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Re: New Beta clones from MCM

Posted: Thu Sep 09, 2010 1:22 am
by SeisTres
Buying CD that reaches down to the crossover point would negate all the cost saving of the woofer and not to mention the woofer section will not keep up at all. So at this point, you will be better getting the 2510 or beta and the cheap asd or the piezos. And no, piezos can't reach that low. Also remembered that the published graphs have the right woofers with the rising response AND the crossovers, so not having the rising response will hurt won't be fixed by low pass filter.

Last I read on the plans, the dispersion for the diffraction horn was 100 degrees, and I would guess 90 for the flat. and you can really use any tweeter with any dispersion as long as it meets the required spl levels and has the dispersion you require. So if 100 degress works for you on close range, then it will do ok.

I got the 2961's and the 8" that were similar to that. Actually i will be tuning it somewhat like the wedge 10 which is extremely low since my brother will be using almost always (if not surely always) at his house for full range. I have no idea on the tuning but I'd would guess it's around 55hz.

So to sum it up, if you want to play around building your own designs or a jack, it will do ok, but if you actually plan to run a paying gig with them, i'd go for betas.

I believe the mcm 8" subwoofer had the same thing as they were not listing the oneway xmax but the overall.

Re: New Beta clones from MCM

Posted: Thu Sep 09, 2010 12:35 pm
by Charles Warwick
SeisTres wrote:Buying CD that reaches down to the crossover point would negate all the cost saving of the woofer and not to mention the woofer section will not keep up at all. So at this point, you will be better getting the 2510 or beta and the cheap asd or the piezos. And no, piezos can't reach that low. Also remembered that the published graphs have the right woofers with the rising response AND the crossovers, so not having the rising response will hurt won't be fixed by low pass filter.
Eh, I beg to differ since the woofers were $15, a cheap CD is about 30 bucks, and no matter kind of woofer you have the CD usually does out pace it. I'm aware that piezos won't reach that low, which is why I suggested the CD's since some can. The rising response is generally 1K and up, so I think think that a 3db bump one way or another isn't going to hurt drastically since 3 db is barely perceptible. Ah, yes the filters are applied to both. Speaking of mistakes, let's examine this bizzare SPL chart. :fruit:


Well that was fun, I wonder what happened... regardless my point was attempting to say that yes indeed the filter does help the at 1000hz since the 2510 it is normally only up 1.5 db from the rest of the chart at 1000hz, my bad. :slap:
SeisTres wrote:So to sum it up, if you want to play around building your own designs or a jack, it will do ok, but if you actually plan to run a paying gig with them, i'd go for betas.
I suppose I should emphasize that they are not for professional use, simply for outdoor use in a home install. I figure a slightly lower performance pair of Jacks will far exceed anything I can buy that is a dedicated outdoor speaker and since the driver is cheap I don't have to worry too much about it getting damaged, since I'm not really interested in putting 120 bucks worth of paper in a box outside. I may end up trying this cheap thing out since they are not for especially high levels of playback: http://www.parts-express.com/pe/showdet ... r=292-2546

Re: New Beta clones from MCM

Posted: Thu Sep 09, 2010 3:56 pm
by SeisTres
Yes, that's what I mean. The NSD is almost $100, and all the other cheaper options have a recommended crossover point that is higher than that and forcing them to go lower would be like using the beta10 in the t39; it will work but will have alot of disadvantages. As for the pyle, I would take most of those things listed with a big grain of salt. I would pyle quality below everything guitar center sells, dayton, mcm brand, nady. But who knows, you might get lucky with that item.

However, for your intended use, they would actually be very good since everything on the front of the woofer is weather-treated unlike the betas which is is just plain paper.

Re: New Beta clones from MCM

Posted: Fri Sep 10, 2010 12:56 am
by Charles Warwick
SeisTres wrote:As for the pyle, I would take most of those things listed with a big grain of salt. I would pyle quality below everything guitar center sells, dayton, mcm brand, nady. But who knows, you might get lucky with that item.

However, for your intended use, they would actually be very good since everything on the front of the woofer is weather-treated unlike the betas which is is just plain paper.
Hm...knowing that perhaps I'll look around for a different CD that still meets my criterion and is of a different brand. I can only take so much salt in my diet and that grain may push my tolerances :lol: . It's at least worth the effort in case I do find something. If I did end up with the pyles (sounds like an STD or something...) could I run a sweep on it to confirm that 1200hz is within its passband, and thus limit the possibility of blowing them straight out? I figure if the sweep shows it at -6db at 2000hz or something I can just return them to PE within 30 days.

I was not aware the woofers are treated, as I will not be getting mine until mid November (apparently the sale really did move some units and I ordered mine too late)! That's quite nice to hear actually, I had been considering putting a coat of clear-coat or something similar to it on whatever I decided on, but was afraid it would alter the fs too much so decided against using it, and now I find the one I've bought already has it applied! Hurray :hyper:

What kind of design were you thinking for the 2X10''? Something along the lines of an MTM? 10'' dispersion really fails above 1600 hz or so, so maybe a 1500 hz crossover depending on what HF you were thinking of using... I'll have two extra to made something out of as well, so I'll be curious to see how yours goes.

As a random side note, I always thought this was a very useful thing to know/keep on hand:
Image

Re: New Beta clones from MCM

Posted: Fri Sep 10, 2010 2:04 am
by SeisTres
I'm basically going to take the generic 215+cd horn (think jbl srx725), shrink it down to accommodate 10" and tune it much lower as will be used inside a will have to do full range. My brother will probably use some peavey stuff for the tweeters and as far the crossover, it will be totally up to him, too. But if it was for me, I would use a single woofer per cab, tune it around 50-60hz, put two piezos cut and glued like the flat array, use only a resistor for the piezos and and call it a day. For porting, I'm going to be doing pretty much like the omni where no tuning tubes are used but the cab itself plays the role (or the jacks too).

As it will just a plain box, without hardware or any type of angled horn cuts, and front loaded, it should only take couple of hour from start to finish. As I told my brother, if he wants any of Bill's designs, they take much longer and for those he can either build them himself or I will charge accordingly, both of which he did no like. However, for what he wants, it will be perfect.

Re: New Beta clones from MCM

Posted: Fri Sep 10, 2010 4:56 am
by Chris_Allen
Charles Warwick wrote:Speaking of mistakes, let's examine this bizzare SPL chart. :fruit:
I really need to fix that - the dataset managed to get merged with another one in the mid section. The Jack's need redoing anyway for the phase plug.