[poseidonsvoice]

Do you have any data to support that claim?

A while back Dr. Geddes performed measurement of Econowave and ESP12 (Abbey?). I'll let the data speak for themselves.

ECONOWAVE:



ESP12 (ABBEY?)




I have neither of the speakers.

The latest measurements of the Abbey are on his website, but you seem to have illustrated the differences nicely here. First, ignore the on axis (0 degree) response curve of the ESP12, it is completely irrelevant as the speaker is firing at you in a 45 degree angle. Start looking at the green curve and go on down. Each curve I believe  represents 7.5 degrees off axis relative to the 0 degree/top dark blue curve (correct me if I am wrong). Notice how as you move off axis, the curves are nearly identical. The one thing that is not illustrated here is the directivity index - read Toole's Sound Reproduction text for a full description. The ESP12's will be much higher and to a lower frequency relative to the Econowave. But how low is beneficial? There are some thoughts and authorities on that, but 500 Hz is ideal, but nearly impossible to achieve in a reasonably sized enclosure. In other words, you would have to go to an 18 inch waveguide. The Summa and Abbey seem to achieve it to just under 1Khz, the Summas being better obviously.

Hi Anand
Hoping you could explain what you mean.  Just trying to learn more.
Thanks

What I meant was that in order to get a very smooth in room response (without EQ and minimal to no room treatment) below the Schroeder frequency (which is about 200Hz in my room) I had to use 3 subs in an asymmetrical distribution. It didn't matter if it was at one seated position or multiple seated positions, the 3 sub technique works great. Of course that increases costs (but you don't have to splurge on your subs), and it takes some more real estate in your room. Those are some idiosyncracies that may be hard to handle. Not impossible, just that it places more priorities on your music system and less on WAF, etc...The funny thing is, the smaller the room, and the more the bass sources, the smoother bass response. A larger room needs more piston area to pressurize the room anyway, so more bass sources are also ideal. Can you get by with just one sub? Sure, but you are no different from any body else who has a monitor with a sub (you will most likely need EQ or lots of bass room treatments or both), except that you have a speaker with phenomenal directivity control. It makes a massive difference in imaging, soundstaging and neutrality as your 1st reflection points in your room, are nearly irrelevant. The multiple bass sources also help in literally 'swelling' your soundstage. Everything starts out with a 'foundation' and the speaker doesn't sound shrill or tipped up at the top. It's very hard to describe but very easy to experience. Those who have more conventional loudspeakers but with multiple bass sources know what I mean already.

I hope that helps,

Anand.

[Russell Dawkins]

First, ignore the on axis (0 degree) response curve of the ESP12, it is completely irrelevant as the speaker is firing at you in a 45 degree angle.
Anand.

...but your listening position is not 45º off the speakers' axes, is it? I know the speakers are toed it at 45º

[poseidonsvoice]

...but your listening position is not 45º off the speakers' axes, is it? I know the speakers are toed it at 45º

Your ears should be at about 22 degrees relative to the speaker not 0 degrees, think about it. If you look at how the Abbeys have been optimized it is specifically over a 22-30 degree arc. You don't tilt your head right or left, you listen with your ears facing towards the side wall. This was discussed a few pages ago, give it a look. When you set up the GedLee speakers you don't sit right where the 2 speakers cross, you sit about 2-3 feet back from that cross, so the angle is somewhat less than 45 degrees.

A drawing would probably be easier to understand.

Anand.

[Russell Dawkins]

I think you are confusing the angle of incidence to the ears with the angle off the speakers axis - and I have thought about this!

If you were to sit right where the speakers' axes cross and the speakers were toed in at 45º the speakers would be ±45º to your frontal axis, 45º in front of your lateral axis and you would be on the 0º axis of each speaker, By sitting 2-3 feet back from this position you would be, depending on the size of the array, as you say - perhaps 15-25º off the speakers' axis. The fact that the response slopes off axis happens to work in our favour in the tonality of the central phantom image, because at these angles the speaker's response curve is not that far off what it would be at the ear for a frontal sound after it had been affected by its path around the head.

[poseidonsvoice]

I think you are confusing the angle of incidence to the ears with the angle off the speakers axis - and I have thought about this!

If you were to sit right where the speakers' axes cross and the speakers were toed in at 45º the speakers would be ±45º to your frontal axis, 45º in front of your lateral axis and you would be on the 0º axis of each speaker, By sitting 2-3 feet back from this position you would be, depending on the size of the array, as you say - perhaps 15-25º off the speakers' axis. The fact that the response slopes off axis happens to work in our favour in the tonality of the central phantom image, because at these angles the speaker's response curve is not that far off what it would be at the ear for a frontal sound after it had been affected by its path around the head.

Yup. You worded it much better than I did, thanks!

Anand.

[jtwrace]

If you think that this is in any way "unfair" or that I have "no business sense" then I am sorry.  You said something about "If Dr. Geddes is happy with his business, then that is fine".  This is precisely the point, and yes I am. In business you can't please everyone - the price is always to high to someone, no matter what it is.

So darn true...

[dwr]

OK lets take this in a little different direction here. Anand I have a question for you about your amps. I see you use a gainclone and a class D. I am going to build my first gainclone here in the next few weeks/months? I am going to build a dual mono design around the 3886 chip. My question for you is about how much power does your chip amp put out per channel and how do you like it with the Abbeys? Also if you can describe the differences between the chip amp and the class D amp I would appreciate it. Now I have ordered the kit for the amp and power supply but am holding off on the transformers for now. I noticed you went for the Lundahl transformers can you explain what it was that made you decide to go with those over say the transformers I can get at parts express for about half the cost. I am not opposed to spending the extra coin if the results are worth it, I just want to hear the advantages from someone who owns and uses them.

Dan

[jtwrace]

OK lets take this in a little different direction here. Anand I have a question for you about your amps. I see you use a gainclone and a class D. I am going to build my first gainclone here in the next few weeks/months? I am going to build a dual mono design around the 3886 chip. My question for you is about how much power does your chip amp put out per channel and how do you like it with the Abbeys? Also if you can describe the differences between the chip amp and the class D amp I would appreciate it. Now I have ordered the kit for the amp and power supply but am holding off on the transformers for now. I noticed you went for the Lundahl transformers can you explain what it was that made you decide to go with those over say the transformers I can get at parts express for about half the cost. I am not opposed to spending the extra coin if the results are worth it, I just want to hear the advantages from someone who owns and uses them.

Dan

Dan

I loaned him my Class D that I built and he has now built one for himself.  I will let him chime in here...

Post #102 here http://www.audiocircle.com/index.php?topic=65332.100

[poseidonsvoice]

OK lets take this in a little different direction here. Anand I have a question for you about your amps. I see you use a gainclone and a class D. I am going to build my first gainclone here in the next few weeks/months? I am going to build a dual mono design around the 3886 chip. My question for you is about how much power does your chip amp put out per channel and how do you like it with the Abbeys? Also if you can describe the differences between the chip amp and the class D amp I would appreciate it. Now I have ordered the kit for the amp and power supply but am holding off on the transformers for now. I noticed you went for the Lundahl transformers can you explain what it was that made you decide to go with those over say the transformers I can get at parts express for about half the cost. I am not opposed to spending the extra coin if the results are worth it, I just want to hear the advantages from someone who owns and uses them.

Dan

Lots of questions but I will try to answer them one by one.

My gainclones are based on the LM3875 chip, and they are dual mono in build with 2 toroidal transformers from Plitron. They put out about 40 watts/8 ohms and 100 watts instantaneous. They will blow me out of the room with GedLee Abbeys.

My review on the Class D amp (original design, not my latest build) is right here. The primary difference\ is that the Class D amp image outlines are sharper, the soundstage is deeper,tonality is smooth while being extended on top. Overall at least a 20% improvement over my gainclone for less coin. My gainclone with the diyenclosures chassis cost me about $700 to build. My Class D as posted on the Lab forum cost me about $550.

The input transformer on the gainclone was an attempt by me to make the unit like the Gill Audio Lissa which uses a Lundahl input transformer. After consultation with Kevin Carter, the U.S. Lundahl distributor, he gave me the thumbs up and I went ahead with the design. I have found Lundahl input transformers to be very transparent and have also tried Jensen in this application. The Lundahls were superior in my honest opinion. I've also used Magnequest, Electraprint, One-Electron, and O-Netics, and of course Lundahl however NOT in this application (in tube amps - they are all quite good actually!). The Lundahl input transformer provides galvanic isolation, a balanced/differential input and the ability to have 1:1 or 2:1 step down ratios, making the overall gain of the amp variable from 24dB or 30dB.

With the Class D SDS254 design, we have a differential input stage designed by Bill Whitlock (designer of Jensen transformers) and a variable input gain from 18dB to 32dB, so no input transformers are needed obviously.

I hope that helps. I enjoy them both, but the SDS254 is more transparent and a better value since it is a cheaper build. It's my reference to compare with solid state amps < $1K and beyond. Any amp that comes through here must have at least the fidelity of the SDS254 to pass for high end. Or else it's out!

Anand.

[dwr]

Excellent thank you both for the replies, I am going to build the gainclone first and see how I like it, I should get about 60 wpc out of it and if you are getting 40 wpc and its fine Ishould have plenty of power. I'll let you guys know how it sounds when I get it finishe, probably won't be till after the holidays though. Thanks again.

Dan

[jtwrace]

Playlist is made for the 18th...

[dwr]

Watcha going to listen to???

[jtwrace]

Watcha going to listen to???

Umm.  Music.   

Seriously, all kinds of stuff.  I did a playlist on my Mini and it quickly became 50 songs.  I will not be able to listen to all of them but at least they're all in one spot. 

The very kind host will have to approve my selections though.     I'm stoked!

[TomS]

Don't forget to crank it  if it suits you (and Anand).  The speakers don't really care.  In fact, the mo' the betta.  Clapton Live at Earl's place was terrific 

[jtwrace]

Don't forget to crank it  if it suits you (and Anand).  The speakers don't really care.  In fact, the mo' the betta.  Clapton Live at Earl's place was terrific 

Anand isn't affraid to crank it.  In fact, he listens a bit loud for me....I found out when he came to my house and handed him the remote. 

[goskers]

Yeah, tell me about it

[jtwrace]

Yeah, tell me about it

Glad to know it wasn't just me...at first, I thought he was really trying to blow something up.  I did ask "do you always listen this loud"?  Answer: "Yes".   

[dwr]

Way to go Anand you sound like my kind of listener!! I have a MFSL vinyl copy of the Alan Parsons Project I Robot on the way, so yesterday I pulled out the "standard" copy I have now and let it rip, can't wait to get this MFSL copy.

Dan

[jtwrace]

Here are some of the tracks...

[dwr]

Oh yes you have some really tasty choices there. Thick as a Brick is an excellent choice, very dynamic, you will see how easily these speakers handle it. The whole Keep it Simple album is an excellent one. You have a real good variety of tunes for the evaluation of the speakers, can't wait to hear your impressions.