|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
75.91.53.177
In Reply to: RE: How large is too large for HE? posted by tomservo on June 28, 2015 at 09:08:13
Hi All
Thanks for the suggestions and thoughts, this was helpful.
The reason for my asking is that once in a while I get a driver sample that yells out "do this" and I have one of those on my desk now.
Everything we do at work is aimed at large scale hifi sound however my first love is hifi and at work I have found a couple drivers that allow one to make a synergy horn with a single coax driver (a compression driver is at the rear of the cone driver) like the sbh and sm-60 type cabinets use this approach.
The driver sample I have now seems unusually well suited to this, especially with a more exponential style horn. At least in the computer, it seems like an ideal driver to make a more or less full range horn with it. The computer model shows that the low corner could be pushed down pretty low but the size is the issue, the only "cost" is a lower efficiency of about 108 if extended down to 140Hz in a larger horn.
With a cutoff around 250 and a shorter horn, the sensitivity is around 110 1w 1m at the low corner and the impedance appears to show about a 50% efficiency below 1K.
I am going to make a horn to try this out in the next month as an unofficial project for my own curiosity and see if there are any sonic warts in the real item as opposed to the computer model.
I will post again here if it looks / sounds good.
Best,
Tom
Follow Ups:
Might I suggest as an alternative to the large horns that you have proposed that another potentially smaller horn be additionally considered.... one crossed over at say approx 500Hz.
This way one could still augment the 500Hz Synergy horn with a 100-500hz mid-bass front horn (see link below... I have no affiliation with inlow) plus a tapped sub-woofer. This makes it a three unit system instead of a 2 unit system and yes does occupy more real-estate but might be easier to integrate and still have an all horn system.
Cheers and thanks for posting.
Frank M
Hi Frank,It's interesting you posted a link to John's 135hz horn. Same high pass. It came to my mind also. Inlow uses an 8" driver and it only goes up to 1000hz. It wouldn't be too much different from what Tom is talking about if you just stuck a coax on the end. Of course it's Tom that has "The Driver" sitting on his desk.
Chris has on his tag a quote by Dinsdale. Mr. Dinsdale wrote in an article about how you can overload the throat of a horn with high frequencies. He said that's why a horn is only good to about a decade from it's theoretical cutoff. I wonder if that is true. I wonder if it will come into play with Tom's proposed horn.
OTOH I wouldn't be surprised if this driver peeters out at 15khz. That would be just over a decade.
Of course it will beam, but if you look at the FR/impedance curve on the SM-60M it's very flat, of course on axis.
I always say you have two choices with horns. A wide dispersion that fills the house with music. That's good. Or you can, I think, have a narrow dispersion with small sweet spot that gives ultimate sound quality. That's good too. It's also why JMLC always kept two sets of horns around. The K-402 is a little of both. Being big doesn't hurt at all.
Jamie
Edit: Ooops, my math was wrong. 140hz to 15khz is more than TWO decades. I knew there was a reason warning bells were ringing.
------------------------------------------------
Big speakers and little amps blew my mind!
Edits: 07/01/15 07/02/15
Hi Tom,
One last suggestion. If you are looking for an "exponential style" profile, then check out the Spherical expansion profile. It loads well, sounds great, and tends to be shorter than a true exponential. The mouths are compact as well.
Jamie
-------------------------------------------------
Big speakers and little amps blew my mind!
To trade away from controlled coverage is a big trade. For instance, the JMLC horns also made that trade, and the results mean that you have to sit on-axis--like the other 99% of "audiophile speakers".
When I walk from side wall to side wall in my listening room, the presented sound doesn't change...a rare experience with horns in home audio. The benefits of that are enormous.
Chris
"As far as the ear can tell, consistently clean and spacious bass can be reproduced only by a driver unit coupled to a horn-type acoustic transformer..."; Jack Dinsdale, May 1974
The horn you are talking about is the SM-60M. That was the horn I almost pulled the trigger on all those years ago.
It's a coaxial 5" driver in a Constant Directivity horn. It's 3db down at 270hz and goes up to 15khz, but it's only 100db efficient.
So this new horn Tom is talking about trades directivity and increased size for an additional 10db of efficiency. That may not be worth it to you, but two choices are better than one.
I read the phrase 10db efficiency gain, and I think; ooh, a 90% reduction in the power requirement!
It seems that the fundamental difference between waveguides and horns is; directivity vs acoustic gain.
-------------------------------------------------
Big speakers and little amps blew my mind!
Your guess is correct, the system i am looking at uses a coax driver similar to the sm-60 where it is adapted to a Synergy horn as in fig7 here;
https://www.google.com/patents/US8284976?dq=tom+danley&hl=en&sa=X&ei=FJKWVeOgBonBgwTq2YHgCQ&sqi=2&pjf=1&ved=0CEcQ6AEwBg
Best,
Tom
Thanks for the reply Tom.
Yep, that's an acoustic horn alright. I like it. I see you call it a Synergy horn, because it meets the criteria in your patent.
I can't think of one single acoustic horn that can cover more that two decades and still sound good. There are plenty of coaxial compression drivers that nobody cares too much about.
I wish you luck. If you can do it, then it's not be an exaggeration to say it would be a first, and it would be an incredibly useful speaker.
You said in a previous post that you would report back if it sounded good. It would be interesting and appreciated if you reported back either way.
Thanks,
Jamie
------------------------------------------------------
Big speakers and little amps blew my mind!
The horn that I talk about is actually a "spherical-conical" (modified tractrix) with 110+ dB/m...and not made by Danley. It retains controlled coverage, and is 18.5 inches in length.
Chris
"As far as the ear can tell, consistently clean and spacious bass can be reproduced only by a driver unit coupled to a horn-type acoustic transformer..."; Jack Dinsdale, May 1974
Edits: 07/01/15
Chris, what driver does the 110dB constant directivity tractrix use? All the drivers I'm familiar with roll off (if not boosted by beaming from the horn) toward HF, requiring the entire response to be flattened to the level of the top corner (usually around 15kHz). What drivers are 110dB SPL/m at 15kHz?
TAD TD-4002s. They're magnificent on this horn. I've had them for six years running on the conical/tractrix horns and they have been the highlight of my day (besides my family, of course). It takes two very mild PEQs and two LOSLV filters (required for controlled directivity horns) to get the response flat from 400-19K Hz with +/-2 dB on-axis. Off axis performance follows the polar plot that I linked above.I've heard a hastily EQed/crossed BMS 4592ND on the same horn in Hope, and it was very interesting--but it needed further active crossover settings work to get things dialed in.
The LF drivers- well, I'd like to defer discussing that for a while until I get things sorted a bit. I'll be ready to talk about that after some tests are completed and I get to look at relative performance.
By the way, thanks for the good software and spreadsheet that you've provided--you're a real asset to the DIY community, you know.
I just finished reading the online article of the interview with Bruce Edgar, and I can see that things have changed rather dramatically since he began to build his horns--not the least of which are the tools. It made me stop and think for a while about how fortunate we all are for the work that a few people have donated to other DIYers. Thanks again.
Chris
"As far as the ear can tell, consistently clean and spacious bass can be reproduced only by a driver unit coupled to a horn-type acoustic transformer..."; Jack Dinsdale, May 1974
Edits: 07/01/15
Isn't maximum possible something like 112dBSPL/m?
Granted, directivity would help some. Have you measured this? Most drivers I've seen are down about 10dB down at the high end, from their "midband" sensitivity.
That's about right for this driver/horn combination without any sort of gain correction...about ~113 dBSPL/m peak. I've measured it and have anechoic measurements.Corrected on-axis SPL/Phase response using the filters mentioned.
Chris
"As far as the ear can tell, consistently clean and spacious bass can be reproduced only by a driver unit coupled to a horn-type acoustic transformer..."; Jack Dinsdale, May 1974
Edits: 07/02/15
No gain corrections? It looks like TAD doesn't publish response curves of the 4002, but here is one curve I found measured by Radian (with TAD's and their replacement diaphragm).
Something doesn't add up...
Not to diss the driver or the horn, just trying to figure out physical limits.
Hi Bill
A plane wave tube response for a compression driver is essentially the same as a truly constant directivity horn except for level.
In this case, there are no drivers which have 110dB 1w sensitivity up high because the mass roll off begins around 2K for most 1 inch exit drivers and about an octave higher for drivers like the TAD.
The only way to get flat response on axis without compensation is by using a horn who's directivty narrows at a rate that compliments the fall off in electro-acoustic efficiency.
Conversely, if one examines the impedance curve for a "perfect" 50% efficient driver (in the frequency range it is 50%), one see's a resistive impedance that is 2X the Rdc, half the power is lost as heat (Rdc) while the other half is radiated. At the upper end of the frequency range, the mass controlled roll off becomes sharper due to the inductance which raises the impedance and the sum often gives that nice curve as the mass break is added to the inductive roll off gradually.
For an omni directional point source, 109 dB 1w 1m is 50% electro-acoustic efficiency and 112 would be 100% so "up high" figures in this neighborhood or higher certainly include directivity for example a horn with a directivity index of 10 increase the on axis level by 10dB over the driver on a CD horn.
The part of the horn that governs the directivity up high is near the throat or even inside the driver and can be seen by Don Keele's pattern loss formula. If one knows the horn wall angle and dimension (inches) inside the horn or at it's mouth, one can figure out where the pattern loss is. That thumb rule is for frequency = 10^6 / (angle X dimension) or for the dimension where pattern control is lost (inches)= 10^6/ (angle X frequency).
Working through a curved wall horn, one can follow why they narrow up high and why a CD horn must have a lower spl on axis.
Best,
Tom
Thanks Tom, that's roughly how I understood it.
In my playing with diy Synergyish horns, I never found it feasible to really get > 100dBSPL flat responses because of the mass rolloff issue.
CASK05,
Thanks, that clears it up. I know the TAD is good, but didn't think it was (un-EQd) that good!
I agree that separate amps for each driver (type) is a better approach, though it does complicate things and makes transporting a speaker (and getting it working again after) a lot more difficult. These days, it might even be cheaper with the high cost of copper and the low cost of class D.
Perhaps my response was confusing (due in part to the inability to format pictures within the message here). Sorry for any misunderstanding.
The response that I posted was after gain corrections. I do have anechoic response for the driver and horn, but I'm not at liberty to post it here. I did confirm your question, however.
The output of this driver/horn has never been an issue, in fact it is very easy to drive.
A comment: there seems to be a tacitly stated mindset on pursuing extremely low power amplifiers driving reactive and resistive passive crossover networks, then driving both extremely high efficiency MF/HF drivers and lower efficiency woofers by padding down or by increasing input impedance to the higher efficiency driver portions of the passive networks. This is not how I do it and I don't recommend doing it that way--it really doesn't sound very good, IMHO.
Rather, active biamping with a high fidelity active digital crossover and direct driver control separates concerns and eliminates the need for adding losses in the signal path and worrying about absolute efficiency across the entire band. This enables the use of a single high fidelity MF/HF driver without attending issues of FM/AM and compression distortion of other cone-type drivers in 3-way systems--3-way systems that are typically designed with sheer output SPL in mind, i.e., not typically a goal of home sound reproduction systems.
I assume that you saw the resulting phase curve using IIR filters only - no phase correction was used except by adjusting digital delays for the one crossover point at 420 Hz. Other benefits also ensue, like the reduction of one crossover network over typical 3-way implementations, which is a really big deal for fidelity.
Additionally, if one focuses on some intermediate measure of merit, like reducing required input amplifier power in the above (not-recommended) configuration, it actually sub-optimizes the system-level goal of sound fidelity by focusing instead on that intermediate measure of merit to the detriment of system-level performance. I don't recommend doing it that way.
But I will acknowledge that way of thinking is a mind set that has developed over many years within the home entertainment community and I would add, largely by those that may not be consciously aware of the resulting effects of making those choices on output sound fidelity.
Since we're here actually blue-skying the design of the greater part of a sound reproduction system, I thought it would be prudent to explicitly state these observations. YMMV.
Chris
"As far as the ear can tell, consistently clean and spacious bass can be reproduced only by a driver unit coupled to a horn-type acoustic transformer..."; Jack Dinsdale, May 1974
"A comment: there seems to be a tacitly stated mindset on pursuing extremely low power amplifiers driving reactive and resistive passive crossover networks, then driving both extremely high efficiency MF/HF drivers and lower efficiency woofers by padding down or by increasing input impedance to the higher efficiency driver portions of the passive networks."
That's not me is it? Cause I stated in my previous post I am using an analog active crossover. That long post has to do with co-entrant Synergy horn, which is a very different beast from an acoustic horn like the K402.I was just listing off to Tom all the ways I tried to skin that cat.
Then come to find out Tom isn't talking about that kind of horn. IMHO the Fig. 7 horn has much more in common with the K-402 than the SH-50.
"Rather, active biamping with a high fidelity active digital crossover"
I can't go with you on that one. I like DSD, and you can't manipulate a DSD file in the digital realm. It is what it is, so I treat my DSD dac like any other analog source, and manipulate the analog signal in the analog realm. I could get more sophisticated for a lot more money. Just consider it one way to skin that digital cat.
Don't like passive crossovers? Guess what. The coax driver in the SM-60M has a mechanical/passive component crossover, and one amp feeds both drivers. You may find yourself using a passive crossover if you use this horn.
Looking at some coax drivers on parts express, some of them are bi-ampable. I too would prefer that.
Big speakers and little amps blew my mind!
I think of the K402 (without the extra ports cut through yet) as an improvement on the double flare conical horns that Mr. Danley uses. Small differences in geometry lead to big differences in performance when it comes to horns. with the spherical (or tractrix) mouth being that big difference in this case. I've posted the polars of this horn (employed without close arrays for home use, i.e., not in close commercial arrays like the SH-50, et al.). The horn is shown above.Actually, you can edit DSD files in the digital domain: http://www.superaudiocenter.com/images/Sonoma32.pdf
"I can't go with you on that one."
I don't argue anymore, but rather invite to listen to a digital active crossover of quality: and I'm not talking about a $250 DCX-2496 or an even cheaper miniDSP here, but rather a more recently developed 24/96 active digital crossover of higher quality than the first generation 24 bit/48 kHz units. Clearly, you haven't heard one of these newer units if you make that argument.
And you're right...I don't see any use for passive crossovers:
"Crossovers may be implemented either as passive RLC networks, as active filters with operational amplifier circuits or with DSP engines and software. The only excuse for passive crossovers is their low cost. Their behavior changes with the signal level dependent dynamics of the drivers. They block the power amplifier from taking maximum control over the voice coil motion. They are a waste of time, if accuracy of reproduction is the goal." Siegfried Linkwitz - October 2009.
http://www.linkwitzlab.com/crossovers.htmDigital actives enable digital delays - something that you don't get with analog actives. When using horns or multi-channel loudspeaker arrays, i.e., 5.1, 7..1, etc., digital delays are an enabler.
Chris
"As far as the ear can tell, consistently clean and spacious bass can be reproduced only by a driver unit coupled to a horn-type acoustic transformer..."; Jack Dinsdale, May 1974
Edits: 07/05/15 07/05/15
I did mean to tell you the FR/phase plot looked excellent, and I' sure it sounds excellent too. I hope you are not going to cut any holes in your 402s!
Wow, you mean I only have to purchase a recoding studio grade workstation to be able to play my hi-rez files? And it's only $16,000. I almost fell over myself running for my checkbook. What am I, Abbey Road Studios?
I was thinking more along the line of HQ Player. Then I could use the 24/192 files I have, manipulate them, convert them on the fly into DSD, blah, blah, blah. It would probably take three dacs. I have looked into the Twisted Pear Buffalo Dac III. I have also looked at the DEQX.
To me 24/96 sounds as good as most vinyl, and 24/192 sounds better. Why would I want to downsample to 24/96? So I can correct a .25ms delay in my PSE-144 horn? I'm not sweating it. In fact, I'm not sweating the 3.5ms delay between my bass bin and my mid horn at 350hz.
Believe me, if a company made a three way 20bit ladder dac active crossover, then I would be the first in line. Until then I have to compromise.
I also prefer low level crossovers to high level ones. However, I still recognize that they still have their uses. I would never use one to pad down a horn to match a direct radiator, but I would use one to join and pad down a 112db horn to a 110db horn.
-----------------------------------------------
Big speakers and little amps blew my mind!
What I was trying to say was, he didn't walk away from constant directivity. He already has a horn similar to proposed one that covers that angle.
--------------------------------------------------------
Big speakers and little amps blew my mind!
Ah, yes, the best mid horn I've ever owned. Hats off to Roy Delgado of Klipsch.
But I like Tom's SH-50 better because of the ROOM I must use and the phse coherehence like not other, except Tom's other designs.
Claude, I believe that you hit on a good point.What do you design to, i.e., coverage angles, based on where you're going to listen to the resulting products? Will anything be effectively done to the listening space? That's an interesting dilemma in terms of coverage design trades.
Personally, my preference is for wide controlled coverage: I'll work on my room to get the speakers integrated into the room acoustically--controlling early midrange and HF reflections, and addressing LF defects due to insufficient boundary coupling.
But I also see a LOT of people that actually do almost nothing acoustically even though they have a room with enough L x W X H dimensions and good placement options. I believe that many wind up with a very narrow coverage angles in both axes when the room isn't the best. It's an old story, I know, but one that I see especially in cases where those people should know how to fix it.
Lastly, I clearly understand those instances where the architectural environment isn't very good to start with, notably too small or poor relative dimensions/placement options. But that also sets an upper limit, I would think, on setup investment if the environment you're going to place them in is severely limiting.
I do know what I'd personally design to, however.
Chris
"As far as the ear can tell, consistently clean and spacious bass can be reproduced only by a driver unit coupled to a horn-type acoustic transformer..."; Jack Dinsdale, May 1974
Edits: 07/01/15
I agree with you on all counts IF the residence/listening is permanent, like I had before.
However, if one has a job that may be transient in nature, having narrower dispersion, with my SH-50's allows me to have good sound anywhere I'm able to put them, bypassing the usual methods of "cleaning up room messes," so to speak.
As former owner for about 2 1/2 years, did like the wide presentation of the Klipsch K-402 horns, Klipsch's best, IMHO.
but so far, nothing beats Danley SH-50's in present situation.
Claude,
I sure would like to know what crossover you are using on your SH-50s, and the power amp you use.
Thanks,
Jamie
-----------------------------------------
Big speakers and little amps blew my mind!
It's the factory passives, which makes it a plug and play to any amplifier. 100 DB /watt. Even without subs, it's got pretty nice bass, much better than the old TD-1's.
Thanks, 100db with passives isn't bad at all.
It's plug and play for any SS amplifier given the current Danley networks.
Now if Mr. Danley took my advice, and hired Mr. K to design him a network with a flat, resistive, 8ohm impedance, then you could run the SH-50 with a 300B amp. That would be so sweet. Tasty sweet.
------------------------------------------------
Big speakers and little amps blew my mind!
Firstly, it's "input", not "input's"."The driver sample I have now seems unusually well suited to this, especially with a more exponential style horn. At least in the computer, it seems like an ideal driver to make a more or less full range horn with it. The computer model shows that the low corner could be pushed down pretty low but the size is the issue, the only "cost" is a lower efficiency of about 108 if extended down to 140Hz in a larger horn.
With a cutoff around 250 and a shorter horn, the sensitivity is around 110 1w 1m at the low corner and the impedance appears to show about a 50% efficiency below 1K."Some of us "get" your shameless self-promotion. Others don't. Others even worship your name (but they live in a small audio world).
Reading your comment, cited here, I have a few observations:
Why?
What exactly is a "more exponential horn"? What calculations or measurements have you made?
Full range? Really, you're kidding, right?
You asked for input (input's). Here's my advice: Call John Meyer at www.meyersound.com, and LEARN from him.
:)
Edits: 06/30/15
Dude, you appear to be a troller or a hater and have "reached" way beyond the intent or the literal words written by the O.P.
I don't know about you, but I have only worshipped God and not men.
But I like to compliment people when I appreciate their good works on a more personal level, usually over lunch, but sometimes on the internet, here or by Email. The list includes Paul W. Klipsch, Saul Marantz, Roy Delgado (chief engineer)and designer of the fabulous K-402 horn (and many others things), Don Keele and many other great contributors to the Audio Art and Science we all pursue.
What have you done, Inmate51, except be an unfair critic, which is basically a penny a dozen proposition. How many horns have you designed and built?
I have spent time with pretty much all the horns ever made commercially as their OWNER. The list is too long. But I do know a good one when I measure it and hear it.
As a DIY guy who designed the famous LAB Horn, got Eminence to design a great driver for a reasonable price, and gave it away for free, much to the delight of those who build it, I don't think there is much to critize in the "shameless plug" department.
I also know your BS when I read it. Get a clue.
I.
Your recent post on Inmate Central referenced in-detail a colonoscopy which apparently went well for you, and best wishes to you in that regard!
Bringing everything back to audio, horn loading of the final aperture of the lower digestive tract would seem to be contra-indicated for several reasons. Not the least of which would be due to social prohibitions concerning audio emissions from that area. A direct radiating array of such emissions from multiple apertures is possible, and is apparently used on a certain cable news channel which Fusses Over Xtremely petty things, but I seriously doubt that Meyer Sound could be involved in any way as Meyer seems quite legit from their website.
P.
"Firstly, it's "input", not "input's""
Given the diversity of responses, it seemed like the plural captured the result better.
"Some of us "get" your shameless self-promotion. Others don't."
I don't get your angle here, at work, we don't market or build products for home hifi, that's my hobby along with DIY.
A fellow I work with is into single ended triode amplifiers and he was very encouraging so far as following this idea into a prototype, the issue was size and this is the only high efficiency forum in know of and seemed like a logical place to ask.
"Why?"
Why not?
"What exactly is a "more exponential horn""
At work, most horns have to be constant directivity types which have straight or nearly straight walls. In the home, curved wall horns like exponential horns are ok because the seating area is small.
"What calculations or measurements have you made?"
I have measured the drivers electro acoustic properties and used that for a computer model like I use for work projects. As I explained, I have not built the horn yet and was trying to zero in on a size.
"Full range? Really, you're kidding, right?"
No, not kidding or at least full range down to 140-200Hz.
"Here's my advice: Call John Meyer at www.meyersound.com, and LEARN from him."
I am not sure he could be of help and they are a competitor, but you could call him and ask what we do, how our designs work compared to line arrays etc.
We are not advertising / marketing based company like most but among the engineering and commercial sound area we are known, in the last 4 years, we have replaced line arrays in half of the country's largest stadiums and many other venues based on sound quality and uniformity of coverage using full range Synergy Horns.
If you have facebook, you can get a better idea what I do at work below or pick up the latest Handbook for Audio Engineers, I was asked to write the chapter on loudspeakers.
https://www.facebook.com/DanleySoundLabs?ref=ts
Best,
Tom
HAHAHA Tom you almost lost it this time with the contentious at times obnoxious and appropiately named INMATE51. Since the times of the disagreements with the Pi speakerīs owner in the early 2000s I have not seen you so angry !! Pay no mind to Inmate51 he uses this agravation technique to draw attention to himself but really respects you most of all otherwise he would not pick on you. I called him "grasshopper" in response to one his posts a long time ago because he reminded me of that young Kung Fu TV character. Seems like he is a young greenhorn in this field. I advised him not to jump too high but as expected he never listened and even with his grasshopper legs always ends up jumping too short.
In regards to advice for a reasonable size horn you gotten more than enough advice, I will only add that horn cabs especially those for home use can have the last section of the horn hinged so that in closed position they have better WAF and yet have very large mouths when opened up. I use this idea in most of my designs.
Lastly I remind you to try to keep to your companiesī "mission statement" although at times it can be very difficult.....yes luck with this one.
My regards
Rafaro
And it's 1 - 2 - 3 PIN! Congratulations, you won that one Tom! Some people are trolls, some are just asses, and some are both. Dave W. oh yeah... P.S. you are a better man than me when confronted like that. You seem to be a nice guy in addition to being a darn fine horn designer type person. Sorry, I don't know your proper title.
Everyone thinks I'm strange except my friends deep inside the earth
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: