Here's the before and after of the scrapped out Santana crossovers I used, these fit the Model 19 and A7's without any alteration, Dave.dgwojo said:Here's the pics of the crossovers I recently worked on, the first one is MJHAMMER's Altec Model 19 upgrade, and the second was mentioned earlier in this thread, both have excellent results, Dave.
streckfu said:
mhardy6647 said:
onplane said:
onplane said:
Mike Stehr said:
SET12 said:I think the Altecs look great! A very nice job is done on those!
Here you go I have a CD for scale notice that it is about the same dia. as the stock crossover plate and crossover componets the large inductor is of course the low frequency inductor the other inductor being for the tweeter these are just stock componet values nothing was changed although the DCR's of the inductors are lower.
The Forte for having a passive radiator has very taut powerful bass I won't call it any where near world class bass ( that is bass with excellent pitch defination) but the Forte has a strength that has never called a need for a sub often people ask where is my sub and often are shocked to hear there is none and often further shocked when I tell them after I put some Rap on for them that they are listening to just 5.5 watts rms when their car stereo is usually several hundred watts then I usually get a statement like "How can that do that"
The midrange is very full lots of defination and body and life size imaging.
The top end is smooth and extended but very revealing of ambiant ques especially of relaying the recordings acoustic size.
Lateral imaging is nothing short of astounding imformation often extends 5-10ft left and right of the speakers thru the side walls they are about 9ft apart, Depth and layering are extordinary, Image height could be a little taller according to some listeners but more than enough for me.
Little did I know a few yrs ago that I would be listening to of all things a "Klipsch"
SET12
My advice would be to find a proven "recipe" from a proven design and build that as a first time project. While off the shelf crossovers work OK in the realm off high eff. stuff with horns and compression drivers, for speakers discussed here they really dont. One of many things not taken into consideration in these discussions is the natural roll off of the drivers. when using off the shelf drivers they must first be broken in and carefully measured. Relying on printed specs will lead to problems, rarely have I found a driver that consistently measures like printed specs. Once you know the actual response of your indiviual drivers can you properly design a cross over to work with those drivers. Installing a "12 db" 2nd order crossover with random drivers does not mean you will get 12 db per octave. some drivers may very well, depending on the selected crossover frequency, already be dropping off at 6db or 12 db per octave...adding an additional 12 db would result in either 18 db ( third order) or 24 db (forth order)...not 12 db. now your phase relationships between the two drivers are off and the srossover region is anything but smooth. Also, off the shelf crossovers will never make up for driver response abnormalities, like tweeters with peaks at their resonant frequencies, or mid ranges or mid woofers with rising responses, particularly kevlar or other stiff cone materials. To cure these problems, again, the drivers must be individually measured and then a crossover designed to correct for them. Many crossovers will appear to mix 6 db with 12 db or 18 db circuits (electrically) but when combined with the actual driver response results in the correct slopes at all crossover points. This is also the explaination for a lot of the cost of commercial speakers besides shipping, packaging,etc...The R and D to design proper drivers with proper crossovers and proper compensation built into said crossovers for the drivers chosen, and then get all the phase relationships between the drivers to be correct. This is sometimes why, as others have mentioned here, that sometimes you will see drivers polarity reversed compared to the other drivers. In cases like that, the phase relationship between the drivers is off 180 degrees (hopefully), so a driver is reversed. Putting together speakers is great fun, but throwing drivers in a box with an off the shelf, or designed from a chart of crossovers showing impedance and crossover point and slope does not result in those slopes, points or impedances (which vary wildly between drivers and frquency of any given driver), and the results suffer. Yes, many expensive speakers sometimes use surprisingly inexpensive drivers, but get great sound....but they have invested lots of time and money measuring those drivers and designing the perfect crossover for them. Similarly, buying expensive drivers and using off the shelf crossovers, or "chart designed" crossovers will give mediocre, and sometimes terrible results. Many "expensive" drivers have all sorts of frequency abnormalities that MUST be corrected through crossover comensation net works to glean the advantage of the driver. If one must use off the shelf parts, you want first, as simple a speaker as possible, i.e. 2 way instead of 3 way, and find drivers that are flat for a couple of octaves either side of the crossover point. ( not easy to do) Then, measure the impedance of the actual driver at THAT crossover point, and use your chart to come up with components for that impedance. Now, you may need some sort of ciriut across the woofer to hold its impedance as flat as possible through this region. Now, All you need is a tweeter with the same measurement at the same point...GOOD LUCK! at best, youi will likely end up with a compromise. Try threeway? it gets much more messy. the first speakers I built were based on the "select the drivers" and select a crossover, and for the money, didnt sound bad at all...but, once you see what can be had with a properly designed speaker the margin is not small. For all these reasons and more, I would work from a known recipe, from a designer ( like Joe Diappolito for instance) who has taken the time to get to know the drivers and has the skill and equipment to properly compensate the drivers, not just cross them over. This said, there are many speaker driver manufacturers out there who offer "recipes" that are no more than throwing textbook crossover in with their drivers. If you are not seeing compensation for resonant peaks, mixed slopes between drivers and other hints of an individually designed cross over for that specific application, you are probably being sold just a text book crossover. Yes it will work, but if you want to strive for true HIGH END results, "off the shelf throw togethers, while fun, will not get you there.streckfu said:
Again, using an 18 db crossover does not mean you will end up with 18 db crossover slopes, the ACTUAL response of the driver must first be known. This entire discussion presupposes that drivers are spot on their rated impedance and response extends smoothly through a few octave either side of the crossover region....this simply does not happen. As to having no reason not to use an 18 db cross over, well, there are many. One, is that as already stated, using an 18 bd "crossover" does not mean that is what you will end up with. Say for instance, you are building a two way speaker crossed over at 2500 hz. Lets say your woofer/mid range driver's response is fairly smooth and naturally falls off at 6 db per octave at 3500 hz. Adding an electically 12 db per octave crossover will result in 18 db per octave slope when combined with the natural 6 db slope of the driver, while if you had added an electrically 18 db per octave crossover would actually result in 24 db per octave. Plus, there are various different types of crossovers out there available in 6, 12, 18 or 24 db per octave. If used on both sides, the actual crossover point will sum differently at said crossover point for each of these different types. There is simply no way that throwing in a calculated crossover into a box with a couple of drivers is going to result in a proper blending of the drivers. This only begins the discussion, as phase, step respose, baffle width, lobbing, resonant peaks, and other myriads of factors needs to be considered to really properly meld drivers in a system, let alone get all there is to get out of the selected driver.MarkAnderson said:Good reading, Paul. I actually learned a thing or two today. Thanks.
Yes, this is the type of info that will result in a truely satisfying speaker, with out breaking the bank. Someone must do the r and d to design a system which properly mates the drivers and compensates for their various response qwirks. This can only begin after the drivers have been properly measured, in terms of response, impedance at various freqncies, resonant peaks and so forth. appears this chap has done so and lists the results of many of the drivers on this site. Going to this trouble can make the difference between a nice sounding ( or sometimes not so nice) system and a great one, whether one is using expensive or inexpensive drivers.lndm said:
the path you took is another way....Improving a known properly designed system. Capacitors and so forth are a lot better than what was available 20 years ago. This way also uses a properly designed crossover, designed specifically for these drivers in a particular apllication. Klipcsh did the R & D, you improved on it. Agreed, this is much much more likely to give a proper result than throwing chart info into a box.SET12 said:
Parts Express used to have a whole bunch of designs available from various sources. While you may have to examine them, some of them are vary scienced out, while others are possibly "textbook" designs, you may want to look at them, or the ones on the link Indm provided.streckfu said:
