Large high efficiency WMTMW speaker project

[Brett]

As some of you may know, I've been a long time horn fan, having at one time a large fully front loaded horn system of my own design, with corner loaded LABhorn subs and modified KHorns as rears.

Stupidly, I took a job interstate and dismantled the system and sold off most of the enclosures. As I look like moving back there soon, I want to build a new system that equals the performance of the previous monster, removes some of its faults and hopefully takes less space.

I'm after high efficiency, low dynamic compression, low distortion, excellent sonics, no glaring faults and easier integration than multiple large format horns whilst not giving away much in sensitivity. I've been using KEF 104/2's for the last two years and am looking to keep the coherence and 'integrity' of these beauties (they'll become my bedroom speakers) but with the dynamics and ease of large horns. There is no substitute for cubic inches.

Happy for any/all constructive suggestions on system design, enclosure, crossover, tuning etc as what I set out below is only the first iteration of the 'paper' design so far, even though I have been mulling it over for a while.
I'm happy to measure and tinker for a while to get it right, but am looking for input from others to minimise the development curve.

System will be a combined music/HT with about a 50% duty ratio between the two.

Music is mainly rock and some jazz and classical. Sources will be TT, CD, DVD, AM/FM radio, PC server (MAudio 24/192), Pioneer HT receiver via pre outs and Studer R2R. Preamp / selector is my own hybrid tube / S&B TVC that is awaiting a case and some more relays to complete.

The room is very large, and cathedral ceiling (~5.2m) for about 60%, then drops back down to standard 2.5m for the open plan kitchen and dining room, about 18x8m total. There is no real partition between these areas, except for a large inbuilt garden enclosure that's maybe 600mm high and runs across the space parallel with the change in ceiling height. Mains will be placed in front of the garden (which will hide some of the electronics) with the sub manifolds exiting on the vertical just behind and above and will face into the cathedral roofed section. The speaker's won't be placed symmetrically with the room axis, but it's an all-in-one area, for music, movies, reading, socialising etc so some compromises need to be made. Room is heavy rammed earth foundation, thick slab floor, rendered double brick with lots of windows and double drapes which are quite heavy.

--------------------------------------------------------------------------------------

Mains

Initial inspiration came from these beauties;
http://www.audioheritage.org/vbullet...ad.php?t=12126
I pretty much agree with everything else in the thread and like the overall design and approach, but I'll have a lot of difficulty with the cylindrical enclosures, and I reckon they look a bit ugly (no offense Jack). So, with that in mind, aesthetically, these are closer to what I'm looking at, but WMTMW.
http://www.audioheritage.org/vbullet...2390&highlight

I'll start at the HF and work down as I have the drivers.

HF: BMS4590 with some mods, on a flare the same as Jack Bouska's above. A friend has said he can turn the flares, and I have the drivers (since 2002) and like them.
http://www.audioheritage.org/vbullet...93&postcount=3

MF: Say 150~300-1kHz, mounted in small sealed Q=0.5 formatube sub enclosures.
The JBL 2020H is my fave candidate so far.
Any other suggestions gladly accepted as I'll need to source the JBLs secondhand and it may take a while to score 4. I like the huge efficiency, low dynamic compression and the ease that the large format JBL's I've heard have.

Other possible drivers include
JBL: 2123H, 2012H, 2020A, 2227H, 2220H , 2220A
18Sound: 12MB700, 12NDA520, 10NDA610, 10NDA520, 10MB600
B&C: Several candidates here that look possible, but no experience with any of them.
BMS: 12n810, 12n630, 12n820
Ciare: Several candidates here that look possible, but no experience with any of them.
Tone Tubby Alnico 12's (longshot)
Something else?

LF: Above about 50Hz from the IB subs, to around 300Hz clean, even if I cross lower. Sealed enclosures, 50Hz-3dB, q=0.5, with a Linkwitz transform if neccessary to get the LF response right and the enclosures to a decent size

Prime candidate at the moment is the 18Sound 15MB606 or 15MB650. The 18Sound neos are about 35% more expensive here, and I don't see much performance improvement for the money. But I'm willing to be proven wrong.
There are a heap of other drivers that could be used here. Please add suggestions and experiences with them.

One last 'oddball' option is a pair of P Audio C15 300MB (4/enclosure) mounted on the sides in a push-push configuration a la AR9. Strongly braced between the drivers with force cancelling rods, and perhaps even one of each pair reversed for push-pull if it'd make an improvement. I already have some of these drivers that were earmarked for another PA project, and can get the rest cheap. Not the greatest drivers in the world, but with 4/channel in this configuration, non linearities and dynamic compression should be low. Needs more enclosure volume, but I don't think internal volume will be the limiting dactor in this design. The M9500 project linked above is 430l / 15cu ft and I'm happy with that.

Amps will be UCD400 for the LF and my 12W PP tube amp above that, passively crossed, but if that proves too difficult I also have some 5W PP amps and could bi or tri amp with a tube active xover. The electronics are easiest for me to do, so it may end up active.

I'm happy to hear of experiences and suggestions for all the drivers mentioned above, and your reasons for why I should/should not use a particular model. As this is a fixed installation, I don't see the need for the extra expense of many of the Neos mentioned unless there is a clear performance improvement, assuming I can get them through the local distributor. If I need to import them, then the extra cost will likely be offset by lower shipping. I'm experienced with shipping items all over the world by post and couriers like Fedex, so I have a good idea of costs. Performance is the main issue here.

This is a big and expensive project, but I have a ton of other gear to sell which should offset all but maybe $A2500 for the speakers (depending on what I buy) and then the cost of the UCD modules. I have all the parts for the tube amps and xovers, but not many passive xover parts, so it may end up active due to cost and ease. Once completed and tweaked (and I tend to leave systems alone for long periods once they stabilise) it would take a new house with a custom listening /HT room to substantially better it, so the expense and effort is worthwhile to me. I'm patient and I expect it to take a couple of years to complete.
Do it right and do it once.

People regularly question my sanity - I'm used to it.

[Brett]

Just for completeness, here's the rest of the system.

Rears:

These will be a slight compromise, but I'm happy with that because I'll be using a lot of stuff I have on hand.
LF: 2 x LAB12 in push pull on the front panel. Sealed common enclosure, should be able to get 40Hz / -3dB in room, Q=0.5. Will juggle exact numbers later (lost my original sims in a ‘puter failure). Happy to use Linkwitz Xform if neccessary.
MF: EVM12L; Surprisingly good in initial tests in this application. More money on a new 'better' driver will not bring enough improvement for the added cost I reckon in a rear application, but should sound enough like the fronts not to draw attention to themselves.
HF: BMS 4552 on 18Sound XT1086. These are the only components I need to buy.
Xover: Active, slopes to be decided, but likely LR24 all round; 120Hz/1 - 1.2kHz. Nothing fancy, just solid opamp design.
Poweramps: LF: I'll use the Yamaha P7000S (700W/8R/ch) from my bass guitar rig, when not gigging.
Poweramps: MF/HF: Initially probably chipamps with UCD180's later.

These will be completed first as I have almost all the parts on hand and some enclosures that I got from an old theatre install that I can hack around to experiment with. When finalised, I'll make something that looks nice.

These will be tallish, but have a small footprint and have much better placement possibilities than the KHorns which have exactly one possibility which messes with the view from the bay window and means I can't put my fave 'reading' couch there. I don't care if they're as heavy as hell and will massively brace and damp them, using SL's 4" square area bracing rule. The EVM12's will be in a sub enclosure that I have some formatube for.

--------------------------------------------------------------------------------------

Subs

Drivers:16 x 15"in an IB in the loft space, above and just behind the mains. Will be mounted in 2 manifolds, in a 2x2, with the other 2x2 in push/pull. Drivers are being ordered.
Xover: Active LR24, around 50Hz, but will be tweaked.
Power: 2 x Quest QA3004, which I already have. Each 650W channel will power 4 drivers for 8R load. I know it's overkill, but I have them, and running them this way should mean the fans are never audible. Placing them in the loft isn't an option (way too hot in summer).
EQ: Behringer Feedback Destroyer.
All similar to
http://www.subwoofer-builder.com/ib.htm

30 litres of displacement should be enough I think, and compete with what the LABhorns did, without consuming the equivalent floorspace of 4 large refrigerators in my living room. Hell of a lot easier to build too!

[el`Ol]

What about a compression driver from 150Hz up?
http://cgi.ebay.de/ws/eBayISAPI.dll?...1295&rd=1&rd=1

[Brett]

Originally posted by el`Ol
What about a compression driver from 150Hz up?
http://cgi.ebay.de/ws/eBayISAPI.dll?...1295&rd=1&rd=1

Big flare, big cost and not the sensitivity of the 2x2020H.

Great suggestion though.

[el`Ol]

And what about the KL.L405 in OB?
http://cgi.ebay.de/2x-Siemens-KLANGF...QQcmdZViewItem

[Brett]

Originally posted by el`Ol
And what about the KL.L405 in OB?
http://cgi.ebay.de/2x-Siemens-KLANGF...QQcmdZViewItem

Never heard an OB that sounds right to me. Thanks for the suggestion, but not interested. I'd rather listen to stock 1974 KHorns.

[HiFiNutNut]

Hi, Brett,

I built your 12B4 preamp and liked it.

I have designed a pair of OB speakers with a sensitivity of 94dB with SPL capability of 120dB from 50Hz up that should suit your tube amp. I expect the risk of project failure is rather small after checking with quite a number of simulation software programs, all suggesting that they are going to do good. I am getting a carpenter to build them for me.

From our last exchange of a few emails more than a couple of years ago I knew you were moving to Sydney for a job. If you are still in Sydney in 3 months time then you could come and have a listen to the speakers and see if you like them. I estimate that they will be completed in a few months and by the end of the year the latest.

If you are selling your tube power amps and if they sound good on my speakers I would possibly get one. We can exchange something.

Send me a private message if you are interested.

Regards,
Bill

[HiFiNutNut]

Sorry Brett. I only found your post that you did not like OB after I posted my last one. I did not mean to offend. I clicked on REPLY then was interrupted so I posted possibly a hour later.

Regards,
Bill

[Brett]

Thanks for the suggestion and the offer of a listen too. I'll take you up on it. Even if I move I'm in and out of Sinny regularly. I haven't heard an OB I like yet, but am willing to have my mind changed, if it does the sort of dynamics I'm after. Not a big imaging and soundstaging fetishist.

I'm glad you like the pre, and will PM later re amps. Crook as a dog at the moment.

[Brett]

Originally posted by Brett
Rears:

These will be a slight compromise, but I'm happy with that because I'll be using a lot of stuff I have on hand.
LF: 2 x LAB12 in push pull on the front panel. Sealed common enclosure, should be able to get 40Hz / -3dB in room, Q=0.5. Will juggle exact numbers later (lost my original sims in a ‘puter failure). Happy to use Linkwitz Xform if neccessary.
MF: EVM12L; Surprisingly good in initial tests in this application. More money on a new 'better' driver will not bring enough improvement for the added cost I reckon in a rear application, but should sound enough like the fronts not to draw attention to themselves.
HF: BMS 4552 on 18Sound XT1086. These are the only components I need to buy.
Xover: Active, slopes to be decided, but likely LR24 all round; 120Hz/1 - 1.2kHz. Nothing fancy, just solid opamp design.
Poweramps: LF: I'll use the Yamaha P7000S (700W/8R/ch) from my bass guitar rig, when not gigging.
Poweramps: MF/HF: Initially probably chipamps with UCD180's later.

I feel foolish replying to my own post, but after a long night where I was quite sick and unable to sleep, I did a ton of research and simulating of drivers. It appears the LABs may not work up to 175Hz as I wanted. So looking at what I might be able to get for them, and remembering that I have some new Beyma 15G40's that I'd intended to use elsewhere, I think I'll substitute these in instead. I won't be able to get the same LF response in a sealed cab, but in a ported SBB4 I get F3=63, Fb=37 in a 60 litre box, single driver. A pair / channel mounted push / pull isn't really much bigger than the same box with the LABs.

I'd use a flared port, possibly on the bottom, and because the sensitivity of a pair is closer to the EVM12, I may be able to do a simple-ish passive xover and just use one amp on the whole setup.