Peter, the correction for the base cancellation is only necessary for a dipole speaker, what you are proposing is an IB (infinite baffle) speaker which does not need the correction because the wall doesn't allow the front and back waves to reach each other. I was suggesting that doing a dipole rather than an IB would be a better approach.
Sorry if I sounded harsh earlier, it just appears to me that you are looking for confirmation for what you want to do as opposed to a valid arguement against that idea. It is your speaker, so you are obviously free to do as you please, but if you ask a question, and don't want to do all of the hard research yourself, then you would be wise to look into some of the resources that I have pointed out to you.
Well, I saw the photo's but no reviews or track record, for whatever they're worth. I would rather see a complete set of test measurements to fully describe the speaker before I made up my mind. Of course, I'd also like to hear it 😀
Yes, I've seen your speaker. I still maintain that a proper dipole speaker needs the correction filters, unless you are using a very high Q driver. I'm a firm believer in the work of Siegfried Linkwitz, and however complicated his circuits are, they are of exemplary sound scientific and acoustic design.
Ron
Sorry if I sounded harsh earlier, it just appears to me that you are looking for confirmation for what you want to do as opposed to a valid arguement against that idea. It is your speaker, so you are obviously free to do as you please, but if you ask a question, and don't want to do all of the hard research yourself, then you would be wise to look into some of the resources that I have pointed out to you.
Well, I saw the photo's but no reviews or track record, for whatever they're worth. I would rather see a complete set of test measurements to fully describe the speaker before I made up my mind. Of course, I'd also like to hear it 😀
Yes, I've seen your speaker. I still maintain that a proper dipole speaker needs the correction filters, unless you are using a very high Q driver. I'm a firm believer in the work of Siegfried Linkwitz, and however complicated his circuits are, they are of exemplary sound scientific and acoustic design.
Ron
transducer said:
And I've also read the reviews, very positive. The Linkwitz's Beethovens (as I remember the name correctly) were the inspiration for my speakers.
Thanks for your suggestions as well.
transducer said:
What i picked up from my early days picking thru the works of the leading designers of the day, was that a certain amount of spacing gives you the effect of a larger woofer than the sum of the two. This, like many nuggets from the past, is subject to objective verification.
Personally when i use two woofers i like to mount them push-push on opposite sides of the enclosure -- not really applicable here.
dave
transducer said:
I would love to see a complete set of measurements that describe a speaker... this is the holy grail. For now we just have to live with the fact that the sparse set of objective measurements we do on speakers (or any other kit for that matter) only gives us a general indication of the validity of a design, and even then can be completely misleading.
Measurements are a tool to use to aid us in design, they do not tell us how well it sounds.
dave
Well, the complete quote was:
Of course you are correct in that measurements only give an indication of a speakers quality. I prefer to look at the measurements first, if there are some questionable flaws immediately present, which coincide with some suspicious design methodology, I'll probably discount it rather than try to hear it. Too many speakers, too little time 😀
Ron
Of course you are correct in that measurements only give an indication of a speakers quality. I prefer to look at the measurements first, if there are some questionable flaws immediately present, which coincide with some suspicious design methodology, I'll probably discount it rather than try to hear it. Too many speakers, too little time 😀
Ron
transducer said:
I'm from the other end of the spectrum. Listen 1st, worry about measurements later. Heard too many speakers that measured good and sounded lousy and enuff that didn't measure well that had some inherent magic in them, that i don't want to trust the measures to get a short list.
dave
I'm wading in a little late here, but I'd like to throw in my tupence regarding some earlier comments about room interactions.
Assuming you take proper steps to mechanically isolate the drivers from the structure of your house, a wall-mount IB alignment offers the unique room interaction advantage of completely removing the first reflection image source of the wall it's mounted in. Considering only first reflections, your listening room acoustically becomes infinitely deep behind your speakers.
On the other hand, dipoles attenuate the reverberent field by progressively cancelling their own radiation toward 90 deg. off-axis. Their strength is in reducing the amplitude of side-wall and ceiling reflections, though they do not remove them completely. They also throw a backwave, so the rear wall is a bright image source (albeit oposite phase from a monopole's/bipole's, so the additive/subtractive relationship with the direct radiation is different).
So when you boil it down, in-wall IBs and dipoles will excite your room in very different ways because they offer different advantages. I'd be curious to see time-domain measurements of the reverberent fields of in-wall vs. dipole. It would be interesting to hear how the total removal of one reflection would stack up against the attenuation of 3. As usual, in the final analysis, it will mostly depend on the gadrillion other variables of your installation.
Bill
Assuming you take proper steps to mechanically isolate the drivers from the structure of your house, a wall-mount IB alignment offers the unique room interaction advantage of completely removing the first reflection image source of the wall it's mounted in. Considering only first reflections, your listening room acoustically becomes infinitely deep behind your speakers.
On the other hand, dipoles attenuate the reverberent field by progressively cancelling their own radiation toward 90 deg. off-axis. Their strength is in reducing the amplitude of side-wall and ceiling reflections, though they do not remove them completely. They also throw a backwave, so the rear wall is a bright image source (albeit oposite phase from a monopole's/bipole's, so the additive/subtractive relationship with the direct radiation is different).
So when you boil it down, in-wall IBs and dipoles will excite your room in very different ways because they offer different advantages. I'd be curious to see time-domain measurements of the reverberent fields of in-wall vs. dipole. It would be interesting to hear how the total removal of one reflection would stack up against the attenuation of 3. As usual, in the final analysis, it will mostly depend on the gadrillion other variables of your installation.
Bill
Do It Right
The theory explanation that I have read in the past is that two or more woofers at a suitable spacing coexist in each others nearfields, thereby decreasing the radiation resistance of both or more drivers and increasing overall transduction efficiency more so than the increase in the number of drivers.
With the drivers operated at nearfield frequencies the individual wavefronts/pulses coincide and combine (add) and the disturbance acts as though produced by a single driver of diameter similar to the driver spacing.
Note the high level very low bass phantom center sounds that can be produced in a room with the appropriate L/R cabinet spacing.
Note the very high efficiency of guitar quadboxes.
Vertcal line arrays are another instance of increased efficiency and a directional radiation pattern.
The vertical spacing distance of two drivers will determine the frequency of the "crossover" from higher efficiency nearfield coupled operation to lower efficiency seperated individual operation and any lobing characteristics.
This increased transduction efficiency gives a low boost characteristic, and I think this is much to do with Peter reporting that his open baffle cabinets go smoothly down to 25 Hz or so and without EQ.
In the past I ran 2 pairs of 12" 3 way cabinets (the top ones mounted upside down) place on top of a pair of then unconnected large Kef 3 way TL cabinets.
This placed the bottom 12" at waist height and the top 12" at over head height, and these two columns were about 8 feet apart and fed from my 500/4 + 500/4 hot-rodded pro power amp directly connected to the cdp, so no switching or eq or extra connectors - only 2 volume controls.
Power filters and isolation transformers too.
0 Vu out of the cdp would just cause only momentary clip so any cd could be played to max level without gross or sustained overload.
The result of these 4 12" drivers coupling with each other was much more than sum of the individual parts - from the back fence it sounded like I had live blues and rock bands in my loungeroom, and from the couch they were. 😉
Midnight on Friday night is the best time for AC/DC at full throttle 😀 - BTW - Australian ABC TV has been screening "Long Way To The Top - History Of Australian Rock And Roll" - This is a must see for everybody with any interest in modern music.
The vertical spacings and the horizontal spacings are a vitally important considerations as regards NF/FF operation crossing over, lobing and comb filtering characteristics - I suggest you diligently experiment with this and do some maths and measurements before you commit to cutting those holes in the wall.
Girlfriend or no girlfriend, the in wall/infinite baffle experiment is one that we would all love to try - If you do it right she will love you all the more for it I am sure. 🙂
Regards, Eric.
Hi Dave,planet10 said:
The theory explanation that I have read in the past is that two or more woofers at a suitable spacing coexist in each others nearfields, thereby decreasing the radiation resistance of both or more drivers and increasing overall transduction efficiency more so than the increase in the number of drivers.
With the drivers operated at nearfield frequencies the individual wavefronts/pulses coincide and combine (add) and the disturbance acts as though produced by a single driver of diameter similar to the driver spacing.
Note the high level very low bass phantom center sounds that can be produced in a room with the appropriate L/R cabinet spacing.
Note the very high efficiency of guitar quadboxes.
Vertcal line arrays are another instance of increased efficiency and a directional radiation pattern.
The vertical spacing distance of two drivers will determine the frequency of the "crossover" from higher efficiency nearfield coupled operation to lower efficiency seperated individual operation and any lobing characteristics.
This increased transduction efficiency gives a low boost characteristic, and I think this is much to do with Peter reporting that his open baffle cabinets go smoothly down to 25 Hz or so and without EQ.
In the past I ran 2 pairs of 12" 3 way cabinets (the top ones mounted upside down) place on top of a pair of then unconnected large Kef 3 way TL cabinets.
This placed the bottom 12" at waist height and the top 12" at over head height, and these two columns were about 8 feet apart and fed from my 500/4 + 500/4 hot-rodded pro power amp directly connected to the cdp, so no switching or eq or extra connectors - only 2 volume controls.
Power filters and isolation transformers too.
0 Vu out of the cdp would just cause only momentary clip so any cd could be played to max level without gross or sustained overload.
The result of these 4 12" drivers coupling with each other was much more than sum of the individual parts - from the back fence it sounded like I had live blues and rock bands in my loungeroom, and from the couch they were. 😉
Midnight on Friday night is the best time for AC/DC at full throttle 😀 - BTW - Australian ABC TV has been screening "Long Way To The Top - History Of Australian Rock And Roll" - This is a must see for everybody with any interest in modern music.
The vertical spacings and the horizontal spacings are a vitally important considerations as regards NF/FF operation crossing over, lobing and comb filtering characteristics - I suggest you diligently experiment with this and do some maths and measurements before you commit to cutting those holes in the wall.
Girlfriend or no girlfriend, the in wall/infinite baffle experiment is one that we would all love to try - If you do it right she will love you all the more for it I am sure. 🙂
Regards, Eric.
baffle help
Hi everyone.
I was planning to do an open baffle system, but need information and knowledge or direct hints.
Any information that you can give me is GREAT. I should realy like to get some of the mentioned URLS in this thread updated and more links.
Thx for you effort.
Hi everyone.
I was planning to do an open baffle system, but need information and knowledge or direct hints.
Any information that you can give me is GREAT. I should realy like to get some of the mentioned URLS in this thread updated and more links.
Thx for you effort.
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