Horning Eufrodites - help needed with boomy bass

Hi Eufrodites' users,

Can anyone help me with solving a serious issue of boomy bass?
Speakers are about 7 months old.

Do they still need time to break in?
Room acoustics? at first I thought so but the boominess is even at very low levels of sound.
I play them mostly with Jadis JA100 and the Sati 520b from Horning too. Boominess is on both setups.

Help!!!! There's nothing more annoying than boomy bass. I just can't enjoy music anymore.

No doubt you have them placed a good distance from the rear and side walls and of course as required with all horns you surely have a large room.
Have you considered it may be speaker-room interaction?
Acoustic bass traps may solve your problem.
These speakers can generate significant bass energy, how large is your room?
Thanks Charles1dad,

Yap, that possibility of course has crossed my mind.
My room is about 5.5X7.5X3.0 meters.
Speakers are about 3m apart, 60 cms from the back wall and my listening spot is about 3 meters out.

I can also say that in the listening spot the issue is smaller although bass should be tighter. Outside of the spot, the bass is really annoying to my ears and as music is on a lot in the house, it's bothering.

Most of the bass issue is coming from the left side of the room.
The problem with bass traps is that my system is in a family living room and I already hijack a good portion of the room for my musical purposes, adding bass traps can make me even less popular with my dear ones.

Thoughts welcome.
Try Not to sit to close to the back wall. About 2m/7ft away from the back wall.

Hi there,
I have been a Horning owner for 15 months now. Before you do anything to your room ... don't!

So Horning's energize the room in a way few other speakers can (this is both good and bad).

My strongest hunch is that the speaker in that room in ITS current position is causing the problem.

Given that you can't turn the room 90 degrees (short wall to long wall placement or vice-versa) .... I would recommend you start to pull the speaker out a little or move it back a little. Same with toe in, and distance between the speakers. Little changes will change how nodes and standing waves buildup!

I had imaging and bass issues on the short wall, so I moved to the long wall. Then I had boomy bass issues for a while there as well (but the soundstage and depth were insanely huge) ... so I stuck with the long wall, threw in a few plants into the corners and around the inside of the Hornings (between the speakers) and it helped a lot, but the bass was still not tight enough. THEN, on a whim, one day I moved my left speaker (kept the same toe in) closer to the right one by about 1 cm ...and then ..everything clicked! deeper sound stage, super tight bass (everywhere). And if you are wondering ...I measured everything to be symmetric. All I can think of is that the multiple woofers in the back excite rooms and since most rooms are not 100% symmetric ...one side was exciting things more than the other side.

Try that and report back, if you can.

AND UNDER NO CIRCUMSTANCES should you use bass traps around the speaker! The back wall behind your ears is fine for that. Hornings are true dipoles and their soundstage is all behind the speakers .... bass traps will suck the life out of those speakers! If you want to break nodes up .... use plants in the corners ...you want reflection/diffusion ...not absorption!

BTW, the Sati 520 should make those speakers sing! I have the Puresound m845 and it really controls the speaker very very well! I came from KT-88's push pull with a lot more power and the speakers sounded "just ok". Goes to show synergy!

Good luck and keep us posted. We are here to help!

You make some very good suggestions and have experience with these speakers. I 'd agree maximize speaker placement (although it seems there are some practical living room limitations). If this is only a partial solution then proper bass traps are an option to quell excessive bass energy into the room. I believe that the Hornings can work successfully in this room with some effort, it's a very good speaker. Amuseb, have you considered a professional consultant, your system is worth it.
Thanks a lot Assad.
On a business trip this week, will do some trials when back home and report the outcome.

Charles1dad, regarding professional consultants, mmmm, if I knew one that wouldn't take me to bankruptcy and for little result (like many times consultants do), I would consider that.

Has anyone had any experience with resonators and their efficiency in untying nods?


So I've been moving the speakers in, out, more toe, less toe, slanted forward, etc, etc.
But the boominess is there all the time.
Very clearly the issue comes from the left side of the room. I'm not sure why. There's a glass door there leading to a corridor which some experts told me would be where the problems comes from but I've covered the door with 3 types of fabric and carpet and it changes absolutely nothing, nada, gurnisht, niente.
There's also a little wall of about 1 meter that comes into the room on the left side about 3 meters from the back wall which creates some kind of a so called "niche" there on the left and when I stand there the boominess is heavy.
When I stand next to the right speakers, there's no boominess at all.

It is so annoying, I can't even start telling you how much.
I don't even need my system to be the best in the world, all I want is just to listen to music which right now is very challenging.
I'm not into high end hifi for a long time but I have so far maybe 5 pairs of speakers in this room with never even a hint of boominess, and now this.

What can I do?
That`s why I had made the earlier suggestion that a good bass trap for absortion of the excess bass energy.Why not give it some consideration? Changing placement has not helped and I don`t believe your amplifiers are the issue either(certainly not the Horning amp).You have a significant investment in your components, a bit more to try some bass absorption seems reasonable.Have you emailed Tommy Horning for his input?
Try using mechanical grounding devices under your speakers and components they work. They direct mechanical resonace and energy stored within the component to ground. Less boom and blurr.. Tom
It sounds to me like the speakers are getting a lot more boundary reinforcement in your room than what the designer anticipated, and reducing the amount of bass they put out may be a lot easier than changing your room's acoustics.

I have zero experience with the Eufrodites, but eyeballing the speaker, I see four woofers and a big port, and the description sounds like it's a transmission line variant. You might try attenuating the port's output via damping materials. Open-cell foam, polyester batting, a bath towel, whatever you have on hand. The idea is to find out if this general approach makes a net improvement, and then you can fine tune it from there. You might get better results (tighter bass with decent impact) by solidly sealing off the ports completely, turning the bass system into a sealed box, perhaps even with that damping material inside.

That is a good idea for a ported speaker.If that does not work or if it partially solves the problem would some degree of bass absorption benefit him?
These have been around for 15 years or more and they work.

MB Quart had them as well as Audio Concepts



So further positioning trials have somewhat improved the boominess.
And then, following Duke's post, I stuffed towels into the woofers' ports and I think this is making an important contribution to the battle!
For sure, right now, I can listen to music and enjoy it.
Big step forward. Thanks a lot.

What material would be best to use for an appropriate stuffing?

Other than that, from the positioning trials I came to spread the speakers even further apart from each other which opened up the sound stage and brought in a lot of space between the instruments. So way to go for this collateral benefit.

Tom, how would you reckon the Variovent be installed in my speakers?
It seems that large speakers require a few of those. How would that be done, any idea?

Thanks a lot to all the contributors so far. It's helping a lot.

Regards from Paris.
Well there is a Paris Kentucky and I reckon the word reckon is used there many times a day as it is in Louisville, that other French name sake.

I'd have to ponder the variovent and how many and what size. That's probably more than just drilling a random hole I reckon. As far as material to place in the vent well that would be long hair sheep's wool.

Before you do any other mods you must mechanically ground your speakers. And after doing so the speakers and the grounding components will take a few days to settle in. There are several other enhanced grounding methods that could be applied to both the cabinet and the driver. All of which would improve performance and void the warranty. Tom
Tom, you reckon right, neither Kentucky nor Louisville is where base is.
Can you educate my layman self on what the mechanical grounding elements are?
Regards from the city of lights.
"What material would be best to use for an appropriate stuffing?"

I'm not sure. With the towel, what you did was add flow resistance to the port; you made it significantly harder for the low frequency energy to get out of the port. If the towel was filling the port completely, then you added a lot of flow resistance; the more airspace around it, the less flow resistance.

My suggestion is, trial and error. Bigger towel, smaller towel, see which is a step in the right direction. Maybe open-cell foam (when you "haaaaah" into the foam, can you feel the heat form your breath on the other side? If so, then it' open-cell foam), again I can't tell you how completely you should fill port, or how deep the foam should extend into the port.

Long-hair wool was mentioned. That's great for stuffing a transmission line, but imo the intention here is different - we're trying to reduce low bass output, rather than facilitate it. Unless you packed it tightly into a cloth bag and crammed it into the port - then, it would be behaving more as flow resistance than as gentle damping along the length of the line. Imo you can accomplish the same thing for less money with tightly packed polyester batting or fiberfill.

The variovent is itself a flow resistance device, and one with a rather strong flow resistance, maybe more like packing the port tightly with a towel than like open-cell foam. You'd want to turn the cabinet almost into a sealed box, with the only pathway between the inside and outside being through the variovent (which is dense fiberglass compressed inside a plastic housing that has airflow holes in it).

I've stuffed into the ports a couple of polyester pillows I have here under hand.
So far the impressions are that the more stuffed, the better it is for the bass control.
With this understanding, Duke, would you have any fine tuning to make on your recommendations above regarding the material to be used?

How about using better feet for the speakers? There are a few guys that make sort of dedicated such spikes.
Would that add to the gig?

I highly appreciate everybody's help here with bringing me back to enjoying my system.
It`s good to know that such a simple (and cheap) solution has led to this level of improvement.Turning your speaker into a partially sealed box is obviously effective. I`m glad you can enjoy your system now.
Listening along, I find that the stuffing of the ports also takes some good qualities away.
The music is less dynamic, the loss of bass is also making it be missed across the spectrum, overall the sound is more itchy and less musical.
Of course this is just with the two provisional pillows tucked in the cave.
Will check the recommended materials in different configurations to see how they do.
The Horning website is pretty lean of info and pictures. There was a model reviewed on 6 Moons way back and it appears that they have made an attempt to couple the speaker to the floor. You do not want to damp any speaker you want to couple the speaker and provide a specific direction for the resonant energy to travel to ground. In this case the floor. If you impede the flow of energy from the cabinet it will sound different and most likely worse.

You may have an EF5 tornado in a box and your room. The energy is trapped and is trying to make it's way out and you will not be able to stop that energy that you paid thousands for. Why would you want to do that? The end result should be to make a funnel cloud of that 2 mile wide tornado and channel that energy to earth because that is what it is trying to do now. You do not want to stop that flow but to steer that energy full speed ahead to ground. Make use of all that energy make it work to your advantage make it work in one direction. I hope these concepts are of some help.

I myself design and build products that enhance the mechanical grounding of musical instruments that touch the floor. I am also a member of a company that designs, builds and sells similar technology for home and commercial audio products. Tom
Yeah Tom, I figured you had something to offer in this domain.
Where can I see some more details of it?
BTW, I asked Tommy about the damping materials and shutting the bass ports, he said: "all the things you are thinking of doing is against the whole idea of the Eufrodites way of working".
Using absorbent material in the ports isn't the ideal, but if the Eufrodites' way of working isn't working for you and your room, then imo it's reasonable to try to find a solution that is a worthwhile net improvement.

I design speakers too, and most of my designs have user-adjustable ports, because I can't always reliably predict in advance what the room acoustic situation will be like, where the speakers will be positioned, and/or what the output impedance will be of amplifiers they might be used with. I have one customer (a single-ended triode amplifier manufacturer) who went all the way to plugging the ports on his speakers, so they are now sealed boxes. Yeah that theoretically goes against their "way of working", but it's what works best for him, his amps, and his room (speakers up against one wall, listening couch up against the opposite wall, so lots of boundary reinforcement).

As for optimizing the type and amount of damping material, I'm afraid it's a matter of trial and error, and a juggling of tradeoffs.

Even though Tommy's remark, I agree with your statement, Duke.
I'm continuing the research...
This is a long shot, so consider it just the ravings of an insomniac:

It is possible that the enclosure is a transmission line/tuned port hybrid of sorts, and if so, you might be able to tighten up the bottom end a bit by lowering the tuning frequency. One way to do so would be to reduce the cross-sectional area of the port over its entire length.

Remove the stuffing from the port, then measure how far the port extends into the box (horizontally). Cut several boards that long, and just wide enough to fit into the port. Stack enough such boards in the port to roughly cut its cross-sectional area in half.

If the box functions as a reflex box, we've just lowered the tuning frequency somewhat. And that just might be a better "fix" than stuffing the port with damping material. If the results seem promising, find the optimum number of boards by trial-and-error, and then if you want to, glue and/or screw the boards together to make a solid block, and maybe wrap the ends with electrical tape or some such to give you a snug, rattle-free friction fit.

Theaudiotweak's suggestion of improving the coupling between speaker and floor may work very well, I don't know, I have less experience with that approach. I don't see how it could do any harm (unlike the things I've recommended, which very well could be detrimental, especially in the wrong dosages... but at least they're easily reversible).

Your first step should be to couple the speaker and then wait a few days for the unit to find ground. Until you do this properly your retuning of the enclosure may lead down a path of continual frustrating results. There are ways to mechanically ground a ported speaker so that no internal damping material is needed but probably not now in your case without serious intrusion. Damping will reduce dynamics coupling will not. Tom
Tommy wasn't keen on the port damping approach apparently. Did he offer any suggestions for the bass issues you have? As the builder you'd think he knows this speaker better than anyone and could really help you.
Hi there and thanks again for all the inputs.

Duke, I hope it's not over me that you're run into those sleepless nights.

Tommy isn't making many suggestions. He just says it's very uncommon to have such issues with the Eufrodites.

Jefferey of High Water Sound, Horning's importer in the US, recommends using either Eden Sound feet or Symposium bases for the Eufrodites. His recommendation isn't just for solving boominess but is a generic one.
Does anyone have any experience with those products?

I have found that putting speakers on a Symposium shelf will reduce the tendency for bass to boom, particularly if the flooring is suspended (not on a solid concrete base) and made of wood. I use Svelte Shelves (the thinnest Symposium platform) which is less than an inch thick. Other platforms are much taller. I would not say that platforms are a "generic" positive, they can make some systems sound too dry if that is already the tendency of the system. In other words, you will have to experiment.

If booming is an issue, energy absorbing shelves or footers like those by Stillpoint (also energy absorbing, and not designed to couple the vibrational energy to the floor) will be of help.
It would be very interesting to compare the "absorbing" product to the "mechanical grounding" method to hear which is more effective in minimizing/eliminating the bass boom . I'd hope Mr. Horning would offer more input, who has more insight on this speaker than him?
"It would be very interesting to compare the "absorbing" product to the "mechanical grounding" method to hear which is more effective in minimizing/eliminating the bass boom."

It's not necessarily either/or; neither excludes the other.

Also, IF lowering the tuning frequency of the port by reducing its cross-sectional area (as described a few posts up) actually works, I think that approach holds out more promise than port-stuffing because it is less likely to have a downside.

Good morning from Paris.

I'm still not very clear about the what the "mechanical grounding" tweaks are. Can anyone give product examples for those and to the "absorbing" ones?

I'm also not 100% sure I understand the way the wood boards have to be inserted into the bass port. Can you clarify?
Does it matter which wood to use and what the thickness of the board should be?

Re Tommy, I've been in touch with him now for about 8 months and he usually does not provide many suggestions.

If one product`s purpose is to "absorb" or hinder vibrantion/resonance(attempting to isolate), this is different than "mechanical grounding"(MG). With MG there`s no attempt to absorb, rather you allow the vibration/resonance a rapid and complete exit channel to "gound" this energy into the floor.One seems opposite from the other.An example of the MG approach is the Star Sound system brass points and stands.
As described this is the approach to take. Like I said
previous until this is done any amount of retuning will be
masked by the fact that the speaker is Not grounded. Same
thing happens with a acoustic instrument that touches the
floor. In a cello that has increased grounding potential
there is a great reduction of or even the elimination of a
wolf tone. Increase the grounding potential and the
instrument grows in stature and texture before your eyes. The
instrument becomes even more resonant and "alive". I came
here to present ideas and not a product. I prefer for people
to find out on their own. Now that the name was dropped I
have to say I work with Star Sound. Tom
I've been reading this with much interest, and kind of surprised by the fact, that the solutions being offered, only address the speaker, as a source of the boominess.
From the OP description though, it seems pretty obvious, that there is a significant room- related issue.

"Very clearly the issue comes from the left side of the room. I'm not sure why. There's a glass door there leading to a corridor which some experts told me would be where the problems comes from but I've covered the door with 3 types of fabric and carpet and it changes absolutely nothing, nada, gurnisht, niente.
There's also a little wall of about 1 meter that comes into the room on the left side about 3 meters from the back wall which creates some kind of a so called "niche" there on the left and when I stand there the boominess is heavy.
When I stand next to the right speakers, there's no boominess at all"

Before you do anything with the speakers, I would try to address that bass buildup in the left part of your room.
Put some crude DIY bass traps in that space (roll of fiberglass insulation?) just to test the theory. If that alleviates the issue, then you are on the right path.
And after the room- related problem is addressed, only then you can play with the speaker port to fix some (if any) residual issues.
Cones with sharp points are intended to couple the speaker/stand to the floor so that energy is transferred to the floor. If that floor is sitting on something like a concrete foundation, this huge mass will dissipate the energy without that much being re-radiated as sound. If the flooring is wood suspended on floor beams, that might result in the floor itself acting as a kind of sounding board. This could exacerbate a problem with booming. Whether one approach is better or the other (absorption in a compliant pad, or the fooring doing the absorption) is something that has to be tried.

But, before even doing this kind of experiment, you should experiment with room placement. You can sort of do this by random movement, or use a more systematic approach. I sort of like the "Sumiko" approach which emphasizes proper bass balance. You can find directions on the internet. When using this approach it is amazing how a movement as small as one inch will dramatically change bass response.

The next thing I would try are bass traps in the corners of the room. The primary downside to bass traps is that they are often ugly and take up a lot of room. The lower the frequency that needs to be trapped, the bigger the trap that is needed. I use double stacks of 16" ASC tube traps myself and they do work well.

I have not tried equalization in my own system, but, I have heard it effectively used in some systems.

Good luck.
Everything mentioned are steps.The first step should be grounding the speaker. Until the grounding is done there will be no stable launch pad. As for the room itself geometric angles and shapes strategically placed will redirect low frequency and help with standing wave resonance. Tom
Bass traps were suggested early in this thead(there` no harm in trying them) to address room acoustics. There`s no reason why that and mechanical grounding can`t be done simultaneously,this is fundamental physics and the promblem can be solved.

If you listen near any boundary, floor, wall and even the ceiling you will hear more bass travel along those surfaces than travel down the more central areas of the room. The idea I suggest and one I use is to redirect the energy from those flat surfaces and scoop that energy into the central part of he room. Try to eliminate some or all 90 degree angles as mid bass punch and sound stage integration will be enhanced. Elimination of the 90's can look very cool as well.

I have some small portable angled units I put on the floor to reduce standing wave's that also add acoustic air to the performance. These can easily be added or subtracted when the family requests you to do so. Tom
Speaking of grounding speakers- I just wanted to share my personal experience, that doesn't necessarily will apply to any other speaker/system.
I have tried multiple approaches- spikes, cones (Mapleshade, Audiopoints, BDR, etc.), isolation platforms (Mapleshade maple blocks, Sistrum, Symposium, Herbie's), etc., etc.
Now my search is (hopefully) over- the best solution by far is Stillpoints Ultra 5s on Symposium Super Plus platform.
The results are simply amazing- increase in resolution, articulation. Very natural and relaxed at the same time presentaion, without any downside, as I experienced with other support systems.
The whole listening experience is at completely different level- I get involved in every single listening session, regardless of what is playing- something, that rarely happened before. And that's what counts.
Again, your experience might not replicate mine.
Should I mention how much I hated to pay the admission price? Absolutely ridiculous if you ask me! But the funny thing is- it was totally worth it.
"I'm also not 100% sure I understand the way the wood boards have to be inserted into the bass port. Can you clarify? Does it matter which wood to use and what the thickness of the board should be?"

Suppose the port is 150 mm tall by 200 mm wide by 300 mm deep. And suppose you have access to 18 mm plywood (the kind of wood really doesn't matter - its main function is to take up space). In this case, I would suggest cutting four or five boards, each about 199 mm wide by 300 mm long, and of course 18 mm thick. See if placing some or all of the boards in the port, thus reducing its cross-sectional area, makes a worthwhile improvement. The theory is, if the box is acting like a vented box down in the bass region, this will lower the tuning frequency and hopefully reduce any upper bass bumpage without detrimental side effects.

"Duke, If one product`s purpose is to "absorb" or hinder vibrantion/resonance(attempting to isolate), this is different than "mechanical grounding"(MG). With MG there`s no attempt to absorb, rather you allow the vibration/resonance a rapid and complete exit channel to "gound" this energy into the floor.One seems opposite from the other.An example of the MG approach is the Star Sound system brass points and stands."

I don't see these two approaches as opposites. Your approach addresses mechanical vibration, and mine addresses airborne vibrations, better known as sound waves. One can have a speaker with a resistive port (such as a Variovent, or a DIY variant like I described above), and that speaker can also be sitting on brass points. The opposite of your approach would be de-coupling the cabinet from the floor, via something like Herbie's Big Dots.

I have not experienced mechanical grounding to make a significant difference in the frequency response of a loudspeaker system. From the description, it sounded to me like a large change in the bass response was called for, and so I suggested a possible acoustic solution. Nothing wrong with trying a mechanical solution as well.

Nothing against bass traps or speaker re-positioning either. The more options Amuseb has available, the greater his chances of success. I'm just trying to add to his options by describing a couple of unorthodox approaches that are inexpensive and easily reversible.

I think Duke's idea is a very good one and easy to undue if you don't like the results. The following is also easy to try. The replacement or reduction of 90 degree angles that I mentioned earlier there is one major angle you can try replacing. The niche or nook, that angle can be changed in a fairly easy experiment. If you had a solid wood panel like a door or you could take a door off its hinges temporarily you could place that barrier at the niche. The barrier wall of the niche is at a 90 degree and if you experiment by placing that panel at a 35 to 58 degree angle so it intersects the front edge and the side wall I think you will hear a big improvement. You can use this panel to steer the bass and listen for a change in angle and a change in how the room loads the bass. You have to use a solid not a rug or other porous material. If this idea works well you and the family need to decide what looks good and sounds good. I have performed these experiments before and have made permanent changes as a result. Tom
Amuseb, have you had the problem from day one? Lots of interesting suggestions, but maybe this isn't the spkr for your room, period?
I used to run Zu Definitions Mk2s, with xoverless full range drivers and 4 x 10" bass drivers out the rear, so some major similarities with your Hornings. Bass integration was a major issue, and I mostly solved it using the Spatial Computer Black Hole anti-bass wave generator, which sitting behind the listener, uses a mic and dsp to sample the bass from the main spkrs, and pumps bass into the room to eliminate phase issues, standing waves and bass nodes. The problem wasn't totally solved, but improved a good 60-70%.
I've upgraded to the Zu Definitions 4s which dispense with rear firing woofers for a single floor firing one. Bass better than ever, but still helped by the Black Hole.
For $1250, full money back guarantee, it's worth a try.
I've been trying some of the suggestions you guys have gathered for me, the stacked wood, some polyester stuffed, some more positioning, a large painting on the corner created by the little wall on the left to break the 90 degrees, etc.
so far, nada.
the boominess is there at all cases, sometimes it's even worse, except for those two pillows that were very strongly pushed into the ports but that have also significantly reduced the dynamics and extensions on both ends of the music.
tonight I have here a Karan KAI180MKII integrated at home to listen to a little but even though I can tell there's more control in the bass department, it's still boomy, and still the left side is the more boomy part of the room.

the best "proof" of the bomminess is my 6 years old daughter who walks in front of the speakers, while playing softly, and says "it breaks my ears".

bottom line, frustrating.

spiritofmusic, yes, this thought has crossed my mind but a) I think these speakers setup right really play lovely music. b) the last thing I feel like doing now is selling/buying etc namely in the current economic mood here in Europe.
so I'd rather try anything possible before giving up on these.

what's next?

thanks again for the help from you all.
Time to give bass traps a try, you have nothing to lose.
Have you swapped speaker position left to right? The angle thing..needs to be larger and denser than the painting. Tom
There are various forms of digital or analogue bass equalizers that can greatly reduce bass booming. Since this is a very serious problem for you, this approach should be considered even though it is anathema to a "purist" approach. This is much more of a certain cure than any other cure.
I agree with Charles1dad, you really should try placing some bass traps in the room. There is obviously a lot of low frequency sound that needs to be absorbed.
yap, swapped speakers left/right a while ago. today also the thought came to me that maybe the dual mono of the amp is to blame so I swapped the outs from it too... niente.
I thought the painting is probably too light but that's what I had...

irrespective of, this Karan integrated, brand new out of the box, is playing very nicely.