Danley DTS-10 "Super Spud" DIY kit - Page 11

Amateur.

lmao, Yep!

"It's the same reason that a square wave doesn't have any DC..."

Then it's not a square wave.

Audio amps don't have any reason to go down to DC, but some do, and many instrument grade amps do.

"What a clipped signal does contain, however, is extra HF energy. The damage that ensues on the tweeter is usually going to be a burnt out coil instead of excursion damage."

Seems to me there's less; the steep slope representing HF is prevented from going as high as it would have by the clipping.

I think it's the top of the waveform that applies the additional power, since it is low freq.

"Would you mind explaining the problems with the Ultimate AV's ultimate gear article on Transducers and how the inertia affects a speaker?"

Adding mass to any particular driver will just reduce its efficiency. It's response (away from the region of its now lower Fs) will have the exact same time response, but will be lower in level.

Perhaps this animation will help, it demonstrates how adding more high frequencies causes a sine wave to become a square wave:


The rest of the wikipedia article is pretty good and provides the math for calculating the FFT and shows how it is contained of strictly harmonics (not low frequency):
http://en.wikipedia.org/wiki/Square_wave

The reason all of this applies is because a 100% clipped sine-wave becomes a square wave.

The only time you can get a low frequency component from clipping is when the positive and negative clipping isn't symmetrical, but that's really a different issue and totally unrelated to the false notion that because a clipped wave is flat that it has a DC component.

I once believed there was DC present in a clipped signal until I got my degree in electrical engineering...

http://www.classicspeakerpages.net/I...ndpost&p=80190

Seems like Rane and QSC agree....

Ivan, do you foresee a problem with copyists? I imagine the plans would be available for free on several well known self build sites within hours of the first flat-pack models being delivered, and then being copied by certain unscrupulous manufacturers soon afterwards (possibly for resale), so how would you deal with this? Or is the plan to release the plans freely as with the LAB sub?

Regards,
Jazomir

Neither one of us has taken the prototype home yet.

It is currently on a truck headed to a trade show (Show East-a Cinima show) in Orlando for the next week.

So untill I build one-there won't be any listening for a little while.

The demo room is small at the show- something like 25x30 with 14' ceilings-so it will be kinda like a large home theatre setup.

Maybe Mike will have time to report-but like most shows they are long and busy.

Yours and Josh's kits are "in line" to be cut and shipped-as far as I know.

Bass are not more directional than front loaded boxes (generally) untill they get to be large in relation to the wavelengths involved.

You will not get that anywhere near that in a home type environment.

Yes it is true that most horns have a very jagged response (especially on the low end of things). that is because the mouth is to small.

The Tapped Horn does not have this problem.

Read this for a better idea

http://www.danleysoundlabs.com/pdf/danley_tapped.pdf

Agreed. My statement was in regards to the post that was seemily confusing acoustical and electrical impedance.

So my statment was a "broad" statement.

Both are complicated issues and cannot be generalized so easy. That's all.

We are not releasing any plans. We are selling the precut wood and the instructions on how to put it together-drivers (if wanted) etc.

All of the pieces are precision cut to fit together. If you change one measurement just a tad the whole thing starts to change/not fit etc.

I am sure Brandon and Josh will comment on this when they get their kits.

At the price of the kit-it would not make much sense to try and DIY completely. It would take way too long.

The extra expense (above the actual cost of the wood) would be well worth the lack of hassle-in my book anyway.

Will this be a factory direct sale to the DIY market, or will this go through distribution of some sort?

What is the estimated weight of the unit assembled with drivers?

Another small matter, if you blow a driver is it easy to change the driver after assembly?






Yup, I am a potential subwoofer DIYer. This kit is exactly in line with what I am interested in doing. A precut kit that takes the majority of the hassle out of the DIY process.

This kit will be a direct sale from the main office.

Not sure of the weight-and the prototype is out of the office till week after next.

It is very easy to change the drivers if either one gets damaged or you want to experiment.

There are large access panels than come off (the input panel is a sub panel within the access panel) and the drivers are right there.

If you want to power it with one of our amps, the input panel is the same size, so just swap out the inptu panel with the amp. Our amp is 1000 watts into the impedance of the cabinet-so 500 watts/driver-a nice match up-but you could power it with 1000watts/driver and be fine.

Hmm I already contacted the Montana distributor and dealer to get a quote. I will call Monday then and see if I got quoted on the right stuff.

Sigh. I was talking about uncompressed in the sense of high dynamic range, not in the sense of lossless bit compression.

Sure, but you gotta leave room (dynamic range) in the recording media for those peaks.

"the false notion that because a clipped wave is flat that it has a DC component."

How is a constant voltage for x amount of time not DC, at least for the half-period of a cycle?

If the half-period is infinite, then it is DC

DC (from an electrical engineering standpoint) refers only to a steady state non-varying current. Anything else is either transient or AC.

As mentioned before, a periodic or aperiodic continuous non-DC (i.e. varying with respect to time) signal may have a DC component but this does not mean the signal is DC.

Another way to look at it that there is no way to reconstruct the signal with only DC sources.

"As mentioned before, a periodic or aperiodic continuous non-DC (i.e. varying with respect to time) signal may have a DC component but this does not mean the signal is DC."

Fine, but I consider that semantics irrelevant to how clipping damages drivers.

Looking at the pic, I don't see any problem with laying it flat as long as you do something to keep people from stepping in the hole. Bass wavelengths are so long compared to the size of the hole, there's no need to aim the hole any particular direction. It looks to me like the preferred orientations would be either flat or standing up with the vertical dimension being 42". You could stand it up the 60" way but that would put the drivers up/down firing and you might have driver sag issues.

It's not semantics, it engineering fact. Clipping damages because of the high frequency harmonics, not because of the 'DC.' If it were true DC it is true that thermal speaker damage may occur (or occur at lower power levels) due to the driver being static and the loss of airflow induced by mechanical motion, but in the scenario we are talking about, such is not the case.

I think Penngray meant the "end" looking at the photo. This is what I meant when I commented on the possibility of different opening options. This sub would make a great (if somewhat tall) riser.

"Clipping damages because of the high frequency harmonics, not because of the 'DC.'"

Ah, now I get it - the harmonics are what's added to create the steep sides of the waveform.

Thanks

Love the text at:
http://www.audiovisualdevices.com.au...ne/note128.pdf

Makes sense to me!

Bingo

And though not as intuitively obvious, they also (via their summation) create their flat tops.

Consider that the squre-wave signal goes through the speaker's crossover, which separates out those high frequencies and sends them the tweeter. The woofer never sees the short DC periods that you see.


Read the pdf file in my previous post. It argues very well that it isn't clipping per se, but rather users that keep pushing the volume such the the HF energy content amplified from the original recording becomes greater than what the tweeter can take (the high frequencies are not clipped when the low frequency signal is absent). The resulting clipped music sounds brighter and brighter as the volume is increased, but more from original spectral content than by added clipping harmonics.

DC means direct current. Constant voltage means nothing. Constant polarity for each half of the cycle is all DC with a variable voltage.

I'm sure someone will eventually show the plans. But will they be 100% accurate? And then will the average DIY'er be able to get them perfect if they were right to begin with? The time would be fairly large.

Now if another company were to start copying and selling the design, I'm sure there would be legal issues to deal with.

Obviously there's a big difference between a weekend builder and a company stealing, copying, and selling a design.


There were leaked designs for a Danley product at least once before. I don't think they got horribly upset because my guess is that they could tell fairly quickly that the builder screwed it up from the get go......or not everything was listed on one of the drawings posted.......

My understanding is that once you start guessing a missing piece for one of these complex designs, it's going to perform well under what the original did.

I don't get why y'all are speculating about this. Any company that wants to copy the design need only buy one to do it....