tf1216 said:
Yes, I have heard of the Vandersteen 5A but I can't recall exactly what they look like. THough in my recollection all of the Vandersteen speakers have been amoung the highest sound quality for the dollar of any brands.
tinitus said:Other than Vandersteen isnt a dipole
Man, those pyramid top section is so ugly, been there ... but thats just me and a matter of opinion, now I despite odd shapes and prefer a straight squared design ... getting old I guess
I'm just the opposite. I hate plain square objects unless they are small.
pjpoes said:
the one reason I suggested a higher XO point was to avoid having a XO in the midrange. In fact using a widerange (like the TB 4") for a midrange makes good sense.
I was not recomending push-pull but push-push.
Lastly 2 4" drivers might be SPL limited at 150Hz. So if you want to use 2 x 4" you might want to crossover higher.
pjpoes said:
The Focal 120Tdx tweeter is pretty effcient. Are the 2 x 4" midrnages more efficient than a single Focal? Even after baffle step?
Also I doubt 2 x 8" woofers will meet your SPL requirements. FOr this you are the best judge. Going by your earlier posts I thought your SPL requirements were quite high.
navin said:
I dont think its a matter of having xo in the midrange or not ... if done right you may chose to place xo points where ever you like, well almost
Theoretically I believe the best solution is to waveguide the tweeter to have better controlled directivity and better suit the directivity of the mid above xo point
And I think people have missed the point completely when they do a tweeter waveguide to have a lower xo point
There is no xo to suit an all solution
if you look at the concept system I posted, you can clearly see that I chose higher xo points. The tweeter is at around 3.2khz and the woofer hands over to the midranges at around 300-350hz or so.
As I'm sure you know, efficiency numbers lie, and often take into account the highest amplitude point. Sometimes that means that over the majority of the band its actually of a lower efficiency. Looking at the response graph I showed you, yes, the two midranges are more efficient than the tweeter. Now this is a model, I have no idea what it will be like in real life. My best guess as to whats going on is that Speaker Workshop uses voltage sensitivity instead of 1 watt, and thus the 4 ohm load coupled with the 3db increase in output makes for a 6db increase in output. However, the tweeter is just one tweeter, remains 8 ohms, and thus has no increase in sensitivity. I mean, I really need to get some measurements before any of this makes sense and I can turn that concept crossover into something real.
I was playing around with padding down the midrange to get a more even response, and it can be done with a fairly small amount of added resistance as well as still maintaining high sensitivity. Again, if I'm willing to accept a small tilt in the response, I can still have around 94db efficiency through most of the response. However, since one of my goals was high efficiency, and I'm seeing that I may be able to get 97db's of voltage sensitivity, I hate to be padding things down.
You know I'm finding that efficient tweeters not in waveguides or horns are rare. I'm also finding that truely efficient tweeters in waveguides and horns are also not what I expected, you still don't have much efficiency at 15khz on up.
As I'm sure you know, efficiency numbers lie, and often take into account the highest amplitude point. Sometimes that means that over the majority of the band its actually of a lower efficiency. Looking at the response graph I showed you, yes, the two midranges are more efficient than the tweeter. Now this is a model, I have no idea what it will be like in real life. My best guess as to whats going on is that Speaker Workshop uses voltage sensitivity instead of 1 watt, and thus the 4 ohm load coupled with the 3db increase in output makes for a 6db increase in output. However, the tweeter is just one tweeter, remains 8 ohms, and thus has no increase in sensitivity. I mean, I really need to get some measurements before any of this makes sense and I can turn that concept crossover into something real.
I was playing around with padding down the midrange to get a more even response, and it can be done with a fairly small amount of added resistance as well as still maintaining high sensitivity. Again, if I'm willing to accept a small tilt in the response, I can still have around 94db efficiency through most of the response. However, since one of my goals was high efficiency, and I'm seeing that I may be able to get 97db's of voltage sensitivity, I hate to be padding things down.
You know I'm finding that efficient tweeters not in waveguides or horns are rare. I'm also finding that truely efficient tweeters in waveguides and horns are also not what I expected, you still don't have much efficiency at 15khz on up.
well now you have my concern too. None the less, the efficiency of the TB 4" Ti driver is rated at 88db's into an 8 ohm load. Now if you consider efficiency as voltage sensitivity (Since thats how the amplifier is really going to treat it), then if we parallel two of them, the speaker becomes a 4 ohm load, and the midrange will give about 3 db's more voltage sensitivity. Then you also have the increased number of drivers, that will also give you a 3db increase in sensitivity, for a total of roughly 6db's, which gives you 94 db's efficiency. Now add to that the extra 2-3 db's you get from the crossover shaping of the response, and we have an explanation for the 97db efficiency I am seeing in my model. If you don't look at is as voltage sensitivity, but the 1w/1m method, its probably more like 92 or so. Again though, my amplifier isn't going to look at each driver and give them each all 1 watt, it will supply power based on the drivers impedance, and if the midrange and woofers have a nominal 4ohm load or so, then the amp will be supplying more current, and thus more output in reference to the tweeter.
I was a bit shocked when I put together the model, but I have modeled a few other crossovers with the same midrange driver, and sure enough, this seems accurate. This is the best explanation I can come up with, and I'm fairly certain I'm right. I have to imagine your comment wasn't about the drivers size but brand right? I mean, it being only 4"s has nothing to do with what its sensitivity is going to be.Joe Rasmussen on Sensitivity vs Efficiency I've been quoting Joe a lot lately, so I will do it again. None the less, he does a decent job explaining what I'm talking about here.
I was a bit shocked when I put together the model, but I have modeled a few other crossovers with the same midrange driver, and sure enough, this seems accurate. This is the best explanation I can come up with, and I'm fairly certain I'm right. I have to imagine your comment wasn't about the drivers size but brand right? I mean, it being only 4"s has nothing to do with what its sensitivity is going to be.Joe Rasmussen on Sensitivity vs Efficiency I've been quoting Joe a lot lately, so I will do it again. None the less, he does a decent job explaining what I'm talking about here.
The TB 4" Ti is rated at 87db, but maybe we are not looking at the same driver, further TB has been mentioned to be a bit optimistic about specs
According to Zaph its more like 85db, which makes more sense
Besides, my experience with paralel drivers is that the gain in sensitivity is not completely FR linear, but I may be wrong and on dedicated midrange it may not be an issue
Quote from your link to JoeRasmussen:
2. High sensitivity vs. electrical impedance/phase response
Selecting the driver affects the sensitivity of our total design, but so do other things. At the beginning I had in mind a speaker system with high sensitivity and yet also 8 Ohm. There are speakers that boosts the sensitivity by paralleling drivers, so two 8 Ohm drivers gives us an extra 6dB in sensitivity, but now being 4 Ohm together, draws twice the current. Now let us use our selected 88dB driver as an example. Put two in parallel, giving us 94dB. Take away 4dB for DL compensation, and we will have a final system sensitivity of 90dB and four Ohm. So in terms of sensitivity we have gained 6dB, but in terms efficiency, only 3dB since we have cheated an extra 3db by drawing twice the current.
But I want to gain the whole 6dB and to do that I must use four drivers is combined series and parallel that will give 8 Ohm for the system. I have now gained 6dB in both sensitivity and efficiency. This makes for a speaker system that will be easy to drive and also have very large power handling. It will be compatible with a huge number of amplifiers. Being an 8 Ohm system, we can also avoid the pitfalls of many expensive speakers, where we have frequencies where the impedance and the negative phase angle coincide and place great demands of the amplifier. Our projected system impedance should not drop below 6 Ohm at any frequency and hence even a moderate negative phase angle can easily be accommodated. And this is like most only to occur about 100-200Hz – this will be confirmed when we measure the final impedance/phase of our completed speaker system
According to Zaph its more like 85db, which makes more sense
Besides, my experience with paralel drivers is that the gain in sensitivity is not completely FR linear, but I may be wrong and on dedicated midrange it may not be an issue
Quote from your link to JoeRasmussen:
2. High sensitivity vs. electrical impedance/phase response
Selecting the driver affects the sensitivity of our total design, but so do other things. At the beginning I had in mind a speaker system with high sensitivity and yet also 8 Ohm. There are speakers that boosts the sensitivity by paralleling drivers, so two 8 Ohm drivers gives us an extra 6dB in sensitivity, but now being 4 Ohm together, draws twice the current. Now let us use our selected 88dB driver as an example. Put two in parallel, giving us 94dB. Take away 4dB for DL compensation, and we will have a final system sensitivity of 90dB and four Ohm. So in terms of sensitivity we have gained 6dB, but in terms efficiency, only 3dB since we have cheated an extra 3db by drawing twice the current.
But I want to gain the whole 6dB and to do that I must use four drivers is combined series and parallel that will give 8 Ohm for the system. I have now gained 6dB in both sensitivity and efficiency. This makes for a speaker system that will be easy to drive and also have very large power handling. It will be compatible with a huge number of amplifiers. Being an 8 Ohm system, we can also avoid the pitfalls of many expensive speakers, where we have frequencies where the impedance and the negative phase angle coincide and place great demands of the amplifier. Our projected system impedance should not drop below 6 Ohm at any frequency and hence even a moderate negative phase angle can easily be accommodated. And this is like most only to occur about 100-200Hz – this will be confirmed when we measure the final impedance/phase of our completed speaker system
I thought I was very clear in saying that the efficiency number I was mentioning was the "Cheating" kind. I bought a 4" TB Ti fullrange to test, so I based my guess as to the efficiency on my own measurements. I had the ATB average the amplitude from 300hz-5khz to come up with 88db's. That then avoids the peak in the upper range, which I won't be using, and the roll off that I won't be using.
None the less, as I said, using the voltage sensitivity method, which is sensitivity, not efficiency, the systems sensitivity is going to be circa 97db's at 2.83 volts at 1 meter. I go with this number because its what crossover software uses in calculating the response, and because in the end, all I need is a convention, and thats good enough.
As for the real issues that Joe is dealing with, he was trying to make a speaker which was an easy load and had high efficiency. He likes tube amps and wants a speaker that could be driven by tube amps. He also like Class A solid state and wanted an amp that could be driven easily by Class A solidstate amps lacking the stability of some more robust amp designs (not saying class A isn't robust, its a design choice, just know one of his favorite solidstates doesn't do 4ohm very well). Given the type of amplification I am using, I am not overly concerned with the speakers ease of being driven. I have multiple amplifiers which can easily handle a 4ohm and below load. I'm ok with a nominal 4 ohm load, in fact, given that the speakers I'm thinking of making are so large (By my standards), I think a 4 ohm load will be a good thing as it will give me more amplifier power to work with.
None the less, since you aren't happy with the way I am assessing efficiency, then if I remove the cheating efficiency (The added current), I'm still at 91, and again, the crossover will add a few decibles, not a ton, but 1-2 is reasonable. Assuming I don't zap away all that extra efficiency in heat, we could have a total system efficiency of 91-92 db's, which is ok, no 94-97, but ok. Again though, who cares why its playing louder when the fact remains that it is playing louder in reference to the 8ohm tweeter.
Ok let me just add that as for the difference that Zaph and I came up with for efficiency, its probably a difference in how we calibrate our systems and normalize our curves. Rather than rely with how much gain I think the system is actually measuring, I measure the decibel output with a reference tone, and then adjust the setup for my software until it matches my db meter. I also take voltage measurements of the amplifier during testing to try and ensure I am being consistent. While I think i do a good job, I don't know that I do, I may make mistakes, and in general, my efficiency numbers have been higher than Zaphs. It's also possible that his number is derived from the T/S parameters he measures, where as mine is taken from the response measurement. I want to say that my derived number was 85 or 86 as well.
None the less, as I said, using the voltage sensitivity method, which is sensitivity, not efficiency, the systems sensitivity is going to be circa 97db's at 2.83 volts at 1 meter. I go with this number because its what crossover software uses in calculating the response, and because in the end, all I need is a convention, and thats good enough.
As for the real issues that Joe is dealing with, he was trying to make a speaker which was an easy load and had high efficiency. He likes tube amps and wants a speaker that could be driven by tube amps. He also like Class A solid state and wanted an amp that could be driven easily by Class A solidstate amps lacking the stability of some more robust amp designs (not saying class A isn't robust, its a design choice, just know one of his favorite solidstates doesn't do 4ohm very well). Given the type of amplification I am using, I am not overly concerned with the speakers ease of being driven. I have multiple amplifiers which can easily handle a 4ohm and below load. I'm ok with a nominal 4 ohm load, in fact, given that the speakers I'm thinking of making are so large (By my standards), I think a 4 ohm load will be a good thing as it will give me more amplifier power to work with.
None the less, since you aren't happy with the way I am assessing efficiency, then if I remove the cheating efficiency (The added current), I'm still at 91, and again, the crossover will add a few decibles, not a ton, but 1-2 is reasonable. Assuming I don't zap away all that extra efficiency in heat, we could have a total system efficiency of 91-92 db's, which is ok, no 94-97, but ok. Again though, who cares why its playing louder when the fact remains that it is playing louder in reference to the 8ohm tweeter.
Ok let me just add that as for the difference that Zaph and I came up with for efficiency, its probably a difference in how we calibrate our systems and normalize our curves. Rather than rely with how much gain I think the system is actually measuring, I measure the decibel output with a reference tone, and then adjust the setup for my software until it matches my db meter. I also take voltage measurements of the amplifier during testing to try and ensure I am being consistent. While I think i do a good job, I don't know that I do, I may make mistakes, and in general, my efficiency numbers have been higher than Zaphs. It's also possible that his number is derived from the T/S parameters he measures, where as mine is taken from the response measurement. I want to say that my derived number was 85 or 86 as well.
Well to be honest I don't know the technical reason why. I first started seeing in when designing my first 3-ways and saw an extra decibel or two. I thought it was just a computer modeling artifact, but found my first crossover where I made this assumption was too loud in the midrange, by...interestingly enough, around two decibels. When I got into my discussions with some different designers I found they were making the same claims, that, at least with the midrange and tweeter, you will often see a decibel or two extra from the crossover shaping. I also noticed its in that Elsinore writeup I cited earlier. Like I said, I don't know why it does it, just know it happens.
Again, I normally wouldn't even talk about that, the only reason I brought it up was that I was trying to find a way to explain the 97db efficiency that my models were suggesting. The only way to make the math work was to figure on a decibel or two from the crossover. I actually included in the model too much dcr for the coils too, in order to create a sort of worst case scenario, and still saw that staggering number.
Well after taking some more measurements I went back to the ol' focal towers I've been using to experiment on. I built two new crossovers for them today to try out. The first involved a refinement on the topology I had been using. For whatever reason, I feel like the changes caused the soundstage to become less distinct and more diffused. One change involved putting a 30uf cap in series with the tweeter, so that might have something to do with it. I'm going to remove it, change to a 2nd order, and see if I like things better. The other design I will call a disaster for now, but I'm quite sure something is hooked up wrong. I made a series 2nd order crossover, which modeled pretty well, but doesn't actually sound all that great. Another possibility is that I didn't really have all the parts I needed, so I put in the closest values I had. However, the bass sounded all wrong, I'm wondering if something is hooked up wrong. It measured ok actually, but did have more peaks and valleys than expected. That was one of my first real attempts at a series crossover, so who knows.
Again, I normally wouldn't even talk about that, the only reason I brought it up was that I was trying to find a way to explain the 97db efficiency that my models were suggesting. The only way to make the math work was to figure on a decibel or two from the crossover. I actually included in the model too much dcr for the coils too, in order to create a sort of worst case scenario, and still saw that staggering number.
Well after taking some more measurements I went back to the ol' focal towers I've been using to experiment on. I built two new crossovers for them today to try out. The first involved a refinement on the topology I had been using. For whatever reason, I feel like the changes caused the soundstage to become less distinct and more diffused. One change involved putting a 30uf cap in series with the tweeter, so that might have something to do with it. I'm going to remove it, change to a 2nd order, and see if I like things better. The other design I will call a disaster for now, but I'm quite sure something is hooked up wrong. I made a series 2nd order crossover, which modeled pretty well, but doesn't actually sound all that great. Another possibility is that I didn't really have all the parts I needed, so I put in the closest values I had. However, the bass sounded all wrong, I'm wondering if something is hooked up wrong. It measured ok actually, but did have more peaks and valleys than expected. That was one of my first real attempts at a series crossover, so who knows.
pjpoes said:
Sorry I thought your tweeter was being corssed at 1.6kHz or thereabouts.
Does this bump from 94db to 97db occur across the entier range or only in the region of the crossover to the tweeter?
I dont see much wrong with waveguides. In many cases (SS 9900) they might even be beneficial.
pjpoes said:
tinitus said:
A crossover that is less reactive is nicer on amps than one that just has a highish nominal impedance or high minimum impedance.
Maybe this is important for this thread:
Yesterday I stumgled across this company, which as carbon fiver bass drivers up to 96dB sensitivity. As far as I know the only solution for someone who wants to avoid paper cones.
http://www.davis-acoustics.com/
Yesterday I stumgled across this company, which as carbon fiver bass drivers up to 96dB sensitivity. As far as I know the only solution for someone who wants to avoid paper cones.
http://www.davis-acoustics.com/
There have been some consistency issues with Davis drivers, and typically they don't measure great. They are known for high efficiency, but I'm afraid to use them. The only driver I ever measured was a kevlar unit and it had pretty high distortion and a pretty poor response.
I just want to say that, after a full weekend of crossover experiments, this stuff is hard. I feel like I'm always making tradeoffs with choices. Also, often I find problems that no amount of parts can fix, so then I start removing everything I can until it messes stuff up again. Keep things as simple as possible and no simpler, right. I also find that something can look great on paper (Well computer simulation), and then not measure at all as expected. The current setup I have doesn't look so good on axis at 1 meter. At 2.5 meters around my listening position, it looks fine, overall pretty smooth. It's still nowhere as smooth as I would hope, but I have been taking all final design measurements in room (it's a pain to always go outside for this stuff), and I just found out how to take into account room acoustics, and didn't use them when I was taking measurements.
The final issue is phase measurements. Acoustic phase measurements are really hard to get accurate. Any extra noise, any disturbances, any room interactions seem to massively mess them up. I read through the manual, and they make it pretty clear that, regardless of program, acoustic phase measurements are difficult without an anechoic chamber. I live in a bunched community, so my neighbors look at me funny when I get out a ladder, plop some funky looking wooden towers on top, and start stringing wires everywhere. Then follow that with some obnoxious noises. I often wonder what they think I'm doing
I'm wondering about constructing a miniature anechoic chamber with acoustic sheets like Owens Corning and acoustic foam or felt, one that is just large enough for close measurements of a driver on a test baffle.
I just want to say that, after a full weekend of crossover experiments, this stuff is hard. I feel like I'm always making tradeoffs with choices. Also, often I find problems that no amount of parts can fix, so then I start removing everything I can until it messes stuff up again. Keep things as simple as possible and no simpler, right. I also find that something can look great on paper (Well computer simulation), and then not measure at all as expected. The current setup I have doesn't look so good on axis at 1 meter. At 2.5 meters around my listening position, it looks fine, overall pretty smooth. It's still nowhere as smooth as I would hope, but I have been taking all final design measurements in room (it's a pain to always go outside for this stuff), and I just found out how to take into account room acoustics, and didn't use them when I was taking measurements.
The final issue is phase measurements. Acoustic phase measurements are really hard to get accurate. Any extra noise, any disturbances, any room interactions seem to massively mess them up. I read through the manual, and they make it pretty clear that, regardless of program, acoustic phase measurements are difficult without an anechoic chamber. I live in a bunched community, so my neighbors look at me funny when I get out a ladder, plop some funky looking wooden towers on top, and start stringing wires everywhere. Then follow that with some obnoxious noises. I often wonder what they think I'm doing
I'm wondering about constructing a miniature anechoic chamber with acoustic sheets like Owens Corning and acoustic foam or felt, one that is just large enough for close measurements of a driver on a test baffle.
PJ,
Did you ever come up with a design idea for your new system. The reason I ask is that I think I have come up with a good way to design a high efficiency medium sized floor standing speaker with a reasonably narrow baffle. I have this design problem which is different than the one I have for the HT. I want to replace some inexpensive stand mounted two-ways which are in the living room system with a nearly full range, dynamic, easy to drive speaker. Right now I have a Morel MDT33 hanging around unused and my idea is to use it as the starting place. The idea is to select drivers that allow for high dynamic range and sensitivity which will also sound better at low volume levels. After all of my iterations I have hit upon this formulation and I though you might consider it.
First, I have a 92.5 db sensitive tweeter that I want to use and I want to use it without having to pad it down much, if at all. So then I need to find a mid bass with around a 93-94 db sensitivity. The only one that I have been able to locate thus far with a reasonably smooth response is a Foxtex 6 inch full ranger. I generally like my upper end about .5 db lower in volume and crossed around 3kHz and this driver should work for this. Pro tweeters and drivers could be used to create an even more efficient system.
Next come the rest of the design concept. Dealing with baffle step and getting good bass in a small narrow cabinet.
The idea is kind of like a Watt/Puppy with a pyramidal upper two way unit on top of a lower bass unit. THe difference is that it will be a little taller and narrower and have a slightly sloping side wall on the lower cabinet. The kicker is that I will use 4, 6.5 or 7 inch drivers wired in series parallel to give an 8 ohm load for the lower section. This will keep the cabinet narrow enough to make it easier to place and have higher WAF. Now, since there will be four drivers shouldering the load and operating in only the lower frequencies, they do not need to be expensive drivers but can be of good quality value priced drivers.
The idea is to cross the lower units at or near the BSC frequency and select the sensitivity of the drivers so that combined they give the needed BSC. This should give me the full 6db of BSC without any additional power drain from the amp if the woofers have the same sensitivity as the mid/bass. Together, the lower drivers will have the surface area of a 12 inch driver so I should get good air coupling for better bass dynamics.
I will probably only want 2-3db of BSC in the room for these speakers so I will find some drivers of a little lower sensitivity than the mid/bass. So as I see it I could have 96-99db sensitivity in the lower octaves which should be quite dynamic for a speaker using standard home audio drivers.
The beauty of this approach is that I don't have to waste driver efficiency and use much if any resistor padding on the drivers which can rob the life out of drivers.
Did you ever come up with a design idea for your new system. The reason I ask is that I think I have come up with a good way to design a high efficiency medium sized floor standing speaker with a reasonably narrow baffle. I have this design problem which is different than the one I have for the HT. I want to replace some inexpensive stand mounted two-ways which are in the living room system with a nearly full range, dynamic, easy to drive speaker. Right now I have a Morel MDT33 hanging around unused and my idea is to use it as the starting place. The idea is to select drivers that allow for high dynamic range and sensitivity which will also sound better at low volume levels. After all of my iterations I have hit upon this formulation and I though you might consider it.
First, I have a 92.5 db sensitive tweeter that I want to use and I want to use it without having to pad it down much, if at all. So then I need to find a mid bass with around a 93-94 db sensitivity. The only one that I have been able to locate thus far with a reasonably smooth response is a Foxtex 6 inch full ranger. I generally like my upper end about .5 db lower in volume and crossed around 3kHz and this driver should work for this. Pro tweeters and drivers could be used to create an even more efficient system.
Next come the rest of the design concept. Dealing with baffle step and getting good bass in a small narrow cabinet.
The idea is kind of like a Watt/Puppy with a pyramidal upper two way unit on top of a lower bass unit. THe difference is that it will be a little taller and narrower and have a slightly sloping side wall on the lower cabinet. The kicker is that I will use 4, 6.5 or 7 inch drivers wired in series parallel to give an 8 ohm load for the lower section. This will keep the cabinet narrow enough to make it easier to place and have higher WAF. Now, since there will be four drivers shouldering the load and operating in only the lower frequencies, they do not need to be expensive drivers but can be of good quality value priced drivers.
The idea is to cross the lower units at or near the BSC frequency and select the sensitivity of the drivers so that combined they give the needed BSC. This should give me the full 6db of BSC without any additional power drain from the amp if the woofers have the same sensitivity as the mid/bass. Together, the lower drivers will have the surface area of a 12 inch driver so I should get good air coupling for better bass dynamics.
I will probably only want 2-3db of BSC in the room for these speakers so I will find some drivers of a little lower sensitivity than the mid/bass. So as I see it I could have 96-99db sensitivity in the lower octaves which should be quite dynamic for a speaker using standard home audio drivers.
The beauty of this approach is that I don't have to waste driver efficiency and use much if any resistor padding on the drivers which can rob the life out of drivers.
yeah I have also considered designs of a similar nature. I'm really unsure at this point what I want to do. I'm even considering the Geddes kits, which I know go against everything I have been saying, but I dont know. I mean, I just can't come up with something that sounds good to me, has the efficiency I want, and the dynamic abilities. I'm trying to decide if I can live with such large speakers.
Earl is saying the 12" is better in every way and I should get those, but I mean, 22" wide isn't exactly a small thing to hide. I feel like my best bet would be to turn them into a work of art, and not try to hide them. you know, fancy veneer, unusual enclosure shape, and maybe painting the baffle some bright color or something. We shall see, I still prefer the idea of a smaller profile speaker, but I keep hearing good things about them, and there seems to be some pretty sound science behind the designs.
I ended up getting a bunch of those Dayton 8" reference woofers and building a test baffle for my focals. I wired them so the Focals were basically a mid and tweet, around 90db efficient. Then wired up 4 of the woofers per side in a series parallel configuration giving me around 91-92db's efficiency. I wired them up using a series crossover on top, and a parallel configuration for the woofers. Still wasn't enough for me, I wanted more. I felt like the midrange and tweeter still could sound compressed durring large peaks. I tried replacing the tweeter with the HDS peerless, it was no better. I mean, its a great tweeter, but it just didn't give me what I was looking for. I even tried replacing the focal midrange driver with a Seas unit, running that with the Focal tweeter and the HDS tweeter, still wasn't what I wanted. I'm just thinking I really want serious efficiency to get the kind of dynamics and realism I'm looking for. None of these setups, as good as they may be, gave me the effortless sound I'm looking for.
Now, having said all that, I've never heard a big wide monster speaker that imaged good. I've owned two large towers, which imaged horribly. My father owns Klipsch Corner Horns, they don't image well, IMO. Only speakers I have heard that imaged well generally had a narrow footprint, so that is one thing that concerns me about the big wide speaker idea. I mean, will I be making another trade-off.
Earl is saying the 12" is better in every way and I should get those, but I mean, 22" wide isn't exactly a small thing to hide. I feel like my best bet would be to turn them into a work of art, and not try to hide them. you know, fancy veneer, unusual enclosure shape, and maybe painting the baffle some bright color or something. We shall see, I still prefer the idea of a smaller profile speaker, but I keep hearing good things about them, and there seems to be some pretty sound science behind the designs.
I ended up getting a bunch of those Dayton 8" reference woofers and building a test baffle for my focals. I wired them so the Focals were basically a mid and tweet, around 90db efficient. Then wired up 4 of the woofers per side in a series parallel configuration giving me around 91-92db's efficiency. I wired them up using a series crossover on top, and a parallel configuration for the woofers. Still wasn't enough for me, I wanted more. I felt like the midrange and tweeter still could sound compressed durring large peaks. I tried replacing the tweeter with the HDS peerless, it was no better. I mean, its a great tweeter, but it just didn't give me what I was looking for. I even tried replacing the focal midrange driver with a Seas unit, running that with the Focal tweeter and the HDS tweeter, still wasn't what I wanted. I'm just thinking I really want serious efficiency to get the kind of dynamics and realism I'm looking for. None of these setups, as good as they may be, gave me the effortless sound I'm looking for.
Now, having said all that, I've never heard a big wide monster speaker that imaged good. I've owned two large towers, which imaged horribly. My father owns Klipsch Corner Horns, they don't image well, IMO. Only speakers I have heard that imaged well generally had a narrow footprint, so that is one thing that concerns me about the big wide speaker idea. I mean, will I be making another trade-off.
PJ,
I may have an idea for you. I saw a pair of the most interesting speakers the other day on the internet. I think it was a picture from a trade show in Europe. I've got a picture of it on my other computer and I will go get the picture and post it. It was essentially to me a beautiful way to organize a two box speaker system utilizing a large bass module combined with a separate upper mid/bass module into something that was geometric art.
The reason I think these are artistic is because the box configuration makes it look like the boxes are balancing precariuosly on each other and are about to fall over. The metal brackets holding them would be easy to weld up and fabricate.
Here is a picture of it. Now here is the idea. Build an upper head unit like the Geddes in either a 12 inch or 8 inch high quality pro driver combined with a higher frequency driver using a 8 or 12 inch wave guide. Make the upper cabinet as narrow as possible to fit the drivers. I like the idea of open back or aperiodic in the upper unit. The bottom you should be able to build a 5-9 cubit foot cube and put a good 18 inch pro low frequency driver in it. Or even a 21 inch unit!!
I'm thinking that the way the air spaces around the upper cabinet are with this configuration it could get better imaging like a smaller speaker on a stand. Tell me what you think.
I may have an idea for you. I saw a pair of the most interesting speakers the other day on the internet. I think it was a picture from a trade show in Europe. I've got a picture of it on my other computer and I will go get the picture and post it. It was essentially to me a beautiful way to organize a two box speaker system utilizing a large bass module combined with a separate upper mid/bass module into something that was geometric art.
The reason I think these are artistic is because the box configuration makes it look like the boxes are balancing precariuosly on each other and are about to fall over. The metal brackets holding them would be easy to weld up and fabricate.
Here is a picture of it. Now here is the idea. Build an upper head unit like the Geddes in either a 12 inch or 8 inch high quality pro driver combined with a higher frequency driver using a 8 or 12 inch wave guide. Make the upper cabinet as narrow as possible to fit the drivers. I like the idea of open back or aperiodic in the upper unit. The bottom you should be able to build a 5-9 cubit foot cube and put a good 18 inch pro low frequency driver in it. Or even a 21 inch unit!!
I'm thinking that the way the air spaces around the upper cabinet are with this configuration it could get better imaging like a smaller speaker on a stand. Tell me what you think.
Attachments
it is very cool looking. The negative would be how to make everything sturdy. I mean, it looks like they have some v-shaped "saddles" to hold everything in place. I would wager money they are metal, probably steel. I bet I could have something similar fabricated, but I think it would be out of my own construction abilities.
What I like about that most though is that as far as box design, they are just normal boxes, used in unusual ways. The fabrication of the boxes themselves isn't anything difficult.
Now as for the supports, I wonder if another way would be to secure them from the rear? Another idea would be to build a reinforced wooden saddle with dowels out farther offering further support.
I wish i had better metal fabrication skills, I'm sure that isn't hard for someone with any abilities in that area.
You know Hezz, while I love all your input, I'm starting think you just like spending my money
. This would be very cool if I could get it together.
What I like about that most though is that as far as box design, they are just normal boxes, used in unusual ways. The fabrication of the boxes themselves isn't anything difficult.
Now as for the supports, I wonder if another way would be to secure them from the rear? Another idea would be to build a reinforced wooden saddle with dowels out farther offering further support.
I wish i had better metal fabrication skills, I'm sure that isn't hard for someone with any abilities in that area.
You know Hezz, while I love all your input, I'm starting think you just like spending my money
. This would be very cool if I could get it together.- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.