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

[john61ct]

Almost won an eBay auction for a pair of cheap Cerwin-Vega S12. The shipping cost is crazy!

At under $400 delivered for new is really a bit high for my budget, and a bit bulkier than I want.

The SL8 are an inch too shallow 8-(

 

[kemmler3D]

Pretty much have to DIY this idea, but it's probably the easiest thing to make as far as speakers go.

Yes, if you're only looking at 200hz or so, being able to ignore directivity simplifies things a lot.

 

[john61ct]

If it turns out I need a real sub as well, yes I might only use one.

But this thread's topic / project is definitely stereo, directivity / imaging is needed at the higher end of the intended mid bass range maybe 350Hz or higher

and the primary function is the speaker stands one.

 

[ChrisG]

I don't need to go THAT narrow, I am very impressed by Tang Bang's reputation online, maybe their 6.5" is strong enough vs 8" ?

So a 9" face external width?

Even 11" width is OK, or whatever minimum to use a good 8" woofer.

So, given that, SB Acoustics 5"x8" oval woofers seem like an unnecessary compromise?

not sure how SB23CACS45-4 compares...

Fair enough. I thought you might want to match the baffle width of the LS50. I'll admit that I haven't checked the dimensions of that particular speaker.

The Tang Band 6.5" mini-sub drivers need a rocket up them to produce useful output. Figure just below 80dB@1w once baffle-step is factored in. I've hit mine with 500w peaks (Behringer iNuke 6000 hitting -6dB occasionally) per driver, and they were starting to get good at that kind of level.
Also, the motor is so heavily optimised towards excursion, that IMO the distortion performance is mediocre.

If you're happy with an 8" driver (NB: you could probably get the baffle width below 10" without trying too hard), then I'd be looking at the Dayton RSS210HO. They'll be fine up to about 1kHz - the cone is hard aluminium, so the cone breakup is severe, but high in frequency.
Softer paper cones might have resonances down in the hundreds-of-Hz range.
Add in healthy mechanical power handling, demodulation rings etc etc etc, and a couple of those 8"s would do a really nice job.

 

[Matt34]

I built one of these back in the day. *Not my thread, not even sure if that driver is still a available, but could help with ideas.

Reed Exodus Anarchy 25hz Tapped Horn

Well here it is..Exodus Anarchy 6.5" 25hz tapped horn designed by yours truly, LilMike. Much appreciation to lilmike for sliding me the plans and letting me build it early before he measured it and made them available. I Got the pleasure of hanging with lilmike and getting this sub measured...

www.avsforum.com

 

[john61ct]

> the baffle width of the LS50. I'll admit that I haven't checked the dimensions of that particular speaker.

7.87 x 11.02 x 11.89 inches

aka footprint 7.9" W (200 mm) x 11" D (280.5 mm)

and 11.9" (302mm) high

> Tang Band 6.5" mini-sub drivers need a rocket up them to produce useful output

that's OK I think

> heavily optimised towards excursion

My understanding is that down in those bass frequencies, our ears are pretty forgiving.

Also using lots of Passive Radiator excursion capacity will help, weight-tunable to boost SPL down lower. Planning on using the (maybe larger > 11") sides for those.


> Dayton RSS210HO. They'll be fine up to about 1kHz - the cone is hard aluminium, so the cone breakup is severe

They would be filtered to never get past 5-600hz, 2-300Hz more likely

Add in healthy mechanical power handling, demodulation rings

Sorry no idea what those mean, will google later


> an 8" driver

Front baffle width ~ 10" will be fine too

IF that Dayton will get me much greater SPL efficiency AND get it down to lower frequencies

driven by the likes of Fosi V3 Mono, or 3e A7 Mono (call it 150-200W)

also important - clean tight bass? I def do not want boomy!

 

[john61ct]

Reed Exodus Anarchy 25hz Tapped Horn

Well here it is..Exodus Anarchy 6.5" 25hz tapped horn designed by yours truly, LilMike. Much appreciation to lilmike for sliding me the plans and letting me build it early before he measured it and made them available. I Got the pleasure of hanging with lilmike and getting this sub measured...

www.avsforum.com

Very interesting! Drivers indeed hard to find, and that enclosure is a bit too deep and tall for my current thinking.

 

[john61ct]

@ChrisG Maybe RSS210HF-4 "High-Fidelity" version?

since SQ above 80Hz is a higher priority than SPL at the bottom of the sub range

> They would be filtered to never get past 5-600hz, 2-300Hz more likely

> also important - clean tight bass? I def do not want boomy!

 

[ChrisG]

The HF version makes tradeoffs that will give lower distortion, but IIRC requires a larger cabinet. Both are good drivers which will be a step up from the TB 6.5" mini-sub.

"Boomy" bass is a function of speaker + room combined: if the room has a big 50Hz peak, anything that reaches down to 50Hz will sound boomy. People often blame bass-reflex designs for "boomy" bass, but that's because they tend to be designed to be approximately flat into the LF, which means any room modes are strongly activated. A sealed box might sound "tight" because it's -12dB@50Hz, so that peak might get the LF response to somewhere-near-flat again.


FWIW, our hearing system is actually most sensitive to distortion at low frequencies: look at the Equal Loudness Contours. They tell us that our hearing is pretty insensitive to very-low-frequencies, but their harmonics are easy to hear.
Fortunately, music often contains harmonics anyway, which can sometimes help to mask a driver that's adding some distortion.


With regards to the upper cutoff of this project, the reason I pointed out that the Dayton 8"s are looking fine up to ~1kHz is because typical crossover slopes are finite: if you choose a 300Hz crossover, the driver doesn't just stop working at 301Hz. It's a gradual rolloff. It might be 3dB down at 300Hz, 15dB down at 600Hz and 27dB down at 1.2kHz.
That's a 12dB/oct Butterworth crossover. A 24dB/oct Linkwitz-Riley would be -6dB@300Hz, -30dB@600Hz, [email protected]. The LR24 crossover, however, would introduce more phase shift in the summed response, so then you might want to look at FIR processing to linearise the phase of the system, whether that's a global filter or just using FIR crossovers. Depends on the hardware you're using etc.

There's more I could write about crossover design if you're interested, but for now I think it's worth sticking to figuring out drive units etc.


FWIW, I built the Anarchy tapped horn using the Tang Band 6.5" mini-sub. Fun box, but large for a 6.5" driver. A 12" would've fit in that volume.

 

[Digital_Thor]

I tried a few different woofers, when I had the LS50 Meta, and think that you can get good results with a couple of Dayton RS180 woofers.
Me and one of my friends put three 60 liter closed boxes next to each other with speak-on plug on the rear, level matched them and swapped quickly between 2 x SB23NRX, 2 x Purifi PTT6.5X and 2xRS225. Not really easy to identify any real difference, when just used as a woofer from around 3-400Hz and down.
All done active and with only the room-gain-boom removed - since that is equal for all when it's purely room related - so we could easier hear if any difference was noticeable.
The only "better" woofer that I've ever tried - and use now - was the Satori WO24P, which is way too large and expensive for your project. So I feel confident that something like the Dayton properly, will fit you the best.

 

[john61ct]

There's more I could write about crossover design if you're interested, but for now I think it's worth sticking to figuring out drive units etc.

Well while I've gotcha

ICBM ...
let's use or create a separate thread for the finer points of crossover / pass filtering to keep this thread on the topic of speakers.

@Waxx @JohnnyNG @Flaesh @kyuu @chrispdx

here's a "branching thread wrt crossovers :

J

'Crossover / Bandpass for LS50 "Bass Stands" and HT/SYN'

Sep 7, 2025

To try to keep my "Budget tall mid-bass to sub speaker, to act as stand for LS50s" thread


limited to OTS products like Rythmik FM8, or on the DIY side, driver selection and enclosure issues.

As pointed out there, my Outlaw ICBM will let me set a "high" crossover of 120Hz between the LS50s and these stereo bass stands, which is OK I guess so long as placement happens to work out wrt room modes.

If not, I will really want to bandpass...

• john61ct
• Replies: 43
• Forum: Speaker Reviews, Measurements and Discussion

 

[john61ct]

I tried a few different woofers, when I had the LS50 Meta, and think that you can get good results with a couple of Dayton RS180 woofers.

Good stuff!

I'm thinking maybe going with RSS210HF instead will MAYBE allow me to go without a "true sub" completely.

RS180 does not go as low, and its "clarity and detail higher up in the mid range" has a lot more overlap with the LS50s, that will get bandpassed away thus wasted?

If it turns out I do put in mono "true subs" for say <70Hz then I can see RS180 being just as good as RSS210HF maybe better?

 

[Digital_Thor]

Well... it all depends on the final setup.
How are you going to power this woofer? Mentioned already?
EQ?
The RSS210 is great, but I thought you wanted it narrow and cheap
Subwoofers can be put in more "elegant" places in the room - maybe even hidden, making the mains stand free and optimal for stereo, and this also makes for more bass sources, which in return makes it way easier to smooth out the response overall around the listening position.
Everything from around 150Hz and down, is made up from a complex mix of reflections in your room, so you can easily have quite big dips and tops in the response, by just moving 30-40cm.

 

[john61ct]

How are you going to power this woofer?

Well there may end up being 4 of them, maybe a dozen boxen in total. So a gaggle of power amps, low end stereo for satellite, big monoblocs for the thirsty ones, all DC powered .

Everything discussed in these threads is at the pre-amp line level I think.


> Everything from around 150Hz and down, is made up from a complex mix of reflections in your room, so you can easily have quite big dips and tops in the response, by just moving 30-40cm.

Amazing! EQ including room correction can be discussed in the bass management / crossover thread.

> Subwoofers can be put in more "elegant" places in the room - maybe even hidden, making the mains stand free and optimal for stereo, and this also makes for more bass sources, which in return makes it way easier to smooth out the response overall around the listening position.

Yes but here the primary goal is getting stands for the LS50s, secondary is augmenting the mid-bass range. The possibility of foregoing true subs completely is just a possible side benefit, roll of the dice I admit.


> The RSS210 is great, but I thought you wanted it narrow and cheap

A face baffle big enough for an 8" driver is fine.

If I can go without "true subs" that's worth spending $120-200 more per pair I think?

But you're right I was not aware the difference was so great. A PR design is already adding costs too.

Maybe best to just save up over time for those Rythmik FM8s

or settle for Polk T50 or Cerwin-Vega S12...

 

[john61ct]

How are you going to power this woofer? Mentioned already?
EQ?

Thinking of standardising on Wiim Amp Ultra as a "dumb power amp" with free extras included.

Hoping they can do at least the crossover HPF / LPF, also per speaker type calibration EQ

if not also helping with room acoustics EQ

J

Post in thread 'Wiim announce WiiM Amp Ultra'

Sep 8, 2025

> when using it as a power amp for outside source signals

The included EQ feature could handle crossover filtering separate for each speaker pair, right?

How to connect the multiple Wiim's in the same room / system? Analog patches or

digital Linkplay over Ethernet, Group Lead handles the source, rest are Followers.

• john61ct

 

[john61ct]

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

That puts out 400real watts going into 2ohm
So maybe y'all have new reco's, 6-8" woofer speakers and maybe subwoofer also that can handle such high wattage to produce outdoor-level SPL?

I see TangBand W6-2090 but only rated for 30W ???
I like the waterproof / extreme heat design for when in a mobile context...

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

I'd prefer 2x RSS210HF-4 to get cleaner sound, more mid-bass flexibility (they're spec'd up to 1000Hz ? )

Should Scanspeak still be in the running?

 

[john61ct]

Note that I could go fully sealed, but for high SPL I'm looking at a triple displacement passive radiator design, not ported.

And I take it tuning with weights might help obviate the need for separate true subwoofers, unless needed for placement flexibility to handle room modes?

 

[john61ct]

FWIW, our hearing system is actually most sensitive to distortion at low frequencies

That seems to be contradicted by this?

How Much Distortion Can We Hear With Music?

How much distortion can we hear with music? An experimental study at Axiom.

www.axiomaudio.com

"our detection threshold for noise (made up of harmonically related and non-harmonically related test tones) is practically non-existent at low frequencies"

"Even in the mid-bass at 280 Hz and lower, the noise can be around -14 dB (20% distortion), about half as loud as the music itself, before we hear it."

 

[ChrisG]

I'm not convinced of that study's methodology: they're introducing "pure" (as pure as loudspeakers will produce) sine tones via an additional loudspeaker during music playback, and asking test subjects to indicate when something seems to have gone "wrong" with the music playback.

This does not seem representative of loudspeaker nonlinearity.


Given how easy it is to deliberately introduce some harmonic distortion into a recorded signal, I feel like it would have been pretty trivial to test harmonic distortion detection much more directly.

 

[melomane13]

Peerless SLS-P830668 ferrite magnet motor with aluminium shorting ring for improved distortion performance.
used by linkwitz in pluto subwoofer https://www.linkwitzlab.com/Pluto/subwoofer.htm
Use in a sealed enclosure of 20-70 liters; equalization required.

Nominal impedance 8 ohm
Dimensional category 10.5 inch
Frequency coverage type Sub, Low, Midbass
sensitivity 88.8 dB
Nominal power handling 70 W
Bandwidth 30÷2000 Hz
Fs 34.5 Hz
Qes 0.65
Qms 7.28
Qts 0.59
Vas 62.94 L
Xmax ±10.92 mm
Xvar, Xmech, Xlim ±19.15 mm