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Double Advent System Advice Needed

Read your own charts I see +- 3.5db from 50-17 khz. I am indeed qualified as I have heard many of those hack jobs performed on classic systems by people who don't have a clue as to what a neutral system should sound like. You obviously don't listen to live acoustic music or have any concept of power response.
 
What are the three different graphs, Jackfish, and the source?

[Thank you for posting these.... :yes:]
 
I added some info about the charts in my above post.

grateful, I think I may have ruffled some feathers. I'm sorry. However, as an Advent advocate I also have spent some time with them (30 years) and appreciate the opportunity to improve the sound of my system. I have backed my assertions with uncolored, neutral facts, not loyal emotion. Advents are not perfect, they can be improved upon. Why would people try alternate placement if that weren't true? I think essentially we're on the same side. I have advocated for multiples of Advents, have not heard any negative effects of stacking them, and am just relating some things I have found out in my years with them. Again, I suggest you try frequency alteration of the Advents to see for yourself if I'm really a hack job or not. You may be surprised, like I was.
 
Sure no problem but I think I remember reading that article also. I think it was performed on some very early prototype Advents and the crossover was completely redesigned. That abberation only occured when the switch was in extended mode on that lot. Those early systems had tweeters with no screens. You may like the bsc sound better but i will bet the system is far less accurate. I own the best AS systems in the world including AR-9 AR-98ls AR-3a AR-10pi AR-11 AR-18 AR-2ax AR-2x AR-4x AR-58 AR-94 AR-93 AR-6 I think the Advent is smoother than any of them.The Advents's complete neutrality and wide range makes badly recorded music sound bad. The AR systems certainly have their own charms and charecter and may be superior in other ways such as lower distortion bass in the 12 inch systems.
 
Zilch said:
We can pretend it's better, yes, if we like to listen to a swirling soundstage of phase interference, but it's no longer about the music.

I'm not opposed to anyone trying it, and would encourage everyone to do so, actually, but with an awareness of what is actually going on and attentiveness to the sonic consequences. Nobody's going to lose an eye.

Use stacking intelligently, like the pros do (well, most of them, :p: ) and there are significant benefits to be derived.



Bottom line: Get better speakers.... :yes:
Click to expand...

http://www.celloseattle.com/ctdocs/prodserve/speakers/proamati.html

Then these multithousand dollar speakers must be a real mess.
 
I have never understood "stacking" of speakers in the context of stacking 2 AR what evers or some such. If you want to play around, well thats understandable, I would encourage anyone to play with the components they have, harmless fun.

That said, the esults of stacking are not that substantial, other than more sound in terms of sheer volume. I guess that might sound better to the uninitiated. I cant imagine it could have any other advantage, but if you enjoy that , then by all means enjoy it.But dont expect thos who know better to agree, thats all.

Most of the speakers people stack are inexpensive ( which doesnt necessarily mean bad) models that members have purchased at a reasonable price, and they like them well enough they buy another set. Stacking 2 pairs of speakers that are acceptable in and of themselves, does not mean you now have a set of speakers that performs twice as good, it means maybe twice as loud, but the attributes of what made that original pair of speakers "nice" dispite the price is now hidden behind a wall of volume poluted with all manner of distortions.

OK, now flame suit on: Sell the 4 speakers, and build some econowave guides! If this extra impact by stacking 2 ho hum speakers turns you on, you ARE a closet horn freak! Come out of the closet! There has been several members, zilch and others, who have vast experience and equipment to verify the results who have nothing to gain by telling you what time it is. Listen, it will save you time and money if you are really in pursuit of excellent sound. On the other hand, stack your speaks to the ceiling and if it gets your mojo running, great! ****, I wish i could enjoy cheap beer, it would save me a fortune!

Really guys, one pair unstacked will sound better than two, except in terms absolute out put. Its kind of a juvenile frat boy thing. If you like it, by all means do it, but dont tell people who know better it is superior, it isnt, you just haven't figured it out yet...Ignorance is bliss! OK, comence the flames!:music:

PS that said everyone is entitled, myself and you included. Do what you enjoy and revel in it. I do, and over the years I have done many stupid things, in audio as well as other facets of life. Go for it, you're entitled! Just dont expect everyone to agree.

Russellc
 
They look like a multi thousand dollar waste of money to me, what do I know? sorry never been a fan of the "look how many drivers I have" speakers.

Russellc
 
Russellc said:
Stacking 2 pairs of speakers that are acceptable in and of themselves, does not mean you now have a set of speakers that performs twice as good, it means maybe twice as loud, but the attributes of what made that original pair of speakers "nice" dispite the price is now hidden behind a wall of volume poluted with all manner of distortions.
Click to expand...
"Twice as loud" is subjective, of course, and generally accepted to mean +10 dB, i.e., 10 times the power.

Doubling up gets only +3 dB, typically, and up to 6 dB total in the low frequencies through mutual coupling. So, what you achieve by doing it is minimally improved dynamic headroom and somewhat boosted bass. Those trade off against the known consequences of multiple sources playing concurrently in the same listening space.... :yes:
 
Zilch said:
"Twice as loud" is subjective, of course, and generally accepted to mean +10 dB, i.e., 10 times the power.

Doubling up gets only +3 dB, typically, and up to 6 dB total in the low frequencies through mutual coupling. So, what you achieve by doing it is minimally improved dynamic headroom and somewhat boosted bass. Those trade off against the known consequences of multiple sources playing concurrently in the same listening space.... :yes:
Click to expand...

BTW, thanks for the tip on the JBL 4647! I'm going to "stack" a wave guide on top!:D

russellc
 
Stacking;It's done to make cheap speakers sound big. I like the way my cheap- stacked speakers sound! :thmbsp:
 
Russellc said:
They look like a multi thousand dollar waste of money to me, what do I know? sorry never been a fan of the "look how many drivers I have" speakers.

Russellc
Click to expand...

The Cello Amati is a redux of the Acoustic Research LST. I've not heard the Amati. I've heard the LST. I'd buy the hell out of some LSTs if I had the money or could find some, and I'd be pretty much done with it.
The tweeters and mids are on a 45 degree from the front baffle, like my Allison: Fours, and have outstanding dispersion characteristics. As a result, they produce very even frequency reproduction *all over* the listening space (even Zilch would like them once he measured them), and are fairly placement flexible.
 
Dynaco did not get critical press acclaim on their double system. Those comments are from Dynaco the manufacturer. The Double Advent is way more than misinformed hacking it is in fact a superb product that was first suggested by Henry Kloss himself. He was asked the question in the early 70s "Do you plan to make a better system than the Advent?" He said "We do a pair on each channel" They do not suffer from the ill effects that most stacked systems suffer from.
 
Love this "spirited" debate.
I don't want to drift too far off the OP. I have gotten some great help from many of you concerning fixing 2 pairs of Advents, as well as some BA 150's. I am playing with 4 other pairs of "good" speakers, mixing and matching different types.
Since I am relatively new to this hobby I feel unqualified to post opinions on what should sound good. But I know what does sound good to me. When I bring folks into the listening room in my house they are usually amazed that music can sound that good coming from a recording.
So stack 'em, put them at both ends, mix and match, and have some fun. You will find that combination that will put a grin on your face. I know one thing, it doesn't have to be good on paper to work well.
 
I recently set up my 2 pair of New Large Advents with my Kenwood KA-8006 70WPC amp. I'm using the A+B speaker selector, wired in series, with 6ft home-made 3-braided cat5 speaker cables. I know everybody here recommends wiring in parallel, but I didn't want to stress my amp too much. I was expecting the worst because of the series wiring, but contrary to popular belief, they sound quite nice. I still don't think that stacking fills in the midrange quite enough, but the imaging is phenomenal.

Oh yeah, I just recently recapped them using Solen polypropelenes and the improvement was quite drastic. Before I recapped them, I was considering putting them on CL because, well, they're kinda ugly and I have other speakers to play with. Right now, stacked, recapped, and set up on my home theatre system, I just don't know. Maybe I'll leave them as they are for some time.
 
SPL Gains - Bipoles - Go back to Mono!

This seems to be a good place to offer a few comments about stacking speakers.

Funny that there is such a fuss made about comb filtering. Are people aware that anything in a modern close mic'ed recording that is center placed in the recording is essentially mono? There's only one mic on vocals for example and if it's placed center it is essentially mono. Yet we play this back through a pair of right and left speakers spaced apart and comb filtering results, LOL. So those making such a fuss over comb filtering should go back to mono, LOL!
I'm not suggesting that stacking is a perfect solution, I prefer to get the tweeters as close as possible, better yet - use just one, however there are certainly significant advantages to stacking.

Years ago, when I first started building speakers I noticed that two drivers seem to provide much more than a 3 dB increase or twice the power. I learned many years later what was going on here. The SPL produced by a speaker is calculated from the volume velocity that it produces, this is the volume of air being displaced at a given frequency. Volume velocity is analogous to voltage and if you double the voltage in a circuit the power goes up by a factor or 4 or 6 dB. This is because power is square law with regard to voltage, power = V^2/R. When two drivers produce equal volume velocity the total doubles and the acoustical power radiated goes up by a factor of 4 or 6 dB. This is true at all frequencies where the volume velocites add in phase, not just the bass as some claim in this thread. You can read about this in Beranek, you could have asked Professor Wadesworth at WPI if you took his class as I did, or you could measure it (broadband) as I also did years ago. It is intersting with speakers that we only put in twice the power, driving two speakers, yet we get four times the acoustical power out. The answer to this is that the pair is more efficient. Something else to consider is that the maxSPL also goes up by 6 dB and not 3 dB as would be expected, due to this same addition.

A single pair of Advents while providing decent max SPL as compared to most loudspeaker systems are not even close to the capabilities of world class systems. A pair with the 6 dB increase in headroom do it much better.

I had a thought for those who are so concerned about comb filtering - why not try aiming the lower system toward the wall to provide something more like a bipole speaker: http://www.stereophile.com/floorloudspeakers/689mirage/

Bipoles are not my favorite type of system, however it might work well in some rooms and for some placements. Many high end speakers use a rear firing tweeter to fill out the power response. One of the tweeters in an Advent pair could be removed and made rear firing. I'm not strongly advocating this, just another alternative.
 
Of course they sum in the plane of equidistance. It's called the "sweet spot."

Modern mixers automatically attenuate a pan to center accordingly.

The problem with stacking is that there are more than two sources, and if a sweet spot exists at all, it is a point in space, and cancellations upset the program balance at all others.

This is NOT hard. Loudspeaker designers minimize overlap to create coherent sources and a quality image. Stackers destroy all that in favor of minimal increases in SPL at those frequences and locations where the incoherent sources happen to sum.... :yes:
 
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