Ah, that's an endless debate -- the feel of realistic vs real precision.
For me, if the presentation is reasonable and life-like, I don't really care it's a copy of the recording scene (or master room) or not.
I believe real multi-channel can be excellent. However, to complete the whole thing -- from recording to playback, there'd be so many more possible mistakes than plain stereo. We can't stop that. (no one can)
In comparison, it's nothing wrong keeping the simple stereo format and improving it somewhat in the range we can.
My point is that "realistic sounding" does not automatically equal to "good sounding". Under certain acoustic conditions speech is more intelligible. At certain seats within a symphony hall there is localization and not just a spacious cloud. Drums sound best in acoustically dry environments and the list goes on.
Just because a stereo recording can be made to sound more realistic, doesn't necessarily make it sound good too. A "good" painting doesn't need to be photorealistic. In fact the artistically most interesting paintings are nowhere near to photorealism.
I'm all for trying to get the most out of stereo but a one-size-fits-all approach simply doesn't cut it. It ignores the recording and the listening room.
If obsessed with delaying the center driver, at least do it with care since it will ruin the midrange vector operation. The three elements are integrating as a directional sound field and the direction is depending on the stereophonic signal.
- Elias
Hi - Yes, I'm aware of the Jordan delay line thread. It was the reflector system which struck me as having parallels here. Using slightly larger (and more directional) single drivers, the reflector achieves a measure of HF roll-off without filtering components.
The current SSS layout looks as though it may suffer from reflections from the rear wall. When you get it going, I'll be interested in reading if there are any changes ot the imaging as you bring the system forward. (I'm not in a position to build boxes to have a go myself yet.)
The current SSS layout looks as though it may suffer from reflections from the rear wall. When you get it going, I'll be interested in reading if there are any changes ot the imaging as you bring the system forward. (I'm not in a position to build boxes to have a go myself yet.)
In the late 1950s, when stereo burst forth there were a number of schemes derived to "fill in the center hole" of stereo systems. The first consumer systems were housed in coffin like consoles with the left and right speakers at each end. Stereo affect was limited and the word imaging was not used in audio. Paul Klipsch did a number of papers on how to derive the "third channel", both pre and post amplifier'n and a number of systems were sold using a third channel speaker. You might want to look up some of his work.
I like the idea, and in this era, when most everyone gets their music through ear buds the single speaker concept could find a market. Have you tried isolating the three drivers to prevent modulation artifacts? Also co-ax speakers might get you better highs and 4 ohm auto speakers would give 8 ohms impedance instead of the 16 ohms sum your design would produce per channel. I'm going to build a system using some old auto speakers I have in the collection, along with 10" DVC woofer.
I like the idea, and in this era, when most everyone gets their music through ear buds the single speaker concept could find a market. Have you tried isolating the three drivers to prevent modulation artifacts? Also co-ax speakers might get you better highs and 4 ohm auto speakers would give 8 ohms impedance instead of the 16 ohms sum your design would produce per channel. I'm going to build a system using some old auto speakers I have in the collection, along with 10" DVC woofer.
Three speaker with linear stereo matrix is the system I'm using at the moment.
As pictured in post #4, the single speaker stereo is a simulation of the three speaker concept.
Since the driver signals are on linear dependency through the matrix there is no 'modulation artefacts' ?
Sure coaxial elements might also perform well.
Check again the impedance math, total is not 16 ohms what the amplifier sees but 12 ohms. In practice it is a bit lower due to the psychoacoustic filter.
- Elias
Thanks for the reply Elias, and you are right on the impedance due to two the speakers in parallel seen as 4 ohms. I was looking at each independent leg. 4 ohm drivers would be seen as 6 ohms, a closer match to most modern amps. What typical values have you used in your filters with the drivers shown?
For 8 ohm drivers good values for psychoacoustic filter as a starting point for experimentation can be found here:
It depends on the side wall reflectivity, room width and the specific drivers used, among others. So this is a guideline only
- Elias
An externally hosted image should be here but it was not working when we last tested it.
It depends on the side wall reflectivity, room width and the specific drivers used, among others. So this is a guideline only
- Elias
months have passed so ...how's the EP21?
I've been really busy of late with work/family !
I already have all the stuff needed, drivers, terminals, even cables !
Only need the box.... Hope to kickstart this project again really soon
I agree, the box is usually the hardest part
You could even try cardboard box to get first feelings like I did
Here is my version of the single stereo system. Three four inch mids with Piezos in a separate chamber with a sealed ten inch DVC with the crossover at 400HZ. OK, the color is strange but I had the paint left over and what else to you do with MDF?
It needs a narrow room ten feet of less to give stereo, however place it in a corner and you get some good imaging and of course more bass than you need.
The Piezos are attenuated 6dB to match the mids and the center channel is down 3dB. An interesting experiment that saves you some wood and work but it was tried in fifties and sixties but never caught on.
It needs a narrow room ten feet of less to give stereo, however place it in a corner and you get some good imaging and of course more bass than you need.
The Piezos are attenuated 6dB to match the mids and the center channel is down 3dB. An interesting experiment that saves you some wood and work but it was tried in fifties and sixties but never caught on.
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