[trebejo]

I keep running up this hill, maybe somebody here has a better view...

I like my speakers, 12" Tannoys, but they don't do so well in the bottom octave or two. I could try to find better speakers, but I worry that the improvements in those two octaves would be offset by what happens in the remaining eight octaves. Furthermore, this change could be expensive on top of the uncertainty.

The alternative is to get some subwoofers in the chain. That involves putting a hi-pass and low-pass filter between the Avastar and the FVU 550. You can imagine how I feel about that, inserting resistors, capacitors, opamps where there was only a wire before--makes me want to tell that first octave to go play with itself. Furthermore, this change would also be expensive, even before I factor in the additional AVA hybrid amp.

I confess, I have a (formerly) secret hope, that somebody here will point out some very obvious audio chain fact about how the effect of the crossover decays exponentially as one goes away from the crossover point, so that by the time you're up around 320 hz, you would never know about that crossover at 80 hz.

However, if the correct answer is forget it, that crossover will always remind you of its existence once you've had the unmolested AVA trifecta in place, then that will be useful information, I'll just bite the bullet and start to think about spending waaay too much money on a pair of full-range speakers.

[martyo]

My brother runs a sub with his Salk HT2's and all AVA gear. Sometimes it's on, other times I've been there it's off. Maybe he will chime in. Many folks on the Salk Circle run subs, even a couple of them with HT3's that have an F3 of 29hz. It might be worth talking to Jim Salk. Besides normal Subs he sells he is often building "specials". They're a pretty sophisticated bunch over there when it comes to subs.

[avahifi]

You guys just need the Fet Valve 400R or 600R amplifier to fix all your bass problems.

You will have the best bass performance you have ever heard, guaranteed.

Ask Larry or Jim Salk.

Regards,

Frank Van Alstine

[Wayner]

We recently came into a pair of Tannoy 15" silvers. They are a 2 way concentric speaker with a center deep throated tweeter.

I have to ask a couple of questions here. Do you have the original cross-overs for them, and secondly, many of the cabinets for these speakers were actually DIY, with Tannoy supplying basic plans. The results were, in many cases, bad.

More info needed.

Wayner

[trebejo]

I have to ask a couple of questions here. Do you have the original cross-overs for them, and secondly, many of the cabinets for these speakers were actually DIY, with Tannoy supplying basic plans. The results were, in many cases, bad.

Right, I've heard about those old cabinets, diy or otherwise... mine are the 12 DMT II, they are made of a material (DMT) developed by Tannoy for inertness. They are remarkably inert. Here they are,

http://spectradesign.com/Equipment/tann_sys12ii.html

Unfortunately, from about 50-60 hz on down, it's not the same speaker. I might get a 15 DMT or a 215 DMT, but apparently, even they have something of this issue. It's not that the speakers are awol at lower frequencies, test tones confirm quite audible sound even at 29 hz, but of course, at the same power level it's much louder at 90 hz and there goes the warm balance...

If Salk ever develops something like a hi-efficiency dual-concentric model, I'm in of course! At the moment I'm really sold on this concentric hi-efficiency design on octaves 2-10, but I sure could use a more rounded bottom (in my sound, that is).

Wayner, what did you do with the 15" silvers? They are a previous generation, I think they are not rated for more than 100 watts (i.e. not as high max SPL), but they're supposed to sound excellent.

Frank, the 400/600R is right there on my to-get list (maybe biamp with 400, maybe one 600), but the low-hanging fruit at the moment is the speaker and your double 550+ is still a pretty good amp. I was going to post a bit of a follow-up review comparing the regular 550 with the double 550+ but then of course you had to go and put out a better amp. 

[martyo]

Frank, the 400/600R is right there on my to-get list (maybe biamp with 400, maybe one 600), but the low-hanging fruit at the moment is the speaker and your double 550+ is still a pretty good amp. I was going to post a bit of a follow-up review comparing the regular 550 with the double 550+ but then of course you had to go and put out a better amp.

If it wouldn't be too much trouble you could pm me your review, I'd be interested in hearing what you heard on your set. Thanks either way.

[trebejo]

If it wouldn't be too much trouble you could pm me your review, I'd be interested in hearing what you heard on your set. Thanks either way.

PM sent, as they say.

Basically, I tried a single 550 (review available in an old post of mine), a pair of 550s in monoblock with the avastar phase inverter (better), and a single double 550+ (better than the monoblocks). Improvements were shocking in an audible/psychoacoustic sense, as I did not expect them. Based on all that, I have to get the 400R or 600R.

Filed in "Frank was right". 

[Wayner]

They were sold for $10,000. Should have gotten $15,000 for them. The buyer didn't want the cabinets, but took them anyway as that was the easiest way to ship.

Having recently refurbished a pair of Altec Lansing Santiagos, it was learned that they (the Altecs) needed an EQ circuit for the woofer, which I built. The cross-over was at 800hz, which was correct, not 500 or 1200 as some others have done, but the woofer output was up and down in it's frequency range. This is what I suspect you may be suffering from as well. That was a problem with the Altec woofer and the only way to correct for it was thru a cross-over EQ installed on the output of the 800hz primary cross-over.

I suggest you really need to do a lot more hunting on the internet to find out more info on these speakers. I know that there is a Tannoy Group and they may have the answers that you speak, and perhaps Frank's suggestion is right in line. Perhaps you will need both.

Wayner

[trebejo]

Wayner making Tannoy crossovers, impressive!

I don't want to dwell too much on Tannoy stuff for all the obvious reasons, I'll just comment that, indeed, their speakers tend to require some equalization and perhaps that's part of the reason for the high price tags (which is not so high when one goes for the "pro" models with their divorce-me-now cabinets).

So apparently, if I continue down this road, I will be treading on the diy path before long. In-room frequency measurements, active crossovers, two or three 400/600R amps, and of course as soon as one tube burns out, spend all day figuring out which of the many, many components in the chain is having the problem. $2k+ for the subs, $3k for the extra amp, $1-2k for the crossover.

A cheap alternative is to get a low-pass crossover set at 40 or 50 hz, plug a cheap amp into a pair of subs that can somehow keep up with a 96db speaker, and pretend that it sounds correct. It would probably sound better then what I've got now, but the question becomes, why be so happy with the AVA trifecta in all its glorious accuracy and then do a wink-and-nod thing with the bottom octaves?

<sigh> This is turning into another one of those "Frank was right" threads...

[Wayner]

My bad english steered you in the wrong direction. It was the Altecs that I built the cross-overs and EQ for.

It would be nice if you could locate a response curve for your Tannoys. Perhaps a nice 1/3 octave graphic equalizer would be of benefit in this case. Soundcraftsmen made some damn good ones back in the day, but dbx has some nice ones, intended for studio work. Why 1/3 octave? That would give you something like 20, 31, 40, 50, 63as opposed to a 1 octave EQ that would go like 20, 40, 80, 160, 320 and so on. One octaves are just not fine enough in your lower frequencies (where you have the problem) and the 1/3 might be the cat's meow!

Like this one:

 

At: http://www.americanmusical.com/Item--i-DBX-231SV-LIST

Wayner

[Mark Korda]

Hi Trebo,I read your first message that you didn't want extra resistors,caps,and op amps,whatever instead of a wire.I had that idea swirling around too in my head when I wanted more deeper bass but didn't want my main amp to be compremised by what you said.First,listen to Wayner and Frank,they know what there doing.But this is how I got out of it.I first of all made a sub from stuff from Parts Express.I had a real nice crossover,a prototype called the Shadow Mark 4 made by a freind I met thru Audiomart in 1978.I found a Marantz 500 mono 125 watt,much newer.I don't know if the cross over needed some attention but I wasn't getting much bass.Then Parts Express came out with this sub amp called the Bash 300 which is used by Klipsch and another Canadian speaker company.The amp had a control to a low pass cross over set from 150 to 50 hertz.It had jacks so I could plug my amp into the sub cross over and amp.I did not want that hook up,I wanted the pure tube sound of my Dyna-35 that Frank and crew had fixed up for me 5 or so years ago after I made some mistakes in rebuilding.The Parts Express guy told me to try Y cables.This way my cd player goes to 2 Y cables.That way the 1 set goes to my main amp (Dyna_35),and the other goes to my sub,where every thing above 100 hz,thats where I set it,gets chopped off.This way my main amp has only another cable in its path,not the fore mentioned parts.Sounds awesome,but I can only listen to it when my landlord,living next door like Mr. Furley,(Threes Company)goes home for the holidays.Just one way to tackle it,listen to Frank and Wayner first!They know more about Hi-Fi than anyone on the planet,(No Brag,Just Fact)Walter Brennan,The Guns of Will Sonett.....Mark Korda

[trebejo]

Well, gentlemen, I think I found a nice app for this task.

http://sbooth.org/Play/

This is for OS X, i think the microsoft and linux platforms offer similar options but I cannot say. This "old" player (Decibel is supposed to be the current version) actually offers a GUI controller for the OSX 31-band digital equalizer. So by fiddling with that, I got "psychoacoustic" linearity down to about 30 hz from speakers that, in principle, are down by about 15 db at that point (JBL LSR32). The eq curve that I applied for those speakers in this particular room is about 10 db per octave starting at 63 hz, then leaving the 10db boost constant through 20 hz (seems a bit pointless by then).

I'll be getting a microphone and other such stuff in the next few weeks, and hopefully I'll be able to make a more quantitative followup. In principle, this option keeps the AVA signal squeaky clean, and perhaps the single FVU 550 or 400R or 600R is meaty enough to push through the additional watts required by bass boosting in the low bass. If not, then the monoblock option (with phase inverter) comes in quite handy.

Hopefully this will work well enough to dispense with notions of adding additional subs, crossovers and amps which, while undoubtedly very nice, are nonetheless priced at several thousand dollars, adding lots of complexities, and most sadly of all, inserting analog filters between an AVA preamp and amp. The digital correction looks like a much, much cleaner option, and although it does require the usage of a computer, there tends to be one of those lying around anyway.

If this is the path, then the ol' squeezebox will be retiring after many years of excellent service. There is supposed to be a digital EQ option for it as well (Inguz) but I could not get it to work properly and it seems nice to be able to use a big Mac cpu for this task rather than the little circuits in the squeezebox.

[Æ]

"The alternative is to get some subwoofers in the chain. That involves putting a hi-pass and low-pass filter between the Avastar and the FVU 550."

NO, NO, NO!

You don't need to add any filters between your preamp and amp or loudspeakers. Why don't you just get an active subwoofer with its own internal crossover. You don't need to crossover the Tannoys to use a subwoofer. The Tannoys have their own natural acoustic roll off, no need for any crossover.

[trebejo]

"The alternative is to get some subwoofers in the chain. That involves putting a hi-pass and low-pass filter between the Avastar and the FVU 550."

NO, NO, NO!

You don't need to add any filters between your preamp and amp or loudspeakers. Why don't you just get an active subwoofer with its own internal crossover. You don't need to crossover the Tannoys to use a subwoofer. The Tannoys have their own natural acoustic roll off, no need for any crossover.

Well, this is not quite as relevant with the JBLs, but one of the reasons for rolling off the Tannoys is to avoid having the woofer go into the low frequencies where it doesn't do well, not just because of its low frequency performance but also because the woofer performs double duty as a horn for the tweeter.

Hopefully this is all moot if the digital EQ does well enough.

[festuss]

Xilica DSP and sum REALTRAPS room treatments. w w  w.realtraps.com   http://www.xilica.com/?c=78&cat=2&video=44 AND lotsa AVA pure WATTS Not louder CONTROL!  BASS CONTROL, no slop, no flap.  WATTS am CONTROL.  The DSP and room treatments do make a difference, but if your amps ain't doing it, no amount of DSP or treaments change horrible uncontrolled bass, distorted and floppy.  WATTS keep it controlled, but a bad room is a bad room.  AVA PRISTINE WATTS sound GREAT!  4800-5200W RMS is CONTROL. 

[OldCoder]

I just got home from hearing the 600 amp at Frank's.  Very impressive with tremendous bass control.

If the 600 cannot deliver BASS with your Tannoy's, either what you listen to has NO BASS or or your speakers have a serious problem.

Before spending lots of money on subwoofers (which I have done), try a 600.  Or get one of your amps upgraded to one.

I'll be trying a 600 to see if I can get rid of subwoofers....

[rcag_ils]

Before spending lots of money on subwoofers (which I have done), try a 600.  Or get one of your amps upgraded to one.

I'll be trying a 600 to see if I can get rid of subwoofers....

Having an amp that can deliver good bass is obviously a good thing.

The purpose of having a sub is not only to give you more bass. The sub will free your main speakers from trying to reproduce low bass, and focus on what they are good at, which is reproducing mid and mid bass.

The characteristics of a system with a sub is totally different than a system without one. I would not discount having a good sub just because you have an amp that can reproduce good bass.

[Wayner]

Generally speaking, a system with a separate sub usually sounds more to my liking. However, if the sub is crossed-over poorly or placed in a poor position, it will sound worse then an ordinary 2 speaker system.

I also think that 2 subs may be better then one, but if one is used, it should never be placed in-between the speakers as it will create a pressure dome and destroy the imaging. In fact, I don't think any subs should be between the mains. IMHO.

Wayner

[mal]

mine are the 12 DMT II

New amps my help some of your bass definition issues, but these things don't really go much below the mid-40's. Anything below 50 at a relatively high output should be considered a near miracle. The only time I've heard my pair hold together at all below 40 (and not much below 40) was when paired with a pair of PrimaLuna Prologue Sixes. Those amps had other problems in my system that made them very temporary residents, though.

While you may be looking at problem with matching electronics, the biggest single problem you'd have getting deep bass out of those cabinets is that there is just no deep bass to be had from them. Shopping for subwoofers is, I think, a very good way to go.

I'd have to agree with the folks here who think that you're overcomplicating things by trying to find the right crossovers before finding out whether subs will integrate well with your room. Find  two or three subs, amp them, and fit them to the room. See if that solves your bass problem. I think you'll be surprised at how well it works.

If you feel that you're seeing an unacceptable level of distortion on your mains, then have a passive high-pass fitted to the input of your main amps.  It's not going to be a complex (or expensive) addition, and you'll have a better idea of your needed points and slopes *after* you see where your remaining weaknesses are.

If you just outright hate the subs, you're either going to want to build a new box or buy new speakers.

[rcag_ils]

Generally speaking, a system with a separate sub usually sounds more to my liking. However, if the sub is crossed-over poorly or placed in a poor position, it will sound worse then an ordinary 2 speaker system.

The woofer in a two way speaker system (maybe an 8" the most?) generally is not capable of producing anything lower than 40Hz accurately in my opinion.

In a three way system, the bigger woofers unfortunately are housed in the same cabinets and can not achieve optimal positioning in most rooms. Also the low bass resonates in the same cabinet as the midrange driver, that often degrades the image.

Years ago, I played with the Cambridge Soundwork's Emssemble system by Henry Kloss, a four piece small box sub/sat system that could generate reasonablly deep low bass and good image at medium volume level. But small box produces small sound, the law of physic can't be changed. So after awhile I realized that at higher volume, this small box system just not making it.

Recently I've found the holy grail of subwoofers, a sonographe SW-1000 which has two 10" woofers housed in the same cabinet with the size of a coffee table, I can hear the stereo bass, yes, stereo bass, how many single sub can actually reproduce bass down to 25Hz with stereo image? Not many. Not to mention that this sub was designed to mate with my SL-21 monitors as a match set, crossover at 110Hz, my monitors sound much, much more dynamic and fast, sound totally like a different pair of speakers, because they don't have to reproduce anything under 110Hz anymore.