Thanks!
And yes, it appears I'm getting every bit of 30Hz at significant SPLs. Color me a happy camper.
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Thanks!
And yes, it appears I'm getting every bit of 30Hz at significant SPLs. Color me a happy camper.
A proper tripod...
Measurements to follow.
http://www.hostboard.com/forums/hbmc...2012/12/19.jpg
I downloaded the calibration file. My Mac won't save it as a txt file. I copied the data and pasted to Word and then saved as a txt. Yes?
Anyway, this was my first measurement after adding the calibration file to REW. I'm not sure I did it right though.
Do I use 128K length? Single or multiple sweeps?
http://www.hostboard.com/forums/hbmc...2012/12/13.png
Quote:
Originally Posted by alancohen
Single sweep will suffice .
Choose a length that gives an @ 5 sec sweep ( usually that 256K at these sample lower rates ) .
Remember to watch your vertical scaling ( you're trying to make it look "pretty" again by squishing the info ) .
The .txt file must have loaded correctly ( assuming you went through the procedure ) if REW didn't put up a warning box ( about non-compatible "this & that" , etc. etc. " ).
That +8db spike at @ 1400hz is pretty worrisome . Is it adjustable in any way ( such as lowering the Lpad drive amount to the horn ) or maybe physically raising the level of the mic so that it's even to the center of the 811H ) ???
:)
I moved the mic to the center of the horn and about 12" away. Red is L-pad all the way up. Blue is L-pad at 50%.
http://www.hostboard.com/forums/hbmc...2012/12/14.png
Mic at my head...
http://www.hostboard.com/forums/hbmc...2012/12/15.png
Blue is with HF comp circuit, green is without.
http://www.hostboard.com/forums/hbmc...2012/12/16.png
Don't second guess yourself. Usually your first impression is the right one..If they sound good to you just enjoy them for a bit..We are all here to try and make some improvements however small they maybe.It is part of the fun of enjoying your Altecs.. It will become an addiction, but a healthy one.Beware ! :Big smile:Quote:
Originally Posted by alancohen
Hi Alan,
Thanks for the pics . Boy, the response of that horn sure changes with different positioning of the mic .
http://www.hostboard.com/forums/hbmc...2012/12/15.png
This one ( test mic by head ), where you standing or sitting ? It's interesting how it has the flattest response from 2K to 10K .
As AB said, it's really important to trust your ears ( me paraphrasing ).
:)
Here's a measurement I took of my 19's a couple years ago. 1/6 octave smoothed.
It's pretty flat from say 1300 Hz - 15k. Your 802's should look similar to this,although I'm using the M19/1201 networks obviously.
http://www.hostboard.com/forums/hbmc...2012/12/20.jpg
http://www.hostboard.com/forums/hbmc...2012/12/14.png
This pic showing the effect of the variable Lpad shows the acoustic crossover is right around 1K .
:)
PS ; When are you going to install the 802G drivers ?
http://www.hostboard.com/forums/hbmc...2012/12/20.jpg
Hi John,
That's a nice response target for Alan to work towards getting ( should sound real nice ! ).
:)
PS ; I like the horizontal "width" of the pic ( fwiw ) .
Thanks Earl ! I just maximized Holm.Then snip the graph with windows snipping tool upload to photobucket Voila.And post the IMG link..Quote:
Originally Posted by Earl K
I agree those graphs are much easier to read then the smaller ones... None of us are getting any younger..Our eyes only get worse as we age so we have to compensate. :smile2:
In Holm you can save a graph directly. Under the |File| menu look for Save bitmap images. This saves in a nice, sharp, small file sized png. Perfect! Don't know if Photobucket will accept png files, will it?
Don't know for saving out of REW.
John, the graph looks good. You've got most of the spectrum covered and a gently falling response. Should sound well balanced.
Holm sounds like a servicable program, but it seems to be only Windows based. I try using Windows as little as possible. I figure I've lost 3-4 months of my life sitting around waiting for Windows to reboot.
So...I'm willing to make a bet that no one has actually installed 802Gs in a Heathkit AS101 cabinet before.
See, they do not fit. They are too deep by exactly this much:
http://www.hostboard.com/forums/hbmc...2012/12/21.jpg
The 806s press right up against the insulation on the back. The back will not attach with the 802s.
Better curves though:
http://www.hostboard.com/forums/hbmc...2012/12/17.png
Bummer , about that .
Some older Altecs had a plastic top-hat extension to allow for deeper horn/driver setups .
OTOH, GPA may have a solution for you ( if they still sell those plastic loading caps for diaphragms, as found on some 802/902s ) .
- Then the metal back-cap isn't used .
:)
Come to think of it--even the 806's didn't fit in Valencia 846a cabinets. The back panel of Valencias (at least the 846A's that I owned and others I've seen) had a hole "cut out" in the back panel (where the h.f. driver was) that was covered on the outside of the back panel by a very thin piece of wood to allow enough depth for the h.f. driver to extend. The 806-8A drivers do fit in AS-101 cabinets without the hole cut out in the back panel because AS -101 cabinets are a little deeper so maybe this kind of setup would work to get 802-8G's into your AS 101 cabs depending on how much more distance you need. If you add the thickness of the (compressed) insulation and the thickness of the back panel itself, does that total equal the difference in depth between the 806-8A and the 802-8G? If so, rather than cutting a hole in your two back panels, you could (fairly easily) make two brand new back panels with the holes in them for the h.f. driver to extend--and you cover the hole from the outside of the back panel. If you need even more room for the 802-8G, you could use thicker wood for your back panel. Either way, I recommend saving the original back panels so you can return your speakers to original condition someday. Here's a photo of how 846a Valencias allowed for the depth of the h.f. driver....Quote:
Originally Posted by alancohen
http://www.hostboard.com/forums/hbmc...2012/12/22.jpg
VOTT: So I'm not crazy...excellent!
They only miss by about 3/8" with the insulation removed. I think I can get away with a 3/8" strip of wood around the perimeter. The back panel would protrude by that much, but no biggie, it's the back of the speaker anyway. A project for another day. I suppose I could route out a 3/8" deep depression in the existing back panel. That would be about 1/2 the total thickness.
Earl: Thanks for the tip. I'll ring up Bill and see what he has to input.
As far as the sound, they are a little harsh right now. They sound more metallic. The 806s were creamier, if less bright. Is there a break-in period for HF compression drivers like there is for LF drivers?
A 3/8" strip of wood around the perimeter would work as long as you can still achieve a (relatively) air tight seal. Otherwise, it will affect your cabinet tuning and it may actually be quicker and easier to make two new back panels with (covered) holes if you find there's a lot of monkeying around required to get a good seal with a wood strip around the perimeter. You may have to adjust your port size anyways as increasing the depth of your cabs by (at least) 3/8" by using wood strips around the perimeter will have a significant effect on their tuning. On the other hand, using new back panels with (covered) holes in them for the h.f. driver won't really affect your cabinet tuning because the hole will be filled with the end of the driver and the internal cabinet depth remains unchanged.....Quote:
Originally Posted by alancohen
As far as using loading caps on your 802-8G drivers, there is significant controversy about this option. Yes, they can be used instead of the rear cover for many Altec h.f. drivers and that saves you some space, but many Altec users (here and elsewhere) believe that the loading caps change the sound of the driver and that they are not good for hi fi use. They were mainly used by Altec IIRC for P.A. applications (and later on for cost cutting applications!) to protect the h.f. driver/diaphragm from over extension when exposed to high power levels during P.A. use. Of course, it doesn't hurt to buy and try them--they're not expensive and if you find it doesn't affect the sound to your ears, then it's a good solution.
Build extensions for the back cover to screw to, An inch or maybe a lot- nobody will ever know.
So, after loaded with all of this response information, what are we supposed to do with it? Whip out the trusty 15 band EQ and trial and error the what looks like a 20db discrepancy by adjusting the EQ, doing another sweep, adjusting the EQ...? And then finding out we don't like flat response anyway?
Just curious, I didn't pay much attention to the products used in this exercise. How much would it cost to gather all of this stuff. I will probably just keep tuning by ear since every time I am financially ready to send my 416's to GPA in for a recone, some great deal on a set of speakers comes along and blows my budget out of the water. :)
Also, base and treble responce seams to be very volume db dependent. I bet the responce is very different @110db.
OT post--true story. Volvo Heretic--I used to date a girl who drove a Volvo and she actually said to me that it was embarrassing to drive a car with a name that sounded like a part of a woman's body.....
LOL Voice of the Theater! married to her now? :)
Lets not Hi-Jack Alan's thread guys.
Sorry AB. Anybody have a responce to my previous questions?
I had most everything I needed already: laptop, tripods, cables etc. I needed a good mic which thanks to Earl's recommendation was under $100 shipped. The software was free.Quote:
Originally Posted by VolvoHeretic
As far as bass and treble being volume dependent, I think that depends on your signal chain. My system includes a signal source (TT, computer CD player and cable box) and a very fast and transparent tube based preamp, phono preamp and 15W OTL amp. The preamp has a 3 input selector and a volume knob. The amp has an on/off switch. That's it. No tone controls, let alone an EQ. What comes from the source is what I get. It's uncanny how volume INdependent the frequency response is. I do not have to turn up the volume to hear excellent bass response. Even at very low volumes, heavy bass passages coming by just fill the room. Of course they don't pound my chest like at louder volumes, but I don't feel like anything is missing at low volume. Sparkling high-hats are right there regardless.
Now, a hole at 500Hz and a spike at 1K is another story. I'm not going to be concerned about it until I get everything bi-amped and see what a pre-amplifier active crossover offers. I'm still pondering Earl's suggestion to rebuild the crossovers and eliminate the L-pads. I think every crossover between the amp output and driver is going to have a signature it leaves on the signal. That's why full-range speakers are getting lots of play.
But like you say, all that matters is what it sounds like. I'm just having a little fun trying to figure out why I like some things and not others. My full-range speakers have a gloriously flat response, but sound restricted compared to these. Frequency response curves are two-dimensional. Music and it's successful reproduction are at least three.
http://www.hostboard.com/forums/hbmc...2012/12/23.jpg
You would lose if 40-50 yrs ago I'd of ever conceived in my widest dreams that I would ever need a picture of it to post on a world wide 'Telstar' system. Anyway, a capped off, damped cardboard tube deals with the extra depth. ;) Others have used food cans, Tupperware bowls, you name it. This tweak was quite common among the Ga. Tech Fraternity crowd back when these kits were 'way rad'.Quote:
Originally Posted by alancohen
GM
Yeah, I don't pay much attention to folk's measurements unless all the particulars are listed since they're like statistics, you can prove whatever you want with them. For HIFI/HT apps, what matters is in-room with the mic at the [various] LP[s], then averaged out. For LF outdoor apps, far enough away ground plane for the lowest frequency to unfold and math correct to 1 m /whatever. For the rest, ideally in 4pi space [up a high pole], otherwise however high off the ground the mains are likely to be.Quote:
Originally Posted by Earl K
GM
Yeah, with high Vas woofers and compression horns you don't normally need any smiley face 'loudness' control, especially if driven with a high output impedance.Quote:
Originally Posted by alancohen
This implies either a poorly done XO or a crapped out one, but my memory says the Heathkits sounded a bit more tonally balanced than the Valencias or maybe we just convinced ourselves they were since we could buy them cheaper due to having a Heathkit store willing to 'deal'.
GM
Thanks for that. :)Quote:
Originally Posted by alancohen
Thanks for the tip on the back cap mods. I assume some tweaking of the sound could be achieved this way. Of course, only for someone that really enjoys taking the back panel on and off a lot. I am not included in that group.Quote:
Originally Posted by GM
I'm just starting to learn about the significance of room acoustics. I guess it's nice to know what is coming directly out of the speaker, but unless you listen to music with your head 12" away from the speaker, it really doesn't have much practical value. It matters more how the speakers play the room. If you take the same system and move it from room to room, I'm sure you will get very different frequency curves and a very different sound.
I'm moving very soon and my system will be in an unusually shaped, large open space with a big stone fireplece smack in the middle. I picked up Jim Smith's book and DVDs "Get Better Sound" to begin the learning process of how to set up this room. I'll be moving that mic all over the place and I'm certain there are many diffusion and absorption panels in my near future.
Yes so very true. And that is where the use of L-pads come in.They help you tune the speaker sound to the room.But the most important part IMO&E is your measurements will help you to build a perfect crossover for your particular speakers.With your measurements and impedance plots and T/S parameters of your speakers, if you have them ? You can build a spot on crossover instead of using a universal crossover like an 500 Hz,800 Hz,1200 Hz,etc, Crossover..Quote:
Originally Posted by alancohen
I'm of the school crossovers are as important as drivers...
You're welcome! Yes, rear panel removal to tweak sucks, so initially I used carriage bolts, wing-nuts and access panels, but due to cab weight and life long back issues, I finally switched to fixed/glued backs to increase cab rigidity and removable driver baffles a couple of years before Altec did on the 846B. Since the local distributor's in-house design team was aware of this and other tweaks I was doing............
Really, consumer cabs for the most part are just so-so furniture construction with mediocre audio performance, so consider either getting 'new' components and/or at least using what's in the Heathkit cabs and DIYing some cabs more appropriate for your new room's acoustics.
1 m measurements are fine for designing XOs and comparing different speakers, but this current obsession in the DIY community with billiard table flat responses at raw data to 24 dB/octave smoothing just because they can when no normal human can hear better than ~6 dB/octave resolution and will be much further away in an acoustically small room is not the best overall choice unless one sits at < 1m from the speakers in an acoustically large enough O.B. located outside on an open/flat field or similar.
Not familiar with Jim Smith's work, but unless it's very current and a thousand or two pages I suggest Googling for room acoustics websites and browsing the various DIY audio forums for DIYing room treatments to fill it out somewhat, though using horns with the proper polar response, speakers and listening position for the room, etc., treatments other than carpet or area rugs typically aren't required since LEDE rooms are best overall for horn and other 'focused' systems.
GM
More so actually, along with cab design/construction since some of the world's most expensive, best reviewed super-fi speakers use inexpensive, 'plain vanilla' drivers available to the DIYer except with their markings to garner exorbitant replacement parts pricing. Up to a point then, thanks to our typical hearing acuity not being all that good combined with our penchant for preferring most things 'rich', be it visual, taste, feel, hear, we can be fooled into believing you really can make a 'silk purse out of a sow's ear'.Quote:
Originally Posted by Old Guy
GM
Apology not necessary Volvo ! :wink2: But Thanks, I appreciate that ! I was just trying to keep it on track as he has put a lot of work and expense into this.And would like to see him arrive to that perfect Altecness ! You know the one ? Where you have that grin from ear to ear,kinda like this guy ----> :Big smile:Quote:
Originally Posted by VolvoHeretic
And as why I only ever go to 1/6 smoothing. It's good enough.Quote:
Originally Posted by GM
Now here's a good point. Ultimately, I will be using a Behringer DCX2496 active crossover and biamping.Quote:
Originally Posted by Old Guy
Those little black boxes on top of my Heathkit in the previous pic are (8) 300B tubes. I'm patiently waiting for the kits to start building (2) 300B OTL monoblocks to drive the horns.
So realistically, I will not have any components in between the 300B cathodes and the 802G drivers. No output transformers, capacitors, inductors or resistors. Mmmm...
So I watched Jim Smith's DVD and started reading his manual, "Get Better Sound". He seems to be a very hands-on guys, with decades of experience setting up rooms for speaker manufacturers at trade shows like: Acoustic Research Corp, Magnepan, Dahlquist and Advent as well as running his own audio shop in Atlanta for years where he has personally set up hundreds of systems. His claim to fame is being able to set up a room to get the best possible sound. He currently works as a consultant for hire, where he will come out and analyze your room and set it up for you.Quote:
Originally Posted by GM
His thing is more about working with the room rather than overtreating it. He does advocate well placed diffusing and absorbing panels, but spends most of his effort "finding the best bass" in the room and setting up the speakers and "THE" listening chair in exactly, and I mean exactly, the right position where the "sound just pops and the walls and speakers disappear". His mantra is, "If you don't get the bass right, you'll never be happy with your system". He advocates taking the time to get the best out of the system you have and have it "play the room" before you even think of buying a new component. His claim is the room is the most important component in your system.
Like has been mentioned here before, he believes the "out of context" frequency response of a speaker is irrelevant. After all, most speaker manufactures are pretty good at making speakers. It's what happens to the sound in real time in a room that matters. Peaks and suck outs can be enhanced or eliminated depending on where you and your components are located. He uses gaffer tape to set up a grid on the floor and a laser tape measure to perfectly align everything. He uses specific reference CDs that he knows well. He speaks of a certain chime at a specific part of a particular song that is supposed to be located just inside the right speaker of the stereo image. If the right speaker is located even as much as 2" too close to the listener, the chime will be more centered.
He cited one system that he had set up where the customer called him back after a couple of months noting that the mid bass had become mushy. When he got there, sure enough he measured a 6dB peak around 100Hz, I think. He measured forward of the listening area a foot and it disappeared. He thought that odd since nothing had been moved. His marks were still on the floor. So he moved the sofa up a foot and the the peak was back, but had disappeared 12" back where they started. This was puzzling at first, but then he noticed from his notes, that the sofa was different. The customer had bought a new one. It was leather with a firm back panel that was found to be resonating at 100Hz. They damped the sofa back and the peak was gone.
Now this might be all well and good, but he's using "conventional" two and three way "tweeter" loaded speakers. He likes Vandersteens to give you a reference. But I'm curious as how all this relates to horns. I do notice an uptick in image when I get my head perfectly centered between my Heathkits, but I get a nice stereo image throughout most of the room as well.
So how directional are Altec horns compared to "conventional" speakers? And if there is something to this, do I need to either get them off the floor or tilt them up a bit?
As far as this "sound just pops and the walls and speakers disappear" stuff, I think mine do that already. If I close my eyes while listening to a well recorded piece of music, the sound stage is huge and I can pick out every instrument in the band and where they are sitting (or at least where the engineer has them sitting). But I will need to "get the bass right" in the new place before anything. I hope the best bass is in a place I can live with. I will not have a dedicated listening room.
BTW, here's an article where Jim won the 2001 Soundstage Reviewers Choice Award while working for Avantgarde. He had a day to set up the room that was supposed to have 3 rows of 3 seats each for listening. He realized that was impossible due to the acoustics of the room and strong-armed the powers that be to setting up with only 1 row of three, 'cuz that's where the right bass was. Of course this meant a lot less people would get to listen and it was a very risky play, but it worked. People were lined up all day to hear the Duos and he won the award.
http://www.soundstage.com/earmarked/earmarked200110.htm
It depends on which Altec horns you're discussing. Altec Mantaray horns have a relatively large "sweet spot" whereas the 811b horns that you own have a relatively narrow sweet spot. Most "audiophiles" who own Altec sectoral horns like the 811b's "toe them out" slightly to get the best dispersion pattern relative to the listening spot that they're "aiming" at. In other words, if your listening spot is back a ways from the speakers and centered between the two speakers--rather than pointing both speakers right at your head, ideally you would want to point the right speaker more towards (and maybe even slightly right of) your right shoulder and the left speaker towards or just left of your left shoulder. Trial and error/experimentation is your friend here/YMMV...Quote:
Originally Posted by alancohen
As far as your other question, yes, you should either build risers for your AS 101's or prop up the fronts IMHO. Valencias (and AS 101's) are sometimes called "low boys" as they are not very tall and sound great if you sit on the floor! If you're sitting on a couch etc. they will sound noticeably better either on risers or with the fronts propped up. Putting them on risers or propping them up will help the horns to be pointed at ear level, but will also affect the bass response. Some people swear by risers, and some don't like what having the speakers that far off of the floor does to the bass response. No matter what theories or measurable phenomenon are in play in this regard, in the end it really depends on your room acoustics and your personal taste as far as what sounds "best". Same thing for propping up the fronts of the speakers. Some people don't like what that does to the bass response, and some swear by it.... FWIW, Altec 416's have great low end and shouldn't rely on the floor for bass anyways (with either of these two proposed set up options) IMHO....
Thanks VOTT. I'm learning more and more every day!! And the sound is getting better too.
I just tilted them to see and yes, I like it better. Bass is not an issue. The right bass is. More is definitely not always better.
I finally closed on the house yesterday. Whew! Here is a pic of the room I will be setting up in. Or I should say two or three rooms.
http://www.hostboard.com/forums/hbmc...2012/12/28.jpg
My initial thought is to have the speakers against the far wall and my personal listening chair on the other side of the fireplace. Yes, I will have to treat the stone behind my head. The floor they will be on is built up and could be have resonant vibration issues. I will have to wait till I get everything in to measure. I might have a problem. The double glass doors on the right will be a first reflection problem as well. Heavy drapes I'm thinking. I could open them up little by little and see where the best sound is. There is also a cathedral ceiling in that area. That will have to be treated as well.
http://www.hostboard.com/forums/hbmc...2012/12/29.jpg
So I will likely build risers with floor spikes or some other vibration isolation for the time being. It will certainly be an adventure. My big decision is whether to incorporate my home theater or keep audio separate. Decisions, decisions...
More pics of the space...
http://www.hostboard.com/forums/hbmc...2012/12/30.jpg
http://www.hostboard.com/forums/hbmc...2012/12/31.jpg
Wow--congrats on the new house Alan--it is gorgeous! Glad to hear it's in a quiet neighborhood too--I'm sure you won't miss the constant noise that you mentioned in your old neighborhood. I like your proposed set up plan and I think you're asking all the right questions/have some good ideas as far as heavy drapes for the glass door etc. Yes, the ceiling, floor, and fireplace may be issues--you'll most likely hear the answer to those questions as soon as you crank up your Altecs in that room. Being a professional musician, I've always been fortunate enough to achieve great results doing everything by ear with my three Altec systems as far as set up and tweaking/fine tuning the speakers and the room (largely thanks to help/advice from many good people here), but of course measuring can be a good tool as well. My band has played in rooms with cathedral ceilings, and (untreated) they can add an unbelievable amount of reverb to your sound (not a good thing!). As far as your hardwood floor, an area rug (and maybe tilting the speakers or some risers?) can do wonders...Quote:
Originally Posted by alancohen
As far as your home theater debate, two of my Altec systems are not only used for audio, but are also connected to blu-ray players/satellite TV DVR's, and 50" plasma TV's. I love the way movies and music "videos" (DVD/Blu-ray/Satellite TV Broadcasts) sound over my Altec systems, and would consider it a waste to try to enjoy those things with inferior speakers. I'll be interested to hear what you end up doing with your room as far as sound treatments, as well as what you do with your Altecs/crossovers/risers (or tilting)/etc. (and whether or not you incorporate your home theater with your Altecs).....