| gedlee |
| quote: | Originally posted by tinitus
Sorry, but I have made an error on the price of 10PS26 ... price will be 208USD
Just looked at a Scandinavian supplier ... 10PS26/288USD ... 12TBX100/493USD ... about 30-40% higher |
Ouch!
It would be cheaper for you guys to buy the speakers assembled and painted and have me ship them that way. At $3600 for a pair of finished Abbeys you would have to pay over $4000 for just the parts. |
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| tinitus |
Many suppliers dont announce their prices, so I suppose more input would be good
Personally I looking at AE IB15 at 100USD ... converted to what we usually pay fore quality drivers such prices will account fore some shipping cost |
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| deiksac |
There is a very good BC distributor in czech republic - check http://www.prodance.cz
prices for most of the stuff are almost lowest in europe
pity for you about the strong koruna at the moment :-) |
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| DrumDude |
| quote: | Originally posted by Patrick Bateman
I'm so happy with my Summas, I'll probably get in on the DIY kits too. Yesterday I was working in the garage on my unities, so I hooked up an old line array that's been gathering dust for two years. It was SHOCKING how awful the line array sounds, now that I'm used to the Summas. |
This is the comparison I have been looking for. I started looking at DIY a few years back in search of a speaker for my home studio that could be used as live band PA and mid-field monitors. ie play at pro audio levels when needed with studio monitor accuracy. Most horns I have heard exibit some sort of nastiness so it looked like the only thing close was a line array. I've heard they have their own issues so I put off building one.
Then I started reading of Dr. Geddes work with waveguides. It sounds like his design goals (theater levels, high fidelity) meets what I am looking for very well. |
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| Patrick Bateman |
| quote: | Originally posted by DrumDude
This is the comparison I have been looking for. I started looking at DIY a few years back in search of a speaker for my home studio that could be used as live band PA and mid-field monitors. ie play at pro audio levels when needed with studio monitor accuracy. Most horns I have heard exibit some sort of nastiness so it looked like the only thing close was a line array. I've heard they have their own issues so I put off building one.
Then I started reading of Dr. Geddes work with waveguides. It sounds like his design goals (theater levels, high fidelity) meets what I am looking for very well. |
Yeah line arrays are completely busted - they only make sense in a very large venue.
I can't figure out why so many people fawn all over line arrays. I started building my first line array before I even HEARD one. I just ate up the internet hype, and started buying drivers.
Then I heard the "Straight 8" at the Bottlehead show in Washington, and was horrified at how bad it sounded.
The sound improves when you get REALLY far back, but who wants to listen to their speakers from 25' away?
If anyone wants to know more about my Summas, you can hit me up on instant messenger. Send me an email and I'll give you the info. |
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| tinitus |
| quote: | Originally posted by Patrick Bateman
Then I heard the "Straight 8" at the Bottlehead show in Washington, and was horrified at how bad it sounded.
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Makes you wonder, doesnt it ... I reckon there are mostly awfull designs out there and you will be bloddy lucky to find a good one, I mean THE real thing ... I dont like being so harsh about it but I am afraid thats the reality we have to face ... fact is, when someone praise a design I really dont believe any of it ... well, I sure hope you are in fore the real good stuff here :o |
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| Patrick Bateman |
| quote: | Originally posted by tinitus
Makes you wonder, doesnt it ... I reckon there are mostly awfull designs out there and you will be bloddy lucky to find a good one, I mean THE real thing ... I dont like being so harsh about it but I am afraid thats the reality we have to face ... fact is, when someone praise a design I really dont believe any of it ... well, I sure hope you are in fore the real good stuff here :o |
It's true that subjective evaluations should be taken with a grain of salt, but there's plenty of logical explanation for why line arrays are unlistenable when you're in close proximity to them. |
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| tinitus |
| quote: | Originally posted by Patrick Bateman
... but there's plenty of logical explanation for why line arrays are unlistenable when you're in close proximity to them. |
I suppose that could be said about almost any design ... maybe even this one
You know the saying ... "its good untill you hear something better"
Just fore the record, I believe Earls speakers are very good, maybe even better than most, but you will never know how good untill you have heard them yourself :) loud rock and pop and they will shine fore sure, no doubt about it ... classical music, well if they can do that convincing I will take a deep bow ... and maybe make one fore myself ;) |
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| Patrick Bateman |
| quote: | Originally posted by tinitus
I suppose that could be said about almost any design ... maybe even this one
You know the saying ... "its good untill you hear something better"
Just fore the record, I believe Earls speakers are very good, maybe even better than most, but you will never know how good untill you have heard them yourself :) loud rock and pop and they will shine fore sure, no doubt about it ... classical music, well if they can do that convincing I will take a deep bow ... and maybe make one fore myself ;) |
I own them LOL |
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| JoshK |
I was pretty hyped up about line arrays until I heard a pair for myself in my own home. They were well made and designed. I did really like some things about them (dynamics) but not everything.
They have a pretty unusual presentation, projecting into the room more, like on top of your lap if you are sitting close. I ultimately wasn't convinced to go this route. I think integration of bass with line arrays is a tricky issue as well. |
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| gedlee |
| quote: | Originally posted by tinitus
Just fore the record, I believe Earls speakers are very good, maybe even better than most, but you will never know how good untill you have heard them yourself :) loud rock and pop and they will shine fore sure, no doubt about it ... classical music, well if they can do that convincing I will take a deep bow ... and maybe make one fore myself ;) |
The hyped up marketplace is the reason that I never went the route of claiming "audio nirvana" and instead went the route of showing real data, the likes of which no competitor can compete with.
I have heard virtually all of the "great" speakers and, well, in all honesty, I don't think that any of them can compare in terms of performance and value. A few have comparable performance, but none can compete at the price.
I've been in audio almost 40 years now. You'd hope that I would have heard what the different designs can do (I'd be totally out of it if I haven't). And there is almost no one who can speak to the technology with the depth that I can.
So why is it surprising that I have done something remarkable? To me it only makes sense. I'd be a misreable scientist if after all this time I hadn't learned to make something exemplary.
And there is good news! I will be able to get 15" waveguides at a price that I can live with. So there will be an Abbey+ and mabe a Summa again. |
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| chrismercurio |
| 15" waveguides is excellent news! |
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| tomcat9 |
| This is good news. I am most interested in the Abby+. |
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| mike galusha |
| I'm definitely still interested in a pair of Abbey +'s. |
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| Michael Ando |
| Me too. Just let us know when you want to start taking deposits. If the 15" guides are coming from Thailand is there any chance they could come straight to Australia ? Thanks Mike |
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| gedlee |
| quote: | Originally posted by Michael Ando
Me too. Just let us know when you want to start taking deposits. If the 15" guides are coming from Thailand is there any chance they could come straight to Australia ? Thanks Mike |
Actually the big break through was finding a local source that is competitive with Thailand.
Its very interesting what is happening in international economy. Asian labor rates are growing rapidly, the dollar is falling and transportation cost are going through the roof. All this says that in a very short time manufacturing will start to move back to the US as its cheaper.
This is exactly what happened in Thailand. When I started the Baht was at 40 / $, now its 32 / $. Their labor rates have increases 10% in that time and now transportation costs are nearly double. It used to be that a waveguide from Thailand was 1/2 of the cost here. Now it is very close - only about 20% less - but at the current rate it will be cheaper here.
I am talking with Ai in Thailand now about selling into Aus directly instead of the parts coming from here. |
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| MEH |
| Out of what material will these locally produced waveguides be made? |
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| gedlee |
| quote: | Originally posted by MEH
Out of what material will these locally produced waveguides be made? |
Fiberglass |
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| Grumpy_Git |
Earl
Are the new fibreglass waveguides going to be molded with the baffle or are you still planning on using MDF baffles?
Cheers
Nick. |
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| gedlee |
| quote: | Originally posted by Grumpy_Git
Earl
Are the new fibreglass waveguides going to be molded with the baffle or are you still planning on using MDF baffles?
Cheers
Nick. |
The baffles will still be MDF. What else could they be? They could be wood, but the edge of the waveguide would be hard to hide. Maybe someday in the future I'll offer an all wood baffle option - at an exhorbitant price of course. Waveguides in wood would be prohibitively expensive and the foam would cover it anyways. |
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| MEH |
| quote: | Originally posted by gedlee
Fiberglass |
Excellent. I was a little concerned about the long-term dimensional stability of polyurethane. |
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| gedlee |
| quote: | Originally posted by MEH
Excellent. I was a little concerned about the long-term dimensional stability of polyurethane. |
Do you have reason to believe that it would not be stable? Polyurethane is the backbone of modern plastics. In fact polyurethane has replaced wood as the material of choice for model making precisely because of its long term and environmental stability - wood is the one thats not stable. I am not familiar with any problems that poly has with stability once it has properly cured. |
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| chrismercurio |
I really wouldn't worry about the stability of modern plastics in the world we live in unless you were going to move to a planet other than earth in the near future. Maybe I'm missing something but plastics are used for EVERYTHING (even guns).
I really don't mean to be sarcastic, or an @ss, but the only thing I can think of that people make horns/waveguides out of that is really dimensionally unstable is WOOD.
Chris
p.s. Any preliminary pricing on the Abbey+ or potential (Summa)? |
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| MEH |
| quote: | Originally posted by gedlee
Do you have reason to believe that it would not be stable? Polyurethane is the backbone of modern plastics. In fact polyurethane has replaced wood as the material of choice for model making precisely because of its long term and environmental stability - wood is the one thats not stable. I am not familiar with any problems that poly has with stability once it has properly cured. |
More uncertainty than any positive reason to believe there would be a problem. Saying that polyurethane is the backbone of modern plastics doesn't really mean much, because there are plastics and there are plastics, and there is a great deal of difference between polyurethane foams or flexible, two-part PU and thermoset rigid moldings, e.g. GRP just makes me a little more comfortable than small-scale production of unreinforced plastic. |
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| gedlee |
| quote: | Originally posted by MEH
More uncertainty than any positive reason to believe there would be a problem. Saying that polyurethane is the backbone of modern plastics doesn't really mean much, because there are plastics and there are plastics, and there is a great deal of difference between polyurethane foams or flexible, two-part PU and thermoset rigid moldings, e.g. GRP just makes me a little more comfortable than small-scale production of unreinforced plastic. |
Thats up to you, but as far as I am concerned the Poly that I use is perfectly stable and preferable to fiberglass in that it has less dimensional variation on setting than fiberglass. And the fact that poly is used for pro modeling (making masters from which the parts are made) in every industry that I know of IS reason to belive that it is stable. |
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| chrismercurio |
| quote: | Originally posted by chrismercurio
p.s. Any preliminary pricing on the Abbey+ or potential (Summa)? |
Earl,
I just noticed that your webpage was updated with the Abbey pricing as well as the breakout that another forum member had asked for.
Thank you,
Chris |
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| gedlee |
| quote: | Originally posted by chrismercurio
Earl,
I just noticed that your webpage was updated with the Abbey pricing as well as the breakout that another forum member had asked for.
Thank you,
Chris |
No pricing yet on anything that uses the 15" waveguide because I don't yet have the sourcing for that ironed out. Not too long though.
What would be the interest level in a full Summa size speaker? |
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| chrismercurio |
Very interested. :D
If it doesn't come to fruition...the biggest one available is what I will get. I want dynamic speakers that can be driven by amplifiers of all sizes capable of reproducing real world SPL's. One of the biggest disappointments as a musician is to listen to audiophile systems that do not reproduce dynamics.
A friend of mine has Quad 989's and though tonally I like the midrange on them, I have a hard time listening to them as they have almost no dynamic range.
:D |
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| mike galusha |
| I'd prefer the Summa to the Abbey+. Since the baffle has to be wide enough for the 15" waveguide fitting the 15" driver shouldn't require much extra material except for the additional cabinet size. The price difference on the woofers at US Speaker is only $16 each, so I can't see not going for the Summa for what appears to be a minimal cost difference. At least it appears to be a minimal difference from here, there may be plenty of things I'm not aware of. :) |
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| chrismercurio |
I'm sure the crossover difference won't be minimal...just different.
Which is the woofer used in the Summa?
Chris |
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| mike galusha |
| I think it was the B&C 15 TBX100 but my memory could be wrong, happens often enough... |
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| gedlee |
| quote: | Originally posted by mike galusha
I think it was the B&C 15 TBX100 but my memory could be wrong, happens often enough... |
The woofer is the 15TBX100 and the difference in price to be is greater than what you quoted.
The Abbey+ will have the waveguide "cropped" so there is a lot more cabinet, but thats not a big factor. The biggest factor is the 15" woofer as I have to pay a lot more for it than the 12. I can't explain others pricing on them. |
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| mike galusha |
| quote: | Originally posted by gedlee
The woofer is the 15TBX100 and the difference in price to be is greater than what you quoted.
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It may be one of them is old stock and newer ones will be more. No idea, I just looked them up to get an idea. :) usspeaker.com shows the 12TBX100 at $294.95 and the 15TBX100 at $309.95. Hopefully your supplier is giving you a better deal on both. In any event I'm up for either of the 15" choices, the Abbey+ or the full Summa, preferring the Summa of course. |
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| MartinQ |
For the Canadian interest, Q-components in Waterloo, ON has new pricing for Eminence and B&C.
$163.03 / $131.96 - Drivers for Nathan10 are: B&C 10PS26 / DE250-16
$301.39 / $131.96 - Drivers for Abbey12 are: B&C 12TBX100 / DE250-16
$316.10 / $131.96 - Drivers for Summa are: B&C 15TBX100 / DE250-16
$119.99 / $54.99 - Eminence drivers in Nathan10 are: Kappa Pro 10A / PSD2002-16
Earl, the part number is off from your web page:
"Sub Eminence drivers in Nathan10 (Kappa 10, PDP2002) for B&C: $80 off" |
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| MEH |
| quote: | Originally posted by gedlee
What would be the interest level in a full Summa size speaker? |
For myself, I can't answer that until I see relative pricing and at least your design performance numbers -- and preferably actual measurements of both Abbey+ and Summa. |
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| MartinQ |
| quote: | Originally posted by MEH
For myself, I can't answer that until I see relative pricing and at least your design performance numbers -- and preferably actual measurements of both Abbey+ and Summa. |
Same here. I'm eagerly waiting the first DIY builder reports regarding construction, final cost, listening, measuring. I am most interested in the size/cost/performance comparison.
If the Nathan10 allows for 'excellent' performance with the Eminence drivers, then that be very interesting to me for a 3, 5 or 6 channel theatre setup. If the Abbey+, Summa, Summa+ offer 'outstanding' performance for double the money... I would probably go for the Summa+ ... but then probably only for a pair due to limited space.
I could see a scenario where I build / test / audition the Nathan10 to set the benchmark and make a decision after that (to build more, swap to B&C drivers or build a 12 / 15 / 18). |
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| Grumpy_Git |
Earl
sorry to reply so late in the day but regarding my baffle question, i was wondering if you were planning on casting the waveguide and baffle as a single piece of fibreglass. Obviously you have answered my question and stated it will still be mdf.
As it stands at the moment, i am interested in nathans or summas, it all depends on pricing, i'm after quotes for the nathan drivers from the uk distributors.
The summas are impressive though (and i assume they measure better), mortgage overpayments or speakers....... :confused:
Thanks again.
Nick, |
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| tomcat9 |
| quote: | | If the Nathan10 allows for 'excellent' performance with the Eminence drivers, then that be very interesting to me for a 3, 5 or 6 channel theatre setup. |
That's a good point. For my main front 2, I want Abby+ or Summas. But the Nathan with Eminence should be great for rear channel. |
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| gedlee |
| quote: | Originally posted by tomcat9
That's a good point. For my main front 2, I want Abby+ or Summas. But the Nathan with Eminence should be great for rear channel. |
Personally, I would NOT use directional speakers for the surrounds. I'd love to sell you 5 speakers, but I have to tell you that these designs are not what I would, or do, use for surrounds. Surounds should be dipoles or very wide directivity. Bandwidth in the surronds is not important nor is LF. Buy bigger LCR speakers and spend less on the surounds - like a lot less. |
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| tomcat9 |
| I was going to ask if you used these for your rear speakers, but I did not. Thanks. |
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| Patrick Bateman |
| quote: | Originally posted by gedlee
No pricing yet on anything that uses the 15" waveguide because I don't yet have the sourcing for that ironed out. Not too long though.
What would be the interest level in a full Summa size speaker? |
You could sell a TON of kits if you did an Abbey with a low-cost woofer. Here's why:
The "real" Summa is a no-compromise design that mates a 15" waveguide & a 15" woofer. The achilles heel of the Summa is the woofer. There are only a handful of 15" woofers which can play into the midrange. The B&C 15TBX100 fits the bill, but it is E-X-P-E-N-S-I-V-E.
The Nathan 10 is a low cost alternative to the Summa; the kit costs less than 1/4 of what the Summa retails for. The Nathan ten has two drawbacks. It offers controlled directivity down to 1400hz, and the smaller woofer can't play as low as the Summa. Of course these are nitpicks; it's IS dramatically less expensive after all. You can save a few bucks by going with Eminence drivers, but why bother? The B&C woofers are superior, and the cost difference is less than 15%.
As I see it, the Abbey has the potential to be the most popular in the line. Here's why:
The Summa offers controlled directivity down to 920hz, while the the Abbey goes down to 1150hz. That's a *very* small difference, less than a quarte of an octave. To me, the most interesting aspect of the Abbey is the choice of woofer. The B&C 12TBX100 is an exceptionally expensive 12" woofer. Retailing for $295 here in the states, there are only a handful of woofers in it's class.
Your own studies have proven that the choice of drivers has little impact in the sound, despite popular belief. For instance, the substitution of TAD for B&C didn't improve the sound. Knowing that, you could easily substitute a dramatically less expensive woofer for the B&C.
For instance, the P-Audio SN12MB retails for half the cost.
I have a hunch that an Abbey which uses a low cost woofer would cost half the price of the Summa, while offering 80% of the performance.
Two other options are the Eminence Kappa 12 and the Deltalite II 12". Each retails for $130, vs $295 for the B&C.
Of course, there's no free lunch. The use of a less expensive woofer has drawbacks. However, I believe they would be all but inaudible in this application. The motor in the B&C 12TBX100 is a real work of art. B&C used a 100mm voice coil so that it could handle shocking amounts of power - two thousand watts! But that single design aspect carries drawbacks. A huge voice coil increases inductance, which then limits how high the woofer can play. B&C puts shorting rings in the motor to counter this.
Compared to the B&C, the Eminence and P-Audio woofers look liliputian. The P-Audio can only handle 600watts, due to it's dramatically smaller voice coil. But there's an upside! The P-Audio offers dramatically lower inductance, less than 1/4 of the B&C. This is easy to explain, there's simply less copper in the voice coil. Lower inductance allows the P-Audio to play a full octave higher than the B&C. Based on published specs, the P-Audio appears superior to the offerings from Eminence. The Kappa 12 has higher inductance, and the Deltalite 12 has similar performance to the P-Audio, but with a dramatic rise in the midrange.
Another upside to the use of a 12" woofer is a simplified crossover, which would further reduce the cost.
If the Abbey kit offers 80% of the Summa's performance for under $1998 a pair, that would be remarkable. And it seems like it's do-able IF the woofer was replaced. |
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| MartinQ |
Thanks for your take on the situation Patrick. Its really great to have an outsiders opinion who is 'in the presence of' a Summa. :)
| quote: | Originally posted by Patrick Bateman
The Nathan ten has two drawbacks. It offers controlled directivity down to 1400hz ... The Summa offers controlled directivity down to 920hz, while the the Abbey goes down to 1150hz. That's a *very* small difference, less than a quarter of an octave. |
So directivity to 1400Hz is a drawback, but 1150Hz isn't? Is that 250Hz difference (from 10" to 12") more significant than the 230Hz difference (from 12" to 15") ?
| quote: | Originally posted by Patrick Bateman
You can save a few bucks by going with Eminence drivers, but why bother? The B&C woofers are superior, and the cost difference is less than 15%. |
Going from B&C drivers costing $300 per box ($163.03 + $131.96 CDN) to an Eminence set costing $175 per box ($119.99 + $54.99) is significant. I understand it is only one cost out of many, but when you are building 3-channels, all those little bits add up.
If what Earl is saying applies to this specific scenario (about different drivers having almost no sonic impact), then I'd be happy to save over $100 per box at this level. On top of that, my local supplier has a 7 year warranty on the Eminence, but only 1 year on the B&C.
| quote: | Originally posted by Patrick Bateman
Compared to the B&C, the Eminence and P-Audio woofers look liliputian. The P-Audio can only handle 600watts, due to it's dramatically smaller voice coil. |
For an indoor home audio scenario I can't see needing (or wanting) more than 100-300 watt per channel for the mains (subwoofer excluded). I am interested in quality and efficiency, not high power handling.
For a different venue (dj, outdoors, club, bar) I could certainly understand higher power drivers and amps being involved. |
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| gedlee |
All quite interesting.
But here are some points:
1) I never said that the drivers make NO difference only that competent drivers are all equivalent - that the differences aren't noteworthy. P-audio are not competent drivers. I have a closet full of them and not one of them met its "published specs", so much for the really cheap option.
2) You are missing the single biggest reason that I use the 12TBX100, it has a shorting ring. This I consider critical in a "competent" design because quite honestly I can't see why anyone would make a speaker without it. I'll have to look over the Eminence drivers to see if any of the woofers have shorting rings.
3) What I get the drivers for and what you are quoting are not the same thing and it factors into the equation.
4) I have already quoted the Abbeys at $1100 ($2200 / pair) is it really critical to get that last $101 out? I could do it, but I might question the value of that. The Eminence woofers might be a good idea since the ESP12 actually used an Eminence woofer. That change alone would not reduce the price $100 however.
But thanks for the options review. Very interesting. |
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| Variac |
I have to admit that despite what Earl says about it not mattering much , I find the B+C horn driver very appealing. It has a non-titanium diaphram and made by a company with a very good reputation.
I don't think that Patrick is saying that 600 watts will be used, but just emphasizing the quality of the driver. Also a speaker that can handle lots of power has less power compression, which IS relevant,
The Summa has a great reputation. The kits will sell better if they are "Summa clones", not some unknown.
I think that Patrick makes a good point about how the 12" version may require a less special woofer, to get into the midrange, than a 15", so may well be the best value speaker.
However , if the 15" goes low enough to make it possible to enjoy music without a subwoofer, then there is a large savings- even if the sub is a Costco! - less space taken also- better SAF.
So my opinion is that if you have any option, make it an alternative woofer,
EDIT: I was writing this as Earle Posted In answer to his question:
is it really critical to get that last $101 out?
My answer is NONONONONONONO!!!!!!
We want quality- that is the appeal of the Summas
I always want to love Eminence, but my experience with them hasn't been all positive, soundwise.. |
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| Patrick Bateman |
Shorting rings lower distortion and inductance right? But a smaller voice coil also lowers inductance. Bastiani and Emerald Physics went this route; each uses a very inexpensive woofer paired to a high quality compression driver.
Admittedly, the cheaper woofer would have higher distortion.
When it comes to the compression driver, there is little excuse to use a $50 CD. First of all, we want very low inductance so that our response is extended. The Eminence is 1.6mh while the B&C is just 0.11mh.
In addition to lower inductance, the B&C uses a diaphragm with superior damping, while the Eminence uses titanium. If people don't like the sound of 1" titanium dome tweeters, they're going to hate the sound of an Eminence CD with a 3" diaphragm!
To make a long story short - it seems that the use of an inexpensive compression driver is a big compromise, but the use of a inexpensive woofer is less so.
Also, 99% of DIYers are complete cheapskates :) |
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| MartinQ |
| quote: | Originally posted by Patrick Bateman
To make a long story short - it seems that the use of an inexpensive compression driver is a big compromise, but the use of a inexpensive woofer is less so. |
This makes good sense. Again, I'm looking for the best compromise for a given situation, not the cheapest.
| quote: | Originally posted by Patrick Bateman
Also, 99% of DIYers are complete cheapskates :) |
Totally agree .... not that this is entirely a BAD thing. :) |
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| Patrick Bateman |
| quote: | Originally posted by Variac
I don't think that Patrick is saying that 600 watts will be used, but just emphasizing the quality of the driver. Also a speaker that can handle lots of power has less power compression, which IS relevant |
My main gripe with high power woofers is inductance. Hi-end prosound woofers use a 4" voice coil which drives up inductance dramatically. That limits your high frequency response. The addition of shorting rings offsets this, but increases cost. Even worse, the addition of shorting rings requires a larger motor, which FURTHER increases cost. Take a look at the motor on the 12tbx100 and the 15tbx100 - they're HUGE. And expensive.
| quote: | Originally posted by Variac EDIT: I was writing this as Earle Posted In answer to his question:
is it really critical to get that last $101 out?
My answer is NONONONONONONO!!!!!!
We want quality- that is the appeal of the Summas
I always want to love Eminence, but my experience with them hasn't been all positive, soundwise.. |
JBL made a speaker inspired by the Summa, but it's really REALLY cheap. Because the cabinets are crummy, the Summa KILLS it in the imaging department. I've taken my MP215s apart, and the drivers look like little toys. They are seriously the cheapest drivers you've ever seen in your life. But there's an upside to cheap drivers, and that's low inductance. If you look at the power handling of the JBL, it's just 250 watts, which is tragically low in the prosound arena. Yet I think JBL was *forced* to go that route - if they used a motor that was even a little larger, it would have been impossible to mate the 15in woofer to the 15in waveguide without resorting to shorting rings.
Check out the response graphs on the MP215 - you'll see that the cheap 15" they're using is just starting to run out of steam at 1khz. To my ears, the midrange response of the MP215s is pretty damn special, and I believe it has to do with the waveguide they're using, which was certainly inspired by Geddes. In other words, it's the waveguide not the drivers that's magic.
I'd really love to see tons of people with Summas, and it seems like a $999 speaker with 80% of the Summa's performance would be just the ticket. |
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| augerpro |
| quote: | Originally posted by Patrick Bateman
Shorting rings lower distortion and inductance right? But a smaller voice coil also lowers inductance. |
Shorting rings can keep inductance low throughout the cone's stroke though. These drivers may similar or better inductances on paper, where inductance is measured with a small signal, but I ask you: how will they behave when the woofer is actually moving? I think that is where the money is well spent for the B&C driver. |
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| Patrick Bateman |
| quote: | Originally posted by augerpro
Shorting rings can keep inductance low throughout the cone's stroke though. These drivers may similar or better inductances on paper, where inductance is measured with a small signal, but I ask you: how will they behave when the woofer is actually moving? I think that is where the money is well spent for the B&C driver. |
I'm really cheap, like a lot of DIYers. I didn't buy the Summa because I wanted "the ultimate" speaker, I bought the Summa because I realized that there was absolutely no way that my personal attempts at making a speaker would come close to what Dr Geddes is capable of.
So, absolutely, there are people out there who want "the best."
But there are also cheapskates like me who would be interested in a bit of cost cutting.
As far as the woofers moving, I can barely detect if the woofers are moving in the Summa. If they use 1mm of stroke I'd be surprised. They're sensitivity is so high I can't imagine I'm using more than a watt or three. |
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| Variac |
I do agree with Patrick's analysis, If a compromise must be made that results in a significant cost savings , then the woofer seems the place to do it.
The inductivity issue is very interesting. It is kind of a truism that big woofers with smaller voice coils tend to handle the midrange better.. Maybe I know why now..
| quote: | | The baffles will still be MDF. What else could they be? |
I thought that possibly the entire front baffle could be molded with the waveguide. It would have to backed with rigid foam to be stiff though..
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| gedlee |
Comments:
1) Where the shorting ring is placed determines if it reduces the inductance or not. If its below the VC around the pole, and not too close to the VC then it won't affect the inductance.
2) I prefer the higher inductance on the woofers because I use this in the crossover to help to create a steeper slope. To me its not a bad thing.
3) A copper cap on the center pole is the cheap method of shorting ring, but it robs BL and lowers inductance. Its worth doing on a CD where inductance matters a lot, but the wrong way to do a woofer.
4) The TBX drivers have shorting rings not Copper caps (see http://www.bcspeakers.com/download/...ison/Design.pdf). I need to check on the Eminence drivers.
5) Inductance modulation is a big issue when one takes the woofer as high as I do and I take this into consideration. Inductance modulation is the only loudspeaker distortion mechanism that is broadband and not displacement dependent - it happens with no displacement at all. If there is a nonlinearity in the loudspeaker that would be audible this is the one. Displacement distortion will always have a LF signal component and the upward spread of masking will thus tend to mask its effects. But a current distortion can happens with no masking signals at all.
6) I also would be concerned with a smaller voice coil because of thermal compression - it will be greater. So the larger VC with a shorting ring looks attractive to me. The lowest cost woofer with these features is clearly what I want, B&C or otherwise. I only get dealer pricing on B&C and Eminence, so other drivers thus tend to be out of the picture. I would entertain any woofer that meets these minimum requirements if the price is lower than what I get from B&C and Eminence. |
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| gedlee |
| quote: | Originally posted by Variac
I thought that possibly the entire front baffle could be molded with the waveguide. It would have to backed with rigid foam to be stiff though..
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I'm looking into doing this now. The material for casting is expensive - a lot more than MDF, so its a dollars thing. But I tried some things today that look attractive. Casting the baffle instead of MDF is not likely to get the cost down.
What would you guys think of a waveguide or waveguide and bafle that looked like cast bronze? Would that be almost as good as wood? Wouldn't that improve the WAF! "Look dear its a bronze sculpture!" |
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| Patrick Bateman |
| quote: | Originally posted by gedlee
I have already quoted the Abbeys at $1100 ($2200 / pair) is it really critical to get that last $101 out? I could do it, but I might question the value of that. The Eminence woofers might be a good idea since the ESP12 actually used an Eminence woofer. That change alone would not reduce the price $100 however.
But thanks for the options review. Very interesting. |
I could probably sell ice to an eskimo; both my mother and father were entrepreneurs, so I picked it up at an early age.
Does the last $101 count? Absolutely - because getting them in under $1000 has a strong psychological component.
If you run the numbers, it will look like a bell curve, with a handful of people ponying up for the Summas, a handful opting for the Nathans, but the "sweet spot" is certainly the Abbey.
Again, these are just my opinions, but it seems that The Abbey offers the best compromise between cost and performance. Because of that, eking out a few bucks would certainly result in additional sales. If changing the woofer doesn't do it, I'd start thinking about using smaller inductors in the crossover. True, it increases the resistance, but the cost benefits are substantial, and the effects are less audible than if you used cheap caps.
A $999 Abbey has a nice ring to it. |
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| Patrick Bateman |
| quote: | Originally posted by gedlee
Comments:
2) I prefer the higher inductance on the woofers because I use this in the crossover to help to create a steeper slope. To me its not a bad thing.
3) A copper cap on the center pole is the cheap method of shorting ring, but it robs BL and lowers inductance. Its worth doing on a CD where inductance matters a lot, but the wrong way to do a woofer.
4) The TBX drivers have shorting rings not Copper caps (see http://www.bcspeakers.com/download/...ison/Design.pdf). I need to check on the Eminence drivers.
5) Inductance modulation is a big issue when one takes the woofer as high as I do and I take this into consideration. Inductance modulation is the only loudspeaker distortion mechanism that is broadband and not displacement dependent - it happens with no displacement at all. If there is a nonlinearity in the loudspeaker that would be audible this is the one. Displacement distortion will always have a LF signal component and the upward spread of masking will thus tend to mask its effects. But a current distortion can happens with no masking signals at all.
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Given two woofers with a conventional motor, one with an LE of 2.0 at 1khz and one with an LE of 0.25 at 1khz, wouldn't it be safe to say that the one with lower inductance will also have lower inductance modulation?
In other words, isn't the amount of inductance modulation relative to the amount of inductance?
Keep in mind, I agree that a woofer with a shorting ring is the best option, if cost is not an issue.
BUT - if you must use a woofer without one to save money, wouldn't you go with the woofer that has the lowest inductance?
This appears to be the route that's been chosen by a lot of commercially successful high efficiency speaker manufacturers. Whenever I go to CES, I'm always astounded by how cheap the woofers are which are used by most of the high efficiency companies.
The $5400 Bastanis Prometheus uses a woofer which looks suspiciously like the $99 Eminence Alpha. (http://www.6moons.com/audioreviews/...prometheus.html)
Pi Speakers uses Eminence Alpha and Delta (http://www.pispeakers.com/Products.html)
Emerald Physics uses Eminence Alpha. (http://www.polkaudio.com/forums/showthread.php?t=65150)
The venerable Adire HE10.1 kit used Eminence Alpha, with a modded compression driver. (http://www.audioxpress.com/reviews/...3dell2119-1.pdf)
In fact, I can't name a single high efficiency loudspeaker which uses a shorting ring in the motor - those woofers are just too expensive to be commercially viable. |
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| gedlee |
| quote: | Originally posted by Patrick Bateman
Given two woofers with a conventional motor, one with an LE of 2.0 at 1khz and one with an LE of 0.25 at 1khz, wouldn't it be safe to say that the one with lower inductance will also have lower inductance modulation?
In other words, isn't the amount of inductance modulation relative to the amount of inductance?
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I don't think that this is true. There are a lot of factors involved and I am not sure that the total inductance is the dominate one or even a principle one.
| quote: | Originally posted by Patrick Bateman
Keep in mind, I agree that a woofer with a shorting ring is the best option, if cost is not an issue.
BUT - if you must use a woofer without one to save money, wouldn't you go with the woofer that has the lowest inductance?
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Again, I am not sure thet this what I would do. The concept of squeezing out another $100 is not yet one that I have bought into and how I did that to best advantage would take some study.
Can you name another high efficiency system that sounds like the Summa? Maybe there is a reason. Maybe I do things differently. |
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| FrankWW |
John, Remember the woofer has to keep up with the waveguide/CD and this has to happen in a variety of situations the manufacturer can't control.
In this case the manufacturer is aiming at highest performance. That's point of his design.
The limitation in any 2way with competent waveguide/CD is the woofer.
I might want a smaller version of a Summa, but if I do, then I must bear in mind the part that is "handicapped " is the woofer. It's probably more "handicapped" than in the larger version.
So, is cheap, no shorting rings, the way to go if I want optimum performance, given I like like to play big music really loud? |
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| Michael Ando |
Personally I disagree with trimming off every last possible dollar. I think it is a insult to the design not to build it as well as practical. If the cost reduction really makes no difference its ok or maybe a very little difference for a lot of money. Thats not the situation here where the difference in cost between drivers isnt much in the context of high quality speaker systems.
I do diy for personsal satisfaction and to get things that I cant buy. I am not saying price isnt a consideration but if I go to the trouble to buid a pair of loudspeakers I want to feel I didnt compromise the design. Dr Geddes has said he believes he has designed speakers that perform at a very, very high standard...they shouldnt be comprmised for the sake of a few dollars. Mike A |
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| tinitus |
Lets be honest now
Earl is doing this in the hope of jumpstarting his Summa production, not to make a few bucks on cheap kits, and I think its ok that we "help" him with that getting the oppertunity to buy first rate quality kits, right
I think Earl has a name to protect, which is why he shouldnt compromise his design
I probably cant even afford to buy a waveguide because of expencive shipping, custom and taxes
but I can tell you that, if the product wouldnt be first rate quality I wouldnt even consider it |
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| audiokinesis |
Patrick, I agree with Earl on staying with woofers that have shorting rings instead of compromising to meet a psychologically attractive price point. In my experience, shorting rings make an audible improvement (I can give anecdotes if you'd like).
If I were in Earl's shoes, I wouldn't make what I thought was a significant compromise in sound quality to meet a target price. Maybe that's why neither one of us have gotten rich selling speakers yet! But, I presume it matters to Earl that his name only be attached to products which he has no reservations about.
edit: In my opinion Earl's market is the educated customer; that's why he has found success here rather than in traditional high-end audio (which is less educated): You guys are very deeply interested in the technology of acoustically and psychoacoustically advanced loudspeakers.
Duke |
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| Variac |
And it appears that Earl is getting some orders. Good for you!
What are the -3dB frequency responses of the 10, 12 and 15" driver Summas on the low end? I realize the subs are necessary for theater, but for music, the 15 might well be enough..
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| Patrick Bateman |
| quote: | Originally posted by audiokinesis
Patrick, I agree with Earl on staying with woofers that have shorting rings instead of compromising to meet a psychologically attractive price point. In my experience, shorting rings make an audible improvement (I can give anecdotes if you'd like). |
I agree that they make an audible improvement. I also believe the improvement would be more audible in the Summa, because the fifteen is being pushed to it's limit. In the Abbey - not so much.
| quote: | Originally posted by audiokinesis
If I were in Earl's shoes, I wouldn't make what I thought was a significant compromise in sound quality to meet a target price. Maybe that's why neither one of us have gotten rich selling speakers yet! But, I presume it matters to Earl that his name only be attached to products which he has no reservations about.
edit: In my opinion Earl's market is the educated customer; that's why he has found success here rather than in traditional high-end audio (which is less educated): You guys are very deeply interested in the technology of acoustically and psychoacoustically advanced loudspeakers.
Duke |
I'm more cynical than most; I believe the kits have been more successful simply because the price point is in reach of many people. Few can afford to spend $6000 on a set of speakers, but many can afford $1998. Imagine if you could only buy a Honda Accord with a V6? I own one with a 4 cylinder and one with a 6 cylinder, and the V6 rules... but it costs more.
All I'm proposing is $1998 Abbey which has the B&C compression driver coupled to a less expensive woofer; of course those who prefer B&C for CD and woofer could still opt for that. |
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| audiokinesis |
Patrick, my apologies - I hadn't read your post closely; obviously you're talking about a low-end Abbey that foregoes the shorting ring but doesn't replace the high-end model, and I can certainly see an argument for that.
Duke |
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| Patrick Bateman |
| What's your experience been, in terms of using top-shelf components? I know that TAD woofer you use must be hella-expensive. |
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| chrismercurio |
Variac,
Frequency response is on ai-audio's site for the ESP10/12/15. They are all sealed designs....so I think you will want a sub unless you want to build a bigger box and a ported alignment.
Chris |
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| macka |
| quote: | Originally posted by gedlee
Actually the big break through was finding a local source that is competitive with Thailand.
Its very interesting what is happening in international economy. Asian labor rates are growing rapidly, the dollar is falling and transportation cost are going through the roof. All this says that in a very short time manufacturing will start to move back to the US as its cheaper.
This is exactly what happened in Thailand. When I started the Baht was at 40 / $, now its 32 / $. Their labor rates have increases 10% in that time and now transportation costs are nearly double. It used to be that a waveguide from Thailand was 1/2 of the cost here. Now it is very close - only about 20% less - but at the current rate it will be cheaper here.
I am talking with Ai in Thailand now about selling into Aus directly instead of the parts coming from here. |
I will be in this if that comes off.
Ian |
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| audiokinesis |
Patrick, I didn't go with the TAD because of the alnico magnet specifically. I wanted a 10" to 12" woofer with about 92-93 dB efficiency and a high quality motor. No home woofers fit that description, and in prosound 10" and 12" woofers are usually really midranges - the don't go down very deep. A few other companies made "studio woofers", but the TAD was the only one I found that brought it all together.
That being said, "top-shelf" doesn't necessarily mean "best for all applications". Although I didn't participate in the blind study comparing the TAD & B&C Summas, from the sidelines I preferred the B&C. And the TAD was my dog in the fight.
Duke |
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| chrismercurio |
The AE speakers are price competitive with the B&C...
Chris |
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| jcx |
could electronics/dsp effect a cost savings or higher quality?
for diy a current drive servo around a cheap PA for the woofer amp is no problem, custom current drive amp for the compression driver wouldn't need huge wattage?
wouldn't current drive eliminate some distortions that people are throwing money at in high quality motor designs?
current drive needs eq, op amp or dsp? - dsp could fix other probelms that are next to impossible to address otherwize |
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| gedlee |
| I got home late and missed all this. Very interseting discussion of marketing loudspeakers. Marketing is not my strong suite and I will consider these options. I'll think this over and get back. But I do think that an option that saves $101 (about 10%) which has notable and audible degradation (not saying that this would be the case, but I suspect that it might) would not be one that many people would opt for. |
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| Michael Ando |
| quote: | Originally posted by gedlee
Actually the big break through was finding a local source that is competitive with Thailand.
Its very interesting what is happening in international economy. Asian labor rates are growing rapidly, the dollar is falling and transportation cost are going through the roof. All this says that in a very short time manufacturing will start to move back to the US as its cheaper.
This is exactly what happened in Thailand. When I started the Baht was at 40 / $, now its 32 / $. Their labor rates have increases 10% in that time and now transportation costs are nearly double. It used to be that a waveguide from Thailand was 1/2 of the cost here. Now it is very close - only about 20% less - but at the current rate it will be cheaper here.
I am talking with Ai in Thailand now about selling into Aus directly instead of the parts coming from here. |
If this means waveguides from Thailand thats great. If this means only complete built AI systems then I would rather buy parts from US and pay the freight. I wouldnt like to think that the availability of complete systems from AI in Thailand would exclude me from buying parts from the the US particularly as the Abbey + is my most likely prefered configuration. Mike A |
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| augerpro |
| Earl have you looked at many of B&C's neo motor woofers? Specifically something like the 15NW76 in view of the need to run these woofers higher this model seems quite good and the price is about the same as the 15TBX100. I just bought a pair myself for testing. |
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| gedlee |
| quote: | Originally posted by augerpro
Earl have you looked at many of B&C's neo motor woofers? Specifically something like the 15NW76 in view of the need to run these woofers higher this model seems quite good and the price is about the same as the 15TBX100. I just bought a pair myself for testing. |
I've looked at their Neo woofers in the past. If weight is not an issue then the extra price did not seem justified to me. The 15NW76 does look very attractive, except that its efficiency may be too high to mate with the DE250. |
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| gedlee |
| quote: | Originally posted by Michael Ando
If this means waveguides from Thailand thats great. If this means only complete built AI systems then I would rather buy parts from US and pay the freight. I wouldnt like to think that the availability of complete systems from AI in Thailand would exclude me from buying parts from the the US particularly as the Abbey + is my most likely prefered configuration. Mike A |
What came out of Thailand would be the same as what I sent from here, just different locations. There would be the same options for parts etc. The drivers will definately be more expensive so the complete kit would be more, but the waveguide and baffle would be the same price. |
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| gedlee |
| quote: | Originally posted by jcx
could electronics/dsp effect a cost savings or higher quality?
for diy a current drive servo around a cheap PA for the woofer amp is no problem, custom current drive amp for the compression driver wouldn't need huge wattage?
wouldn't current drive eliminate some distortions that people are throwing money at in high quality motor designs?
current drive needs eq, op amp or dsp? - dsp could fix other probelms that are next to impossible to address otherwize |
There is no way that DSP could be a cost savings and from the tests that we did DSP, at best, ends up with the same sound quality as the passive crossover. Since "distortions" are not a problem in the designs I don't see a need to fix them. |
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| gedlee |
| quote: | Originally posted by chrismercurio
The AE speakers are price competitive with the B&C...
Chris |
Not at my prices they aren't. |
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| Variac |
| quote: | | . If weight is not an issue |
I know it sounds crazy, but reduced shipping charges can pay for the difference between ferrite and neo drivers.. |
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| jcx |
| quote: | Originally posted by gedlee
Since "distortions" are not a problem in the designs I don't see a need to fix them. |
then why the discussion of thermal compression and shorting rings? |
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| chrismercurio |
| quote: | Originally posted by gedlee
Not at my prices they aren't. |
Earl,
It was just an idea as they are a US manufacturer, and aren't that far from where you are. Their prices might be competitive (or better) in quantity. John and Nick might be willing to send you a sample for testing.
| quote: | Originally posted by Variac
I know it sounds crazy, but reduced shipping charges can pay for the difference between ferrite and neo drivers.. |
I know it sounds crazy but maybe, if we just let Earl bring to market the kits he wants to bring to market as he is the expert on what he wants out of a loudspeaker, the results will be what they are supposed to be.
Best to all,
Chris |
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| Patrick Bateman |
| quote: | Originally posted by gedlee
5) Inductance modulation is a big issue when one takes the woofer as high as I do and I take this into consideration. Inductance modulation is the only loudspeaker distortion mechanism that is broadband and not displacement dependent - it happens with no displacement at all. If there is a nonlinearity in the loudspeaker that would be audible this is the one. Displacement distortion will always have a LF signal component and the upward spread of masking will thus tend to mask its effects. But a current distortion can happens with no masking signals at all. |
At the moment I'm hanging out in a city where money grows on trees. I'm in Bend Oregon, which is something like Park City UT, or Palm Springs CA. Since there are a lot of people with money to burn here, there are two audiophile boutiques downtown. I visited both.
The first featured Martin Logan gear. Comparing this to the Summa isn't really a fair fight, but what the heck. The boutique was demoing one of those ubiquitous audiophile recordings of acoustic guitar. Which sounds delicate and lovely to the uninformed, but also masks the speaker's shortcomings. Namely, there's no bass and no high treble in a recording of acoustic guitar, and the imaging requirements are nil, since there's only one performer on stage.
The second was more interesting. They were demoing Anthony Gallo Acoustics. I've always found the Gallo speakers are a great alternative to Bose. The spherical enclosures reduce diffraction, and the driver quality is a step up. The drivers appear to be TangBand. I've heard the Gallos half a dozen times over the years, and was always pleasantly surprised by how good they sound. As crazy as this sounds, these $1500 speakers sound better than some of the $5K gear at CES.
First thing I noticed was that they're pleasant sounding, but there is TONS of 2nd harmonic distortion which I hadn't noticed before. After listening to the Summas for a few weeks, the sound of distortion is hard to miss. It's interesting because it's actually not that offensive, but it's definitely audible. The Gallos had a veil of distortion riding over everything. I'm guessing this is because the 3" woofers in the Gallos are suffering from distortion at high excursion?
So it's easy to see why they sell; they're attractive, easy to hide, and pleasant sounding. But the distortion is hard to miss, once you know what it sounds like.
| quote: | | Originally posted by gedlee 3) A copper cap on the center pole is the cheap method of shorting ring, but it robs BL and lowers inductance. Its worth doing on a CD where inductance matters a lot, but the wrong way to do a woofer. |
I didn't even know there was a difference until yesterday! In a previous project I used the B&C 8NDL51, and I was astonished by how smooth and extended it's frequency response is. According to B&C's docs, the 6NDL38 uses a demodulation ring, while the 8NDL51 uses a copper cap. It's interesting to see that the 8NDL51 has higher BL. Of course this could be due to half a dozen factors.
I checked their website, and it appears that Eminence isn't a big fan of shorting rings. In conversations online, I recall reading that Danley was considering having Adire build him a sub for the labsub for this reason. And Wayne Parham mentioned Eminence's stance on shorting rings here:
http://www.audioroundtable.com/PiSp...ages/19880.html
The only Eminence speakers with shorting rings which I could find are these:
http://www.eminence.com/pdf/definimax-12ho.pdf
http://www.eminence.com/pdf/definimax-15lf.pdf
Some may recall the Magnum series, which is apparently discontinued:
http://www.partsexpress.com/pe/show...tnumber=290-580
The price difference between B&C and Eminence is only a few percent, and I've had the same experience that you've had with B&C. Excellent build quality, and performance that's consistent with their specs. Vance Dickason has raved about them in Voice Coil for years also. (I wonder if Dickason has any interest in this stuff? According to Google Maps, Dickason's office is 6.3 miles from my house.)
| quote: | | Originally posted by gedlee 6) I also would be concerned with a smaller voice coil because of thermal compression - it will be greater. So the larger VC with a shorting ring looks attractive to me. The lowest cost woofer with these features is clearly what I want, B&C or otherwise. I only get dealer pricing on B&C and Eminence, so other drivers thus tend to be out of the picture. I would entertain any woofer that meets these minimum requirements if the price is lower than what I get from B&C and Eminence. |
I have to admit, it's amazing to see how difficult it is to cut corners on this design.
- The arguments for a shorting ring are compelling, but there are only a handful of 12" drivers which feature one. The B&C 12TBX100, at a retail price of $250, fits the bill. Eminence offers a comparable model, but it's not significantly cheaper and it's performance is unknown.
- If you forego the shorting ring, there are literally dozens of woofers which will fit the bill. But the benefits of a shorting ring are hard to ignore. Also, excursion in the 12in model will be nearly double that of the Summa, due to the Summas greater displacement. The higher excursion exacerbates distortion.
- Seas, Peerless and Dayton make a number of attractive eight inch woofers with shorting rings in the motor. But these woofers have lower efficiency and less maxium output. For a truly strange project, one could use a quad of them to approximate the output of 16" woofer, but that introduces a whole new set of variables. And costs a lot too!
Trying to cut corners on this is exceptionally challenging. |
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| fred76 |
Hi Earl,
Your kit webpage says that you use the DE250-16, which is the 16 ohm version of this driver(?). Is it a deliberate design choice to use 16 ohm versions? If so, for what reason/s? So if one is to source their own drivers (which I surmise are mostly 8 Ohms in the retail market), would a different set of crossover values be used?
Thank you. |
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| gedlee |
| quote: | Originally posted by jcx
then why the discussion of thermal compression and shorting rings? |
I've already solved those problems. |
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| gedlee |
| quote: | Originally posted by chrismercurio
I know it sounds crazy but maybe, if we just let Earl bring to market the kits he wants to bring to market as he is the expert on what he wants out of a loudspeaker, the results will be what they are supposed to be.
Best to all,
Chris |
Thanks Chris, I can agree with this. |
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| gedlee |
| quote: | Originally posted by fred76
Hi Earl,
Your kit webpage says that you use the DE250-16, which is the 16 ohm version of this driver(?). Is it a deliberate design choice to use 16 ohm versions? If so, for what reason/s? So if one is to source their own drivers (which I surmise are mostly 8 Ohms in the retail market), would a different set of crossover values be used?
Thank you. |
Yes of course its deliberate. The reason is that the voltage efficiency of the 8 ohm is too high so the higher Re helps. If you don't use exactly the same driver that the crossover was designed for it won't work properly. This is always the case. |
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| gedlee |
| We used the Eminence 12 HO with the shorting ring in the ESP12 because we thought (based on some early tests and published specs) it did not have a small dimple in the woofers passband that the 12TBX100 had. But when we got the bulk shipment they all had the same problem as the 12TBX100. If the prices are comparable then I would opt for the B&C, but as I recall the price that I get on the Eminence was quite a bit lower than the B&C and since it worked about the same the Eminence was attractive. But this reduction is not $100, more like $50. |
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| augerpro |
| quote: | Originally posted by gedlee
I've looked at their Neo woofers in the past. If weight is not an issue then the extra price did not seem justified to me. The 15NW76 does look very attractive, except that its efficiency may be too high to mate with the DE250. |
I'll be using the DE250 with your 10" waveguide, what is the sensitivity after it's EQ'ed flat? |
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| tinitus |
15NW76 does indeed look interesting, a bit high Fs and maybe a bit low Qts fore closed
How can a 100db woofer have too high sensitivity fore a 108db CD ?
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| gedlee |
| quote: | Originally posted by augerpro
I'll be using the DE250 with your 10" waveguide, what is the sensitivity after it's EQ'ed flat? |
It should be about 98 dB. That of course depends on the crossover. |
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| Sheldon |
| quote: | Originally posted by Patrick Bateman
The "real" Summa is a no-compromise design that mates a 15" waveguide & a 15" woofer. The achilles heel of the Summa is the woofer. There are only a handful of 15" woofers which can play into the midrange. The B&C 15TBX100 fits the bill, but it is E-X-P-E-N-S-I-V-E. |
I know that others have mentioned the 15" Lambda designs, now sold by AE. I can tell you from personal experience that mine play and measure very well. I have the Lambda Apollo motor TDX, and they are expensive too. But I would guess that the main difference between the Apollo and the single shorting ring would be at very high SPL levels, so the Apollo is likely overkill here.
Sheldon |
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| fred76 |
| quote: | Originally posted by gedlee
Yes of course its deliberate. The reason is that the voltage efficiency of the 8 ohm is too high so the higher Re helps. If you don't use exactly the same driver that the crossover was designed for it won't work properly. This is always the case. |
Thank you Earl... So if used with an 8 ohm woofer, the woofer gets most of the power.
Some Summa pics from an old thread I found online: http://www.audiocircle.com/circles/...p?topic=24627.0 |
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| MethMan |
| I have a pair of DE250 - 8ohms and Nathan uses 16 ohms. Does anybody know if there is a difference between 8ohm and 16ohm version except the coil? Is it interchangeable? |
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| peufeu |
| As I said before I am interested in the 15" version (is it the Abbey ?), anyway let's call this the "director's cut" version of the kit, lol, if the shipping problems to euroland can be solved... |
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| gedlee |
| quote: | Originally posted by MethMan
I have a pair of DE250 - 8ohms and Nathan uses 16 ohms. Does anybody know if there is a difference between 8ohm and 16ohm version except the coil? Is it interchangeable? |
They are identical except for the number of turns on the VC and the wire size. Same performance. But unfortunately they are not interchangable because of the crossover design. |
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| gedlee |
| quote: | Originally posted by peufeu
As I said before I am interested in the 15" version (is it the Abbey ?), anyway let's call this the "director's cut" version of the kit, lol, if the shipping problems to euroland can be solved... |
The Abbey has a 12" waveguide, the Abbey+ is a 12" woofer and 15" waveguide. There are no current plans for a Summa replacement. |
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