Cut lower frequency to help my bookshelf speakers

You are trying to get high volume from a small inefficient speaker. No matter what you do the most likely outcome is you destroy those speakers. If indeed you have not managed to do so already. When you hear the sounds you describe, in my book and in most cases the damage is done.

The "punch" you want does not come from subs. You can add all the subs you want, really good ones too, and still blow those little speakers trying to play them loud enough to get the feeling you want. What you need are Tekton Moabs or something like that. Because the punch you want is above the 80Hz or so frequency range of a sub. And even the top end range of the sub at 80 is beyond the capability of those little inefficient speakers to output at convincing volume. You are in other words trying to put legs on a snake, never a good idea.

If the search I did is right, Dynaudio Special 25 is a $5k two-way speaker with an 8" "woofer" and only 88dB sensitivity. A poor choice for anyone who wants to feel the music. Rather than chase futile dreams of being able to EQ a square peg into a round hole you might want to consider simply replace those awfully inefficient speakers with ones actually suited to what you want.

This is not only the only solution, it is also the most cost-effective, since as soon as you get a proper 98dB sensitivity speaker it will cut your amplifier power needs to a tenth, and you will be able to ditch ML for better sounding and much less expensive amplification. Win-win.

Yes high passing your speakers will make a big difference. The mini dsp is a good place to start as it is cheap. I would try 60z-80z. I think it will give you want you need as long as long as you sit 10’ or less.  Assuming that you are with stand mounts. 

You can use an analog crossover or DSP to reduce the low frequencies to your Dynaudio speakers. High pass filter set to 80Hz. or higher. I personally like analog with a steep 24 dB/octave slope, but digital high pass is much cheaper. You won't be able to get the sound of larger speakers, so don't expect that, but should clear up the bass by reducing cone excursion of your 8" drivers at higher sound levels.

Using subwoofers without a dedicated two way crossover is just a cheap and very inappropriate path into subwoofers. Not only is your woofer bottoming out but before it does it is severely distorting everything else it carries.  Either get a digital preamp that has bass management such as the DEQX Premate or get a digital crossover like a DBx Driverack and totally bypass the analog and very poor crossover in the subwoofers. You will not believe the difference. 

MC is on the right path, even if you equalize and limit the low frequency to the speakers, you will just turn it up more and be right back where you are. Little loudspeakers just don't play large and loud.

Tks all for the hints...

Well, I understand that "small" speakers cannot sound as "big" speakers... but i want to try at least to get the best out of them

I just dont understand if i can somehow prevent the lower frequencies to reach the dynaudio and if it will affect the sound quality ....
For example if i use a minidsp 2x4 in the between the audio research and levinson... will it work or not? ...can be a minidsp or another device (which one in this case)


@mijostyn  ... what does it mean:
Using subwoofers without a dedicated two way crossover is just a cheap and very inappropriate path into subwoofer

I connected the 2 SVS using the rca cable and calibrated via their internal DSP and class D amp... why inappropriate?

Using subwoofers without a dedicated two way crossover is just a cheap and very inappropriate path into subwoofer

What it means is he doesn't understand bass, or subwoofers- or crossovers or EQ. If you have the time and energy you are welcome to click the name and read the posting history, where eventually it will become apparent this is all part of a pattern. Sorry. Please disregard. 

The problem is like russ69 said if you cut the lows you will only turn it up louder and be right back where you are now. You cannot cut enough, because then you will be above the frequency suitable for subs. Your statement "i want to try at least to get the best out of them" begs the question. You already are getting the best out of them!

 You cannot wring blood out of a turnip. Don't put legs on a snake. How many more ways can we say this? Cue Obi Wan Kenobi: These are not the speakers you are looking for!

Well,
i see… the best is to sell the dynaudio and get a floorstand speakers i guess

For example if i use a minidsp 2x4 in the between the audio research and levinson... will it work or not?

Yes, that will work! Your dynaudio special 25 can play louder and cleaner with the help of a high pass filter. The svs 1000 can go up to 270Hz -3dB which is a good choice.

Apparently no-one caught on to the fact you have two SVS subs.

Probably the simplest option is to connect the pre output to the SVS and connect the SVS rca output to the ML and fro, there to the Dynaudios. Start cutoff frequency at 80Hz and take it from there.

Your solution 1) could work with a parametric equaliser, but it might adversly affect the sound quality. Good luck!

Up your budget a bit and get the minidsp 2x4 HD. Read the manual a couple of times until you fully understand it. You will connect your preamp to the minidsp input  and the subwoofers and amp to the minidsp outputs.  Your SVS subs don't have a high pass filter set the crossovers in minidsp.  I would also get the UMIK 1 with it and use REW but do that after you're comfortable using it. Integrating subs properly takes some time and knowledge so don't rush it and learn as you go. Don't worry about the minidsp degrading the sound you'll find it will greatly improve it once you're familiar using the software. Good luck.

Tks everybody for the suggestions

@gregm ... i also thought about the rca out of the svs... but the manual says that those are to connect several svs in line... so im not sure that it is a high-pass output
Even if i can mamange to use the rca out as a high-pass filter im not sure the quality is aligned with the rest of the system

@diones51... the 2x4 HD has a DAC which i dont need, so why not buy just the 2x4... i think thay are the same 

Also why use the 2x4 to pilot the 2 SVS?.... they have a good DSP and iphone app which is very flexible (6,12,18, or 24dB slope, volume, phase 0\180, and several presets in memory)

Im just concerned that the minidsp could somehow degrade the overall quality (im old school... the less you put in the music path the best you get)


@imhififan ... yes im sure it will help, im just worried about the potential degrade of the sound (see above)

Both the 2x4 and 2x4HD use the same DAC the difference is the better DSP engine. 

"Both the 2x4 and 2x4HD use the same DAC the difference is the better DSP engine"

got it!

I found another solution:

the node2 on the rear panel has the analog output L\R and a single sub rca out with high pass filter (which means that when i enable the sub out i can cut the main rca L/R out from 40 to 200 hz)

i can use that ... in this way no minidsp in the between pre and amp and no double conversion AD/DA
(even if the node2 onboard filter is not the best of the best i avoid the double conversion with the external minidsp)

then i will connect the sub rca out of the node2 to the first sub and daisy-chain the second sub (or split the cable)... at the very end calibrate them with the iphone app and their dsp

I should only check if the node2 output level controls both rca and sub out... but i think yes, why not




 

No. Lower frequencies require exponentially more power. Its where most of the work is done, especially if we are talking full range down to 20hz. Smaller drivers will have to work much harder to produce those lows than larger all else remaining the same, just like a smaller engine in a larger car.   Smaller drivers will tend to heat up more and compress.   So it’s always advantageous to have the transducer best suited to handle the frequency deliver the frequency. Even more important is we are generally talking about powered subs which also typically provide a beefy amplifier specifically designed to deliver the power needed for that flat extended bass. Most main amp/speaker combos will never be able to keep up with a good powered sub in terms of delivering clean, undistorted, extended bass. It’s also more cost effective and practical to buy a powered sub for that purpose. Full range speakers capable of doing it will tend to be be large, heavy and pricey if also built well. But of course as always, there are many ways to slay the beast.

this thread should be retitled ’why can’t i get my bedroom dresser into the back of my ford fiesta?’ :)

small drivers in small cabinets can give you good bass... but only up to a certain point

hope the op has the info he needs to move forward

Aurgolo, just what I said. Adding a high pass filter to the main speakers doubles the price of crossovers, and cables increasing the expense and complexity of adding subwoofers. So, to save money and make hook up easier manufacturers just delete the high pass filter. Even if your main speaker can not radiate 20 Hz that does not mean it is not going to try to do it and you can see your woofers wobbling around. These long excursions distort all the other frequencies the woofer is carrying. A high pass filter is necessary so that you can create a smooth crossover better integrating the subwoofer and eliminate low frequencies from the main speakers and their amplifier. This also dramatically increases you headroom overall. Giving you less distortion and more volume. 
This is one issue those of us who have been using subwoofers for decades rail against. You add subwoofer to get lower bass and to clean up your main speakers. Both issues are just as important. It is true that some types of speakers benefit more than others. For speakers that have a woofer that crosses out at 150 Hz the benefit is much less than for a speaker that's woofer crosses out at 2000 Hz. You can get a MiniDSP for $250.00 that will give you an excellent 2 way crossover along with full EQ cababilities. 

"....You cannot wring blood out of a turnip..."

This is the key point. The loudspeaker designer already got everything he could get out of the design they produced. The idea that you can equalize a loudspeaker system into doing something it just can't do will just make the problem worse. Subwoofers are not very good woofers and the heavy stiff cones and low frequency cabinet/driver design will not do a very good job trying to be a 3rd way in your loudspeaker system. Equalizers and crossovers can only do so much and they work best when you are cutting gain, not trying to add high energy frequencies outside their operating range.  

You can get a MiniDSP for $250.00 that will give you an excellent 2 way crossover along with full EQ cababilities.

Can you provide a link to the exact model please?  Thanks.

i see… the best is to sell the dynaudio and get a floorstand speakers I guess

Finally!

Now, the 98dB speakers I mentioned before, Tekton Double Impact and Moab, both are right about 98dB, both will give you the bass impact at volume you are looking for. Without a lot of power. Remember 98dB is ten dB greater than your 88dB speakers, meaning they will play as loud with ONE TENTH the power! ONE TENTH! And people wonder why I keep harping on speaker sensitivity. 

Plus even better in terms of dynamics, speed, detail, tone, imaging- they will walk all over what you have now. Absolutely magical perfect midrange. AND all the slam you ever could want.

All you have to do is stop trying to wring blood out of a turnip, go and buy a side of beef.

AND all the slam you ever could want.

MC, maybe but if so why did you feel compelled to add subwoofers in your case with Moabs? Apparently you wanted more bass. So this statement would appear to be a contradiction.

https://www.minidsp.com/products/minidsp-in-a-box/minidsp-2x4-hd?gclid=CjwKCAjw47eFBhA9EiwAy8kzNMM0M...

The Minidsp 2 x 4 HD. If I was doing it I would dump the preamp and node2 and get the SHD which would give him Dirac as well. 

Looking at Stereophile old measurements of the Special 25 I would try the high pass cross at 100hz then try 120hz if you still hear distortion. 

Get an SPL meter (or app) and measure how loud you are listening when the distortion start.  The phrase bass punch is vague, can you give us a musical example and say which instrument(s) you would like effected?

I'd explore the miniDSP first before any major $ 'excursions'. *S*
And without any idea of the space you're 'playing into' (volume, dimensions, furnishings), it's all a guess & opinion...
The mini isn't a 'cure all', but it's inexpensive to test active eq, imho the obvious 1st shot...
An spl app for your cell is a cheepcheck, and an excellent suggestion, 61....+1.5 ;)

Well tks all for hints

I understand that would be better to measure how loud im listening… but i never did, just follow my ears… anyway i will give a try to install an app in my iphone

also i will try to use the sub out of my node and cut the lower frequencies to the main L/R out… in this way at least i will avoid the double conversion in an external minidsp

((“Cut lower freq to help my bookshelf speakers”)) As stated in a previous post excessive excursion in the woofer causes a dramatic rise in distortion which a properly adjusted high-pass could solve. You could use the Vandersteen M5-HP which is part of their sub-woofer system to do this. This is also a problem when adding sub-woofers to any system because ideally the main speakers should be high-passed to lower distortion in the main amplifier,and lower modulation distortion in main speaker’s woofer and cabinet when hi pass is properly adjusted you will easily know it.
 Best JohnnyR

There is not much music below 30 hz. Search frequency ranges of musical instruments. The Schiit Loki let's you trim 20 hz. I found it very useful gr8 waking up my systems when used light handedly. DZ

Well based on the SVS1000's, I would say the OP is not really into high end, although the Dynaudio's are pretty good. If you don't want to spend a lot of $$, try the route of reducing the low frequencies to the Dyna's with some type of high pass filter, NOT an EQ. If you want big sound and volume, you will need bigger speakers.

Aurgolo, Connect the outputs of the LS2 to the inputs of the minidsp. Connect one set of outputs of the minidsp to the Mark Levinsen and the other set to the subs. If you hear any signal degradation from the subs I will be both amazed and impressed and any signal degradation you might get going to the Mark Levinsen will be substantially less than the improvement you will get from the Dynaudios when they no longer have to reproduce those low frequencies.

Connecting both the Mark Levinsen and the subs to the minidsp will give your better options for dealing with any potential phasing or timing issues between the subs and the Dynaudios. Also the minidsp should have better e.q. options than the Loki.

@audiorusty… why put a mini dsp in the between the pre and amp and have then a double conversion ad/da (with possible sound degradation) when is possible to use the node filter and have already the split low/midhigh frequency?

@fiesta75… what is OP?

Your speakers are great, the volume your searching for will not come from bookshelfs at that efficiency   
  Sounds like it’s time to go shopping.......
 Audition some small towers, they will be better with the subs!

   Or some much larger bookshelfs 
  

what is your budget, and also the space you have for speakers?
can your room/office accommodate larger speakers?

@arcticdeth... yes also i could sell the dynaudio and buy a floorstand.... but before i want to try to get the best out of the special 25

This is from the SVS SB-1000 owners manual. Using the high pass filter should give you the best results!

Line Level Inputs These inputs are used for line level connections to the subwoofer. For a single mono connection to an A/V receiver, use the R/LFE input. For 2-channel applications, use both the L and R inputs. Line Level Outputs These outputs are used in 2-channel applications to high pass the signal being sent to the loudspeaker amplifier. The line level outputs feature a fixed 80 Hz 12 dB/octave high pass filter.

@arcticdeth... yes also i could sell the dynaudio and buy a floorstand.... but before i want to try to get the best out of the special 25

You can lead a horse to water, but you cannot make him think. 

Reminds me of a friend with a Ford Pinto. Why won't the Pinto do 125? He was sure the car would be just fine doing 125. So he goes flat out down the Gorge. Columbia River Gorge. Big downhill grade. Miles long steep hill. Flat out. Almost gets there, too. 120 I think he said. According to the speedometer. Week later, according to the head gaskets he needs a new Ford Pinto.   

Keep it up buddy, keep trying to wring blood out of a turnip. What you will get instead, first scraping, then smoke, then finally the only thing you might just maybe understand, a totally blown little speaker. Perfectly good speaker, ruined by rank mulish stubborn refusal to learn.   

Only thing I am trying to understand, why come here if all you are going to do is refuse to listen to all the good advice? Why not just plug the speaker straight into the wall, put it out of its misery? Where you are headed anyway.

As MC kindly pointed out the OP has his back against the wall and is still trying to push the wall harder. In audio, when you get to this point you have to make BIG changes. Big loudspeakers and big amps, there is no way to fine tune a system that just isn't designed to do what the OP wants to do. 

OP is you, original poster. Somehow reduce the bass below 80Hz. or a little higher to your Dyna's using some type of high pass filter. You're trying to reduce how much your 8" woofers need to move.

Aurgolo, you place the minidsp between the pre and the amps because that is how the minidsp is designed to work. I think that you will get more sound degradation using the Node2 not to mention possibly greater phasing and timing errors, but give it a try and see what happens. You may like the results.

Also, if yogi boy is correct and the SB1000 has high pass filter capabilities that would be the easiest way to go. Connect your pre to the SB1000 and then connect the SB1000 line outs to the Mark Levinsen. The possible down side to this is that an 80 Hz, 12 db/octave crossover point may not be high enough or a steep enough drop off slope to alleviate your over excursion problem.

1) The SVS 1000pro does not have a high pass filter. The app is only for the sub, no output to your main speaker amplifier.
2) A high pass 12dB/octave slope set at 80Hz. will yield 1/16th power to your Dyna’s at 40Hz., that’s 0.0625 times the power at 80Hz. which should yield much better sound from the Dyna’s bass region.
3) Node2 only has a 3.5 mm analog or optical inputs. This is only good for device like a smartphone or something with an optical input as a source. Not needed for what you’re trying to accomplish.
4) Maybe the Schiit loki mino, that if it has adjustable frequency bands. Didn't look like it has adjustable slopes. You want a high pass filter with an adjustable filter frequency (80-100Hz.) to connect between your Audio Research outputs and the Mark Levinson inputs. I believe XLR’s would be your preferred choice, but RCA’s would work too.
5) Insert the "chosen device in #4" between AR and ML. Set high pass filter for 80 or 100Hz.
6) Adjust the SVS 1000 low pass filter to 80 or 100Hz. depending on your frequency choice in #5. You can try different slopes, for the sub 12dB up to 24dB/octave, start with 12dB/octave.
Maybe someone else can give a good suggestion for a variable high pass filter with XLR's?

so im thinking to add a dsp or eq to cut the lower frequncies before they reach the dynaudio

More electronics just sterilizes the sound, just plug up the port on the 25’s to raise it’s bass roll off an octave and drive it direct from the amp, and bring in the SVS up higher.
Experiment with the SVS’s phase setting so it sound is loudest at the xover point then adjust the level so you just detect it when it’s needed.

Cheers George

Well,
the SVS rca out i think is not filtered and, even if yes, would imply a double conversion ad\da which could bring some quality degradation

I emailed the bluesound and they replied:

when the sub out is on, the crossover cut is done by the internal DSP before the D\A conversion, this is a good news as it means that there are no risks of quality degradation 
then is possible to move the cut from 40 to 200 hz, large flexibility to make some test

the cut slope is 12db, which is acceptable i guess

So, Im not experimenting this setup (sub out to Subs and main rca out to the audio research) with frequency cuts of 40\50\60 with good results... of course i will test also more cuts in time
 
In this way, no additional devices in the between pre and amp... and no double conversion ad\da .... 

Then, of course i know that if i really want to make a giant step then i should buy floorstand speakers... maybe i will...

typo
’Im now experimenting’

@aurgolo - what are your listening room dimensions please?

Room around 5x8

Setup is in the 5 mt wall 

on the 5 mt wall

The simplest is to use a passive XO to roll the lows out of the mains
see  ieLogical SubterraneanHomesickBlues for the trials and tribulations of integrating subs with small mains. 
see http://www.ielogical.com/assets/Audio/PassiveXO1.png for passive XO example. 80 [≈4nF] to 90Hz [≈3.5nF] should be about right. 

CA 25's won't ever play as loud as Moabs, but should give a relatively tolerable 90db in a small room. If 5x8 is meters, they may be a bit small unless very close.

Check the woofers for damage by pressing gently either side of the dust cap. If there is any scratching, the woofers are toast.

Here is a nice summation of several reviews of subs and how they were implemented: https://6moons.com/industry_articles/kef-herb-john/

You can also click on the links to go in depth with the few reviews referenced.

All the best,
Nonoise