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Best bass from a closed-box compact standmount speaker?

Arindal

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Dear community,

Was wondering if you could recommend a compact, closed-box standmount speaker of 15-20l cabinet volume that delivers satisfying bass? Satisfying I mean a reasonable compromise of depth, max SPL, subjective punch without any reflex, ported or compound design. It should be a closed-box.

Passive or active, studio or hi-fi, off the shelf or DIY, does not matter. So far, Kii Audio Seven has been recommended to me as a benchmark. Neumann KH310A does also enjoy a good reputation, but this unit would be exceeding the volume limit.

Thanks!
 
Devialet Phantom?

Thanks a lot, did not think of this one, as my experience with earlier iterations was not overly positive. Devialet Phantom Gold is maybe the unit to go for.

What brings you to the specific and limited cabinet volume?

The idea is to replace speakers with similar volume which are not really satisfying in terms of bass.
 
Compromises. Do you want high SPL but maybe not go that deep in frequency, maybe down to 50Hz-70Hz or do you want to go deeper in frequency but sacrifice a little SPL?

Hofmann's Iron Law


Hofmann theorized that when woofers are mounted in speaker enclosures, the designer would have to accept that there are three trade-offs. Hofmann argued that the designer had "...three parameters that cannot all be had at the same time. They are low-bass reproduction, small (enclosure) size, and high (output) sensitivity." Hofmann stated that designers could pick two of these three parameters, but in doing so, it would compromise the third parameter.[5]

For example, a designer who wants good, deep low-frequency sound and high sensitivity can obtain these goals, but they will have to use a large speaker enclosure. Similarly, if a designer is forced by space constraints to use a very small cabinet, and they aim to get good, deep low-frequency sound, the sensitivity will be compromised (i.e., a small cabinet with deep bass would need a very powerful amplifier).
Edit:
BUT if you have a driver with really high power handling, preferably combined with high sensitivity, you can use that driver in a sealed box and force lower bass through a Linkwitz transform. Then you take away the high sensitivity, eat it so to speak, to get down in frequency. Lower sensitivity requires more power for the same SPL, so a high power handling is then good to have from the start. :)

Linkwitz transform:
Screenshot_2024-12-19_153842.jpg


Edit 2:

@Arindal you said: Passive or active, studio or hi-fi, off the shelf or DIY, does not matter

Ok DIY then. This:
LaVoce SSF102.50L in the volume of sealed box you are considering might be something. Good power handling. Suitable VAS. Together with it in a three-way construction. Then it is a whole different ball game to get bass, mid and tweeter designed to work well together, so I'll leave that aspect aside, but the bass driver itself may suit your wishes.:)
You don't have to go all the way DIY three-way speakers. Two bass boxes with Lavoce SSF102.50L that operate up to around 300 Hz-500Hz above that some good commercial two-way speakers. Crossover solution bass boxes - speakers are needed of course plus separate amps to power the units.

Parts Express about it :

The Lavoce SSF102.50L is the perfect candidate for a high-powered woofer or subwoofer application. Boasting 400 watts of RMS power, 34mm P-P maximum excursion and a 2.5” diameter CCAW voice coil, this woofer is ideal for chest thumping bass for home, studio or small PA applications.
Key Features

  • 2.5” copper clad aluminum voice coil for exceptional power handling
  • 800 watt program power handling (400WRMS)
  • Long throw design, 34mm (1.3”) P-P excursion
  • FEM optimized motor and suspensions
  • Long lasting rubber surround
  • Heavy duty treated paper cone

Parts Express Staff Recommended Enclosure Volume
Sealed Volume 0.7ft³
(20 liters)
Sealed F3 60.2Hz

Maybe with Linkwitz transform for lower frequency? If you can accept the compromises it entails.


Screenshot_2025-04-14_101930.jpgScreenshot_2025-04-14_101910.jpg
 
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Thanks for the recommendation, was thinking about something like a big woofer working in a compact sealed enclosure.

Parts Express Staff Recommended Enclosure Volume
Sealed Volume 0.7ft³
(20 liters)
Sealed F3 60.2Hz

Does not really match the standard calculation. My results come closer to a 75Hz resonance in a 20l CB which is net volume, so with the magnets plus midrange enclosure, amp chamber and outer walls, I would be north of 30l. There is sufficient reserve for any method of boost or expansion of the lower cutoff-frequency (Linkwitz, Chebicheff high-pass or whatever), but achieving a 35Hz lower cutoff f in reality would mean a boost of +4...12dB there where the energy in the music is.

But the idea is good, will search for an 8" sub driver with better-matching parameters which might reach lower in a 15l net enclosure and require less boost.

Do you want high SPL but maybe not go that deep in frequency, maybe down to 50Hz-70Hz or do you want to go deeper in frequency but sacrifice a little SPL?

Definitely lower than the current 42Hz, and no vented box anymore. I´d rather go for decent max SPL and sacrifice money on lots of amp power. The compromise with Devialet Gold or Kii Seven is in my understanding the best way to go.
 
Was wondering if you could recommend a compact, closed-box standmount speaker of 15-20l cabinet volume that delivers satisfying bass? Satisfying I mean …
That‘s a quite subjective approach. There are guidelines, though.

If box size is limited, a port is mostly not advisable. Modern drivers bring with them high excursion capabilities. A port would, when exploiting those (costly) merits, exhibit wind noise. The latter is, to me subjectively, very much more annoying than harmonic distortion (anecdotal). Watch the connection between tuning frequency, extension, and foremost excursion below the tuning frequency, and the spectral properties of contemporary music. Cutoff filter, limiter?

You‘ll come to use a sealed design with digital equalization, eventually.

The rest is automatic. Size, power, internal air compression (!) are limiting output proportional to frequency. Dial in your needs. Coming back to answer your initial question directly: what do you define as satisfying in numbers? Then the decision making will be easy, otherwise, alas, impossible.
 
A speaker with Purifi woofer and passive radiators is pretty nice. Gives a better natural deep bass output for passive speakers than sealed - if you're going active, such speakers will usually be able to EQ the bass to get that deeper response from sealed.

Of course, you can always fiddle with DSP on your passives + amp + DSP. Watch that excursion though
 
Thanks for the recommendation, was thinking about something like a big woofer working in a compact sealed enclosure.
A big woofer/ driver in a small box can be, let's say 18 inches in a.. The gross internal volume, before accounting for driver displacement, is approximately 3 cubic feet (~85 liters), which is about 25% smaller than the typical minimum enclosure size recommended for a standard 18" car/home audio subwoofer.

That I think that's a good example of that. Bigger volume than you can imagine, I know. I just thought of that DIY subwoofer regarding big woofer/driver- small box in general. Damn nice DIY. Feel free to check out the pictures in the thread: :)


Does not really match the standard calculation. My results come closer to a 75Hz resonance in a 20l CB which is net volume, so with the magnets plus midrange enclosure, amp chamber and outer walls, I would be north of 30l. There is sufficient reserve for any method of boost or expansion of the lower cutoff-frequency (Linkwitz, Chebicheff high-pass or whatever), but achieving a 35Hz lower cutoff f in reality would mean a boost of +4...12dB there where the energy in the music is.
Aha, I didn't do any calculations, I just took the information as it was.:)


But the idea is good, will search for an 8" sub driver with better-matching parameters which might reach lower in a 15l net enclosure and require less boost.



Definitely lower than the current 42Hz, and no vented box anymore. I´d rather go for decent max SPL and sacrifice money on lots of amp power. The compromise with Devialet Gold or Kii Seven is in my understanding the best way to go.
Maybe hmm. Dayton RSS210HO-8 in that case?
That bass driver seems to go down quite far in frequency for its size. SPL should be okay, or rather it depends entirely on what you want? decent max SPL..?

Power Handling (RMS) 300 watts Power Handling (max)
500 watts gives good potential for SPL BUT Sensitivity 83.5 dB @ 2.83V/1m and you can end up at square 1 again.
In any case, it seems to fit well in smaller boxes.
Screenshot_2025-04-14_112921.jpgScreenshot_2025-04-14_112933.jpg

 
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Dayton RSS210HO-8 in that case?
That bass driver seems to go down quite far in frequency for its size.

That one is indeed offering almost the perfect parameters for a compact sealed enclosure. You can tune it down to 50something Hz in less than 10l, which requires minimum boost below the resonance and is expected to deliver good kick bass at the same time. The only (manageable) downside is its 8 Ohms nominal impedance and low sensitivity at given voltage, so ones needs an amp delivering crazy voltage.

Thanks a lot!

Port or passive radiator is out of the equation anyways.
 
A big woofer/ driver in a small box can be, let's say 18 inches in a.. ..
Coming back to this for one reason: of course the design has to be a three-way. Is there enough baffle space left to mount the midrange? The restrictions will also ask for compromises in regard to directivity (wide), edge reflections and nasty interference of the drivers.


Only as a sloppy side note, Thiele/Small parameters are nearly insignificant here. In case you come to design towards a dedicated target, in terms of power, excursion, extension … you‘ll see.

Wasn‘t this topic best located in the diy section, more knowledgeable people?
 
Coming back to this for one reason: of course the design has to be a three-way. Is there enough baffle space left to mount the midrange? The restrictions will also ask for compromises in regard to directivity (wide), edge reflections and nasty interference of the drivers.


Only as a sloppy side note, Thiele/Small parameters are nearly insignificant here. In case you come to design towards a dedicated target, in terms of power, excursion, extension … you‘ll see.

Wasn‘t this topic best located in the diy section, more knowledgeable people?
Finding the right bass woffer/driver for your needs. In that process making compromises on box size, SPL, power handling...price? or as you said ...a dedicated target, in terms of power, excursion, extension …and so on is one thing. A completely different thing is if you're going to DIY a good three-way speaker. Then you need a lot of calculations, thinking, preferably test boxes plus measurements, then more calculations, new test boxes (different shapes) and so on. That if it's going to be really good speakers, that is.:)
 
Finding the right bass woffer/driver for your needs. In that process making compromises on box size, SPL, power handling...price? or as you said ...a dedicated target, in terms of power, excursion, extension …and so on is one thing. A completely different thing is if you're going to DIY a good three-way speaker. Then you need a lot of calculations, thinking, preferably test boxes plus measurements, then more calculations, new test boxes (different shapes) and so on. That if it's going to be really good speakers, that is.:)
@Arindal lately expressed high interest in the details of directivity. I wonder if the restrictions posed by this attempt here would allow for a good choice of directivity in general, let alone the finer details.

I‘m pretty much sure the design target for bass is easily matched. As I put it, it is more or less automatic what to expect, and what not. Question only is, if that would be satisfactory.

I diy‘ed a smaller box of this kind recently, only half the size. When I listened to a percussion piece, man, this nearly subsonic wooooof impossible with ported, quite satisfying, and conversely it doesn‘t need to be loud. Nice, works.

Only directivity is restricted to ‚wide‘, and a bit less accurate. Who cares?
 
A speaker with Purifi woofer and passive radiators is pretty nice. Gives a better natural deep bass output for passive speakers than sealed - if you're going active, such speakers will usually be able to EQ the bass to get that deeper response from sealed.

Of course, you can always fiddle with DSP on your passives + amp + DSP. Watch that excursion though
The Buchardt E50 (or Anniversary 10 as the active option) sounds like what you’re describing. Of course it is brand new and not cheap! And it sounds like OP doesn’t want port or passive radiators.
 
Definitely lower than the current 42Hz, and no vented box anymore. I´d rather go for decent max SPL and sacrifice money on lots of amp power.
It may be needed. Or it may really be needed.

A few years ago I had an SVS SB-12 NSD subwoofer. A sealed subwoofer box, around 1.8ft³, 50 liter cavity, volume. A 12 inch subwoofer driver. With 400 watts RMS, 800 watts peak power output.
Okay, it had a clipping indicator and already at just a little more than normal listening volume (I didn't measure the SPL) the amp started to drive into clipping. The clipping light started flashing.
I played with it in a medium sized room, at that time with bass heavy music. Probably a bass dynamic recording.

Not just me who noted it:

The SVS SB12-NSD is an affordable 400watt sealed powered subwoofer with a 12” aluminum cone driver in a tiny sealed cabinet to produce satisfying and exceptionally well rounded bass. Small but potent.

Best suited to smaller spaces and/or moderate playback levels



Besides that, a good sub. :)

In any case, a poorly constructed BR/ported bass box vs a sealed one, a sealed one wins. A well constructed BR with its extra bass boost that construction gives vs a sealed one is a completely different match.
 
NHT Classic 3

18 liter, closed box. Matches what you are looking for, sounds fantastic.

I see the Kii is almost $8k. You're probably not interested in a $350 solution.
 
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The Buchardt E50 (or Anniversary 10 as the active option) sounds like what you’re describing. Of course it is brand new and not cheap! And it sounds like OP doesn’t want port or passive radiators.
Radiant clarity 6.2
March Audio Sointuva AWG
AsciLabs A6B or similar, in the future
There was a studio monitor with 8" Purifi I think at one stage.

Also doesn't pushing huge excursion in a tiny sealed box create it's own problem with air pressure linearity?
 
Thank you all! Speakers employing passive radiators or hardly reaching 70Hz, are not really a match here. An off-the-shelf product would be preferred, for experimental reasons, Kii Seven and Devialet Phantom Gold can be given a try. Any rivals to these two known to you? If it does not work, DIY will be the alternative.

Having good, low-reaching and fairly loud bass out of a compact, sealed enclosure does naturally require lots of power. The speaker is not for me in this case, but this price will be paid gladly.

´´Even logic must give way to physics´ (Mr. Spock)
 
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