The ask Tin about audio thread

I got rid of the bridging and switched it to 2 channel mode.

It cooled it down a lot and is still just as loud. I am confused. I thought if I bridged it, it put out 180/rms per channel. If I did that, i could turn the gain down by half and get the 90w to each speaker and put less load on the amp.

Now I'm running in 2 channel mode with the gain at about 75% and it is a lot cooler.
 
raroz28 said:
I got rid of the bridging and switched it to 2 channel mode.

It cooled it down a lot and is still just as loud. I am confused. I thought if I bridged it, it put out 180/rms per channel. If I did that, i could turn the gain down by half and get the 90w to each speaker and put less load on the amp.

Now I'm running in 2 channel mode with the gain at about 75% and it is a lot cooler.
Click to expand...

Watts aren't a good measure of how capable an amplifier is, it's all in the power supply and how it handles voltage peaks. My 3W (yes, 3 stinkin' watts) tube amplifier I sold a few months back had a very stout power supply, and when it needed could provide an extra 10dB of headroom in very short bursts. Your typical amplifier will only provide another 3dB to 5dB of headroom, even the megabuck stuff only afforded by the well-to-do. Every +5dB increase in volume is perceived as twice as loud by the human ear. The other part of the equation is speaker efficiency. An amplifier needs to provide twice the output power to raise the dB level 3dB, and then you have the maximum acoustic output of your particular speakers. If they're only capable of 110dB SPL and are 87dB 1W/m efficient, you really don't need that much amplifier to drive them. With 1W of input power, your ears will get 87dB of sound at a 1 meter distance. Here's a little example chart for you, assuming your speakers are 87dB 1W/m. Wattage output is a means to market amplifiers. 99% of the time, most people are only using a couple of watts of power while listening.

Input power: dB SPL @ 1m:
1W 87dB
2W 90dB
4W 93dB
8W 96dB
16W 99dB
32W 102dB
64W 105dB
128W 108dB
256W 111dB

Conversation level is around 60dB, a jackhammer is 100dB, and a rock concert is about 110dB, FWIW. I normally listen to music at 80 to 85dB, and that's pretty fucking loud :lol:
 
347convert said:
I thought you would like that
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Truer words have never been spoken.

“There exists in society a very special class of persons that I have always referred to as the Believers. These are folks who have chosen to accept a certain religion, philosophy, theory, idea or notion and cling to that belief regardless of any evidence that might, for anyone else, bring it into doubt. They are the ones who encourage and support the fanatics and the frauds of any given age. No amount of evidence, no matter how strong, will bring them any enlightenment. They are the sheep who beg to be fleeced and butchered, and who will battle fiercely to preserve their right to be victimized.”
 
Tin,
Im going to get ahold of mike and see when you and him will be home at the same time so you can check this out..

 
Tin said:
What did you do rig up a bomb or something? :lol:
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Not yet but its half way there lol..I have 2 of the 15 inch DC Audios but only put one in for now running at 1ohm..Pretty much hitting this one sub with around 2250W RMS lol..Once I get another Sundown SAZ-3500D amp,0ga wiring and another battery,im putting the 2nd sub in..I wanna do hair tricks like this :) ..
 
Have any experience/knowledge about Decware stuff? I noticed on the site that they have a D.I.Y. section and got me interested in trying one out. You think something like this would be worth the time and effort?
http://www.decware.com/newsite/HORN.html
http://www.decware.com/newsite/paper120.html
Should it sound better then the generic $150-$200 floorstanding speaker stuff? (Klipsch Synergy F-30, Polk Audio TSi300, etc)
Currently have a pair of Energy XL-16b-1 and Velodyne CT-80 in the room. Got the energy speakers for free from my dad when he upgraded and bought the Velodyne from a neighbor for $50. Not much invested so I don't mind trying something different.
 
Decware is very good stuff, you just need speakers efficient enough to work with a low wattage amplifier. Amps under 5WPC are affectionately called flea amps, and they are probably some of the best sounding amplifiers out there. The Decware Zen uses EL84 output tubes in a single-ended class A configuration good for about 2 or 3WPC, so you'll need speakers of at least 93dB 1W/m and a benign impedance load. Benign meaning there are no dips in the frequency response that will stress the amplifier. For off-the-shelf speakers, you'll want something like a Klipsch Forte, Forte II, Cornwall, LaScala, Klipschorn, etc. Vintage Electro Voice, Altec Lansing, University, Knight, and Jensen speakers are the perfect match. I ran a pair of EV 12TRXB coaxials with a 4W 2A3 single-ended tube amplifier, everybody that heard it told me that hadn't heard anything better. It's very hard to describe the sound of a SET (single-ended triode) because it doesn't sound as if the music is being thrown at you from speakers, but hanging in the air all around you. SET is the oldest form of amplification, but it's also the purest amplifier topography, most times having zero to a small handful of components in the signal path. Awesome stuff. Most speakers that work well with it will be very large. My Electro Voices are in 5cu ft cabinets, they dwarf pretty much any speaker you'd see in a store today.
 
Hey Tin - I am throwing a 10" Infinity sub rated for a .75 cu ft sealed enclosure into a .75 cu ft MDF sealed enclosure...

1) Do I need to take into account driver displacement, or is that typically accounted for in the mfg's ".75" requirement?
2) Should I add polyfill, and if so, how much would be a good starting point? What should I be listening for to determine if I should add or remove any?

Thanks for this thread - I learn a ton reading it!
 
Atrus said:
Hey Tin - I am throwing a 10" Infinity sub rated for a .75 cu ft sealed enclosure into a .75 cu ft MDF sealed enclosure...

1) Do I need to take into account driver displacement, or is that typically accounted for in the mfg's ".75" requirement?
2) Should I add polyfill, and if so, how much would be a good starting point? What should I be listening for to determine if I should add or remove any?

Thanks for this thread - I learn a ton reading it!
Click to expand...

You can use the .75cu ft dimension on an empty cab no problem. You'll definitely want some sort of loose damping material in the cabinet. Polyfill is good, but there are good substitutes that are cheaper. Pillow stuffing and loose fiberglass insulation are my favorite. It's hard to say how much to use, as this is where you'll be best off experimenting. It's a "salt to taste" type of thing. Fiberglass insulation has great acoustic properties, but manufacturers have largely abandoned it because of how messy it is when handling. You want the bass to have punch, but not sound boomy. Boomy bass is a sign of an inadequately sized/constructed cabinet and/or too little damping material. Make sure your cabinet is braced correctly and you'll be good.
 
Cool, thanks! I'll start with pillow stuffing. Any recommendation on how much would be a good amount to start with...I mean, should it loosely fill the entire space, should it just be a little laying at the bottom of the enclosure? I don't really know what a "baseline" would be.
 
Atrus said:
Cool, thanks! I'll start with pillow stuffing. Any recommendation on how much would be a good amount to start with...I mean, should it loosely fill the entire space, should it just be a little laying at the bottom of the enclosure? I don't really know what a "baseline" would be.
Click to expand...

You'll want to loosely fill the entire space. The object of damping material is to minimize internal reflections in the cabinet and diffuse standing waves and resonance. If this were a ported enclosure, then you'd line the walls of the cabinet aside from the speaker baffle.
 
Jacob said:
Not yet but its half way there lol..I have 2 of the 15 inch DC Audios but only put one in for now running at 1ohm..Pretty much hitting this one sub with around 2250W RMS lol..Once I get another Sundown SAZ-3500D amp,0ga wiring and another battery,im putting the 2nd sub in..I wanna do hair tricks like this :) ..
Click to expand...
Should have went with sundown x15. I want to run 2 zv4 12's on a scv 6 k.
 
Ok, so here's an odd one. A buddy has an AppleTV as his sole source to his tv. He wants to hook up a 2.1 audio setup using existing speakers/sub, but needs a way to power them. He doesn't need source switching or processing, just literally a way to power them. The kicker is, he doesn't have room for a full HT receiver and he wants to keep volume control on the AppleTV remote. If he uses optical output, he loses volume control. If he uses HDMI, he keeps volume control via CEC, however there seem to be no amps/receivers that accept HDMI/CEC that aren't full-sized home theater receivers. Basically he's looking for a T-Amp with HDMI input and CEC control, or a way to accomplish the same thing using a generic mini-amp. He also would prefer to not buy a sound bar.

Any ideas??
 
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