SET amp owners thread

[Ron Resnick]

What is wrong technically with my idea of wiring three (or more) same model of AER drivers (say, BD5s) in parallel (in a vertical array)?

PS: I am envisioning a tall and very heavy open baffle of solid ebony wood.

 

[bonzo75]

What is wrong technically with my idea of wiring three (or more) same model of AER drivers (say, BD5s) in parallel (in a vertical array)?

PS: I am envisioning a tall and very heavy open baffle of solid ebony wood.

With a crossover?

 

[DaveC]

What is wrong technically with my idea of wiring three (or more) same model of AER drivers (say, BD5s) in parallel (in a vertical array)?

PS: I am envisioning a tall and very heavy open baffle of solid ebony wood.

Not a new concept, been done many times, for a real "line array" they need to extend pretty close to floor-to-ceiling. AER drivers are too large for this, the acoustic centers will be too far apart and the highs will be a mess. You'd have to roll-off all but the middle driver.

IMO, it would be a massive waste of money to do what you're suggesting, I am sure you can get far better bang for your buck and far better ultimate performance using any other design.

 

[Ron Resnick]

With a crossover?

No, no crossover.

 

[Atmasphere]

What is wrong technically with my idea of wiring three (or more) same model of AER drivers (say, BD5s) in parallel (in a vertical array)?

PS: I am envisioning a tall and very heavy open baffle of solid ebony wood.

You'll get cancellation at a variety of frequencies and you'll have troubles getting LF bandwidth unless the baffle is enourmous. The reason to go open baffle is to allow the rear firing information to be used by the ear to enhance echo location (make imaging more palpable). The problem you're up against is the baffle will have to be pretty wide and in a lot of rooms that will mess with the rear firing information. You could add wings to the sides; their area is worth about 2X that of the front baffle, but you get into troubles with cavity well resonances which color the sound.

IMO if you want open baffle, use a crossover to limit bass excursion, add subwoofers to make the bass, add a tweeter to widen the sweet spot and a rear firing tweeter to improve off axis room response. If two tweeters does not appeal, go with the rear firing only. That will at least keep the tonality right if off axis.

You can see that you are designing a speaker from scratch. Doing it with expensive drivers means an expensive prototype. If you take my advice above you'll save some time and money in the prototype process. If it were me I'd make a bass reflex box with a rear firing tweeter, run subs and a crossover to keep bass out of the box, probably just below 80Hz. In this way you can place the subs where they work and if you do it right the subs won't attract attention to themselves.

As to cone full range, the Whizzer is, IMO a disaster excuse for a tweeter...

I agree. PHY makes a 6" unit that is quite smooth and extended on top. Beamy though...

 

[Ron Resnick]

Not a new concept, been done many times, for a real "line array" they need to extend pretty close to floor-to-ceiling. AER drivers are too large for this, the acoustic centers will be too far apart and the highs will be a mess. You'd have to roll-off all but the middle driver.

IMO, it would be a massive waste of money to do what you're suggesting, I am sure you can get far better bang for your buck and far better ultimate performance using any other design.

I don't know. I think an AER driver might very well be the best conventional wide-band driver around. But I have never liked squirting the entire frequency range out of a single 5 inch diameter anything.

I believe that, with conventional loudspeakers, driver surface area contributes mightily to transparency and presence and realism.

 

[Atmasphere]

I don't know. I think an AER driver might very well be the best conventional wide-band driver around. But I have never liked squirting the entire frequency range out of a single 5 inch diameter anything.

You're likely correct. But you can't get around Doppler Effect. So a driver, especially one that small, either has to be played quietly or crossed over.

 

[Ron Resnick]

Thank you, gentlemen. I will give up my nascent and tragically brief career in loudspeaker design.

 

[bonzo75]

I don't know. I think an AER driver might very well be the best conventional wide-band driver around. But I have never liked squirting the entire frequency range out of a single 5 inch diameter anything.

I believe that, with conventional loudspeakers, driver surface area contributes mightily to transparency and presence and realism.

You just cannot have enough data points to prove you do not like squirting entire frequency range out of a single 5 inch diameter anything.

The whole point of AER is to avoid multiple drivers. If you want to do multiple drivers to cover the whole frequency range there are many options, for 3-way, 5-way, etc. in horns, cones, and planars.

 

[Ron Resnick]

You just cannot have enough data points to prove you do not like squirting entire frequency range out of a single 5 inch diameter anything.

The whole point of AER is to avoid multiple drivers. If you want to do multiple drivers to cover the whole frequency range there are many options, for 3-way, 5-way, etc. in horns, cones, and planars.

Sorry -- I should've been more specific. I should have written "I have never liked squirting the entire frequency range out of a single 5 inch diameter anything in a conventional box speaker." Every conventional box speaker with a single, small midrange driver has taught me this. I consider that to be enough data points to persuade me.

A single driver in a Pnoe is different.

 

[bonzo75]

Sorry -- I should've been more specific. I should have written "I have never liked squirting the entire frequency range out of a single 5 inch diameter anything in a conventional box speaker." Every conventional box speaker with a single, small midrange driver has taught me this. I consider that to be enough data points to persuade me.

A single driver in a Pnoe is different.

Yes but I do not know of many box speakers with a single full range. Cube Audio, which I have now heard in 3 set ups. Tannoy is a dual concentric not single driver. If you are talking about a midrange driver forcibly extending its limit...that's different. You liked Martin Logans which did a fair bit with one driver.

 

[Audiophile Bill]

What is wrong technically with my idea of wiring three (or more) same model of AER drivers (say, BD5s) in parallel (in a vertical array)?

PS: I am envisioning a tall and very heavy open baffle of solid ebony wood.

3 paralleled BD5s will give you a horrid 2ohm load FYI, Ron.

Also these drivers aren’t really designed for conventional open baffle use - their QTS is too low. The “B” versions of the drivers with lower flux and higher QTS would be viable though.

Best way to use these drivers is horn loading either front or back.

One additional point - I advocate for a speaker using bass reinforcement alongside the 8” widebanders but this doesn’t obviate the ability to run with no crossover. You can run the 8 incher fully open and design a horn to have acoustic crossover to allow you to support with your choice of bass.

Best.

 

[DaveC]

I don't know. I think an AER driver might very well be the best conventional wide-band driver around. But I have never liked squirting the entire frequency range out of a single 5 inch diameter anything.

I believe that, with conventional loudspeakers, driver surface area contributes mightily to transparency and presence and realism.

Sure, but it can't compete with 15" woofers and dedicated horn tweeters on the frequency extremes.

I agree with surface area, but this relates to power and a vast majority of power is in the lower frequencies. So the advantages of having surface area decline exponentially as frequency increases. For a mid the advantage of having larger surface area depends on xo frequency. This can vary quite a bit, and it's a tradeoff vs having closer driver spacing. I like the idea of having lower and upper mid driver(s) for a large, cost-no-object speaker with the best large-scale music reproduction in mind.

 

[DaveC]

One additional point - I advocate for a speaker using bass reinforcement alongside the 8” widebanders but this doesn’t obviate the ability to run with no crossover. You can run the 8 incher fully open and design a horn to have acoustic crossover to allow you to support with your choice of bass.

Best.

That was Avantgarde's design ethos, not sure they still run their mid horn with no xo or not. IME it only works at lower SPL and/or with music that doesn't contain any info near near the horn's cutoff. It increases IMD, temp of the voicecoils, and it makes the effects of diffraction around the edges of the horn worse. But it can work well for music where these issues don't make a difference.

 

[Audiophile Bill]

That was Avantgarde's design ethos, not sure they still run their mid horn with no xo or not. IME it only works at lower SPL and/or with music that doesn't contain any info near near the horn's cutoff. It increases IMD, temp of the voicecoils, and it makes the effects of diffraction around the edges of the horn worse. But it can work well for music where these issues don't make a difference.

There are quite a few examples beyond AG employing this, Dave.

 

[Kingrex]

This conversation really has me thinking about trying to biamp my system again. I never spent much time trying to figure out why my dartzeel roared a fault when I had the SET 845 attached to the other drivers. I can only assume the ground issues in the 845 are being carried through the signal cable, to my preamp and coupling to the dartzeel causing a distortion in that amp.

FWIW, after I put a 4.5 KVA wall mount Torus in my basement, my Black Shadow 845 that are really no longer a Black Shadow perform at a much higher level. The distortion on the power line were really messing with that amp. I have had them in the system for about a month. I put the Dartzeel back in one day but took it right back out. The SET is much more exciting, even with its midrange bump. The Dartzeel is far more calm and quiet. Its way more balanced in a good way. But it lacks some sort of life, may it be artificial or not, the 845 brings.

 

[bonzo75]

Thank you, gentlemen. I will give up my nascent and tragically brief career in loudspeaker design.

poorly designed speakers did not stop many from making a career

 

[bonzo75]

Sure, but it can't compete with 15" woofers and dedicated horn tweeters on the frequency extremes

It is not meant to compete at the frequency extremes, it is meant to be better on the coherence and dynamic range and nuance and speed and purity that is created by lack of crossover. Crossover only subtracts. It is sufficient to play Beethoven and Mahler symphonies, in fact the best of them. It is a but counter intuitive as Leif's, Mike's, or Tang's also plays them via multi way. But that is how it is, and applying concepts of one to the other doesn't help as both as doing it very differently.

 

[thomask]

This conversation really has me thinking about trying to biamp my system again. I never spent much time trying to figure out why my dartzeel roared a fault when I had the SET 845 attached to the other drivers. I can only assume the ground issues in the 845 are being carried through the signal cable, to my preamp and coupling to the dartzeel causing a distortion in that amp.

FWIW, after I put a 4.5 KVA wall mount Torus in my basement, my Black Shadow 845 that are really no longer a Black Shadow perform at a much higher level. The distortion on the power line were really messing with that amp. I have had them in the system for about a month. I put the Dartzeel back in one day but took it right back out. The SET is much more exciting, even with its midrange bump. The Dartzeel is far more calm and quiet. Its way more balanced in a good way. But it lacks some sort of life, may it be artificial or not, the 845 brings.

I feel tube Amp give air or sparkle that SS Amp could not provide.
Thus I use SS amp only to drive subwoofers.

 

[Norway]

You guys should try Werner Jargusch's passive crossover (doesn't cost much and with one iteration should sound musical) or fly over Misho from Bulgaria to do a passive for the 817 since he has an excellent sounding one

I am now in dialog with Werner regarding ordering one… I understand from him that it comes av a 3-way network 500hz and 8-10 kHz for a ultra HF unit!? Is 10 kHz the right point on my 288G? I have both a JBL 2404 and Fostex A500.
Another point is that his filters can be bi-wired/bi-amp(filter part for the 515 are separated from 288). Considering to use my First Watt F4s for the 817, letting the 300d SE drive both the 288+HF and also the F4s working the 817. Nelson promotes this idea in the F4 manual, Werner thinks it’s a bad idea but doable… anyone that has experimented with the F4s in this direction ?