Econowave tweeter + which woofer?

[ScottG]

1) He also stated that it did not require HF compensation. His measurement is below. It needs at least 6 dB of HF comp.

2) Despite being too small to match directivity with a large woofer, the CTC spacing will still place the vertical nulls within the pattern of a smaller one.

1. An error. It happens (..obviously).

2. What design are you talking about here?

 

[ZilchLab]

1. An error. It happens (..obviously).

2. What design are you talking about here?

You're saying EconoWave will not mate well with a 15" woofer. Despite the fact that JBL does that in some products, I agree; it won't play low enough to match directivity, no matter what driver is used with it, I don't believe.

You also seem to be arguing that, being asymmetric with a "short" mouth height, it won't mate up with a 10" or 12" driver either, as it loses pattern control in the vertical at a higher frequency than in the horizontal. That's not fatal, either, and Wayne has documented the utility, indeed, advantages, of narrower directivity in the vertical, compensating for this by placing the vertical nulls to augment the pattern in this region.

I don't know RCF H100 from a hole in the ground other than what specs I have been able to find online this morning. It is variously termed a 90° x 75° and a 60° x 40° constant directivity horn. In any case, its 8.66" maximum mouth dimension would appear to belie any applicability one might ascribe to it as resolving these directivity and uniform power response issues in combination with 10" to 15" woofers.

In this context, the fact that one user "likes" it better with DE250 than EconoWave with Selenium D220Ti does not seem to comprise a particularly compelling argument, whereas some other combinations very well might. EconoWave is admittedly "entry level," but I believe we are hard pressed finding any alternative to match it in value. DE250/H100 is three times the cost; I'd be looking for commensurately improved performance....

 

[col]

Econo EconoWave

econo econowave? Post #11 Hi, I am just about to embark on a simple 2 way design based on the econowave ideas using a 12" high efficiency PA type woofer, the Pioneer A30GC50-52F-Q-1 This is my first ever speaker build.. getting lots of help and advice from Col on how to approach it. Thanks Col! I'l be using the Pyle PH612, but one current diversion from the standard econowave script is I'm trying the Pyle PDS221 compression drivers rather than the Selenium ones. I suppose since the Zilch econowave crossover is crafted for the Selenium drivers response I'll have to do a fair bit of measurement to get suitable crossovers happening... but still waiting for that bit of gear to be delivered. Right now gathering information and waiting for the rest of the gear to arrive - though I have the woofers so at least can start scoping out cabinet sizes from the parameters served up from woofertester. Cabinet will be a simple bass reflex MDF design, and the result is to be be an upgrade to my Alesis Monitor One (mk I) speakers. I'll post more updates in a separate thread once things get further underway.

Hi Zog,

This will be an interesting project, I hope we can devise a passive crossover that will mate the Pyle PH612 with the Pyle PDS221, with good results. I have no experience with the Pyle PDS221 but it certainly was cheap! So worth giving it a shot. Trying to find bang4buck drivers in Australia is difficult, we have a very limited market to scavenge and if we have to import drivers from the US or elsewhere the postage costs make the project prohibitive. For example, to import a pair of the Selenium D220Ti would add around a $100 in shipping to the budget.

After searching around the net looking at what the Aussie suppliers had to offer the Pioneer A30GC50-52F-Q-1 12" woofer and the Pyle PDS221/PH612 were by far the cheapest best spec'd drivers I could find.

Usually I don't bother with passive crossovers as all my systems use active crossovers and active EQ'ing. So this will be a good learning process for me too. I hope our friends here in this forum will be able to give us some hints on how to make the Aussie version, Econo EconoWave sound good


col.

 

[Russellc]

"This isn't to say that a 2-way design can't sound good - but rather that the design will likely have *significant* compromises - especially if you are looking for certain character traits in the design. For some, this could be more compromises than they are willing to accept. (..and in fact with the way Zilch was trying to maintain pattern control with low diffraction as Earl had - it would seem that it would be insufficient for Zilch as well.)+


Not only can they, In my opinion as well as many others they do. ( I realize this is all subjective and so forth ...) The 4430 is a great sounding monitor within spl constraints, which are still quite liberal. I went to 2 way
experimentation for exactly the opposite reason, compromises inherent in 3 way systems. Not that they cant also be designed to sound quite good, I found the simplicity appealed to me sound wise as well as design wise. The C-D effect is so large and stable. I hadnt previously experienced any kind of multiway C-D response.

I've got nothing against multiway, and am planning at some point to do a three way with JBL 12-15 in bass drivers, a set of 2123H on some of Wayne's mid horns, and B&C DE 250 on Eminence H290, together with Waynes crossover. My thought was it would give C-D response for the mids and highs to a large degree anyway, in a nice three way package.

Not sure what you mean by any problems Zilch had with the econowave and Earl's measurments, but they seemed to show exactly what we expected them to show. Maybe I misunderstand what you were saying? Sorry in advance if so. As long as everyones having fun.

russellc

 

[ScottG]

You're saying EconoWave will not mate well with a 15" woofer. Despite the fact that JBL does that in some products, I agree; it won't play low enough to match directivity, no matter what driver is used with it, I don't believe.

You also seem to be arguing that, being asymmetric with a "short" mouth height, it won't mate up with a 10" or 12" driver either, as it loses pattern control in the vertical at a higher frequency than in the horizontal. That's not fatal, either, and Wayne has documented the utility, indeed, advantages, of narrower directivity in the vertical, compensating for this by placing the vertical nulls to augment the pattern in this region.

Actually it *might* mate well with a 15", rather it just seems *highly* unlikely, and most notably JBL didn't manage it. (..it would probably be a rather unorthodox arrangement however.) The same of course is true with 12" and a 10".

This is what I'm saying:

I think that ctc spacing between acoustic centers for the drivers, (specifically at and near crossover freq.s), likely will be a problem IF the actual crossover removes the primary resonance for the horn.

In other words, to use this combo (compression driver + waveguide) to it's best effect requires suppressing the major point of resonance and diffraction from the horn which occurs at around 1.8 kHz. Basically it needs to have an *actual* crossover at around 2.5 kHz with a very steep filter, OR even higher in freq. with a filter that is less "steep". Of course combing may not be a problem at higher freq.s because of vertical directivity from both drivers/waveguide, but that won't be true near the crossover (at least for most drivers).

Here is Brandon's decay plot of the compression driver + waveguide:

http://493531664873718246-a-1802744..._0XULuBOCzbQMVFkKGbUQFiUgNQZM6kFghQzTq4W5Cw==


Finally you have to consider both the linear decay of the partnering (10,12, or 15" driver), and its off-axis response at various horizontal axis for a smooth summed response. Most 12" drivers for instance start into their primary break-up right above 2 kHz. (which isn't quite high enough in freq..) They also don't have quite enough loss in pressure off-axis (at lower freq.s) to sum well with the waveguide (and possibly a little to much loss in spl at higher freq.s). Worse, the steeper the filter the worse summation off-axis.


I'm not saying you couldn't find a driver that worked well, rather that I haven't seen one.

I agree with you on the H100. I had thought it's lower freq. extension was more than what it is. The recommendation I gave is worthless.

Interestingly enough (i think) you *could* use the QSC waveguide that Bradon recommends and largely avoid many of these problems. It's mouth transition (to baffle) is so smooth that there is very little ripple or prob.s with decay. Frankly it's *better* than Earl's (..of a similar diameter). I wouldn't have a problem using it pretty much down to its lower freq. limit, AND with a less steep crossover (for a smoother summed response off-axis). It's also priced lower than JBL waveguide. You of course still have the problem of the accompanying driver selection, and while the AE TD12M might work very well for it, that isn't a nice cheap solution. Who knows, maybe that Selenium 15" with an LR 4th order low-pass around 1.4 kHz would work? (I think that the QSC waveguide's outer diameter could be trimmed some - probably nearing a full inch on both "top and bottom" without any serious consequences.) Though perhaps my thinking is shot here as well.

For reference:

http://493531664873718246-a-1802744...GVgu8cn1Lt1H_VMxFboVTJZHunSAml4LH3AQrZWYvdoRY

http://493531664873718246-a-1802744...M4JhL0fMHNC9J9zLoxJohqdt0y41Z2OGo-NW-dQYlAd9q

http://www.avsforum.com/avs-vb/showthread.php?p=16576418

http://soundmaster.tradernet.eu/products/prod00000013/15PW3.pdf

 

[ScottG]

Not only can they, In my opinion as well as many others they do. ( I realize this is all subjective and so forth ...)

russellc

No worries. I was thinking of it in context to get the very best performance it can offer.

Basically Zilch (in a 2 driver format) has opted for inferior linear decay and some ripple, and if that doesn't bother you then it really doesn't matter. Further, I wouldn't be at all surprised if your perspective wasn't similar to many if not most, and likely Godzilla (who, from what I remember, happens to love good sound on the cheap).

BTW, as an "post-edit" to my previous post, here is Brandon's testing (that didn't come up in direct link):

http://sites.google.com/site/drivervault/driver-measurements

 

[ZilchLab]

Though perhaps my thinking is shot here as well.

For starters, several of your links are returning "Insufficient Privileges," but I believe I get your gist.

I assume the CSD you linked is to BMS4540 on Pyle PH612. The impedance plot (not provided) would indicate where the primary resonance is; that driver is not recommended to be crossed below 1.9 kHz, as I recall. It seems as though you are arguing that the primary resonance should NOT be highpassed out, but then pointing to it in the CSD as indication of how bad it is? That combination looks clean above 2 kHz to me.

As example, here's an actual JBL product using the EconoWaveguide (with a JBL driver) crossed at 2.2 kHz:

http://www.jblpro.com/catalog/support/getfile.aspx?doctype=3&docid=668

Despite the obvious minimization of C/C distance with the 15" driver, the vertical nulls are very apparent in the crossover region. However, look also at the horizontal -- why is it sagging at 1 kHz? Not for the reasons you suggest, rather, because the woofer cannot support output to 90° beamwidth there; the directivity match is not optimum, much as is also seen with the Selenium 15" you link. 2.2 kHz is clearly too high a crossover frequency, and that small JBL 2412H compression driver cannot deliver the requisite SPL at a lower frequency, even though the waveguide itself would support it. Those were JBL's design tradeoffs for this product at its price point. The performance compromises of the more expensive variants in that product line may be seen differently.

The subject QSC is a rectangular waveguide, no? Why are you suggesting shaving its "diameter?"

In any case, despite its larger size than EconoWave, it is clearly losing pattern control below 2 kHz, more so in the vertical due to it being asymmetric, as well. In this instance, we do have the impedance measurement (but no CSD) evidencing a DE250 resonance peak at 1.6 kHz, which may become an issue crossing in that region or below once the requisite HF comp is applied, much as is apparent in the CSD using that driver on XT1086, which I have posted elsewhere in this forum.

 

[Godzilla]

I posted this thread seven years ago and finally purchased the Eminence Lil' Buddy!

At first listen it sounds amazing on open baffle (on top of H-frame for bass). The look of the driver is very unique and when I tell people it's made from hemp they usually bring their nose closer to it to smell it. Vocals sound very natural and warm, very realistic and three dimensional in my apartment. The cone is green in color and without a pliable surround. It's like the most expensive cheap driver ever made - I love the simplicity of its design. I know Magnetar has used the Lil' Buddy to good effect and hope he chimes in.

I'm currently figuring out a good tweeter solution without having to build a complicated crossover. I purchased the Eminence 1.6kHz crossover and will leave it at that for a while - and enjoy some music as I wrap my head around pro drivers and swap components in and out. I'm accustomed to 'home' drivers by Tangband, Vifa, Fostex, etc. - mostly full range drivers.

I purchased two compression tweeters:

Dayton DT250-8
Eminence PSD: 2013

And three horns:

PRV Audio WG35-25-B 1" 90 x 60 ABS Waveguide 2-Bolt

Dayton Audio H6512 6-1/2" x 12" Waveguide 1-3/8"- 18 TPI

Dayton Audio H812 1" Exponential Horn 100x60 2-Bolt

The horns look amazing. So far I've only listened to the H6512 and it's got a soft quality I like. No sibilance. But some have indicated the crossover must be more complicated (as in Econowave) in order to balance the falling response. Maybe another seven years will pass before I build a proper crossover? In the meantime, I'm a happy DIYer/music lover and will be busy experimenting and learning for the next several months.

Comments appreciated!

ScottG said: Basically Zilch (in a 2 driver format) has opted for inferior linear decay and some ripple, and if that doesn't bother you then it really doesn't matter. Further, I wouldn't be at all surprised if your perspective wasn't similar to many if not most, and likely Godzilla (who, from what I remember, happens to love good sound on the cheap).


Thanks ScottG - so true!

 

[Flaesh]

Dayton Audio H812 1" Exponential Horn 100x60 2-Bolt
.. the crossover must be..

Try 812
(Can't find old measurements 812-like vs CD WG)

 

[Godzilla]

The H812 is up next! It looks beautiful. I hope it adds a bit of zing. The H6512 keeps things very mellow - great for late night listening. I know it's all crossover dependent but it's interesting to compare these horns. I'm not necessarily looking for the most accurate measuring component, rather the most musically satisfying for me.

Substituting the Lil' Buddy for the Beta 10B on my baffle caused me to raise the volume on the tweeter. The Lil' Buddy is more sensitive and produces a larger image. It's amazing to be working with 95+ db drivers on open baffle.

 

[kec]

Good call on the Lil' Buddy. I'd like to try that too. I currently built Nelson's OB with the Pyle version (PH612) of the 6512 with a Selenium D220. Mid is Alpha 8, bass is a Delta 15. I was using Zilch's crossover and it sounded very good. Then I took the plunge and got the miniDSP 4x10.

Currently, I switched the horn to the PRV WG35 and it sounds good so far, but I need to measure and tweak the miniDSP.

 

[Godzilla]

Thanks kec! I could use some encouraging words since I just spent a couple hundred on drivers I don't need - but certainly wanted to try. They will all find homes playing music somewhere eventually. I'm excited to dive into horns like this and have already been enjoying lots of music in the process. All this keeps me out of trouble.

My first impression of the Lil' Buddy is very positive. It may be the most interesting driver I own. Love the very high efficiency! I have the Beta 10 and 12LTA to compare it to from Eminence - which is proving to offer very musical options for me compared to the usual Vifa, TB, Fostex, etc. offerings. I know pro drivers have a bad reputation among audiophiles (which I consider myself to be) but WOW - the right driver implemented the right way really proves pro drivers can be used to good effect - even for us music loving snobs.

 

[zobsky]

If you want to play with a multitude of drivers, get yourself a mini-dsp of some sort (at least a 2x4 - or better if you can afford it). I have a 2 x 4 HD on order (just sold my 2 x 4 in order to partly fund this experiment) . I know someone who has a mini dsp 2 x 4 lying unused. PM if you're interested and I'll ask about.

You really should be implementing CD compensation if you're playing around with constant directivity waveguides.

As an aside, I'm using quad conductor speaker wire these days to cut down on the inevitable tangle of wire that multi-amping / active crossover introduces