Possible to DIY the B&W 800 Diamond? - Page 4

That tweeter doesn't do so well once it has a few watts running through it.

What are you basing that assessment on?

Double

Measurements.

IME, and that of most acoustical engineers, what you hear has got a lot to do with what you see. I know that if I saw a receipt that said $12k on it I had better hear a difference, and that if I didn't know what I do about how speakers work I'd have no trouble convincing myself that I did. I'm positive that Wilson makes his cabs as ugly as he does intentionally, as the average more money than brains buyer of same would think anything that expensive that's also that ugly must sound good, placing function over form.

Not sure that's enough support to show it would fall on its face crossed at 2.5kHz

Face, I'm pretty sure that's my measurement. But it's not of the tweeter that Jay proposes. That's the CSS LD25x.

I do agree however that I've done a lot of testing like that, and little 25mm domes can't take more than about 8 watts before the lines start to diverge.

For those wondering what that graph means, the blue line is an on axis measurement of the tweeter on a 12" x 12" baffle with a typical cap and coil high pass. Something like 6uF and 0.5mH, can't remember exactly. The measurement software output is reduced to -24db and my preamp is adjusted until I have 2.83V at the amp terminals. That's the blue line. I then increase the software ouput 3db at a time and measure each time. The consecutive sweeps are then overlaid by -3db, -6db, -9db, etc. What happens to most domes is what you see in the red graph. They compress above a certain point. And below a certain point the spew so much distortion they have added ouput. Very non-linear. That particular graph is -24 vs -3db. So a 21db difference. If you wanted to listen that loud (very loud), it would be a totally unacceptable tweeter imo. And it's a good little dome. Very few domes have stood up to my torture test. The SB29RDCN managed ok. Every compression driver I've done it to has performed flawlessly.

PS that little spike at 20kHz is a sound card calibration issue I've fixed.

We're also talking about copying a system using a dome tweeter, so it's a moot point. Thank you for the clarification though.

Well, the system uses a dome, but it's also not a run of the mill dome. It's hard to say how that dome would compare to the SS D2608, LD25x, SB29, or any other. I'd give B&W the benefit of the doubt and say it would do ok in those compression tests. I think the DIY'er would be best of loading a $500 dome into a 6" waveguide and crossing around 1750hz if they wanted to beat the B&W in performance. The tweeter really is the highlight of the 800D. IMHO.

I think I have to agree. I like my inexpensive, powerfull amps just fine. In my listening experience, i am alwasy underwhelmed with high ticket items. As an "el-cheapo" , something must perform worlds beyond to justify some of the prices, and when they don't it dissapoints. If you set the bar low and jump over it, you look good...when you set the bar high and don't reach it, it looks very bad. That is just the way I justify my experience in my head.

I stopped giving hifi companies the benefit of the doubt a long time ago.

If you want to start at the top and work your way down I'd probably go with this for a tweeter:
http://www.parts-express.com/pedocs/specs/276-412-aurum-cantus-g3-specifications.pdf

Maybe a pair of these for midbasses:
http://www.parts-express.com/pedocs/specs/296-440-aurum-cantus-ac12050ck-specifications.pdf

And horn load one of these for the lows:
http://www.parts-express.com/pedocs/specs/296-438-aurum-cantus-ac-250sw-specifications.pdf

The 96dB sensitivity would enable you to use a nice tube amp, paid for with the money you saved versus the B&W.

im building a
1 bayma tpl-150h b/c they cost a lot
1 ae 12m possibly a very good woofer
2 Dayton Audio UM12-22 b/c they look pretty
2 ae 18'' pr for 15-18hz tune somewhere around there depending on roomgain.

box is 16.5x25x50.5. 1.5'' mdf on all sides + bracing a seprate box for mid / highs as small as i can make it making it in a few days so i don't know for sure.
xo @ 100hz / 1200hz

hopefully 15-19khz flat 96db/1watt

also going to make the baffle for the ae12m / beyma removable and back mount every thing and make a baffle for using ae12m + a seos 24 with some ridiculously expensive cd

all active with a $300 class d amp :0 simi diy amp and a ep4k for the subs

Well said!

I understand the coice of tone with amp/speaker guitar as I'm in line with the leslie for organ sound but how can you reproduce all theese sounds! you need a transducer that will reprodure all different sounds corretly without adding it's own color!

For ezample: play a recorded voice trough a Marshall amp;) or trough a Leslie! Sound different? Why? The receipe is in the pudding!

Sounds like a recieipe for success

I do love my TPL-150.

Penngray a while back tried duplicating one of the 800 series B&W's. Looked really good but stopped building because other things or something. I dont recall but he had a lot of trial and error and it would be a good read if trying to build one. I like my setup better than any B&W but would prefer their construction as to mine. Much prettier. And Bill's suggestion would be an awesome setup also. I might have to try that combo.
Edited by chrapladm - 1/26/13 at 4:43pm

Not to be too silly, but seeing how people build so many other things out of Legos, it would be funny if someone built a Lego 800D. I'm sure it's possible

Has anyone posted a link to the measurements done on the 800D by Stereophile? If I remember correctly, the 800D did not measure that well. With that being said, I just want to point out that I find it very interesting that so many people think it sounds so good but yet measure so bad. Like I stated previously, this just goes to show that measuring flat, and sounding completely neutral without any added coloration, is not always going to sound the best when compared to speakers such as the B&W 800D, which have been voiced and designed to be pleasing to the listeners as their number one priority over just measuring flat.

I have hear many speakers that measured flat, including the Salk Songtowers, and Ascend Sierra-1's, both EQ'd flat for movies and music, and although they measure so much better than the 800D, the later still sounds like one of my favorite speakers at any price range!

The Stereophile measurements came up earlier in the thread. Here's the link: http://www.stereophile.com/content/bampw-800-diamond-loudspeaker-measurements

For the most part they loved the 800D, the bump in the treble provoked a rare gripe from Stereophile: "If there was any fault to be found in the 800 Diamond, it was the revealing treble of that diamond tweeter."

My take is that the target audience for the 800D is wealthy and older so a typical buyer might have lost a bit of their high-frequency hearing and probably decorates their home with thick rugs and luxurious fabrics in addition to sound absorption panels and such, so the 'bump' was engineered into the 800D to compensate, to bring it closer to playing 'perceptually flat' to the target buyer - BTW this is pure speculation on my behalf.


Edited by imagic - 1/27/13 at 6:18am

Show me a speaker that they panned for having an average result for an outrageous price and I'll be able to die knowing that I really have seen everything.

They have nice things to say about one of the cheapest speakers out there, Dayton's $40/pair bookshelf - actually on sale for $29.95 right now. Stereophile liked the Daytons enough to bless them with the usual kind words (To cherry pick for a moment): "Listening to "The Nightcaller," from Flying Lotus's excellent new Until the Quiet Comes (LP, Warp WARP230), I heard an impressively large soundstage, good image separation, and a very fine sense of momentum and flow, the up-tempo track moving steadily along with no hint of temporal distortions." - If they are willing to say that about the Daytons, I guess they would say just about anything if the speaker costs between 100-10,000X more.





Edited by imagic - 1/27/13 at 11:26am

"Show me a speaker that they panned for having an average result for an outrageous price and I'll be able to die knowing that I really have seen everything."

yeah, that and all the high dollar advertisers' speakers as well.

advertising-based revenue model and objective performance assessments just don't go together. they can't.

+1. I once bought a Renault based on it's being named the 'Motor Trend Import Car of the Year'. I dumped it at 20k miles after replacing two clutches and a cam. Worst car I ever owned.

Here is my PV horn rig vs my B&W. Listen for yourself.
It's level matched and powered by the same 1000watt amp.

Obviously a horn loaded 1.5" with two 15's is going to be more efficient than two 7" and one 1" in a Nautilus tube. But the PV sounds soo bad it sounds like a "speaker" singing rather than a "human" singing; this is what I'm talking about. I'd rather sacrifice a little efficiency and SPL to gain that nirvana Hi-Fi sound.
If I need to entertain a crowd of drunk people needing to have their ears blasted off, that's when I use the horns if I want to enjoy the sound, I use my B&W's
IMO, the two speakers sound worlds apart and are clearly gear for different purposes.
You are free to draw your own conclusions of course, but this is mine, having A/B compared such systems side-by-side.
When I hear something with higher SQ than B&W 800's, I will make sure I let everyone know about it. Until then, I'm keeping my mains as-is.

Anyone want to explain what any of that gibberish means? What language is that anyway? And some people not only read that without spewing their tea, but actually defend the practice as well?

Those Peavey speakers are just about the 'cheapest' sounding P.A. speakers you can buy (no offense). I am only familiar with 'that sound' from local bands playing at events. That's because they are literally cheap. Like anything else, if you spend more you can get more. A higher-end pair of EAW, EV, QSC, JBL, Mackie... they will sound better than those Peavey towers. Even so, if you were to open up the Peaveys and improve the inside of the enclosure by adding bracing and additional stuffing, you can get better sound out of them. You are listening to a lot of cabinet resonance and reflection. Have you tried putting the Peavey into your actual system with the sound absorption/diffuser treatments? I'm sure that makes a difference, too.

Edited by imagic - 1/27/13 at 11:27pm

Temporal Distortion: "A temporal distortion is a warp in the spacetime continuum, which can oftentimes be associated with the phenomenon of time travel. Temporal distortions can often be detected via tachyon particles, which are created as a side effect."

http://en.memory-alpha.org/wiki/Temporal_distortion

So rest assured, the Daytons do not emit black holes when playing music. Not even a hint.

Edited by imagic - 1/28/13 at 5:18am

Those Peavey's aren't really a good example of what a 1.5 cd / 15 can do.
My Denovo-360 4pi's would sound much better

Since when does high efficiency mean that a speaker automatically is worse / not considered Hi-Fi?

Really, you might as well be comparing a Kia to a Ferrari. Make that Peavey a Meyer of even half the price of the BW and the BW will come up very short.