psg
-
Posts
3503 -
Joined
-
Last visited
-
Days Won
1
Content Type
Forums
Events
Gallery
Posts posted by psg
-
-
Do you pipe insulation foam to seal the speakers to the walls?
No bass could be also be from room interaction rather than the receiver (unless it is setup with speakers set to small instead of large as mentioned above)
-
+1 on that door!
-
If you have a low frequency wave, the high frequency wave will ride on it as shown in figure 2 (figures taken from: http://sound.westhost.com/bi-amp.htm as I'm too lazy to make my own figures).
If that's the case and we think of clipping as exceeding the peak voltage an amplifier can provide, the high frequency waveform will be clipped, as it rides on the low frequency waveform. What seems interesting is you'd think this clipping would only impact the high frequencies as it appears information is lost. What seems very deceiving about thinking about the issue in the time domain is that it appears low frequency information is unaffected and that the woofer and the sound being produced from it will be unchanged...
However, I agree that clipping a waveform will add some harmonics similar to that of a square wave, and this will mean the lower frequency of these new harmonics will have more energy compared to the newer higher harmonics that were added (due to the Fourier transform of a square wave being a sync function). I think this is demonstrated by figure 3C copied below (although not explained in the article at the URL above). Is this your point then that there will be more low frequency energy imparted on the woofer due to the extra lower frequency harmonics from the clipping? Or is there some other nuance I'm not seeing?
Yes for the high frequency riding on top.
Thus, yes, clipping affects high frequencies drastically during the clipped part of the low signal. Whether this creates more high frequencies to kill tweeters, or perhaps less high frequency is a good question, since sometimes there's no voltage headroom left to add them at all (leading to less HF signal).
Correct also that higher frequencies are generated by the clipping itself as in a Fourier Expansion of the square(ish) wave. This generates harmonic distortion, some of which may reach the tweeter past the crossover frequency, but most of which will affect the woofer as distortion.
Thanks for posting the figures! They make it easier for people to understand.
-
Why is that?
-
Do you mean Tuba HT? No way you can hit 15 Hz hard with it AFAIK. I'd say 19 Hz. So maybe go IB?
Maybe if you could extend the THT hornpath another 6', but that would require wrapping the horn around two more sides of the existing driver, and the horn mouth would be as big as the whole THT you started with.
To reach 15 Hz you mean?
-
Minidsp would do the job correct?
It's what I use. I gather XT32 would work automatically?
-
Any of the THT, dual SPUD, Cinema F20 or lilwrecker will keep up and then some. Tapped horns (such as the SPUD) absolutely need EQ while horn-loaded subs still benefit from it, so factor that in as well.
-
Already have. Bass response is very room-dependent anyway, but I don't recall people bragging about the 15 Hz capability of the THT. BTW I didn't say that I couldn't shake the house with 20W; I just wouldn't be doing it at 15 Hz. I put in a high-pass filter in the low teens anyway to avoid over-excursion.
-
Do you mean Tuba HT? No way you can hit 15 Hz hard with it AFAIK. I'd say 19 Hz. So maybe go IB?
-
For example, a 100 w amp push to severe clipping is really pushing close to 200 watts. The cooling of the voice coil is ineffective under these circumstances because the traveling of the coil is not proportionate to the power and heat build up. A 200 w amp can push the voice coil 40% further which results in better air flow aroun the voice coil. The heat build up in the 100 watt amp fries the voice coil.
This explains how to blow a woofer (because clipping usually occurs at woofer frequencies) but not the tweeter. But I guess I didn't specify that in my myth title phrase.
The speaker/tweeter survives with the 200 watt amp.
No, it would be worse, because the 200W would also be into severe clipping (and outputting 400W).
i.e. you can't get to extreme clipping in the first place by raising the volume control by 3 dB over maximum whereby the 200W would still be fine. You probably raised it by 10 or 20 dB to make a square wave (that has double the power of a sine wave).
-
LOL
-
Thanks Youthman. I'm sure someone will find something to argue with, and that's okay as long as we keep it to content and not personal. But I am not in it to get into an argument; thus my reluctance to post it.
-
I liked it too!
-
Ok... Too much power is better than having too little due to clipping and distortion is a myth, for various reasons.
Sure, clipping makes a square wave, which consists of high frequencies added on to the fundamental, but do the math and the power drops quickly with each harmonic. You'd have to be attempting to play a sine wave that happens to be close to the crossover frequency and clip it like crazy for the amplifier to generate really high power that would reach the tweeter; most of the clipping distorsion is still going to go to the woofer at sub-crossover frequencies.
Power kills tweeters. They generally accept much less power than woofers do, so if you have a 500W amp and keep cranking the volume because the woofer still sounds good, then at some point you will surpass the limit of the tweeter. On the other hand, do the same with a 3W amp and how much damage can you do? At some point it will clip and start to sound bad and you'll turn it down without damaging anything. Do the same with a middle-ground 100W amp and here's where the myth comes alive. Say your woofer is getting 100W and your tweeter is getting 5W and everything is good but at the limit of both the woofer and tweeter. You crank it past clipping by 6 dB, but the SPL isn't getting much higher because (1) the woofer is already at it's excursion limit and compressing and (2) the amplifier isn't giving it much more voltage excursion anyway because its clipping. However, most of the clipping power is going to the woofer at first harmonics, not reaching the tweeter. But the music program content reaching the tweeter has increased by nearly 6 dB and is now close to 20W (some of it clipping because it's riding on top of low frequencies clipping, but some of it not clipping in parts of the low frequency signal that goes below rail voltage). Opps, the 20W fried the tweeter. You'd blame clipping but actually you just raised the volume enough for the regular program material to fry the tweeter.
As for the argument that the coil stops moving because of clipping: It has mass and isn't going to stop instantanously when made to oscillate 100 times per second. Won't happen. It will distort like crazy but won't stop moving.-
1
-
-
What would be the argument?
Start a thread and I might go there.
-
Screw the theater; when I can own the Blu ray for less?
There was belief at one point from some critics. With the rise of ht, that there would be less multiplex theaters, and movies would be simultaneously be released to pay per view or alike for a high price something around the 60.00 rental fee. But I haven't seen any of that happen yet. It may not since there were reports of less people building dedicated ht. Would be cool, and save me money to watch a movie.
Renting for $60 would save you money? As opposed to renting for $5 now?
-
However, if using behind an acoustically transparent screen, you will sacrifice both audio and video (unless you have high powered projector ($$$$$) or an elaborate Equalizer and engineered room (more $$$$$$$))
The OP did not mention screens, but I disagree on both fronts. For video, sure an AT screen has less gain than an opaque screen, but you don't need a super light canon for one either. I have no problems with this using a BenQ W6000. For audio, my mid-grade screen has about a 1 dB attenuation that is pretty even, so no EQ required.
-
No problem at all. Too much power is better than having too little due to clipping and distortion
I'd argue with that but this isn't the place.
-
This is very similar to what I was describing above
VERY NICE work.
Peter, your shelves look beautiful! Very nice the way you trimmed it out.
Thanks guys.
In my case, the back has a hinged panel accessible in an adjoining utility room.
-
ok guys cutting out a whole in the wall for audio gear. need a cheap racks or links to ideas how to build something. can't be to complex if i have to build it. bottom needs to hold 125 lbs one more shelf needs to be able to hold 60-70. then regular shovels after that is fine. thanks guys
Made mine out of 5'x5' sheets of 1/2" birch plywood. That gave me nine shelves. I think I got another 3 from another sheet and used the rest of the second sheet to make the 5' high sides. Stained and varnishes the plywood, assembled with a top and bottom and a fixed middle shelf. The rest are dropped onto pins in the side walls.
Look like this : https://community.klipsch.com/index.php?/gallery/image/90-dsc-13472r800/
-
Maybe. Ever notice how a 15-inch never really measures 15 inches of moving surface? Goes for any size. You'd need to use real sizes to tell.
-
I use Heresy II as sides and KPT-100 as rears to save space. Works great for me.
-
1
-
-
Upload jpg format to photobucket. bmp files are huge anyway, a waste of storage for you and of bandwidth for everyone else.
-
Load it in any image program (e.g. paint) and SAVE AS a jpeg file.
In Linux, I'd do:
$ gm convert file.bmp file.jpg
Cable myths
in 2-Channel Home Audio
Posted · Edited by psg
+1 on that!
Sure, wire gauge matters. So we go big enough to minimize resistance for the length required and large enough for the current draw. Saying that if you can hear the effect of 26 AWG, then don't discount that people can hear burn-in or cryo treatments is not a valid argument to me; one is rooted on known principles and the other isn't. Most fancy wire brands aren't selling bigger gauge; you can get that cheap from monoprice. They are selling other qualities.
Anyway, I like to keep my participation in this forum free of useless arguments, just as I stay away from them at family gatherings.