I have a pair of A7s: 416C 902A+811B plus a Fostex A90 supertweeter all going through the JE Labs passive XO (1k6 I think) and 1.33uF direct to the supertweeter. Driven by either 6V6 triode PP at ~3W or EL84 UL PP at ~10W.
I would like a bit more bass (of course!!) any suggestions as to a matching sub design? Not too clued up on LS design but do build all my own electronics so not afraid pf dirtying the hands. Are horn subs possible?
I would like a bit more bass (of course!!) any suggestions as to a matching sub design? Not too clued up on LS design but do build all my own electronics so not afraid pf dirtying the hands. Are horn subs possible?
Interesting, I have followed many of your and others' discussions about Altecs on the forums and have never heard it said they could put out out much below 50Hz...
My port is a full-width slot of 800mm by 60mm - approximately 73 inches squared. Cabinets are in corners, glass wool on all interior surfaces. Cabinets are 828 style.
My port is a full-width slot of 800mm by 60mm - approximately 73 inches squared. Cabinets are in corners, glass wool on all interior surfaces. Cabinets are 828 style.
OK, your vent is already down in numerous DIYer's 'chosen' ~75"^2.
Lots of options, including a bass horn, so need complete info on the total acoustic space, especially if a [somewhat] open one like mine, where in room the speakers, 'sub' can go [dimensioned floor plan, showing all available], any dimension limits within each space, signal chain and any other limitations not listed.
GM
Lots of options, including a bass horn, so need complete info on the total acoustic space, especially if a [somewhat] open one like mine, where in room the speakers, 'sub
GM
Close off the ports completely and use a linkwitz transform. I'm able to get jbl 4560 loaded with 2220h down to 20hz in a small room this way. Using a 40w amp on the bass bins is good enough for my average listening levels and then some. I tried this first, then actually built two huge subs, and then ended up going back. This worked better for me I think because I didn't have a lot of places to put the subs and the response with the subs was way more ragged than without them. It might be kludge but these components can easily handle it when I'm only throwing a few watts at it anyways.
Hello,
If i remember well Pano just like me has been in France, Paris where Jean Hiraga used these Altecs. From the information they published in their magazines they indeed advised to make the event smaller but their main target was to lower the impedance peak ( have to find the magazine in my library)
I know adding the wings make them go lower!
I know that Jean Hiraga uses or used a Magnat active subwoofer with his Altecs.
In my '' home cinema 2.1 '' set i use two active SVS subwoofers. The main speakers there have a 6 DB slope filter at 80 hertz inside the Virtue Sensation integrated amp and the SVS have been adjusted to the set/room by a DSP correction and a microphone.
What i wanna do is use a second DSP correction to integrate these 2 SVS subwoofers into my audio set. Just using the Altecs as a speaker that doesnt produce anything below a certain frequency . Let's say 50cycles and just tell the SVS to do everything below that frequency with its built in 12 db filter.
80 hertz/cps integrates VERY well in my home cinema . But there the efficiency of the system is well balanced. I can make the Virtue going into protection while the SVS couple are not running out of steam!
I think by choosing the cross over frequency as low as possible i might get a combination that will get me an improvement.
Greetings, Eduard
If i remember well Pano just like me has been in France, Paris where Jean Hiraga used these Altecs. From the information they published in their magazines they indeed advised to make the event smaller but their main target was to lower the impedance peak ( have to find the magazine in my library)
I know adding the wings make them go lower!
I know that Jean Hiraga uses or used a Magnat active subwoofer with his Altecs.
In my '' home cinema 2.1 '' set i use two active SVS subwoofers. The main speakers there have a 6 DB slope filter at 80 hertz inside the Virtue Sensation integrated amp and the SVS have been adjusted to the set/room by a DSP correction and a microphone.
What i wanna do is use a second DSP correction to integrate these 2 SVS subwoofers into my audio set. Just using the Altecs as a speaker that doesnt produce anything below a certain frequency . Let's say 50cycles and just tell the SVS to do everything below that frequency with its built in 12 db filter.
80 hertz/cps integrates VERY well in my home cinema . But there the efficiency of the system is well balanced. I can make the Virtue going into protection while the SVS couple are not running out of steam!
I think by choosing the cross over frequency as low as possible i might get a combination that will get me an improvement.
Greetings, Eduard
My room is L-shaped. Approximately 25' by 15' for the main area that houses the hi-fi. 10' by 12' for the shorter part of the "L". The speakers sit at the top of the longer part of the "L". The space is actually bigger than that as there aren't many doors, but the substantive room is as described.
yes, initially I was saying that it was ok ( just an op-amp and a bunch of components+PSU) but thinking of the output transformers that might get stressed of such bass boost...well, no!
Correct. I wanted a "Hi-Fi" PA rig and Mr. Hiraga said that if I upgraded his A5 rig, I could use it for shows. So under his direction I rebuilt, braced and damped the cabinet along with a reduction in port size. 1505 horn with Westrex driver was up top, JBL tweeter. Mr Hiraga lent me a Luxman amp which I used for a few gigs.
The wings do help, mostly they help load the woofer horn so that it has control a little lower than without the wings. Room gain can help below that. I never used a sub, and don't remember Mr. Hiraga using one, but have seen mention of it before in article or posts. That would have been after my time.
Hello,
My memory served me well. I remember the wings and reducing of the ports described in L'Audiophile magazine in the eighties.
I read about the Magnat subwoofer in another French magazine ( La nouvelle revue du son). I must have a copy.
It would be nice if the idea i gave will work hoping it will be possible to blend the active subwoofer going up until the efficiency of the 515 woofer and the cabinet will start roaring so to say.
In my home cinema set the cross over frequency is 80 hertz/cps . I think with the Altec bins it can be lower keeping the advantage of the dynamics coming from the bass bin.
Greetings, Eduard
I guess I want frequencies below ~60Hz. My readings about the A7 all point to the response dropping off quite rapidly below 50Hz. Obviously I could just buy a modern sub and whip up a high pass x-over for the A7, but how well would a modern sub match to the high-efficiency of an A7? I am interested in exploring a 'period tech' sub; horn or high efficiency.
The last time I heard Jean set up VOTTs was at an ETF with the Japanese delegation. Sideways angeled tweeters (JBL bullets probably) and a single, small cube shaped Magnat sub in the back to cover the other end. The whole arrangement sounded pretty impressive.
"period tech sub" I'd say doesn't matter if you use it below 80Hz, preferably below 50Hz. That's where I use my own sub (4 slot loaded RCF 15" drivers) with my 828 inspired cabinets and bass quality to a large extent is ruled by the tweeters to a large extent.
"period tech sub" I'd say doesn't matter if you use it below 80Hz, preferably below 50Hz. That's where I use my own sub (4 slot loaded RCF 15" drivers) with my 828 inspired cabinets and bass quality to a large extent is ruled by the tweeters to a large extent.
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Ha ha, No, but different tweeters can change your perception of the bass. It's a strange and funny effect.
I'm not sure what to suggest for period correct subs, unless you want to go huge. Until the rise of EDM normal pro PA didn't go much below 50Hz, there just wasn't the need. Anything below that was just noise and the real bass punch and boom is higher anyway.
What you may be seeking is more punch centered around 80-100Hz. That's the boom-boom region in live amplified music.
An approached used by some people is to build a modern active subwoofer into the 838 cabinet and high pass the Altec 15". There is plenty of room to do it.
I'm not sure what to suggest for period correct subs, unless you want to go huge. Until the rise of EDM normal pro PA didn't go much below 50Hz, there just wasn't the need. Anything below that was just noise and the real bass punch and boom is higher anyway.
What you may be seeking is more punch centered around 80-100Hz. That's the boom-boom region in live amplified music.
An approached used by some people is to build a modern active subwoofer into the 838 cabinet and high pass the Altec 15". There is plenty of room to do it.
Yup. @jakruby: try listening to only a sub that has it's filter set to 80Hz. There isn't much happening and you might wonder if it's even on. But playing with the rest of the system it makes a difference. And with musical instruments you always have an assortement of overtones that make the sound of the instrument and these overtones are not reproduced by the subwoofer.
The lower the fundamental, the wider its HF BW, ergo the more it [all above the XO point] impacts its tonal balance, 'snap', whatever and since the highest frequency signal 'leads' this sound 'bubble' it's always good to have the speakers capable of at least a half octave above this point, so one ideally needs to know the max frequency response of their recordings or just use a CD's 22? kHz.
GM
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