no longer with us. The only thing I never did and should is take the Morel MDT29 to my friend, so he could measure it. I don't believe it's a polarity issue. In any case that I will also try it when I do my own measurements here.
I believe the original xover crossing was lower than 3KHz. When measuring I will try lowering the series capacitor value to see what happens.
It would be bettern when I measure everything: the speaker, the drivers alone, with each separate crossover and all the stuff.
For that I need a preamp I bought from AE to feed my Sennheiser, AKG and Oktava capacitor mics into my computer, and see which mic works better. Will get here soon, more or less with the SB21.
The problem is the designer, who designed and built the 8" is no longer with us. The only thing I never did and should is take the Morel MDT29 to my friend, so he could measure it. I don't believe it's a polarity issue. In any case that I will also try it when I do my own measurements here.
I believe the original xover crossing was lower than 3KHz. When measuring I will try lowering the series capacitor value to see what happens.
Forgive my curiosity, but which microphones do you plan to use for measuring? The only thing that properly works is a small diaphragm condenser microphone, preferably closed back. You’d need the frequency vs. level correction data also, as these mikes won’t be linear out of the box. In short: any cheap electret like a Behringer ECM8000 will outperform most studio grade microphone for linearity on axis.
You are a stubborn man, carlmart!
I am quite good at crossovers, and don't find 8" bass plus tweeter hard:
https://www.diyaudio.com/community/...r-audio-r300-bookshelf-speakers.203461/page-2
The above works with most well behaved 8" 90dB woofers and most dome 88-90dB tweeters. It's about 3.5kHz.
Easy, Don't even measure, just adjust tweeter for loudness with a resistor.
People have had a good time with that circuit. Quite smooth.
I am quite good at crossovers, and don't find 8" bass plus tweeter hard:
https://www.diyaudio.com/community/...r-audio-r300-bookshelf-speakers.203461/page-2
The above works with most well behaved 8" 90dB woofers and most dome 88-90dB tweeters. It's about 3.5kHz.
Easy, Don't even measure, just adjust tweeter for loudness with a resistor.
People have had a good time with that circuit. Quite smooth.
Fine of you to ask. I just bought an Umik-1. Should get here in about a month from China. From the YouTube of videos I've seen it's microphone of choice for DIY measurements and simulations.
I'm not stubborn: just want to offer the right information for you to comment.
Considering I left out, for now, finding a new 8" that it's up to the quality of the 8" I use now, it's mandatory that I measure this speaker and show the results here. Then we can discuss the matters above.
So let's get into a pause until the mic gets here and I learn how to use it.
Considering I left out, for now, finding a new 8" that it's up to the quality of the 8" I use now, it's mandatory that I measure this speaker and show the results here. Then we can discuss the matters above.
So let's get into a pause until the mic gets here and I learn how to use it.
For the time being I designed the original xover, which you see can't be much simpler. That good the 8" is. You just need a simple low pass filter.
I simulated the MDT29 with two series capacitors: the original 6.8uF, and with 10u". Both Solen. I like the Morel response with the larger cap, so I will replace it tomorrow until the SB tweeter arrives. But with a 900Hz FS for the tweeter I can't go larger than 10uF. It's where the SB21 might improve.
Measuring the 8" driver will have to wait, as well as a confirmation of the inductors values and their series resistance.
I tried to find the SB21 frd and zma specs, but couldn't. Also would like to simulate other 8" drivers if the frd and zma are available.
I don't know how to superpose both speaker curves, so I am enclosing the 6.8u and 10u curves.
I couldn't get the mdt29 impedance right. I don't know why.
I simulated the MDT29 with two series capacitors: the original 6.8uF, and with 10u". Both Solen. I like the Morel response with the larger cap, so I will replace it tomorrow until the SB tweeter arrives. But with a 900Hz FS for the tweeter I can't go larger than 10uF. It's where the SB21 might improve.
Measuring the 8" driver will have to wait, as well as a confirmation of the inductors values and their series resistance.
I tried to find the SB21 frd and zma specs, but couldn't. Also would like to simulate other 8" drivers if the frd and zma are available.
I don't know how to superpose both speaker curves, so I am enclosing the 6.8u and 10u curves.
I couldn't get the mdt29 impedance right. I don't know why.
Attachments
I googled for frd & mza files for recent drivers, but I found almost nothing. Only this old list, with probably all discontinued models.
http://www.rjbaudio.com/Audiofiles/Driver FRD files.html
On one DIYaudio thread it was suggested using FPGraphTracer to draw your own files based on the manufacturer's data, which seems rather laborious. Other than that, I think most people use the frd & mza you get from RMA and other measuring programs, which would be more realistic. Manufacturer measuring conditions are different from actual application.
http://www.rjbaudio.com/Audiofiles/Driver FRD files.html
On one DIYaudio thread it was suggested using FPGraphTracer to draw your own files based on the manufacturer's data, which seems rather laborious. Other than that, I think most people use the frd & mza you get from RMA and other measuring programs, which would be more realistic. Manufacturer measuring conditions are different from actual application.
Typically you'd measure the drivers 'in situ', and unless you're out for practicing the simulation drill, you should wait until you have your own measurements.
As for the UMIK-1: you'll have to use REW and make use of the option to determine the acoustic centers of the units. Otherwise your phase measurements are (way) off. The UMIK doesn't offer the absolute time base like a dual channel measurement does, so there's some training for you too.
A 0,37mH coil for an 8" woofer isn't right in my textbook by the way, unless the driver would stop responding above 2,5kHz by itself. And then you would not need an extra coil. You'd expect values around 2mH there.
As for the UMIK-1: you'll have to use REW and make use of the option to determine the acoustic centers of the units. Otherwise your phase measurements are (way) off. The UMIK doesn't offer the absolute time base like a dual channel measurement does, so there's some training for you too.
A 0,37mH coil for an 8" woofer isn't right in my textbook by the way, unless the driver would stop responding above 2,5kHz by itself. And then you would not need an extra coil. You'd expect values around 2mH there.
Carlmat,
You could try the FAST projct of member XRQ971 with maybe a more versatile 8" than your choice. The8" aluminium has its breakups very far for a metal cone; it has good bass and details, you can choose many 2" to 3" full range with it for instance.
You also can try the more versatile imho NE180W-08 you could use in a MTM with those WG tweeter, TW30A11, CAT378, SEAS DXT, or @augerpro's WGs
a link more for your inspiration : https://ampslab-spk.com/hifi-drivers-2/
I tried Harbett mid driver recessed in the front baffle with a 3" and a 8" below without sucess, break-ups of the 3" with 1.5 cm recesss had too much break-ups.
Nothing wrong to try a System7 philosophy with a 8" and perhaps a Monacor paper cone tweeter. Of course a bit challenging cause 8" directivity and high Fs of such cone tweeters. But they sound musical and non fatiguing to me (had old Jentzen 2 ways like that)
You could try the FAST projct of member XRQ971 with maybe a more versatile 8" than your choice. The8" aluminium has its breakups very far for a metal cone; it has good bass and details, you can choose many 2" to 3" full range with it for instance.
You also can try the more versatile imho NE180W-08 you could use in a MTM with those WG tweeter, TW30A11, CAT378, SEAS DXT, or @augerpro's WGs
a link more for your inspiration : https://ampslab-spk.com/hifi-drivers-2/
I tried Harbett mid driver recessed in the front baffle with a 3" and a 8" below without sucess, break-ups of the 3" with 1.5 cm recesss had too much break-ups.
Nothing wrong to try a System7 philosophy with a 8" and perhaps a Monacor paper cone tweeter. Of course a bit challenging cause 8" directivity and high Fs of such cone tweeters. But they sound musical and non fatiguing to me (had old Jentzen 2 ways like that)
With the bass driver you chose and if you want not to cross it to a little ful range, Pida member used it in one of his well builded projects
https://pkaudio.webnode.cz/lsm-ne/ : he used above the excellent NE128W now NLA alas. It is a 3 ways.
As you see it begs for a non too much highish cut-off... not so made for a 2 Ways with a 3/4 inch tweeter horned or not. Why not an Alpair 4" FR ? Ask @planet10 : XO lower than 400/500 hz. Same philosophy with @xrk971 1 FAST : 8" + 3".
https://pkaudio.webnode.cz/lsm-ne/ : he used above the excellent NE128W now NLA alas. It is a 3 ways.
As you see it begs for a non too much highish cut-off... not so made for a 2 Ways with a 3/4 inch tweeter horned or not. Why not an Alpair 4" FR ? Ask @planet10 : XO lower than 400/500 hz. Same philosophy with @xrk971 1 FAST : 8" + 3".
TBH, I can't see much point in measuring anything. This sort of speaker is quite predictable.
This is a simple circuit that worked for me:
That's a 5kHz tank notch on the woofer. Takes out some breakup and sounds eerily smooth! 3kHz crossover for an 8 ohm tweeter. The 8.2R/2.2uF Zobel is tweeter specific for one that is bright at the top and can be ditched.
The 8.2R at the tweeter input is simple level adjust. I usually tune that by ear. With a 4 ohm tweeter, you can usually just add a 2.2R series resistor to get its impedance up to nearer the 8 ohm range.
This is a simple circuit that worked for me:
That's a 5kHz tank notch on the woofer. Takes out some breakup and sounds eerily smooth! 3kHz crossover for an 8 ohm tweeter. The 8.2R/2.2uF Zobel is tweeter specific for one that is bright at the top and can be ditched.
The 8.2R at the tweeter input is simple level adjust. I usually tune that by ear. With a 4 ohm tweeter, you can usually just add a 2.2R series resistor to get its impedance up to nearer the 8 ohm range.
I'm not thinking of changing this 8" for these speakers, only get a new tweeter that would reach lower.
As I said about this 8" driver:
1) I have to wait for the mic to get here to run an actual FR curve.
2) Yes, it's an exceptional 8" driver that needs very little to work, and I think it does extend 2.5K. But I do have to measure the inductors too. But if the tweeter inductor is alright in the value, then the woofer's is .37mH. I wrote their exact values on the plastic securing the coil. Not the ESR though.
But I was looking around for some 8" that might get close to this driver with a simple crossover and work fine in a closed box.
As I said about this 8" driver:
1) I have to wait for the mic to get here to run an actual FR curve.
2) Yes, it's an exceptional 8" driver that needs very little to work, and I think it does extend 2.5K. But I do have to measure the inductors too. But if the tweeter inductor is alright in the value, then the woofer's is .37mH. I wrote their exact values on the plastic securing the coil. Not the ESR though.
But I was looking around for some 8" that might get close to this driver with a simple crossover and work fine in a closed box.
Last edited: