Vintage HiFi Audio Forum
Audio Discussion => List your system => Topic started by: OldiesButGoodies on March 07, 2015, 07:26:24 PM
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I like the effect, will not design it as a permanent change as I am planning a separate redesign of the baffles and bass drivers, but this is fun in the mean time. Crossed over at 17.5Khz.
(https://farm9.staticflickr.com/8628/16561304669_ceab69d96c_b.jpg) (https://flic.kr/p/ret1TF)IMG_2259 (https://flic.kr/p/ret1TF) by JSifontes (https://www.flickr.com/people/78619205@N00/), on Flickr
(https://farm9.staticflickr.com/8609/16127465093_6bbccaaa59_b.jpg) (https://flic.kr/p/qz8tuZ)IMG_2260 (https://flic.kr/p/qz8tuZ) by JSifontes (https://www.flickr.com/people/78619205@N00/), on Flickr
(https://farm8.staticflickr.com/7289/16561304909_287621626e_b.jpg) (https://flic.kr/p/ret1XP)IMG_2261 (https://flic.kr/p/ret1XP) by JSifontes (https://www.flickr.com/people/78619205@N00/), on Flickr
;D
OBG
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That is a very high frequency, Mosquito tone range. Can you hear it?
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Last time I checked, 17.5khz is about where my hearing starts to roll off. Of course, 16 to 20khz is only 1/3 octave anyway.
What are you plans for the driver/baffle redesign?
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The 17.5K is the designed to number. I put it there because the RTA is saying that the main ribbon drops off like the barrier reef at that point. My 52 year old ears here them though. I think I need to double check the tested value of the caps to ascertain the actual x-over point (but the taper is slow with just one cap, so I am probably getting output from below 17.5). In fact, I will just order decent caps and take it 2nd order.
Come spring I will either:
- Strip the existing baffle and repaint it piano black with several coats of clear (it is scratched up), add the dome super tweeters (or a Dayton ribbon, under evaluation) in a more elegant fashion (tough to do because I like the idea of just continuing the line source, keeps imaging tight, so may just repeat what I have in a nicer finish) or
- Create a new design with an out board bass unit using hivi or JL drivers, and build a rib tower baffle separately that incorporates the domes (or the Dayton ribbon, or a pair on Infinity EMITs modified to have rear output - just use the front frame of a pair of non-working EMITs on the back)
Will see what I decide, but at any rate thoughtI would post my mad tweaks here to stir up activity in the forum.
:-)
OBG
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Your part two seems to take you a fair way to just building a new speaker, which will allow you to maintain the integrity of the Amazings.
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The 17.5K is the designed to number. I put it there because the RTA is saying that the main ribbon drops off like the barrier reef at that point. My 52 year old ears here them though. I think I need to double check the tested value of the caps to ascertain the actual x-over point (but the taper is slow with just one cap, so I am probably getting output from below 17.5). In fact, I will just order decent caps and take it 2nd order.
Come spring I will either:
- Strip the existing baffle and repaint it piano black with several coats of clear (it is scratched up), add the dome super tweeters (or a Dayton ribbon, under evaluation) in a more elegant fashion (tough to do because I like the idea of just continuing the line source, keeps imaging tight, so may just repeat what I have in a nicer finish) or
- Create a new design with an out board bass unit using hivi or JL drivers, and build a rib tower baffle separately that incorporates the domes (or the Dayton ribbon, or a pair on Infinity EMITs modified to have rear output - just use the front frame of a pair of non-working EMITs on the back)
Will see what I decide, but at any rate thoughtI would post my mad tweaks here to stir up activity in the forum.
:-)
OBG
Well, my Vandersteen 4a's are rated to 40khz. It definitely loses something when you disengage the super tweeter. My best guess is that with analog you have a medium that has extension into this range. With a proper super tweeter you will gain a more faithful reproduction of the waveforms of the original sound of the instruments. I would imagine that these waves interact with ones in the "audible" range.
I'd think you want a line source type tweeter in order to best match the dispersion characteristics of the Carver's ribbon. Line sources lose something like 3db per meter in the highs coming from the speaker. Those domes are going to be more like 6db per meter.
A friend of mine used to own these and now has Apogee Divas.
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As a gigging bassist for around 25 years, I've spent a lot of time in crowded bars next to crash cymbals. At 48 I roll off sharply at 14k. I'll have to take your word that this mod is beneficial.
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Wish I knew the frequency of the ringing in my ears? It sounds really high to me and is nearly always present, but pretty low dB. Have been seeing some new drug for tinnitus being advertised lately, should try it I guess.
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I think I need to double check the tested value of the caps to ascertain the actual x-over point (but the taper is slow with just one cap, so I am probably getting output from below 17.5).
Be sure too that you account for the impedance. It looks like you have all three tweets in series, though it is hard to trace the wiring on the photo. If you are using a standard 8 ohm chart, you are crossed much lower (or is it higher, I think it is lower) than you think you are (assuming all drivers are eight ohm). An easy fix might be to add one more tweeter to each side and wire series/parallel.
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How about a hearing test for the old guys here (me included) Look here! http://music.ece.drexel.edu/hearingtest/ (http://music.ece.drexel.edu/hearingtest/)
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I could hear them all up to 19.5 KHz. and down to 35 with out subwoofer.
Post your results
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15 -18.5 Khz using Skull Candy Ink'd 2 earbuds
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Unfortunately that one doesn't work for me as I can't hear 16.5k. This one has a sweep from zero to 20k.
http://onlinetonegenerator.com/hearingtest.html (http://onlinetonegenerator.com/hearingtest.html)
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haha either my shitty $20 speakers at work don't work well, or my hearing literally shits the bed at 13k. I'm fairly certain it's the speakers... a little concerned now though; will check again when I'm home.
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Just use earbuds - almost any earbud will go to 20K (unless it has been run through the dryer)...
Pepe
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haha either my shitty $20 speakers at work don't work well, or my hearing literally shits the bed at 13k. I'm fairly certain it's the speakers... a little concerned now though; will check again when I'm home.
Ha! I laugh because I can relate. When I first took the test a couple years ago, I did it on a laptop. When I couldn't hear anything, I turned it up. So I thought perhaps it was the computer speakers and moved to my wife's computer with better speakers. Still nothing. So I moved to the music system and played it through my mains. I still didn't hear anything, but at this point my teenage daughter yelled down the stairs "Will you PLEASE quit making that horrible sound"! The issue wasn't my speakers. :(
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It's only the top 2/3 of an octave. Very little musical info up there anyway.
Think of it as built in NR.
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Good news guys, it actually was the sprakers haha. I'm good up to 16-17k. I almost wish it stopped at 13, who the hell wants to hear that squeaky shit?
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That is good news.
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Well, I ended up making a project out of the hearing test.
First, the online tone generator was hard to work with. I used the music.ece site with a pair of Grado SR 60s plugged into the computer phones jack and heard bass down to 25hz and high frequencies up to 16.5khz and something beyond that, but am not sure I heard a change in frequency or just noise. Feeding the same source from the computer, into a B & O receiver and a pair of Def Tech Studio 350s, with a Def Tech SuperCube III sub, performance was similar, but only down to 35hz (there was some signal at 30hz).
I have several audio test discs and used a MoFi with 1/3 octave test tones played on a Sony PS3 into the B & O/Def Tech rig-results were the same as above with the Music.ece site (30hz to 16.5khz). Listening to the Grados through only the computer with this disc improved the response at 20 and 25hz, with no change in the high frequencies.
Finally, I played the MoFi disc on the big boy analog rig. 20hz was audible and 25hz was solid. 16.5hz sounded like on the B&O/computer rig and I heard nothing at 20khz. When I measured and set up this system, it rolled off above 16.5 khz, so the 20khz result is not surprising. I also can't hear sh*t beyond 16-17khz. The good news is my hearing is about the same, or only slightly worse compared to 10 years ago.
I gave up chasing the last 1/3 octave in high frequency performance years ago. I don't think a super tweeter will help me much, but would like to hear the effect, or at least try too.
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Unfortunately that one doesn't work for me as I can't hear 16.5k. This one has a sweep from zero to 20k.
http://onlinetonegenerator.com/hearingtest.html (http://onlinetonegenerator.com/hearingtest.html)
Using this test, Ultimate Ears TripleFi 10 earbuds and the soundcard on my ASUS laptop, my hearing craps out completely at 10k Hz.
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I tested my hearing again using my desktop PC, AudioEngine 5 powered speakers, and Bink's Test Tones (can't find these on the net right now), I was able to hear up to 12.5k Hz.
But, when I went back and tried this onlinetonegenerator on this same system, could only hear up to ~10k Hz again.
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bmwr-can you copy the test tones and play them through another system, to verify your results? Loosing almost an octave of high frequencies is a bummer.
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MacGeek - I don't have any other stereo systems set up right now. We have moved to MS and are living in a work shop. Only the essentials have been unpacked.
I'm 53 and have abused my ears over the years (concerts that made my ears ring, shooting guns with no ear protection, and the list goes on and on).
As STaL said earlier, not a lot appears to be doing on above 10k Hz, see the chart below.
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Pepe,
You might be crazier than me when it comes to tweaks! Looks like fun! I want to see photos of how everything turns out!
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I tested my hearing again using my desktop PC, AudioEngine 5 powered speakers, and Bink's Test Tones (can't find these on the net right now), I was able to hear up to 12.5k Hz.
But, when I went back and tried this onlinetonegenerator on this same system, could only hear up to ~10k Hz again.
I'm not sure, but I think he is announcing the frequency AFTER the tone. A very confusing way to do it, but it would explain your discrepancy.
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Loosing almost an octave of high frequencies is a bummer.
Remember, the "audible range" of 20-20k is like 10 1/2 octaves. So,while seeming huge, you are really only losing less than 10% of your useful frequency range. Since frequency is a logarithm, your mind tricks you into wanting to think that since 10k is half of 20k, the top 10k represents a large number, even when you realize it is much less than the 1/2 it seems to be at a glance. It is a small amount. It is also normal for guys our age (though I would have been sad if that had been the case for bj, as he is a good bit younger).
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Being the same age as by, I'm very lucky to still have
most of my hearing. Had mine tested by audiologist
and still have at least 50 to 16,000 which is all he tested for.
Can still hear everything on my test records down to 30 and up to 18.
Religiously use ear plugs while on the bikes for the last 30 years. Wind noise
Even with a good helmet is an ear killer. Lots of near deaf riding friends. My Dad
worked in the mill for 40 years and was pretty deaf even with hearing aides.