New Home for the BG Ribbons - Part 27

[chasw98]

That would be kind of expensive compared with some conventional braces...
:W

Apparently Thomas has enough lying around to use it for paint!

:E :rofl:

[CraigJ]

Paint it with Viagra...... :B

Once you get those twelve drivers upright, they ain't going to move, trust me. No need for major support When playing music, you'll wonder if they're on.

[JonMarsh]

I don't know, with that much flex in the panel, "getting it up" may be the challenge... :W

[ThomasW]

Chuck's baffles will each be reinforced with two pieces of tall 1"X1"x1/8" alu angle. One leg of each piece of metal will be inset to saw kerfs cut into the baffle. A rear metal gusset will be attached to each piece of angle.

[Johnloudb]

Thomas,

I got the aluminum angle part. Kerfs, gusset, mean nothing to me. Don't bother, I'll wait for pics.

Chuck, Is this a test baffle or the real deal?

[Hank]

Well, when I eventually get mine built, I plan to use the 1 1/4" radius roundover bit that I bought a couple years ago :T I think the large radius will look nice (after veneering with rosewood of course).

12 1 rack space 100wch amps

We may have a new candidate for the title "Mr. Overkill".

[Evil Twin]

Yes, I recall the acquisition of similar tooling by our advanced Research and Development group a few years ago- when enclosed line arrays were being investigated. A tool not to be employed lightly without good cause and care.

[chasw98]

Chuck, Is this a test baffle or the real deal?

For the moment, all I have are 24 Peerless drivers so I am going to 'play' with what I have. Until I get an RD75 or some Neo8's, I won't be sure whether this panel will adapt to mounting the other units to it (I think it will). But it is a great way to test some ideas out. And all I will have wasted is $25 on a sheet of MDF. I ordered 50 feet of 6061-T6 aluminum 1 X 1 X 1/8 inch angle today for less than $30 to experiment with bracing.

And of course I will have to wire them up and take a quick measurement and hear them! :B

[Dennis H]

I ordered 50 feet of 6061-T6 aluminum 1 X 1 X 1/8 inch angle today for less than $30 to experiment with bracing.

That will be about as stiff as a 1"x1" piece of oak.

[JonMarsh]

I agree with Dennis- that is to say, not that stiff. Think spines....




Not THAT deep, but you get the idea...

[chasw98]

The 1 X 1 will be used to go vertically on either side of the 12 woofers to stiffen the baffle, not to hold it upright. I plan on running an 1/8" saw kerf for 80 inches up and down the rear of the baffle and then drill and tap to hold the aluminum to the baffle. SOrt of in a sandwich way.

I am still working on a way to brace a 7 foot tall unit with a rear spine.....

[Hank]

A tool not to be employed lightly without good cause and care.

AND used in a table-mounted router with the speed control turned WAY down.

Chuck, IMO, if you go with RD75, as Thomas pointed out, it will provide plenty of bracing/stiffness to your baffle. If you really want metal bracing, I humbly suggest you use steel rather than aluminum. I've been thinking about how to avoid the big ugly spine thing, but so far, no ideas that would result in support that's less ugly :roll:

[chasw98]

I chose aluminum for its non rusting characteristics (I'm in Florida). Even treating steel with a non rusting agent or paint never lasts very long down here. The aluminum struts in the back of the baffle will also give me pick off points to be able to tap and thread for some sort of spine assembly. Right now this is all exploratory.

I will have to say, I have not come up with a way to avoid some ugly spine either. If you have an idea, let me know. I look at the Jamo and can replicate that, but it is $pendy.

[Hank]

If you like the Jamo spine you could duplicate it in MDF and then laminate it with veneer. WilsonArt makes metal laminates: http://samples.wilsonart.com/c-8-decorative-metals.aspx I have 3 or 4 samples and they are very nice. Light colors to perhaps contrast with your veneer species, or darker colors for a complementary blend.
Whether you use aluminum or laminated/veneered MDF for your spine, you don't need to do the dual/split spine like Jamo. You could do a single which should be strong enough.

[Bear]

Have you considered using something like Unistrut as a spine material? It's not the prettiest of mettalurgical creations, but with some wood flanker pieces, that can be mitigated, and it has the advantage of being able to be cinched tight to the baffle. I'm not sure about how it might resonate, though (might "sing" a bit much). It's strong stuff, widely available and relatively cheap.

Bill

[augerpro]

Tom how goes the tweeter testing? BG Neo3 still a go for this new LA?

[ThomasW]

Tom how goes the tweeter testing?

It's real easy to find poor sounding WG/horns....

BG Neo3 still a go for this new LA?

Yep thanks to hearing them in your system..... :T

The idea is to have as low cost a fullrange line as is 'reasonable' (no cheap closeout $0.69 drivers, or weird planar super-tweeters need apply).

So we're starting off with good quality cone drivers, and Neo 3 tweeters. Since I have a spare pair of RD75 those will go in my system. It's cheaper to use a line of Neo8's than the RD series, so Jon is going to evaluate a line of Neo8's vs his RD50's. Based on that comparison we'll make a recommendations about which to use as the mid, the RD series or the Neo8.

[augerpro]

So...you do plan on this being a design for others to build? Just wondering if using the Peerless Nomex is a good idea, given the cost will be back up to $55 or so when the buyout is over? Not that there is a better driver even at that price, but it definitley makes a value judgement in order. You know I like the Nomex though, I'd probably still use it over the Dayton Ref if that was the main competitor.

I have a Geddes' Abbey clone idea I just can't shake, so I may be down in couple months with some new "babies" to show off.

[ThomasW]

Yes the idea is to have a 'reasonable' cost high-end system for people to copy.

My original plan was to use the RS180-4 for the line. And to that end I have 8 sitting here for experimentation...

I jumped on the Nomex simply because they were so cheap, have the truncated frame.

For the line array and it's 650Hz XO point it maybe a toss up. I do like the 'detail' provided by the metal cones. The Nomex are so neutral/dry/polite sometimes I think something is missing.

[JonMarsh]

Yeah, I'll probably be stuck using the Seas ER18NRX or something similar, as the pipeline for these Peerless is probably pretty much sucked dry for now! :W

I do like the 'detail' provided by the metal cones. The Nomex are so neutral/dry/polite sometimes I think something is missing.

Yeah, the distortion is! (linear distortion, and perhaps a touch of harmonic amplification). :B

[Amphiprion]

The Peerless poly cones aren't half bad either, ya know

[Hank]

Thanks to Mark hauling them to Austin yesterday, I'm the proud papa of 25 Peerless 830875's. What a bargain! If enough more of you guys wanted to buy them, would PE let you do a group buy?
Someone mentioned NEO 8's in a thread quite a while ago, and I thought about asking Jon and Thomas if they're as good as the BG's since a line of them would be less expensive, but my feeble memory lost the thought.
I mentioned to Mark that I was considering active crossovers and he offered design input. My main power amp now is the 200 W/channel Acurus, so two channels could drive the two Peerless lines. Any suggestions for amps for the RD's/NEO 8's?

[Amphiprion]

A series/parallel combo for the Peerless line arrays in going to be so sensitive that a 50W/8ohm amp should be fine. I'd keep the Acurus for the RD75s. If you go active and cross around 400Hz you'll furthermore be dividing the audio spectrum near the middle of the power spectrum for most types of music, which theoretically decreases the requirements for each sections power amplifier by a factor of four (each amp only has to swing 1/2 the peak voltage compared to running a single amp full range).

[Hank]

Hmmm...the RD's sensitivity is 88dB 1W/1M and the NEO 8's is 92.5dB 2.83V/1M. The NEO's wouldn't need the Acurus either, but it's a clean amp, so I suppose I'll use it. For the Peerless, I do have a couple of tube power amps that would be interesting to try

[Amphiprion]

If you hook up some cheap Chinese tube amp to the woofer array, I'm going to have to beat you with a sack full of MOSFETs

Actually, at the old job, we DID have a sack full of mosfets. It was called the "Bag o' Fets". We weren't very organized.

[ThomasW]

If enough more of you guys wanted to buy them, would PE let you do a group buy?

PE had a limited number since they bought a closeout lot.

Madisound will give a $10 quantity discount but that means $44ea.

Someone mentioned NEO 8's in a thread quite a while ago, and I thought about asking Jon and Thomas if they're as good as the BG's since a line of them would be less expensive,

I'm sending Jon 1/2 dozen of the Neo8pdr. He's going to measure and A/B them against his RD50. Then there will be a recommendation regarding which to buy. This will be in a month or two.

[chasw98]

Someone mentioned NEO 8's in a thread quite a while ago, and I thought about asking Jon and Thomas if they're as good as the BG's since a line of them would be less expensive, but my feeble memory lost the thought.

I am waiting on the results of the boys to say whether to go RD or Neo myself. And the cash is in hand ready to go!

I mentioned to Mark that I was considering active crossovers and he offered design input. My main power amp now is the 200 W/channel Acurus, so two channels could drive the two Peerless lines. Any suggestions for amps for the RD's/NEO 8's?

I built and refined/designed some very quiet, low distortion, balanced, Marchand based 3 way active crossovers for Thomas and myself. I have since found some information for using Sallen Key filters which might be a better filter and quite programmable in an analog way to use with the tall guys.

Are you really thinking of putting a tube amp on the bottom end? Why not the mid or highs? I will probably end up putting my Aragon 8008BB on the bottom end and then go find some nice used ex-high end 100w/ch amplifier for the mids. And I always have my rebuilt mosfet Hafler 220's sitting around I can use!

How close are you to buying the RD's or the Neo's Hank?

Chuck

[JonMarsh]

You know, guys, I have to wonder if you aren't setting your sights a little low in the materials and sculptural impact department... perhaps something like this is more the target to aim for?

:W





OK, so maybe I'd leave the casters off, and put a good spiking platform on instead, but you get the idea....

[ThomasW]

Simply buying 3/4" plate-glass is just a little on the $pendy side. Having it machined and all cut edges polished would be out of my pay grade...since they charge by the inch to do this.... 8O

[Bear]

Any speculation about a supercooled fluid would act as a launch platform, though? I've always been curious whether this was yet another example of the sculpture getting out ahead of the actual function.

Bill

[Johnloudb]

Well, I think I'm also going with a spine for my dipole array. I was going to do a frame but I don't have a welding torch and fabrication is expensive. Cutting a spine seems much more simple.

[Evil Twin]

Any speculation about a supercooled fluid would act as a launch platform, though? I've always been curious whether this was yet another example of the sculpture getting out ahead of the actual function.

Bill

The closest practical implementation we've found in the Imperial ADRL is liquid carbonite impregnation of MDF- the power required to maintain the modified system in stasis is actually fairly minimal, due to some recent advances in quantum stabilization and power converters, and will generally meet Energy Star standby power specifications.

[Amphiprion]

Well, it's been one week. I expect Hank either to have his baffles fully built and assembled, or a new car in the garage.

Which is it Hank? I've got Praxis ready to go.

[chasw98]

C'mon Hank! Where are you? I have just picked up 22 Neo3-PDR's from the National Sales Manager of Meridian for $20 each shipped. Moving forward, now to see whether to go Neo8 or RD75...................

[JonMarsh]

I can tell you're in high gear, Chuck! I should have some measurements on the older Neo8 this weekend, with luck- SPS FR won't be so relevant, but distortion should be. OTOH, I don't have any distortion data for RD50's- won't have time to do that for a month or so- probably middle of June. Will have to haul them out of storage and build some reasonable baffles.

What are you guys trying to do, get me building my long hinted about, never started Saint-Saens?

[Johnloudb]

What are you guys trying to do, get me building my long hinted about, never started Saint-Saens?

Jon, that would great! :T Saint-Saens? Would be an RD50 paired with six 8" woofers, and some ribbon tweets or Neo3's? No pressure though. :B

[JonMarsh]

well, I have the RD's, I have the bazillion Fountek Ribbon tweeters, it's the midbass that's still up in the air... if I could find an 8" that measured as nice on the bottom end as a Seas ER18RNX, I think I'd be set. I'd like to stay just three way, not go as far as Victor did. Don't know if that's feasible. Though RS270's... Hmmmm, efficient enough to use a fair amount of passive EQ... only have two of those, though.

Somedays I feel like the Noah of loudspeaker drivers. :W

[Hank]

Okay, okay, I do have a high-pressure, high-tech, high-responsibility job, ya know. Never mind, no sympathy here.

Chuck: I am ready to buy when Evil Twin determines which B-G units are best - I have a bit of tax refund money left. When I mentioned active xovers to Mark, I told him that Marchand seems to have sold quite a lot and have been around for years, so they might be good candidates. Mark said he might like to take a stab at a design. He does like digital challenges.

Mark: I have a new car in the garage: 2010 Hyundai Genesis Coupe, Track model. Runs like a bat outta hell, corners flat and rides like a race car! :driving: K-town has sprung a good one on the Japanese boys. :T

Jon: Yes, I've been pushing for the Saint Saens for at least a year. Seems like you're getting the hint

[chasw98]

I should have some measurements on the older Neo8 this weekend, with luck- SPS FR won't be so relevant, but distortion should be. OTOH, I don't have any distortion data for RD50's- won't have time to do that for a month or so- probably middle of June. Will have to haul them out of storage and build some reasonable baffles.

What are you guys trying to do, get me building my long hinted about, never started Saint-Saens?

That would be great if you got some measurements on the Neo8's. I am assuming with the projects in life you fill up your days with that you might not have the readily available time or energy to play with the Neo8's.... And it is hard for me to bribe you when I am so far away! ;x( :T OTOH, if you measured the 8's and did some quick listening, Tom and you could probably come to a conclusion as to whether one is really better than the other or they are very close and you would be splitting hairs to choose one or the other. It is not like I am going to continue looking for a great planar driver because I don't know or haven't found any others under consideration. So exact comprehensive measurements taken for days at a time are not needed, just enough to define a difference between the two. Exacting measurements can be completed once a choice has been made.

But what would it take to bribe you.... anyway? pair of Ayre monoblocks, 100% original NSX, a Ducati 1098? Hmmm.

[JonMarsh]

But what would it take to bribe you.... anyway? pair of Ayre monoblocks, 100% original NSX, a Ducati 1098? Hmmm.

you're getting pretty warm... maybe it's just my boss you need to bribe, so I can get more time off! Because I'd settle for just a good used 98 or 99 VFR 800, and some time to work on my NSX!

I have most of the parts to convert this:





to this,



but also with the R type rear spoiler.




ET's supposed to do the wrenching work, but you know how I have him busy at the moment.

[Hank]

Chuck, if you've got that kind of money, we need to be friends :^x

I honestly do not see the need for 8" drivers. The Peerless 6.5's should be PLENTY of Sd. I also am not convinced to go RD75 rather than RD50. Why go excessive rather than just focus on obtaining world-class music reproduction?

...oh no, I just realized what a stupid question THAT was on THIS forum :stupid2: :banghead:
Admin: you might want to sticky that question as THE question to not ask around here ops:

[JonMarsh]

Chuck, if you've got that kind of money, we need to be friends :^x

I honestly do not see the need for 8" drivers. The Peerless 6.5's should be PLENTY of Sd. I also am not convinced to go RD75 rather than RD50. Why go excessive rather than just focus on obtaining world-class music reproduction?

...oh no, I just realized what a stupid question THAT was on THIS forum :stupid2: :banghead:
Admin: you might want to sticky that question as THE question to not ask around here ops:

Hank, Hank, c'mon now man, think where you're posting...

Besides, ask ANY woman, and she'll tell you a line array is ipso facto proof of going excessive....

[Hank]

Yes, how utterly stupid of me to have asked THAT question. Practical logic has NO place here. My excuse is that I wasn't focused enough. I've been on an hour and a half phone conference with a gaggle of PhD's and listening to pixel, LED performance, white points, condenser lens and glass rod optics, and..... :Z

Okay, here's to practical logic :2guns:

[ThomasW]

Chuck, if you've got that kind of money, we need to be friends :^x

I honestly do not see the need for 8" drivers.

Hank,

Chuck's referring to the Neo8 drivers not 8" cone drivers.

[Dennis H]

One thing that comes to mind about the RD50/75 vs. an array of Neo8s is the sensitivity. The RDs aren't all that sensitive but you should be able to juggle your series parallel arrangements if all three lines were arrays so the sensitivities all matched up -- assuming you wanted to build a passive crossover and avoid the emperor's wrath.