A few years ago I bought a pair of Fostex F120a for a WAW build. I had gotten a taste for full-range/wideband speakers via a pair of 1st gen. Blumenstein Orcas with the Fostex fe103. They hooked me on speed and dynamics, but were quite harsh and shouty even with my Bottlehead Stereomour 2a3-based SET. Without knowing any better I looked at the specs of the 120a, saw that some folks had used them with success (including Blumenstein with his short-lived Makos), and decided to go for it.
My listening room is only 10' wide, so my speakers are only a few inches away from the front wall. To make integration as easy as possible I ended up building a sealed-box WAW, following the general dimensions of the Omega Outlaw 3xrs (27"H x 11"W x 7.5"D). I hadn't heard them, but since I am only a beginner at this and don't have design software, I figured imitating Louis was a good idea. The result is....pretty good, but I wonder if a different enclosure would get more out of the Fostex.
What is "more"? I don't need more bass. The Dayton RSS210HO-8 8" sub is powered by a separate Crown XRS1500 amp with electronic crossover and the combination has WAY more output than I need. The highs are a bit rolled off, but that was understood from the start. That leaves the midrange. I am wondering if the enclosure is muddying the sound in some way? Baffle step loss? Perhaps allowing sound to reflect back through the thin cone of the driver? I've played with a 66.25mf capacitor to attenuate the bass, and eliminating the lowest frequencies seems to have sharpened the midrange, especially at high volume. That said, I haven't modeled it and don't know what exactly I've done.
The internal box measures 11.5" wide, 7.25" deep and 5.5" high and is fully lined with 3/4" wool felt and stuffed with medium-density poly fiber. The driver is centered in the front baffle (see picture).
What do you folks think? Is this about as good as the F120a gets? It is super fast, detailed and rarely harsh. It can get a bit shouty at times, but perhaps it is just revealing poor sources. Does anyone with modeling skills have the time and inclination to help me out? I know a different enclosure (Fonken-steen?) would give me better bass, but would it also help with mids and low mids? Has driver technology gotten so much better that I'd be better off swapping them out with a new Alpair, Tang Band, or something?
I've read all I can find about WAWs, and the prevailing wisdom seems to say I should go with the smallest driver I can that will cross over at the desired low end (150-300hz). That said, I am also open to a new design with larger drivers if it would sound better.
Thanks in advance for any help.
My listening room is only 10' wide, so my speakers are only a few inches away from the front wall. To make integration as easy as possible I ended up building a sealed-box WAW, following the general dimensions of the Omega Outlaw 3xrs (27"H x 11"W x 7.5"D). I hadn't heard them, but since I am only a beginner at this and don't have design software, I figured imitating Louis was a good idea. The result is....pretty good, but I wonder if a different enclosure would get more out of the Fostex.
What is "more"? I don't need more bass. The Dayton RSS210HO-8 8" sub is powered by a separate Crown XRS1500 amp with electronic crossover and the combination has WAY more output than I need. The highs are a bit rolled off, but that was understood from the start. That leaves the midrange. I am wondering if the enclosure is muddying the sound in some way? Baffle step loss? Perhaps allowing sound to reflect back through the thin cone of the driver? I've played with a 66.25mf capacitor to attenuate the bass, and eliminating the lowest frequencies seems to have sharpened the midrange, especially at high volume. That said, I haven't modeled it and don't know what exactly I've done.
The internal box measures 11.5" wide, 7.25" deep and 5.5" high and is fully lined with 3/4" wool felt and stuffed with medium-density poly fiber. The driver is centered in the front baffle (see picture).
What do you folks think? Is this about as good as the F120a gets? It is super fast, detailed and rarely harsh. It can get a bit shouty at times, but perhaps it is just revealing poor sources. Does anyone with modeling skills have the time and inclination to help me out? I know a different enclosure (Fonken-steen?) would give me better bass, but would it also help with mids and low mids? Has driver technology gotten so much better that I'd be better off swapping them out with a new Alpair, Tang Band, or something?
I've read all I can find about WAWs, and the prevailing wisdom seems to say I should go with the smallest driver I can that will cross over at the desired low end (150-300hz). That said, I am also open to a new design with larger drivers if it would sound better.
Thanks in advance for any help.
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You would do well if you purchased Hobby HiFi 3/2017 which has a complete project for building a mini onken F120A. There is also this link where it says that there are 3 networks making out the passive electronics. 2 of the RLC's in series with the driver and one RLC in parallel with it. The parts values are evident, only remains to figure out which goes where. The original manufacturer's FR appears very smooth so I guess the magazine staff must have measured pretty much a different curve if it took a couple of networks more to smooth out the response. And build the impedance flattening RC and RLC to make the best out of a tube amp.
Strassacker: Speaker Building, Components
Strassacker: Speaker Building, Components
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Quattrofish,
I have a pair of F120A in Metronomes which I use as my jazz system. The Mets do fairly well paced near a wall, but the sound stage is better if they are pulled out 18-24" from the wall. For me, I don't want any additional bass; with jazz, the bass provided by the F120A is just fine.
From your photo, it appears you are driving them with a tube amp. This, IME, is critical! I started out using SS amps and was disappointed that the F120A sounded terribly rolled off in the highs and rather mediocre in the mids. Tube amps produced an entirely different result. Here is an excerpt from a Nov 2009 thread by Martin King where he talks about my F120A Mets:
>>>>>>
This past summer I finally broke down and decided to try a tube amp. I won an EL84 integrated amp on e-Bay that produced a fairly decent 15 watts. That is the extent of my knowledge on the tube amp. When I connected it to several of my own speaker designs I was initially very disappointed. While the mids and treble sounded really nice the bass produced by the speakers disappeared. It was almost like a 200 Hz high pass filter had been placed between the amp and the speakers. It seemed to be a common problem with all of my speakers. Jim had been to my house earlier in the week and we had compared the tube amp and my SS amp and he heard the same issues with the significant loss of bass output. The SS amp was the clear winner.
I brought the tube amp, CD player, and my homemade CAT5 speaker cables to Jim's house so we could replicate my set-up but with his speakers. The first speaker we tried the tube amp on were Jim's Fostex F120A Metronomes. Jim and I both have pairs of F120A drivers, in different speaker designs, and we have both been disappointed with their performance. At my house we tried the tube amp on my F120A OB and Goldwood H frames and felt the F120A's performance improved but the bass rolled off significantly. So we started with his SS amp, listened to the Metronomes for a while, and then switched to the tube amp and CAT5 cables. When we connected Jim's Metronomes to the tube amp we were blown away. The improvement across the audio spectrum was dramatic, better and deeper bass with smoother extended highs. This was by far the best sound I have heard coming from a F120A driver and it was really really good. It was also the first time that I had heard the tube amp truely sound great. To try and understand if the tube amp or the CAT5 cables were the reason things improved so much, we switched to a thinner zip cord style speaker cable. Some of the improvement disappeared, so it became clear that both the tube amp and the CAT5 cables contibuted to the improvement in the sound of the F120A drivers. This combination of amp, cables, and speakers was an eye and ear opener. All the problems we had heard in the F120A driver were gone. The F120A sounded like a completely different speaker and more consitent with its stellar reputation.
<<<<
Cheers, Jim
I have a pair of F120A in Metronomes which I use as my jazz system. The Mets do fairly well paced near a wall, but the sound stage is better if they are pulled out 18-24" from the wall. For me, I don't want any additional bass; with jazz, the bass provided by the F120A is just fine.
From your photo, it appears you are driving them with a tube amp. This, IME, is critical! I started out using SS amps and was disappointed that the F120A sounded terribly rolled off in the highs and rather mediocre in the mids. Tube amps produced an entirely different result. Here is an excerpt from a Nov 2009 thread by Martin King where he talks about my F120A Mets:
>>>>>>
This past summer I finally broke down and decided to try a tube amp. I won an EL84 integrated amp on e-Bay that produced a fairly decent 15 watts. That is the extent of my knowledge on the tube amp. When I connected it to several of my own speaker designs I was initially very disappointed. While the mids and treble sounded really nice the bass produced by the speakers disappeared. It was almost like a 200 Hz high pass filter had been placed between the amp and the speakers. It seemed to be a common problem with all of my speakers. Jim had been to my house earlier in the week and we had compared the tube amp and my SS amp and he heard the same issues with the significant loss of bass output. The SS amp was the clear winner.
I brought the tube amp, CD player, and my homemade CAT5 speaker cables to Jim's house so we could replicate my set-up but with his speakers. The first speaker we tried the tube amp on were Jim's Fostex F120A Metronomes. Jim and I both have pairs of F120A drivers, in different speaker designs, and we have both been disappointed with their performance. At my house we tried the tube amp on my F120A OB and Goldwood H frames and felt the F120A's performance improved but the bass rolled off significantly. So we started with his SS amp, listened to the Metronomes for a while, and then switched to the tube amp and CAT5 cables. When we connected Jim's Metronomes to the tube amp we were blown away. The improvement across the audio spectrum was dramatic, better and deeper bass with smoother extended highs. This was by far the best sound I have heard coming from a F120A driver and it was really really good. It was also the first time that I had heard the tube amp truely sound great. To try and understand if the tube amp or the CAT5 cables were the reason things improved so much, we switched to a thinner zip cord style speaker cable. Some of the improvement disappeared, so it became clear that both the tube amp and the CAT5 cables contibuted to the improvement in the sound of the F120A drivers. This combination of amp, cables, and speakers was an eye and ear opener. All the problems we had heard in the F120A driver were gone. The F120A sounded like a completely different speaker and more consitent with its stellar reputation.
<<<<
Cheers, Jim
The Fonken-Steen. Original build:
I can be emailed for the original plans, but note that the Germans have added a whole bunch of notch filters to the design which may or may not clean things up.
Does your electronic XO have a high pass filter? If possible you should be using an active filter (even if just a PLLXO in front of the amp) and not a big cap in an attempt to do a passive XO, at such low frequencies the impedance of the driver/box will be all over the place.
Your sub-enclosure is 7.5 litre… Q <0.67 given th damping. Any XO over a 100 Hz should work.
Th ewoofer is kinda far from the midTweeter so you don’t want to put the XO too high… ideally the centre-to-centre will be less than a 1/4 wavelength at the XO point.
dave
spread the gospel Thank you all very much for your responses.
Lozjek; I've seen that project and the associated magazine article. The article was lengthy and while I couldn't read it, I was intrigued by the addition of the circuitry. I had seen the Planet10 Fonken-steen plans but didn't remember anyone mentioning the need for BSC.
Jim: I know your thread on the Met build well and the snippet you posted in particular, as it showed that both you and MJK ended up liking the driver after initial disappointment. In fact, it is one of the reasons I bought mine and, after considering a change, started this thread. If you and MJK like the F120a in the Met, then perhaps I'm not getting the most from it and it is worth me building a new cabinet rather than just start from scratch.
One thing that gives me pause, however, is that both you and Dave ended up saying that you wouldn't bother with the F120a again as other drivers are available that surpass it for less money. If that is the case, it makes me think that perhaps I should sell the F120as, get new drivers with the proceeds, and build cabinets around them. They can't be too bad if you still use them. Did I misunderstand, or is it just a case of not wanting to go through the trouble to replace them? If I were to replace them, what have you heard that you like more?
Dave: Your Fonken-steens are at the top of my list for my next build if I stick with the F120a. I downloaded the plans linked below years ago.
http://p10hifi.net/FAL/downloads/Fonken-steen-0v81-140808-plans.pdf
Has anyone ever made a WAW with them? At 10" they are more than wide enough for me to make into floorstanders, with a separate enclosure on the bottom for my Dayton 8' sub. Might it be a nice combo? I can mount the F120a towards the bottom of the Fonken-steen baffle (upside-down from the plans) to get it closer to the sub.
I'm not too worried about the WAF on these. One of the other options I'm considering is a 4 Pi build. All I need to do is show my wife a pic of those and she'll be begging me to do the Fonken-steen WAWs!
Speaking of the 4 Pis, if anyone has first-hand experience with them I'd very much like to hear about it.
Lozjek; I've seen that project and the associated magazine article. The article was lengthy and while I couldn't read it, I was intrigued by the addition of the circuitry. I had seen the Planet10 Fonken-steen plans but didn't remember anyone mentioning the need for BSC.
Jim: I know your thread on the Met build well and the snippet you posted in particular, as it showed that both you and MJK ended up liking the driver after initial disappointment. In fact, it is one of the reasons I bought mine and, after considering a change, started this thread. If you and MJK like the F120a in the Met, then perhaps I'm not getting the most from it and it is worth me building a new cabinet rather than just start from scratch.
One thing that gives me pause, however, is that both you and Dave ended up saying that you wouldn't bother with the F120a again as other drivers are available that surpass it for less money. If that is the case, it makes me think that perhaps I should sell the F120as, get new drivers with the proceeds, and build cabinets around them. They can't be too bad if you still use them. Did I misunderstand, or is it just a case of not wanting to go through the trouble to replace them? If I were to replace them, what have you heard that you like more?
Dave: Your Fonken-steens are at the top of my list for my next build if I stick with the F120a. I downloaded the plans linked below years ago.
http://p10hifi.net/FAL/downloads/Fonken-steen-0v81-140808-plans.pdf
Has anyone ever made a WAW with them? At 10" they are more than wide enough for me to make into floorstanders, with a separate enclosure on the bottom for my Dayton 8' sub. Might it be a nice combo? I can mount the F120a towards the bottom of the Fonken-steen baffle (upside-down from the plans) to get it closer to the sub.
I'm not too worried about the WAF on these. One of the other options I'm considering is a 4 Pi build. All I need to do is show my wife a pic of those and she'll be begging me to do the Fonken-steen WAWs!
Speaking of the 4 Pis, if anyone has first-hand experience with them I'd very much like to hear about it.
Quattrofish,
I still have the F120A Mets in our living room for my jazz system, and have no intension of letting them go! For small ensemble, girl w/ guitar, etc they are the best I have. My feeling is that if I knew then what I know now, I expect I would have purchased the FX120 rather than the more expensive F120A. The FX120 is probably not quite as good as the F120A, but perhaps close enough, and a better value. I'm pretty sure that the F120A wouldn't sell used for enough to buy anything I would enjoy as much.
The question I would be asking, if I were you: would a different cabinet make any improvement? Only you can determine if it's worth the time and money to experiment w/ other cabinets and driver loadings.
Cheers, Jim
I still have the F120A Mets in our living room for my jazz system, and have no intension of letting them go! For small ensemble, girl w/ guitar, etc they are the best I have. My feeling is that if I knew then what I know now, I expect I would have purchased the FX120 rather than the more expensive F120A. The FX120 is probably not quite as good as the F120A, but perhaps close enough, and a better value. I'm pretty sure that the F120A wouldn't sell used for enough to buy anything I would enjoy as much.
The question I would be asking, if I were you: would a different cabinet make any improvement? Only you can determine if it's worth the time and money to experiment w/ other cabinets and driver loadings.
Cheers, Jim
Thanks, Jim. I'm glad you continue to like your F120A Mets well enough to keep them.
The question you mention is the very one I am trying to answer. My speakers do so much right, but if someone with experience like you or Dave said that these speakers would sound much better in a different cabinet I'm willing to give it a shot. Once I am reasonably certain that I am getting the best sound possible from them I'll decide if their limitations necessitate trying something entirely different.
I happen to have a bunch of Cat5 available. I think I'll give that a try based on your experience with it.
When I created this thread my hope was for you and/or Dave to participate. Again, thanks very much for your help.
The question you mention is the very one I am trying to answer. My speakers do so much right, but if someone with experience like you or Dave said that these speakers would sound much better in a different cabinet I'm willing to give it a shot. Once I am reasonably certain that I am getting the best sound possible from them I'll decide if their limitations necessitate trying something entirely different.
I happen to have a bunch of Cat5 available. I think I'll give that a try based on your experience with it.
When I created this thread my hope was for you and/or Dave to participate. Again, thanks very much for your help.
We rarely use BSC as exemplified by the typical series inductor/resistor circuit. Increasing the on-axis to flat also increases the power response to lifted so you have to be careful.
One must keep in mind that the F120A design is near 2 decades old and FR drivers have quickly evolved in the last 5-10 years. Even back when we built Fonken-steen #1 i had reservations about the F120A dynamics.
My favorites are Alpair 7.3eN/10PeN/A5.2eN and FF85wKeN. The A10p in the big boxes gives bass such that few find the need for a woofer, the others shine in a WAW with helper woofer(s). I have been listening to the prototype of Tysen V2 with FF85wKen & a pair of SilverFlute W14 for quite a while — longer than a pair of speakers usually reside in the main system.
I get to hear more drivers than most but there are lots more drivers i would like to hear.
One has to question whether a build like this that is designed to get significant bass out of the driver is a suitable choice for a WAW. It would be more suited to adding subwoofers.
dave
Thanks, Dave
I started all this with the above in mind re: the age of the F120a and how the increasing interest in low-powered amps has likely spurred further development of speakers to match. I like the idea of using a full-range/wide-band driver, but relieving it of low-frequency duty. This is what I tried to do with my current setup, but sadly I lack the knowledge to implement it very well.
Given the developments in driver technology since mine was conceived, I am open to trying another, properly developed/tested version of the concept. Having read your posts on this site for many years, I have come to trust your opinions as they seem to be based in reality and not hifi-marketing BS. If you can recommend what you see as the very best application of the WAW or subwoofer-assisted wideband concept, I'll build it.
I've attached a picture to show my room.
My amplifier is a Bottlehead Stereomour 2a3 SET.
I also have a Crown xls1500 I can use for sub support if necessary.
I'm happy to continue this via email if you'd like.
Thanks.
I started all this with the above in mind re: the age of the F120a and how the increasing interest in low-powered amps has likely spurred further development of speakers to match. I like the idea of using a full-range/wide-band driver, but relieving it of low-frequency duty. This is what I tried to do with my current setup, but sadly I lack the knowledge to implement it very well.
Given the developments in driver technology since mine was conceived, I am open to trying another, properly developed/tested version of the concept. Having read your posts on this site for many years, I have come to trust your opinions as they seem to be based in reality and not hifi-marketing BS. If you can recommend what you see as the very best application of the WAW or subwoofer-assisted wideband concept, I'll build it.
I've attached a picture to show my room.
My amplifier is a Bottlehead Stereomour 2a3 SET.
I also have a Crown xls1500 I can use for sub support if necessary.
I'm happy to continue this via email if you'd like.
Thanks.
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Quattrofish,
You mentioned BSC. The F120A Mets don't seem to need BSC, which surprised me. The other Mets I have built needed at least a touch of BSC (with the exception of the dual FF85K mini-Mets).
I haven't listened to near as many drivers as Dave, but I can recommend the Alpair 10.3 if you really want a different driver. I built a pair of BIBs last summer for the A10.3, and I must say they are quite good sounding and a great bargain, assuming Madisound still has them for $85 each. I broke them in by putting them in 0.25 cft cardboard boxes, and they sounded pretty good in spite of the poor enclosures. The A10.3 would probably work well in a WAW if you wanted to continue with that methodology. Or put them in a vented alignment for satisfying bass w/o a separate woofer.
Cheers, Jim
You mentioned BSC. The F120A Mets don't seem to need BSC, which surprised me. The other Mets I have built needed at least a touch of BSC (with the exception of the dual FF85K mini-Mets).
I haven't listened to near as many drivers as Dave, but I can recommend the Alpair 10.3 if you really want a different driver. I built a pair of BIBs last summer for the A10.3, and I must say they are quite good sounding and a great bargain, assuming Madisound still has them for $85 each. I broke them in by putting them in 0.25 cft cardboard boxes, and they sounded pretty good in spite of the poor enclosures. The A10.3 would probably work well in a WAW if you wanted to continue with that methodology. Or put them in a vented alignment for satisfying bass w/o a separate woofer.
Cheers, Jim
Thanks, Jim.
The frustrating part of all this is that I just don't know what other speakers of this type sound like. It may be that I happened upon one of the all-time great full-range drivers with the F120a, and the sealed box I've got them in is the best cabinet for my application. The ignorance is maddening, but I don't know anyone else that is into this particular facet of the hobby so have to act based on advice from others. Of course, no one else has my ears......
Can you attempt to describe how the Alpair 10 (p or 3) differs from the F120a?
I could just start by building new cabs and see how the sound changes. Have you heard the Fonken-steens? If I were to go with another cabinet I was thinking those because of the forward-firing ports. My speakers have to be very near the front wall and I seem to remember you writing that your Mets sounded best 18-24" out, which I can't do.
Thanks again for your helpful input.
Quattrofish,
I've never heard the Fonken-steens, however, I did build a pair of FE127e Fonkens Prime. The Fonkens extract a decent measure of bass from the FE127e and do a nice 'disappearing' act; I assume the larger version for the F120A would also do well. The only drawback is the complexity of the build.
As to the differences in sound between the F120A and A10.3: Oy! I have no idea how to explain that! You kinda need to listen for yourself--which is why so many of us have so many different drivers laying around...
Cheers, Jim
I've never heard the Fonken-steens, however, I did build a pair of FE127e Fonkens Prime. The Fonkens extract a decent measure of bass from the FE127e and do a nice 'disappearing' act; I assume the larger version for the F120A would also do well. The only drawback is the complexity of the build.
As to the differences in sound between the F120A and A10.3: Oy! I have no idea how to explain that! You kinda need to listen for yourself--which is why so many of us have so many different drivers laying around...
Cheers, Jim
We can talk WAW here.
The A10.3 mentioned by Jim is probably not as good a choice as the A7.3 or even the A6.2 or A5.2 if being used as a midTweeter.
If you were going to not use the woofer, or needed to play loud the A10.3 could be a choice. With a woofer you are looking for the best midrange top, and althou the A10.3 has moved closer to the A7.3 it still has the edge. Currently the A7.3 and A10.3 are the same price with the Madisound price and the perceived vaue equation says pick the larger driver, but i think that would be the wrong direction with a WAW.
You could get the A7.3 and just pop it into the subenclosure you already have. The driver cutouts are both 103 mm.
But as i’d put the woofer closer to the midTweeter you might consider flipping the current boxes upside down and putting the midTweeter in a new box… you could do that with the F120A as well.
Did you answer the earlier question of whether your XO has a high-pass for the midTweeter.
Another point, if you go with one of the Alpair you can likely sell the used F120A for more than the cost of the new drivers.
Here are pictures of the 2 WAW were we use the A7.3eN as midTweeter:
dave
Thanks for all of that, Dave.
Those are both beautiful speakers. Do you prefer the sound of one over the other? I think that the narrower baffle design might work well, but then I can't see how deep it is. Do you have plans for these available for sale, or even rough measurements I could use to decide which would work better in my space?
I think you have given me a good path forward. My Fostex and the 7.3 are both good candidates for a WAW or SWAW application. The only way for me to tell which driver I prefer is to buy a pair of 7.3s, break them in properly, and A/B them with the Fostex. Once I make that decision I can come back to discuss options for a properly designed system with my preferred driver as the midtweeter.
Make sense to you?
In order to give each driver the best shot, I'd like to build new boxes for each for testing. Since this will be for a future WAW application, I'm not going for maximum bass. Can you help me with recommended internal volumes for each cabinet?
As for a crossover, I have only used a single 66mf capacitor as a first order high-pass at around 300hz. Since I don't know what I'm doing, that may have done more harm than good. You mentioned a passive line-level crossover earlier. I'd be happy to build some if you can give me some guidance.
While you have been incredibly generous in sharing your expertise over the years, I am more than happy to pay you for this design assistance.
Thanks.
Those are both beautiful speakers. Do you prefer the sound of one over the other? I think that the narrower baffle design might work well, but then I can't see how deep it is. Do you have plans for these available for sale, or even rough measurements I could use to decide which would work better in my space?
I think you have given me a good path forward. My Fostex and the 7.3 are both good candidates for a WAW or SWAW application. The only way for me to tell which driver I prefer is to buy a pair of 7.3s, break them in properly, and A/B them with the Fostex. Once I make that decision I can come back to discuss options for a properly designed system with my preferred driver as the midtweeter.
Make sense to you?
In order to give each driver the best shot, I'd like to build new boxes for each for testing. Since this will be for a future WAW application, I'm not going for maximum bass. Can you help me with recommended internal volumes for each cabinet?
As for a crossover, I have only used a single 66mf capacitor as a first order high-pass at around 300hz. Since I don't know what I'm doing, that may have done more harm than good. You mentioned a passive line-level crossover earlier. I'd be happy to build some if you can give me some guidance.
While you have been incredibly generous in sharing your expertise over the years, I am more than happy to pay you for this design assistance.
Thanks.
You will probably read my long post in another thread on WAW, PLLXO, etc.
Of the 2 i have a softspot for the 1st one, but in shear peformance the 2nd is mostly better.
The cabinet for the 1st is a bitch to build, but Chris wanted to use it as an excersise in using vacuum bag construction. Over 200 hrs in making those. The Mark Audio copper cones came as a result of Mark trying to get as close to the colour of the copper phase plugs in the SDX7. We really liked the SDX7, and got alot of them as payment for graphics work we did for Bob (Creative Sound Solutions). It has been unavailable for some time but the new CSS is considering bringing it back. It works really wells sealed (and only sealed IMO). We did use the vacuum forms that created the front and back of these for a set of curved back Pensil7.3 so have been able to amortise the work somewhat.
The larger MTM uses w Alpair 12pw in a Woden specified ML-TL. They go lower with more impact and have voiceing closer to the same A7.3eN midTweeter. The box is way simplier to build (but not a cakewalk dur to the hidden midTweeter TL). We have developed a passive XO for these and the planset is available for purchase. If one has the amps and other kit a circe 250 XO is what we recommend, we used a PPLXO and the digital 4th order XO in a modern HT receiver with good results.
You should replace the big passive cap between the amp & speaker and replace it with a much, much smaller (and usually better) cap in front of your HF amp.
As to midTweeters, try both and trust your ears. It only matters which one you prefer.
dave
Of the 2 i have a softspot for the 1st one, but in shear peformance the 2nd is mostly better.
The cabinet for the 1st is a bitch to build, but Chris wanted to use it as an excersise in using vacuum bag construction. Over 200 hrs in making those. The Mark Audio copper cones came as a result of Mark trying to get as close to the colour of the copper phase plugs in the SDX7. We really liked the SDX7, and got alot of them as payment for graphics work we did for Bob (Creative Sound Solutions). It has been unavailable for some time but the new CSS is considering bringing it back. It works really wells sealed (and only sealed IMO). We did use the vacuum forms that created the front and back of these for a set of curved back Pensil7.3 so have been able to amortise the work somewhat.
The larger MTM uses w Alpair 12pw in a Woden specified ML-TL. They go lower with more impact and have voiceing closer to the same A7.3eN midTweeter. The box is way simplier to build (but not a cakewalk dur to the hidden midTweeter TL). We have developed a passive XO for these and the planset is available for purchase. If one has the amps and other kit a circe 250 XO is what we recommend, we used a PPLXO and the digital 4th order XO in a modern HT receiver with good results.
You should replace the big passive cap between the amp & speaker and replace it with a much, much smaller (and usually better) cap in front of your HF amp.
As to midTweeters, try both and trust your ears. It only matters which one you prefer.
dave
I did read that post, thanks. I'm sold on the PLLXO for high pass, though I need help identifying the output impedance of my AES AE3 preamp. I've found 560 ohms for the similar DHD/MKII edition, but nothing for my base model. Are those tolerances super tight? Can I measure it with just a good multimeter?
My Stereomour is 100k input impedance.
My Crown XLS1500 amp is 10k (unbalanced), but it has 4th order adjustable crossovers built in so I can just use those if you got good results using steep slopes.
I am a fair carpenter, but I'm not game for vacuum bagging. I think the MTM would be a far better bet. If I understand correctly, this design can use 2 amps, or one amp with the designed passive XO? If one amp can be used, did you measure sensitivity?
I'm curious about the TL for the midTweeter. Is that just to fatten up the low-mid response until the crossover point? Just wondering why that instead of a sealed cabinet since the idea isn't to go very low with the 7.3.
My Stereomour is 100k input impedance.
My Crown XLS1500 amp is 10k (unbalanced), but it has 4th order adjustable crossovers built in so I can just use those if you got good results using steep slopes.
I am a fair carpenter, but I'm not game for vacuum bagging. I think the MTM would be a far better bet. If I understand correctly, this design can use 2 amps, or one amp with the designed passive XO? If one amp can be used, did you measure sensitivity?
I'm curious about the TL for the midTweeter. Is that just to fatten up the low-mid response until the crossover point? Just wondering why that instead of a sealed cabinet since the idea isn't to go very low with the 7.3.
With a 1st order PLLXO, particularily the HP section the preamp output impedance is not overly critical unless it is super high. The 100k on the stereomour would be used as the R for the HP filter. Use the XO built into the Crown.
The midTL in the MTM is 10:1 runs from the front out the back and is stuffed until aperiodic. The idea to suck up the entire back wave of the driver. No LF enhancement is intended or desired.
MTM sensitivity is going to be that of the Alpair 7.3. Althou rated at about 87 dB, sensitivity is not much different from the F120A. We tend to recommend 10w but have customers happily using SE 2A3. With no need to drive the bass its job becomes easier. As an anecdote, i have been happy driving the less efficient Tysen V2 full-range with a pair of 5 w ACA amps in my largish room. Critical as you start to turn it up is the typically benign clipping behaviour of most SE amps.
MTM can use 2 amps and that is the recommended way, but for completeness (& exploration) Aaron did a passive XO for us for those that find all the bits of a bi-amped system a game killer.
dave
The midTL in the MTM is 10:1 runs from the front out the back and is stuffed until aperiodic. The idea to suck up the entire back wave of the driver. No LF enhancement is intended or desired.
MTM sensitivity is going to be that of the Alpair 7.3. Althou rated at about 87 dB, sensitivity is not much different from the F120A. We tend to recommend 10w but have customers happily using SE 2A3. With no need to drive the bass its job becomes easier. As an anecdote, i have been happy driving the less efficient Tysen V2 full-range with a pair of 5 w ACA amps in my largish room. Critical as you start to turn it up is the typically benign clipping behaviour of most SE amps.
MTM can use 2 amps and that is the recommended way, but for completeness (& exploration) Aaron did a passive XO for us for those that find all the bits of a bi-amped system a game killer.
dave
I built not only the MTMs shown, but experimented with at least 3 different iterations of crossover topologies - PLLXO, digital bi-amping in Onkyo receiver, and the passives designed by Aaron. As Dave has noted several times and places, the cost to implementing the latter well at the XO frequencies involved here (between 200 -300"ish") can easily higher than a simple PLLXO and using spare amps one might have kicking around - but that might well be an acceptable expense for those folks averse to more components and cabling, etc in the low level signal path.
While they're no longer my daily drivers (physical size became an impediment to WAF), I quite preferred Aaron's passive XO to the other methods. Since Dave generally doesn't make allowances for space for internal XOs, and the boxes had already been finished in the Sapele veneer, the passives were built into an external box - as were those for the Tysen - which detracts somewhat from the simplicity of "less boxes & wires"
Several years ago we built something very similar using Mark Fenlon's silly good little EL166 woofers and FF85K, with a series XO that was a bit of a dental surgery to just barely fit inside the box, but it worked .
While they're no longer my daily drivers (physical size became an impediment to WAF), I quite preferred Aaron's passive XO to the other methods. Since Dave generally doesn't make allowances for space for internal XOs, and the boxes had already been finished in the Sapele veneer, the passives were built into an external box - as were those for the Tysen - which detracts somewhat from the simplicity of "less boxes & wires"
Several years ago we built something very similar using Mark Fenlon's silly good little EL166 woofers and FF85K, with a series XO that was a bit of a dental surgery to just barely fit inside the box, but it worked .
Thanks, Chris. Given how much experience you have with wide-band drivers and their enclosures, I truly appreciate your input.
Every speaker is a compromise. I was originally drawn to wide-band drivers by their coherence, sensitivity and dynamics at low to mid volume.
Unfortunately, most if not all start to break up once the decibels rise. I even listened to some Voxativ Ampeggio Signatures, and they exhibited the same kind of breakup. Even that much money can't change physics, so I became interested in the WAW concept. The units I built a couple of years ago sound ok, but did not benefit from any modeling or testing, so here I am looking for improvements.
The MTMs that Dave suggested look fantastic (nice work on those cabinets), and if they are the best example of the WAW/SWAW concept, then I am VERY interested. This is not a cost-no-object build, but it is not anything like low budget either, as I plan to have these for awhile. I'm open to all ideas at this point.
It is interesting that you preferred the passive XO over the PLLXO or Active. I couldn't care less which costs more in this particular case. I want the best sounding speakers I can get given my low wattage (that can go up from my current 3.5w, but I am in love with the SET sound), small room and need for whatever I have to sound good at low to moderate volume. So far the WAW concept seems to provide the best compromise.
Thanks again. Unless somebody suggests a strong alternative to the MTMs that Dave proposed, I'll plan to build them in the next couple of months.
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