Budget tall mid-bass to sub speaker, to act as stand for LS50s

[EJ3]

For speakers I'm not going to power via Wiim Amp Ultra, I'm looking at true "dumb power" amp 3e A7 Mono

I'm also trying to understand taking 4ohm speakers already reco'd, wiring in parallel the pair is now 2ohm?

Dayton apparently designed for this with the RSS210HO-44

To get 4 OHM from two 4 Ohm loads (as I have each of my pair of dual 4 Ohm Voice coil 12" ported [tuned to 29 Hz] subs arranged) chose the second option:

And with a Stereo PROTON D 1200 summed mono (55 LPF, 70 HPF to each (1% distortion @ 40 HZ):
1100 watts RMS each.
So, do it right & you are not at 2 Ohms.
IF I wired the speakers for 2 Ohms:
I would have 1700 watts a channel (1 % distortion at 40 Hz)
In both cases the amp was run on an: Amplifier Dyno AD-1
This AMP is no joke (and some, such as mine) have a switch to run them in bridged mono mode (@ 4 Ohms, not 2 Ohms [unless you like replacing CAPS])

 

[john61ct]

Thanks for the wiring info.

PROTON D 1200 summed mono

That Proton "Dynamic Power on Demand" looks crazy good, must have monster caps!

I guess the D1200 surpasses even GFA-555 at 8ohm for high current peaks? Looks ideal for good headroom into the LS50s, except I need DC driven

posted query here

Any DC-powered amps work like Proton "Dynamic Power on Demand"?

DL1200 came up here: https://www.audiosciencereview.com/forum/index.php?threads/budget-tall-mid-bass-to-sub-speaker-to-act-as-stand-for-ls50s.63906/post-2478584 My top priority is SQ into nom. 8ohm but I need DC-powered. Looking for something with dynamic handling of current/power like this...

www.audiosciencereview.com

 

[john61ct]

I'm now thinking of assembling my "furniture wall" based on plywood cube units, fitting a grid based on the IKEA Kallax shelving system.

So the enclosures can now go to around a foot square at the face, sized to fit inside a 13-1/4" (33.5cm) height and width,

but their depth can go vary more or less than 15" (39cm) - more volume means deeper bass, right?

Still thinking driver baffle to the front, 2x passive radiators to each side.

Peerless SLS-P830668

Looks good! I know pricier, but compare Dayton Max-X MX10-22 ?

 

[EngineerNate]

If you’re willing to DIY I have designed a flat pack enclosure for the CSS SDX10 + 2X APR10 passive radiators meant to do just this. The SDX10 easily plays to 500hz or more. Happy to share the files.

 

[john61ct]

Thanks but that driver is way above my pay grade!

But I guess the cutout can be adjusted for a more plebian alternative. I only have Android not sure I can read your, what CAD / CNC files?

Have you got a link to a build thread or web page with details? If not, what are the outside dimensions?

 

[EJ3]

Thanks for the wiring info.

Too many folks don't get it right when it comes to the wiring. It's fortunately simple when viewed on a diagram rather than explained. But: the results are suddenly, MASSIVELY catastrophic when done wrong. So, I try to help keep amps out of the landfill.

 

[Mark185]

About 30 years ago, a company called Now Hear This (NHT) designed and sold a high end speaker that is basically what you are trying to recreate. It was the NHT 3.3 and I think it sold for about $4000 back then. It used a custom 6" mid bass driver crossed over to a very good 4" midrange made by Seas. That in turn was crossed over to a Seas soft dome tweeter that is no longer made. Actually none of these drivers are made any more.

NHT was famous for years for an LS50 clone they called the Super Zero. It is still sold today but I doubt it has anything in common with the original. Amir tested one a while ago and basically trashed it.

Recoton bought NHT and basically killed the company. I think they still exist today but none of the original designers remain. Story ends there except for one thing. An engineer that designed these speakers got permission from the new owners to liquidate the remaining inventory of raw drivers for pennies on the dollar and sell them to the DIY community. He posted on DIYAudio and sold everything. I was one of the lucky ones that got to purchase some of these drivers. A buddy and I bought a case of the 4" Seas midranges and about 10 of the 6" midbass drivers. We also purchased 10 of the 10" woofers used as the subwoofer section of another of their designs for home theater. These woofers had a very good long throw motor for the time and it is still good today although other designs have surpassed it. I built a dual 10" sub with 2 of those drivers and it is very very good.

Life got in the way and my buddy and I never built our 3.3 clones. I still have boxes of these drivers and I am finally starting to finish what I started. I have attached a post from DIYAudio from years ago that describes an approach to the midbass that you should find interesting. The author reduced the volume of the cabinet the 6" driver was in so that it had a Butterworth 12 dB/octave roll off around 100 Hz. He combined this with a 12 dB/octave active crossover to yield a 24 dB/octave Linkwitz Riley acoustic response. His design used passive components to crossover to the midrange at about 350 Hz. I am going to do this with DSP. The attached pdf may give you some ideas about how to DIY what you want to do.

 

[john61ct]

Interesting stuff!

My target box size now is around 12x12 face, can be over 15" long if needed

and looking for optimising from say 200 Hz maybe higher at the top, down to as low as practical F3 so maybe true sub(s) not even needed?

My understanding is that going to a bigger say 10" driver will make this easier / more effective?

Still looking at side facing PRs rather than ported.

 

[EngineerNate]

Here's my project. Hoping to start assembly on the cabs tonight.

Passive Radiator CSS SDX10 Design and Build

I have had an SDX10 for ages that started life in my car. I haven't had a car system for ages so it's sat in my shop in a sealed car box for a long time. I finally have a little space for a system so I'm giving it a proper home. After corresponding with Dan at CSS I decided on a dual passive...

www.audiosciencereview.com

 

[tineared]

About 30 years ago, a company called Now Hear This (NHT) designed and sold a high end speaker that is basically what you are trying to recreate. It was the NHT 3.3 and I think it sold for about $4000 back then. It used a custom 6" mid bass driver crossed over to a very good 4" midrange made by Seas. That in turn was crossed over to a Seas soft dome tweeter that is no longer made. Actually none of these drivers are made any more.

NHT was famous for years for an LS50 clone they called the Super Zero. It is still sold today but I doubt it has anything in common with the original. Amir tested one a while ago and basically trashed it.

Recoton bought NHT and basically killed the company. I think they still exist today but none of the original designers remain. Story ends there except for one thing. An engineer that designed these speakers got permission from the new owners to liquidate the remaining inventory of raw drivers for pennies on the dollar and sell them to the DIY community. He posted on DIYAudio and sold everything. I was one of the lucky ones that got to purchase some of these drivers. A buddy and I bought a case of the 4" Seas midranges and about 10 of the 6" midbass drivers. We also purchased 10 of the 10" woofers used as the subwoofer section of another of their designs for home theater. These woofers had a very good long throw motor for the time and it is still good today although other designs have surpassed it. I built a dual 10" sub with 2 of those drivers and it is very very good.

Life got in the way and my buddy and I never built our 3.3 clones. I still have boxes of these drivers and I am finally starting to finish what I started. I have attached a post from DIYAudio from years ago that describes an approach to the midbass that you should find interesting. The author reduced the volume of the cabinet the 6" driver was in so that it had a Butterworth 12 dB/octave roll off around 100 Hz. He combined this with a 12 dB/octave active crossover to yield a 24 dB/octave Linkwitz Riley acoustic response. His design used passive components to crossover to the midrange at about 350 Hz. I am going to do this with DSP. The attached pdf may give you some ideas about how to DIY what you want to do.

I still have my 3.3s and all the drivers still perform exceedingly well
Ken Kantor went all out on those speakers and I'm glad he did

 

[john61ct]

Here's my project. Hoping to start assembly on the cabs tonight.

Passive Radiator CSS SDX10 Design and Build

I have had an SDX10 for ages that started life in my car. I haven't had a car system for ages so it's sat in my shop in a sealed car box for a long time. I finally have a little space for a system so I'm giving it a proper home. After corresponding with Dan at CSS I decided on a dual passive...

www.audiosciencereview.com

Nice driver for this use case but pricey for me. Can you reco a less expensive one that still goes up nicely past 300Hz ?

Also, with a short height enclosure and dual side PRs box reinforcement is tricky thinking just full height corner blocks?

Should I go to say 1" MDF?

 

[EngineerNate]

Nice driver for this use case but pricey for me. Can you reco a less expensive one that still goes up nicely past 300Hz ?

Also, with a short height enclosure and dual side PRs box reinforcement is tricky thinking just full height corner blocks?

Should I go to say 1" MDF?

In my case there's a center X support and the walls are all double thickness Baltic birch. It's not going anywhere

You could do the powered driver up high and do two PRs below it front and back or side to side if you're worried about bracing a thinner cabinet.

I'd look into the Dayton reference HF subs plus their passive radiators. They won't play as loud or low as the CSS but IIRC they're pretty smooth up top.

 

[john61ct]

Sorry but the form factor for the enclosure outside is a fixed given - as stated, maximum 12x12" face, the depth could go past 15" if necessary. So no over/under, and limited room for bracing.

I may even put a protective wire grill outside over the side PRs, since the boxen will be stored slotted into 13x13"(interior) IKEA Kallax shelving when not in use.

So to the extent those cages protrude, the enclosure width needs to be reduced.

By double thickness, what is the total? Isn't MDF stiffer than ply?

You could do the powered driver up high and do two PRs below it front and back or side to side if you're worried about bracing a thinner cabinet.

 

[EngineerNate]

Baltic birch is real heavy. It's much denser than hardware store plywood.

MDF is very dense but not particularly strong. I don't know about stiffness.

By double I mean every face is 2x 3/4” sheets bonded together for 1.5” total thickness.

 

[john61ct]

By double I mean every face is 2x 3/4” sheets bonded together for 1.5” total thickness.

Wow heavy duty!! probably overkill for 1-foot cubish

Maybe 1/4" Baltic as an outer skin, 1/2 or 3/4" MDF inside, well bonded together.

Thicker maybe if side PRs mounted recessed so no protective cage needed?

 

[kyuu]

If you're gonna go nuts, why not put a layer of green glue (or equivalent) between the two layers of material to get some constrained layer damping going?

 

[john61ct]

Thanks, interesting I'll look into that.

you need two crossovers on each channel

I'm looking at multi-channel DSP, or xovers built into amps, likely better value than this unit, but what say you (or anyone) about it?

DS18 xohv

Pre-Amp With Crossover For High Volt Amplifier

This Pre-Amplifier’s 2-Channel capabilities allow you to connect 2 or more amplifiers for insane results! Increase your signal strength today with the XOHV!

ds18.com

I thought interesting anyway...

XM3 6 channels all in one, better value

3-Way Active Crossover With Line Driver

Shop online DS18 XM3 3-Way Active Crossover with Sub-Level Control. 3-way active crossover. FREE SHIPPING on all US Orders.

ds18.com

EDIT: but not suitable for this use case, LPF won't go below 250Hz on the basstands, and no subsonic HPF for the true-subs if needed

Edit2: similar misfit choices for
XM5 5-Way Active Crossover https://ds18.com/products/ds18-xm5-5-way-pro-audio-crossover