http://www.e44.com/leskits/audax_home170.html
This is a French site where they use the TM025F1 in three different designs. You can download a .pdf with "Telecharger le plan". They use a different woofer.
This is a French site where they use the TM025F1 in three different designs. You can download a .pdf with "Telecharger le plan". They use a different woofer.
Crossover for the AP100Z0 and the TM025F1
I don't have a web page made up for this yet so I'll just post what junk I have here. I'm not even sure if I'll make a web page for this project, so if you really want this info, save it. This is just one of several small designs that use this enclosure. I swap the baffles out for different projects.
Here's the parts list. All parts are from Madisound, $USD. For those across the pond, convert prices and/or find a local vendor.
L0 1.5 mH Sledgehammer steel laminate (.14ohm) $7.00
C2 5.6 uF Bennic metalized poly $2.25
L3 0.3 mH 19ga air core (.3ohm) $1.90
C6 2.2 uF Bennic metalized poly $1.10
L7 0.55 mH 19ga air core (.37ohm) $2.20
C9 4.7 uF Bennic metalized poly $2.05
R10 25ohm 10 watt Eagle metal oxide film $1.00
C11 1.0 uF Bennic metalized poly $0.65
C12 8ohm 10 watt Eagle metal oxide film $1.00
It's important that L0 be a low DCR coil so as to not kill an already inefficient speaker even further. For the other two, the DCR is a bit more flexible. I hooked these up and listened for a while last night. (had to parallel some caps and unwind some coils to get the values I needed) Sounds great so far.
Raw response in box, no crossover
Crossover schematic, with modeled response
Actual measured response
Cumulative spectrum decay
Box dimensions
Picture - front
Picture - back
Picture - closeup
I'll post more details on my web site if I decide to post this design. Once again, I'll say this tweeter will not work well with a 2nd order electrical crossover. The designs at the French web site that Rudibe posted will result in a response curve that fatigues after a few minutes of listening. The design's got the famous Joe D'Appolito's name all over it, but there's no nice way to say that the design is terrible. This Design does well with it, paired with a Vifa woofer. I think there was an Adire kit (281 or something) that did ok too.
Overall I like the woofer. The tweeter is only worth it if you get it for half price or less.
I don't have a web page made up for this yet so I'll just post what junk I have here. I'm not even sure if I'll make a web page for this project, so if you really want this info, save it. This is just one of several small designs that use this enclosure. I swap the baffles out for different projects.
Here's the parts list. All parts are from Madisound, $USD. For those across the pond, convert prices and/or find a local vendor.
L0 1.5 mH Sledgehammer steel laminate (.14ohm) $7.00
C2 5.6 uF Bennic metalized poly $2.25
L3 0.3 mH 19ga air core (.3ohm) $1.90
C6 2.2 uF Bennic metalized poly $1.10
L7 0.55 mH 19ga air core (.37ohm) $2.20
C9 4.7 uF Bennic metalized poly $2.05
R10 25ohm 10 watt Eagle metal oxide film $1.00
C11 1.0 uF Bennic metalized poly $0.65
C12 8ohm 10 watt Eagle metal oxide film $1.00
It's important that L0 be a low DCR coil so as to not kill an already inefficient speaker even further. For the other two, the DCR is a bit more flexible. I hooked these up and listened for a while last night. (had to parallel some caps and unwind some coils to get the values I needed) Sounds great so far.
Raw response in box, no crossover
Crossover schematic, with modeled response
Actual measured response
Cumulative spectrum decay
Box dimensions
Picture - front
Picture - back
Picture - closeup
I'll post more details on my web site if I decide to post this design. Once again, I'll say this tweeter will not work well with a 2nd order electrical crossover. The designs at the French web site that Rudibe posted will result in a response curve that fatigues after a few minutes of listening. The design's got the famous Joe D'Appolito's name all over it, but there's no nice way to say that the design is terrible. This Design does well with it, paired with a Vifa woofer. I think there was an Adire kit (281 or something) that did ok too.
Overall I like the woofer. The tweeter is only worth it if you get it for half price or less.
Zaph
thanks for the info, Do you think any changes would be required to the crossover to allow for a different enclosure design?
I like the look of your speakers, very nice.....
You are right about the crossover design on the link above , they are the same as the Madisound design for the AV project they feature...
m
ps I wish our (UK) crossover components where available at comparable prices!
If I copy your design, this crossover will be the most expensive part of any speaker design i have ever built!
thanks for the info, Do you think any changes would be required to the crossover to allow for a different enclosure design?
I like the look of your speakers, very nice.....
You are right about the crossover design on the link above , they are the same as the Madisound design for the AV project they feature...
m
ps I wish our (UK) crossover components where available at comparable prices!
If I copy your design, this crossover will be the most expensive part of any speaker design i have ever built!
D1GGY said:
As long as the width of the enclosure is pretty close, there should to much variation in the resulting response curve. This design has full baffle step compensation built into it.
nubbins said:
I get mine from wilmslow audio, www.wilmslow-audio.com.
After having just completed my DAC (posted in the Digi forum) im now free to do the audax storm in a box. I was at B&Q yesterday with me ma to get something for the shower and I went to get some MDF but they didnt have any in the size I wanted 🙁 So I guess Ill have to wait a lil bit. The local B&Q sells it but its much more expensive? I dont understand that. Those boxes Zaph look great. Nice work.
As this thread is active again, I hope it's ok to post this here…
Just recently, I rescued the crossovers from an old pair of Musical Fidelity Reference 2's - I remember these being quite good in their day. This lead me to think about testing my F1's that have been sat in my office drawer along with my AP100Z0's.
Using some storage cartons rescued from the skip, I made a quick mock-up (see the attachment). While these suffered from a few rattles, etc, they actually sounded very promising. I had to add a couple of resistors to bring down the level of the tweeters, but that's the only attempt so far to optimise the crossovers. The midrange and stereo imaging was particularly captivating...
This led me to thinking about proper enclosures. I downloaded WinISD, and started playing with enclosure design. I've only really done this by hand before, although I've played a bit with PerfBox (DOS), so it's nice to be able to experiment with ideas quickly…
But re-reading this thread, I found wildly varying TS parameters for the Z0. So I decided that I needed to make my own measurements (TNF). For the first time in about 6 months, I actually had some spare time at the weekend to devote to audio, so I made some measurements, and built a box suitable for measuring VAS…
Just recently, I rescued the crossovers from an old pair of Musical Fidelity Reference 2's - I remember these being quite good in their day. This lead me to think about testing my F1's that have been sat in my office drawer along with my AP100Z0's.
Using some storage cartons rescued from the skip, I made a quick mock-up (see the attachment). While these suffered from a few rattles, etc, they actually sounded very promising. I had to add a couple of resistors to bring down the level of the tweeters, but that's the only attempt so far to optimise the crossovers. The midrange and stereo imaging was particularly captivating...
This led me to thinking about proper enclosures. I downloaded WinISD, and started playing with enclosure design. I've only really done this by hand before, although I've played a bit with PerfBox (DOS), so it's nice to be able to experiment with ideas quickly…
But re-reading this thread, I found wildly varying TS parameters for the Z0. So I decided that I needed to make my own measurements (TNF). For the first time in about 6 months, I actually had some spare time at the weekend to devote to audio, so I made some measurements, and built a box suitable for measuring VAS…
Attachments
LCR caps are great for tweeters. They are physically large though, and 'mid'-priced. These come from Maplin.
Audiocom (www.audiocom-uk.com) sell good stuff, but they're expensive. Might be required if you want MOX or better resistors, and good air-cored inductors.
I wouldn't use the MKP type of caps on a tweeter, unless it's strictly a budget project. They sound crap compared to Maplin/LCR ones. The LCR are similar to ICW [Clarity] caps AFAIK.
Audiocom (www.audiocom-uk.com) sell good stuff, but they're expensive. Might be required if you want MOX or better resistors, and good air-cored inductors.
I wouldn't use the MKP type of caps on a tweeter, unless it's strictly a budget project. They sound crap compared to Maplin/LCR ones. The LCR are similar to ICW [Clarity] caps AFAIK.
Normally when I make anything from MDF, it's horrible. Not that this mattered for this application. But, the first box turned out so well that I just had to make another 😉 I spent a bit more time on the second, and it was even better. I bought a power-plane a few months ago to do some jobs on the house, and it works really well on MDF…
Onto the results: I only took 2 speakers home to measure, and they had not been used at all yet. But, despite no run-in time, the results aren't too bad:
#0 FS: 64.0 - VAS: 4.72 - Qms: 2.16 - Qes: 0.63 - Qts: 0.49
#1 FS: 66.9 - VAS: 3.46 - Qms: 1.65 - Qes: 0.67 - Qts: 0.47
#2 FS: 65.6 - VAS: 3.56 - Qms: 1.78 - Qes: 0.74 - Qts: 0.52
(#0 is Audax's spec's)
I suspect that VAS is a bit out because I didn't include the volume of air taken by the cone. The individual Q values vary a bit, but the total Qts isn't bad. These results were made using good "old fashioned" manual measurements, and I used the spreadsheet you can download from here http://www.diysubwoofers.org/measure.htm to make things a little easier. So how are you all measuring them? I've seen FS results as high as 90Hz, which is worrying!
Anyway, here's a picture of one of the prototypes, made from scraps of 6 and 18mm MDF - box volume is 3.3 litres, and the walls have been lined with some of the foam from the old Ref 2's. The finished versions will use birch ply if my crazy plan turns out to be practical, and should be slightly smaller… I've been listening to these in the office all week, and they're rather nice. The bass response is very clean, and quite well extended for their size (F3 is around 95Hz) 😉
Onto the results: I only took 2 speakers home to measure, and they had not been used at all yet. But, despite no run-in time, the results aren't too bad:
#0 FS: 64.0 - VAS: 4.72 - Qms: 2.16 - Qes: 0.63 - Qts: 0.49
#1 FS: 66.9 - VAS: 3.46 - Qms: 1.65 - Qes: 0.67 - Qts: 0.47
#2 FS: 65.6 - VAS: 3.56 - Qms: 1.78 - Qes: 0.74 - Qts: 0.52
(#0 is Audax's spec's)
I suspect that VAS is a bit out because I didn't include the volume of air taken by the cone. The individual Q values vary a bit, but the total Qts isn't bad. These results were made using good "old fashioned" manual measurements, and I used the spreadsheet you can download from here http://www.diysubwoofers.org/measure.htm to make things a little easier. So how are you all measuring them? I've seen FS results as high as 90Hz, which is worrying!
Anyway, here's a picture of one of the prototypes, made from scraps of 6 and 18mm MDF - box volume is 3.3 litres, and the walls have been lined with some of the foam from the old Ref 2's. The finished versions will use birch ply if my crazy plan turns out to be practical, and should be slightly smaller… I've been listening to these in the office all week, and they're rather nice. The bass response is very clean, and quite well extended for their size (F3 is around 95Hz) 😉
Attachments
Re: Crossover for the AP100Z0 and the TM025F1
Hi John,
Just wanted to say that these are beautiful!
Is it veneered MDF? How did you get the black baffle - is it spray-painted? Going by the diagrams, it looks like you've got a volume of around 4.8 litres - what's the tuning frequency? The measured response looks like it's rolling off at 12dB/octave, which confusing me slightly...
I haven't been able to measure mine yet, but the bass end looks very similar, according to WinISD. Sealed, 3.3 litre...
Cheers,
Mark 😉
Zaph said:
Hi John,
Just wanted to say that these are beautiful!
Is it veneered MDF? How did you get the black baffle - is it spray-painted? Going by the diagrams, it looks like you've got a volume of around 4.8 litres - what's the tuning frequency? The measured response looks like it's rolling off at 12dB/octave, which confusing me slightly...
I haven't been able to measure mine yet, but the bass end looks very similar, according to WinISD. Sealed, 3.3 litre...
Cheers,
Mark 😉
Re: Re: Crossover for the AP100Z0 and the TM025F1
Thanks for the comments. Good eye spotting the 12db rolloff, yet a port on the back. There's actually a cork plugging the port on the inside to make it sealed. 🙂 Getting port output, nearfield woofer and farfield woofer output to sum correctly in measurements is kind of a pain so sometimes I will just plug the port and do sealed for measurement purposes.
This box is actually a little large for a sealed alignment but small for an optimum vented alignment. However, vented still works great with a little extra thought into how to tune it. I will lower the tuning to about 50hz for this box size. That will allow for more output and power handling in the 40-70hz range without significant midbass peaking. See this thread over at the Madisound forum for my take on the benefits of non-optimum tuning.
These are my after-breakin t/s parameters:
Qts - .56
Vas - 2.4 l
Fs - 81hz
mhennessy said:
Thanks for the comments. Good eye spotting the 12db rolloff, yet a port on the back. There's actually a cork plugging the port on the inside to make it sealed. 🙂 Getting port output, nearfield woofer and farfield woofer output to sum correctly in measurements is kind of a pain so sometimes I will just plug the port and do sealed for measurement purposes.
This box is actually a little large for a sealed alignment but small for an optimum vented alignment. However, vented still works great with a little extra thought into how to tune it. I will lower the tuning to about 50hz for this box size. That will allow for more output and power handling in the 40-70hz range without significant midbass peaking. See this thread over at the Madisound forum for my take on the benefits of non-optimum tuning.
These are my after-breakin t/s parameters:
Qts - .56
Vas - 2.4 l
Fs - 81hz
Zaph, what would you consider acceptable for vented then? I'm designing around ~14l for vented at the moment (2 drivers).
Re: Re: Re: Crossover for the AP100Z0 and the TM025F1
Ah! Mystery solved!
Yes. I'm generally a fan sealed boxes, but I've heard some excellent reflex designs. Unfortunately, I've heard many more bad ones 😉
I'll read up once I've finished reading through your site, because going ported isn't completely out of the question... One thing that I found - according to WinISD, a 50Hz tuning didn't seem terribly practical in such a small cabinet - it needed a very small diameter port...
How did you measure these? These are more typical of the results I've seen in this thread. I was very careful with my measurments, and I'm confident in the results. I've got another 4 drivers that I can test at the weekend - 2 have had no use, the others were used for a week in the cardboard prototypes...
Cheers,
Mark 😉
Zaph said:
Ah! Mystery solved!
Yes. I'm generally a fan sealed boxes, but I've heard some excellent reflex designs. Unfortunately, I've heard many more bad ones 😉
I'll read up once I've finished reading through your site, because going ported isn't completely out of the question... One thing that I found - according to WinISD, a 50Hz tuning didn't seem terribly practical in such a small cabinet - it needed a very small diameter port...
How did you measure these? These are more typical of the results I've seen in this thread. I was very careful with my measurments, and I'm confident in the results. I've got another 4 drivers that I can test at the weekend - 2 have had no use, the others were used for a week in the cardboard prototypes...
Cheers,
Mark 😉
Hello,
This is my current design.
Internal volume of inner cab is ~3 litres (110x150x179mm).
Internal vol. of outer cab is ~20.6 litres (500x150x275mm), which leaves ~17.5 litres for the bass drivers tuned to ~49Hz.
What do you guys think?
This is my current design.
Internal volume of inner cab is ~3 litres (110x150x179mm).
Internal vol. of outer cab is ~20.6 litres (500x150x275mm), which leaves ~17.5 litres for the bass drivers tuned to ~49Hz.
What do you guys think?
Vikash said:
Hi Vikash,
Not sure if I'm qualified here, but here goes 😉
It looks good. I'm interested because I plan to make a centre speaker, and would like as much BW as possible. For the closed section, I know from experience that 3 litres will give a good response down to a F3 of 95Hz, before rolling off at the normal 12dB/oct. Do you plan to run this speaker this low? You might be able to make this section smaller, but I guess that's not really an issue here...
I've no experience with slotted ports, but have you worked out the dimensions for ~49Hz yet?
Also, can I just clarify something I said earlier?
I just want to be clear here - I'm not doubting anyones results here - I'm keen to find out if I'm doing something wrong.
Cheers,
Mark 😉
Hi Mark,
Well I think at least three of our measurement sets are close (Mine, PM's, and Zaph's), and we've used different measurement methods too IIRC. In case you missed it: http://www.vikash.info/audio/audax/break-in.asp
I covered my design a few posts back, but I'll refresh again 🙂
Yes, the inner sealed cab is the mid enclosure and will run down to the baffle step and this is where the bass drivers will take over. Doubling up for bass duty will correct for the baffle step.
The port area is the internal width (150mm) and I think 2cm high will be adequate giving port area of 30cm^2. Port length is 161mm which tunes it to 49.2Hz. Modeled f3 is ~45Hz based on my T/S params.
Sreten where out thou? Anyone else see any probs?
Well I think at least three of our measurement sets are close (Mine, PM's, and Zaph's), and we've used different measurement methods too IIRC. In case you missed it: http://www.vikash.info/audio/audax/break-in.asp
I covered my design a few posts back, but I'll refresh again 🙂
Yes, the inner sealed cab is the mid enclosure and will run down to the baffle step and this is where the bass drivers will take over. Doubling up for bass duty will correct for the baffle step.
The port area is the internal width (150mm) and I think 2cm high will be adequate giving port area of 30cm^2. Port length is 161mm which tunes it to 49.2Hz. Modeled f3 is ~45Hz based on my T/S params.
Sreten where out thou? Anyone else see any probs?
Nope vikash I cant see any problems at all with that design. Ive just had a thought myself. Ive got some old trapezoid shaped cabinets which are WAAAAY to big for this application but are built really really well.
Im gonna chop em up and create a tall slim speaker floorstanding instead of a small sealed standmount. This shape also fit the veneer much better then the other design.
90cm tall 15.5cm wide at the front and about 12 at the back. I just need to get out the circular saw hehe, which worked surprisingly well with the angles used when I originally made this boxes.
Ill go for about 12ish litres internal tuned to about 45-50 hz. I think ill put em in a room with a TV which sounds terrible and a musical fidelity A1 which ive modded!
Mhennessy might like to know that I used his preamp replacement with OPA2134 and a vishay pot. Ive also made another PS with a bigger 200VA traffo, dual bridge rectifiers and the same original caps. All this made it have more grunt and a better overall sound. Guess Ill be limited to class AB with a 3ohm min load lol.
Im gonna chop em up and create a tall slim speaker floorstanding instead of a small sealed standmount. This shape also fit the veneer much better then the other design.
90cm tall 15.5cm wide at the front and about 12 at the back. I just need to get out the circular saw hehe, which worked surprisingly well with the angles used when I originally made this boxes.
Ill go for about 12ish litres internal tuned to about 45-50 hz. I think ill put em in a room with a TV which sounds terrible and a musical fidelity A1 which ive modded!
Mhennessy might like to know that I used his preamp replacement with OPA2134 and a vishay pot. Ive also made another PS with a bigger 200VA traffo, dual bridge rectifiers and the same original caps. All this made it have more grunt and a better overall sound. Guess Ill be limited to class AB with a 3ohm min load lol.
mhennessy, what was your measurement method?
People might like to add their own data to the following questions. It may help clarify a few things.
If you use the potential divider method, what value was your 'fixed' resistor? (I usually use 2.2k, but watch for voltage clipping!)
What would your voltage across the speaker be with 10 ohms impedance? (I calibrate so that 10 ohms gives 100mV)
I too am curious as to the different results people are getting and am really itching to get my drivers measured, but until the weekend at least, I will not get the chance.
I have found that there can be potential for error if your setup is not calibrated first. However, the error only rears it's head from 50Hz down, so would probably not be an issue in this case. To calibrate, substitute a 10 ohm resistor for the speaker and do spot frequencies every 5Hz from 20 to 60. You should get the same reading each time.
People might like to add their own data to the following questions. It may help clarify a few things.
If you use the potential divider method, what value was your 'fixed' resistor? (I usually use 2.2k, but watch for voltage clipping!)
What would your voltage across the speaker be with 10 ohms impedance? (I calibrate so that 10 ohms gives 100mV)
I too am curious as to the different results people are getting and am really itching to get my drivers measured, but until the weekend at least, I will not get the chance.
I have found that there can be potential for error if your setup is not calibrated first. However, the error only rears it's head from 50Hz down, so would probably not be an issue in this case. To calibrate, substitute a 10 ohm resistor for the speaker and do spot frequencies every 5Hz from 20 to 60. You should get the same reading each time.
Vikash said:
Hi Vikash,
Yes, I had seen those, and I agree, you do all seem to be in agreement. I'll talk about my method in a sec...
Right... the reason I asked was because I couldn't get a practical port in a 5-6 litre box for a single driver tuned to around 50Hz. IIRC, something like 20mm might have fitted in the box, but would have had mach problems. I didn't bother trying to model a slot, but actually it seems like it might be possible - albeit a very narrow one (like, less than a cm!)
One thing that worried me about a slot: might it be hard to tune once the box has been built?
Thanks,
Mark 😉
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