Linux version worked pretty well for me. Don't remember if I tried the Mac version.
EDIT: I remember using JACK on the Mac.
http://www.jackosx.com/
Might do what is needed.
Not sure what you mean. When PureMusic is running (in full mode, i'd not run it at anything less), it is hogging all the audio and nothing else can get at the audio.
dave
Thanks all.
I didn't realize a 421 basket and magnet would make a difference, Bill at GPA said they were basically the same, and honestly forgot about it since I did the recone a few years ago.
Makes me wonder though. That would explain the dip at 500hz. There is a pair of 416-8b locally for $400 I've been thinking of getting. Alnico's are tempting, especially in an onken!
Having 4 massive boxes I'm constantly moving around can get tiresome but my wife won't let me sell the onkens nore the A7's saying "You will regret it". Plus the local theatre gave them to me, so I'm apliged to keep them around. She is right.
-I don't think even a 2nd mac would work because the gated response requires the source computer to be the measuring device as well correct? I do have 2 macbooks to try. So one would do the sweep and the other measure? No gated response though right?
-The Dac is only 2 channel, but I'm using the headphone out for the lows so it is 4 channel out via a "agregated device" in the midi setup. I will eventually get another good USB DAC and do 3 way (or just get better 2way by not using the headphone out)
So back to the A7's. Is anyone surprised at how flat the 805b multicell horns are? They are quite amazing in the world of audio. I think it's inspiring how "purpose built" they were. They had a job to do, (fill a large venue with clear vocal reproduction on a few watts) and they do it so effortlessly. They sound nothing like the many modern PA I've heard. NEO high wattage drivers tend to sound harsh in comparison. Even at the cineplex watching 007 Spectre lastnight, all the classical music was impressive but my brain knew it was artificially fake and basically digital sounding. The altecs have such a...pure tone to them, and in a relatively live room like the garage, they are convincingly real. Especially with the Telefunken tube amp I just pulled out of a old console!
BTW, the garage is 25x25. The bass response is poor compared to my 18x20 living room. Also, once we finish knocking a wall out, doubling the room length, the A7's will go back in the living room. I will remove the castors wheels and set on granite slabs. This made the biggest difference in bass 'bar none' before the reno.
I didn't realize a 421 basket and magnet would make a difference, Bill at GPA said they were basically the same, and honestly forgot about it since I did the recone a few years ago.
Makes me wonder though. That would explain the dip at 500hz. There is a pair of 416-8b locally for $400 I've been thinking of getting. Alnico's are tempting, especially in an onken!
Having 4 massive boxes I'm constantly moving around can get tiresome but my wife won't let me sell the onkens nore the A7's saying "You will regret it". Plus the local theatre gave them to me, so I'm apliged to keep them around. She is right.
-I don't think even a 2nd mac would work because the gated response requires the source computer to be the measuring device as well correct? I do have 2 macbooks to try. So one would do the sweep and the other measure? No gated response though right?
-The Dac is only 2 channel, but I'm using the headphone out for the lows so it is 4 channel out via a "agregated device" in the midi setup. I will eventually get another good USB DAC and do 3 way (or just get better 2way by not using the headphone out)
So back to the A7's. Is anyone surprised at how flat the 805b multicell horns are? They are quite amazing in the world of audio. I think it's inspiring how "purpose built" they were. They had a job to do, (fill a large venue with clear vocal reproduction on a few watts) and they do it so effortlessly. They sound nothing like the many modern PA I've heard. NEO high wattage drivers tend to sound harsh in comparison. Even at the cineplex watching 007 Spectre lastnight, all the classical music was impressive but my brain knew it was artificially fake and basically digital sounding. The altecs have such a...pure tone to them, and in a relatively live room like the garage, they are convincingly real. Especially with the Telefunken tube amp I just pulled out of a old console!
BTW, the garage is 25x25. The bass response is poor compared to my 18x20 living room. Also, once we finish knocking a wall out, doubling the room length, the A7's will go back in the living room. I will remove the castors wheels and set on granite slabs. This made the biggest difference in bass 'bar none' before the reno.
Altec A-5 Optimum Bass Reflex Port Area
Pano, I have had a pair of A-5s for 25 years, and I have loved the sound of these speakers for every minute I have listened to them. My A-5 system consists of the Altec 828 bass enclosure, the 416A bass driver, the 1505B multicellular horn with the single-driver throat, and the 288H compression driver. I added the Hiraga crossover network to this system in 1997.
With regard to your suggestion above that the standard bass port is much too large for good bass performance, what is your recommendation for reducing the reflex port area for optimal bass with this speaker? I have read that other users reduced the port area for these speakers to 64 square inches, and 100 square inches, but you seem to be particularly well informed about the A-5, and I would value your input.
Thanks in advance!
Bruce
With proper ports and corner placement, mined played down into the low 30s with no EQ. The standard ports are much too large for good bass. I also saw the peak at 60 and nothing below with the stock ports. Not too hard to fix.
The horn flares on mine buzzed at several frequencies. I braced and then painted the backs of the flares with bitumen and sand. Made a huge difference.
Don't forget the sides and back, they talk, too. And there is a lot of surface area there to make noise.
Pano, I have had a pair of A-5s for 25 years, and I have loved the sound of these speakers for every minute I have listened to them. My A-5 system consists of the Altec 828 bass enclosure, the 416A bass driver, the 1505B multicellular horn with the single-driver throat, and the 288H compression driver. I added the Hiraga crossover network to this system in 1997.
With regard to your suggestion above that the standard bass port is much too large for good bass performance, what is your recommendation for reducing the reflex port area for optimal bass with this speaker? I have read that other users reduced the port area for these speakers to 64 square inches, and 100 square inches, but you seem to be particularly well informed about the A-5, and I would value your input.
Thanks in advance!
Bruce
Hi Cal,
Thanks very much for your input.
75 square inches seems to be a good compromise, based upon some of the other numbers I have seen. I think I'll give it a try. I'd still be curious to see what Pano finally ended up using for the port area on his modified A-5s.
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Cal, just a few quick questions for you, if I could, as 75 square inches of port area sounds like a good compromise for this speaker system:
-Did you reduce the internal volume of your 825 or 828 enclosure when you reduced the port area to 75 square inches, such as closing off the short horn flare within the enclosure? Did you make any modifications to the enclosure that could have substantially reduced its volume?
-Which Altec woofer are you using in your enclosures; the 416A or B, or the 515 series?
Thanks again for your help with this.
Bruce
Hi Bruce,
No other changes to the 828 cabinet. They are used outdoor only mostly for parties. I usually use them with a more robust woofer, although occasionally with a 416C. They are a three way satellite cabinet.
I have even used them with 604's. I really like the cabinet.
No other changes to the 828 cabinet. They are used outdoor only mostly for parties. I usually use them with a more robust woofer, although occasionally with a 416C. They are a three way satellite cabinet.
I have even used them with 604's. I really like the cabinet.
Attachments
Just saw this.
I do not remember what size the ports were in my final version. I just did a lot of measuring until i found what was best; using boards of various sizes to close off the port bit by bit. I ended up with a narrow port at the bottom of the box. Maybe 3-4" tall and the width of the face.
Glad you got the Hiraga crossover to work for you. I could not get good results out of it on my A5. Of course the version we built in Paris 32 years ago worked just fine, but that published crossover never worked right for me. I don't know why. Maybe because I had the 1005 horn, not the 1505.
I do not remember what size the ports were in my final version. I just did a lot of measuring until i found what was best; using boards of various sizes to close off the port bit by bit. I ended up with a narrow port at the bottom of the box. Maybe 3-4" tall and the width of the face.
Glad you got the Hiraga crossover to work for you. I could not get good results out of it on my A5. Of course the version we built in Paris 32 years ago worked just fine, but that published crossover never worked right for me. I don't know why. Maybe because I had the 1005 horn, not the 1505.
A quick search listed 3" x 30", though in actuality it's a bit narrower, so ~81"^2 with 75"^2 popular enough to be considered a consensus. Both put tuning in the mid 30s same as the M19.
[4] 4" tubes x 6" was popular for a long time with tuning down around 32 Hz, typically a good tuning for corner loading or separate sub system.
GM
[4] 4" tubes x 6" was popular for a long time with tuning down around 32 Hz, typically a good tuning for corner loading or separate sub system.
GM
Thanks very much, Pano, Cal, and GM! Your input is much appreciated.
I think there is clearly a consensus here. The port area all of you have described is nominally 80 square inches, and that is the area I will try with my 828 bass enclosures.
Pano, I wonder if I could ask you to describe the subjective improvement you were able to obtain in the bass performance of your A-5 system when you narrowed the reflex port area down to around 80 square inches, from the original 210 square inch area as built by the factory. I expect to find out soon enough when I install a new port board in my enclosures, but I'd like to see what I may be in for.
I think the Hiraga network is clearly tailored to the use of the 1505B horn, and that is what I have used in my A-5 system since day one. I have heard many complaints of less than satisfactory performance when the more readily available 1005 horn was used with the Hiraga crossover, but I have also heard of some listeners using the 1005 that were thrilled with the result, so go figure.....Personally, I have heard the 1005s in the past, and I was less than enamored with the sound, when compared to the 1505Bs. By the same token, the choice of capacitors utilized in the Hiraga network are quite critical, and I used all paper-in-oil for both the LF and HF sections of the network.
My A-5 system appeared in the long defunct "Sound Practices" magazine back around 1997 or so. At that time, I was using the 288K ferrite magnet compression drivers, and then shortly thereafter, a good friend of mine was kind enough to buy a pair of the Altec 288H Tangerine phase plug compression drivers for himself and for me. The Alnico 288Hs literally blew away the ferrite 288K, and the 288Ks left here shortly thereafter.
I drive my A-5s with a transformer volume control, and the power amplifiers are two-stage, with an input transformer providing around 22 dB of voltage gain, and that drives a 45 tube as the driver stage. The 45 is transformer-coupled with a Tango NC-20 to a WE-300B. The output iron is a Tango X5-S, with a 5K ohm primary impedance, so the 300B is very lightly loaded for the lowest distortion. I use mercury vapor tubes for rectification, with separate power supplies for the driver and output stages. With this amplifier configuration, the A5s have a powerful and fast sound, but I always thought the lowest octave of music was missing with these speakers. Hence my interest in improving the low-bass performance of the A-5s.
Best Regards,
Bruce
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Thanks for the info on your system Bruce. I believe I read that article in SP.
As for the port, it added low bass that was not there before, and subjectively it all sounded more even, more complete than the big port. With the stock port the bass was sort of plump, but not even or smooth. With the smaller port it seemed more like I was listening to the recording, and less to the speaker. I hope that description helps. On the A5 that Mr. Hiraga and I built, I never heard it before the mods, so can't comment on the changes. IIRC, the woofer was something like an EV cone on a Westrex frame. The port was small and placed in the center of the space.
I agree with your assessment of the 1005 vs the 1505. The 15 cell is in another league. I liked my 10 cell horn, but it never had the life-like magic of the 1505. Hiraga used Westrex drivers on the 1505 when I was working with it. The same drivers got used on the W.E. 15A horn at some demos we did. Quite amazing.
Cal Weldon has a pair of 1803 horns, which I've been able to see and caress, but never heard them in action. Maybe some day.
As for the port, it added low bass that was not there before, and subjectively it all sounded more even, more complete than the big port. With the stock port the bass was sort of plump, but not even or smooth. With the smaller port it seemed more like I was listening to the recording, and less to the speaker. I hope that description helps. On the A5 that Mr. Hiraga and I built, I never heard it before the mods, so can't comment on the changes. IIRC, the woofer was something like an EV cone on a Westrex frame. The port was small and placed in the center of the space.
I agree with your assessment of the 1005 vs the 1505. The 15 cell is in another league. I liked my 10 cell horn, but it never had the life-like magic of the 1505. Hiraga used Westrex drivers on the 1505 when I was working with it. The same drivers got used on the W.E. 15A horn at some demos we did. Quite amazing.
Cal Weldon has a pair of 1803 horns, which I've been able to see and caress, but never heard them in action. Maybe some day.
Hi Pano, Cal, and GM,
Pano, once again, thanks very much for the detailed reply!
I modified my A-5s earlier today to reduce the reflex port area to 80 square inches. Like the port modification you had performed on your A-5s, I located the reflex port towards the bottom of the enclosure. My initial listening impression is that the bass definitely tightened up, in the sense that the boominess in the bass I had taken for granted all of these years as most probably being a part of the recording, seems to have gone away. I am assuming that "plump" sound you had described with the standard port area could be considered as boomy bass reproduction.
Unfortunately, I did not have the opportunity today to really spend a lot of time listening to the speakers with the reduced bass port area, but with the little listening I did, I did not really hear much extension of the lowest octave of bass. My definition of low bass with the A-5s is anything much below 60 Hz, which I believe is the cut-off frequency of the bass reflex mode with the stock 210 square inch port. I would like to get your, Cal's, and GM's thoughts on the bass extension issue.
I wish I had the real estate in my listening room to add the wings that Mr. Hiraga had described for use with his A-5 system. The wings were of course standard equipment with the larger (A-1, A-2, & A-4) Voice of the Theatre systems, and were a critical component to enhancing the lowest octave of bass reproduction with those speakers.
The 1803s would be most interesting to listen to, when compared to the Altec 1505 15-cell horns. You and Cal were lucky; I have never seen an 1803 in the flesh!
All the Best,
Bruce
Pano, once again, thanks very much for the detailed reply!
I modified my A-5s earlier today to reduce the reflex port area to 80 square inches. Like the port modification you had performed on your A-5s, I located the reflex port towards the bottom of the enclosure. My initial listening impression is that the bass definitely tightened up, in the sense that the boominess in the bass I had taken for granted all of these years as most probably being a part of the recording, seems to have gone away. I am assuming that "plump" sound you had described with the standard port area could be considered as boomy bass reproduction.
Unfortunately, I did not have the opportunity today to really spend a lot of time listening to the speakers with the reduced bass port area, but with the little listening I did, I did not really hear much extension of the lowest octave of bass. My definition of low bass with the A-5s is anything much below 60 Hz, which I believe is the cut-off frequency of the bass reflex mode with the stock 210 square inch port. I would like to get your, Cal's, and GM's thoughts on the bass extension issue.
I wish I had the real estate in my listening room to add the wings that Mr. Hiraga had described for use with his A-5 system. The wings were of course standard equipment with the larger (A-1, A-2, & A-4) Voice of the Theatre systems, and were a critical component to enhancing the lowest octave of bass reproduction with those speakers.
The 1803s would be most interesting to listen to, when compared to the Altec 1505 15-cell horns. You and Cal were lucky; I have never seen an 1803 in the flesh!
All the Best,
Bruce
Greets!
'Boomy'/'flabby'/'loose' is the way I describe them, especially when driven with the high output impedance they were 'voiced' with. The crux of the matter is that the horn is a good 6 dB more efficient than the bass cab, so tuning it lower, while 'tightening up' the bass, is also rolling it off; consequently one needs to either use variable DF tone controls or couple to a matching impedance amp like they were designed for to shelve down the system - 6 dB for starters and tweak from there till it's tonally balanced.
Note too that one gets less bass output with later drivers than the 803B/416A and if you have the original 803A, then with a 50-60 Hz Fs, that's all there is folks.
BTW, the wings have very little impact on low bass, only upper mid bass to more gradually blend the horn's roll off to the bass cab's peaky tuning to tonally sound more 'full' like a mini 'A' series bass horn, so I still recommend them [including the upper one used on the original A800] when space permits. Note too that you can 'cheat' a bit by folding them: Hasling Audio Systems Denmark
GM
Yes, what GM says about the wings. It mostly helps the crossover region with the horn.
"Plump" was being polite. Boomy, flabby, bloated would be more direct terms. With the standard port there as nothing below 60Hz, and a peak above that. With reduced ports and some corner placement, I was getting an f3 in the lower 30s. The Hiraga A5 didn't go much below 50 Hz, but did everything above that with smooth elegance and ease. Not the least bit boxy.
As GM states, the horn flare in front of the woofer makes that range louder than the lower registers. What I did to combat that was to cross the woofer lower than the horn, and that works out the better match levels all around. E.G. low pass woofer @ 500 Hz and high pass horn @720 Hz resulted in the best blend. Don't remember the exact points, but may be able to look them up. They would vary with different horns and drivers anyway.
"Plump" was being polite. Boomy, flabby, bloated would be more direct terms.
With the standard port there as nothing below 60Hz, and a peak above that. With reduced ports and some corner placement, I was getting an f3 in the lower 30s. The Hiraga A5 didn't go much below 50 Hz, but did everything above that with smooth elegance and ease. Not the least bit boxy.As GM states, the horn flare in front of the woofer makes that range louder than the lower registers. What I did to combat that was to cross the woofer lower than the horn, and that works out the better match levels all around. E.G. low pass woofer @ 500 Hz and high pass horn @720 Hz resulted in the best blend. Don't remember the exact points, but may be able to look them up. They would vary with different horns and drivers anyway.
Hi Pano & GM. Thanks once again for the input here!
Pano; Wow, you measured an F3 of in the lower 30 Hz region with the modified A-5s? The way I look at it, reducing the port area (to around 80 square inches or so) will certainly improve the transient response/damping on the bass driver to reduce the overhang or boominess I was noticing with the stock 210 square inch reflex port area. But I guess what I don't understand is how the lowest octave of the bass could be extended so much, and down -3dB to around 35 Hz by reducing the port area, as the bass response will still fall by 24 dB/octave below the cut-off frequency of the speaker when it is in the bass reflex mode. 24 dB at one octave below 50 or 60 Hz is a huge reduction in acoustic output, whereas a 3 dB reduction is of course for all intents trivial and a very impressive achievement with a vented enclosure.
Yes, corner placement will of course enhance the low bass output, but getting the A-5 to provide an F3 of the low 30s is a bit beyond me. If you could clarify this for me, it would be really appreciated. I always thought the only way to achieve this kind of F3 would be to use a subwoofer, as the bass reflex mode would be incapable of reproducing anything that low.
The 50 Hz response as exhibited by Mr. Hiraga's system with the reduced port area, along with the improved smoothness of the bass response makes good sense to me.
Best Regards,
Bruce
Pano; Wow, you measured an F3 of in the lower 30 Hz region with the modified A-5s? The way I look at it, reducing the port area (to around 80 square inches or so) will certainly improve the transient response/damping on the bass driver to reduce the overhang or boominess I was noticing with the stock 210 square inch reflex port area. But I guess what I don't understand is how the lowest octave of the bass could be extended so much, and down -3dB to around 35 Hz by reducing the port area, as the bass response will still fall by 24 dB/octave below the cut-off frequency of the speaker when it is in the bass reflex mode. 24 dB at one octave below 50 or 60 Hz is a huge reduction in acoustic output, whereas a 3 dB reduction is of course for all intents trivial and a very impressive achievement with a vented enclosure.
Yes, corner placement will of course enhance the low bass output, but getting the A-5 to provide an F3 of the low 30s is a bit beyond me. If you could clarify this for me, it would be really appreciated. I always thought the only way to achieve this kind of F3 would be to use a subwoofer, as the bass reflex mode would be incapable of reproducing anything that low.
The 50 Hz response as exhibited by Mr. Hiraga's system with the reduced port area, along with the improved smoothness of the bass response makes good sense to me.
Best Regards,
Bruce
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Hi GM!
Thanks for the clarification re the wings. I did not know that, and what you have described makes good sense.
Could you clarify your comment regarding, "so tuning it lower, while 'tightening up' the bass, is also rolling it off". The way I look at it, reducing the port area (within limits) would perhaps improve the lowest bass response somewhat, but I don't see how it would roll it off. Especially when you consider that Pano has claimed that reducing the port area improved the F3 of his A-5 system to the low 30 Hz region, when the cut-off of the stock A-5 with 210 square inches of port area is around 60 Hz or so.
I would be the first one to state that I am not a speaker expert, and my area of expertise is more towards the electronics.
Your guidance and clarification here would be appreciated!
With Best Regards,
Bruce