Flex Your PCD Mettle:

[Zilch]

Re: Flex Your PCD Mettle:

I'm not so sure the slope at the extreme high end is an issue; it's certainly not in EconoWave Deluxe, which I've been listening to for weeks now. I was mostly just commenting on the differences in the results of these two approaches.

See Geddes's Abbey, for example, now $1000 EACH more in kit form than Deluxe:

http://www.gedlee.com/abbey.htm

http://www.gedlee.com/Loudspeakers.htm

[I'll try the impedance taming.... ]

[Pete Schumacher]

Re: Flex Your PCD Mettle:

I'm not sure the slope at the extreme high end is an issue; it's certainly not in EconoWave Deluxe, which I've been listening to for weeks now.

See Geddes's Abbey, for example, now $1000 EACH more in kit form than Deluxe:

http://www.gedlee.com/abbey.htm

http://www.gedlee.com/Loudspeakers.htm

Hey, the extra components are fairly cheap to improve it, at least on paper, so why not give it a whirl? Might be an audible improvement. ;)

I like the look of this Deltalite response plot. And the price sure is right. I could see this thing in a tower, folded, tapered TL. It would make a nearly full range two way with some serious low end grunt that most dual 8" systems couldn't touch.

[Zilch]

Re: Flex Your PCD Mettle:

I like the look of this Deltalite response plot. And the price sure is right. I could see this thing in a tower, folded, tapered TL. It would make a nearly full range two way with some serious low end grunt that most dual 8" systems couldn't touch.

Weather's gettin' warm; time to wheel out the table saw. :D



Zilch = Blue

Schumacher 1.1 = Red, Green

Bypass cap is 1.5 uF
Notch inductor is 2.0 mH
XO = 1408 Hz
Axis = +1.83°

The impedance correction notch flattens the peak at 2.2 kHz.

[There's just three more to go.... ;) ]

[dantheman]

Re: Flex Your PCD Mettle:

Looks great Zilch!

congratulations,

Dan

[Zilch]

Behind the Curtain:

Looks great Zilch!

Thanks, Dan!

Now what? :p



[Guess I'll listen awhile.... ;) ]

[coctostan]

Re: Flex Your PCD Mettle:

Zilch and Pete, this is some awesome work.

Zilch, do you have any feedback on the subjective differences between the HO, LF and Deltalite? Are they distinguishable?

[Zilch]

Re: Flex Your PCD Mettle:

Zilch, do you have any feedback on the subjective differences between the HO, LF and Deltalite? Are they distinguishable?

Recognize first that these have been whirlwind rounds of loudspeaker design with no opportunity for extended quality listening anywhere outside ZilchLab.

The highs are the same, because they are all mated with the same compression driver/waveguide combination in the same cabinets crossed flat within a few dB in the same region.

The mids are very similar and a step up in clarity and dynamics, in general, from the lower-efficiency drivers with which I am more familiar in the EconoWave format. I'd certainly have to do more rigorous A/B listening to distinguish among these three in this respect, and against others to ascertain whether there is, in fact, an Eminence sound character, and what that might be.

On the low end, there are easily discernable differences, with the caveat that I am using all of them in this same small (1.6 cuft) vented alignment tuned to 30 Hz, and paying no attention whatsoever to how each might be optimized. All are being played under the same conditions, on the wide test stand you see in the pics, at least 1m away from all boundaries, 2m to the side and rear, typical.

Given these conditions, I am hearing what Dennis's models suggest, basically:

LF will play extended bass with EQ assist, and would probably not need that with boundary reinforcement as a full-range system without sub(s). HO and DL try but can't pull it off, and need subs or a more optimum low frequency alignment as others have suggested above. Recognizing that most home theater installations incorporate subs, either of the latter two would be well adapted to this use.

Also significant in the results thus far is that in this small vented alignment, neither HO nor DL have a major efficiency advantage over LF; their 100 dB sensitivity is measured midband, and we give much of that up in the course of normalizing their respective performances to the region of 100 Hz.

Though I haven't tried it myself yet, I expect Dennis is also correct in suggesting that LF would do as well closed-box in this respect as the others could do vented in this small box size. Does this mean that LF is the slam-dunk driver of preference? Nope, merely that there is plenty of fun yet to be found in discovering how well these three woofers might perform in alternative alignments.... :D

[coctostan]

Re: Flex Your PCD Mettle:

Thanks for the reply. That is exactly what I was looking for.

My intent is to build these soffit style in the corners of my theater so they will cross Geddes style. This should give them a nice pi cornerhorn effect too and I will be able to build the enclosures much larger. I have never built an in-wall style speaker, so we will see how the bass response works out. My plan is to try your Econo passive layout, a tweaked Parham style passive and an active through a Crown XTI1000. We'll see how they work out.

Your crossover work has definitely been helpful and your contributions to the DIY community with the Econowave should be commended.

[Zilch]

Re: Flex Your PCD Mettle:

Your crossover work has definitely been helpful and your contributions to the DIY community with the Econowave should be commended.

Thank you for this.

I believe it is safe to say that we have successfully brought a different design perspective to literally hundreds of DIYers over the past two years, and the results have been most gratifying....

[Pete Schumacher]

Re: Flex Your PCD Mettle:

Thanks for the reply. That is exactly what I was looking for.

My intent is to build these soffit style in the corners of my theater so they will cross Geddes style. This should give them a nice pi cornerhorn effect too and I will be able to build the enclosures much larger. I have never built an in-wall style speaker, so we will see how the bass response works out. My plan is to try your Econo passive layout, a tweaked Parham style passive and an active through a Crown XTI1000. We'll see how they work out.

Your crossover work has definitely been helpful and your contributions to the DIY community with the Econowave should be commended.

If you build these in-wall, the crossover will not be optimized for that use, and will suffer from excessive midbass due to the crossover employing baffle step compensation, which won't be needed with your in-wall effort.

[Zilch]

Re: Flex Your PCD Mettle:

Most importantly, we have illustrated how this might be accomplished for any alignmnent using inexpensive tools.

[I truly hope this aspect is not escaping readers here.... ]

[dantheman]

Re: Behind the Curtain:

Thanks, Dan!

Now what? :p

Get a beer, some music, and enjoy.

Dan

[coctostan]

Re: Flex Your PCD Mettle:

If you build these in-wall, the crossover will not be optimized for that use, and will suffer from excessive midbass due to the crossover employing baffle step compensation, which won't be needed with your in-wall effort.

Definitely. I plan to tweak your crossover to fit my requirements. I think it should get me in the ballpark though. I've done some crossovers and have the necessary tools, but sometimes it helps to have a nice topology to start with.

[Pete Schumacher]

Re: Flex Your PCD Mettle:

Definitely. I plan to tweak your crossover to fit my requirements. I think it should get me in the ballpark though. I've done some crossovers and have the necessary tools, but sometimes it helps to have a nice topology to start with.

Tweeter level will need to come up at least 4dB. That means dramatic changes to values to keep the same transfer function, only raised. Flattening the woofer transfer function is another matter. Changes there are even more substantial.

I'm going to suggest a starting point for you. I used Zilch's plots, but ignored everything below the baffle step.

Here's the PCD sim, and it looks really nice, to me anyway. In the top plot, you see driver responses, power response (waveguide not included), and the tweeter reverse null. It seems the forward axis is straight ahead on this one, and there's nothing wrong with that I would assume.

[Zilch]

Re: Flex Your PCD Mettle:

Maybe I missed it, but have you compared distortion measurements between the Kappalite and Deltalite?