[Housteau]

Pinching putty on the passive radiators works really well setting the quality vs amount of bass.  However, the RM-V60s do not use passive radiators and are a sealed design.  I would like to tighten up that mid bass a bit and was looking for options.  Changing out the amp is one way to experiment.  Spiking the speaker to the floor, while not recommended by Brian for his passive radiator models, might just help out this sealed design.  Any thoughts?

Moving the speakers is not really a good option as their present location already allows the flattest response in the room, as well as the best imaging.

[Wayne1]

What is the floor of your room? Is it suspended over a basement or crawl space? Is it a concrete slab under it?

For my listening room, the floor is suspended over a crawl space. When I isolated the speaker from the floor, the bass cleaned up quite a bit. I have 626Rs. No passive. They are mounted on the OXO.

I used Herbies Fat Dots between the speaker and OXO.

Herbies speaker feet

He also makes various types of floor standing speaker isolators.

VERY highly recommended.

[John Casler]

Pinching putty on the passive radiators works really well setting the quality vs amount of bass.  However, the RM-V60s do not use passive radiators and are a sealed design.  I would like to tighten up that mid bass a bit and was looking for options.  Changing out the amp is one way to experiment.  Spiking the speaker to the floor, while not recommended by Brian for his passive radiator models, might just help out this sealed design.  Ant thoughts?

Moving the speakers is not really a good option as their present location already allows the flattest response in the room, as well as the best imaging.

Hi Dave,

Hope all is well.

I might first ask some questions:

1) What midbass seems to need tightening (instuments? frequencies? etc?)

2) Did you notice this before the D-OXO?  or did you have this interest before with the Analog OXO?

3) What bass amp are you using? And what are the power specs?  Can't tell from your system page.

4) Have you checked all the woofers to make sure all are firing?

5) Do you find something missing in all recordings, or just certain ones, any specific cuts?

[Tyson]

Get a radio shack SPL meter for $35, and a disk of test tones and run the tones through the speaker.  Measure and graph them.  You will have one or 2 very large room induced "modes" that you can use the DCX to knock down with the digital EQ built in (I assume your D-OXO is based on the DCX). 

Also, spiking the subs to the floor will also help.

[Housteau]

What is the floor of your room? Is it suspended over a basement or crawl space? Is it a concrete slab under it?

It is a concrete slab.  I was able to dig up some old original Tip Toes cones to experiment with.  I had used them for my Infinity bass towers.  So far I like the results.

[Housteau]

Hi Dave,

Hope all is well.

I might first ask some questions:

1) What midbass seems to need tightening (instuments? frequencies? etc?)

2) Did you notice this before the D-OXO?  or did you have this interest before with the Analog OXO?

3) What bass amp are you using? And what are the power specs?  Can't tell from your system page.

4) Have you checked all the woofers to make sure all are firing?

5) Do you find something missing in all recordings, or just certain ones, any specific cuts?

Hello John.  I am doing well and so is the system really.  You know how it is, often we are not aware that there may be something at issue until we have something else to compare to.

I was listening to a friends system this morning and noticed a tightness and rightness to his bass.  We use each others systems as benchmarks and often leapfrog back and forth.  Just the other day he heard things in my room that he was missing in his.  That got him to make the changes that impressed me.  It is a great way to work towards improvements.

The D-OXO made huge improvements over the analog one and has only helped in this regard.  My mid bass amp is the aged, but venerable Electron Kinetics Eagle 2a.  A giant killer in its day and possibly its day may have passed.  However, there are still quite a few owners that swear by this amp for bass control.  The system is triamped counting the monos for the VLAs.  I use pink noise to balance all the amps to each other.

The best way I could describe it would be a general semi-bloat with some finer detail missing.  Since I started this thread I have been experimenting a bit and things have gotten much, much better.  In fact I may already be there. 

Spiking the speakers did help, but the biggest problem that I found was that my source was not as refined as my friends Mark Levinson.  I borrowed a Benchmark DAC not currenty in use to replace my Monarchy NM24 as a test.  Sure enough the bass tightened up and sharper lines were drawn around everything.  That beautiful liquid midrange I get with the Monarchy wasn't quite there, but besides the better controlled lows there was also more chrisp highs as well.  There is plainly more information being resolved by the Benchmark DAC.  I had compared these two before and ended up buying the Monarchy for what it did for the vocals, especially the female voice.

I suppose the main reason I started this thread was to see if there were any other tricks to use if they become necessary.  I prefer to tackle the causes rather than just throw a bandaid on things.

[Housteau]

Get a radio shack SPL meter for $35, and a disk of test tones and run the tones through the speaker.  Measure and graph them.  You will have one or 2 very large room induced "modes" that you can use the DCX to knock down with the digital EQ built in (I assume your D-OXO is based on the DCX). 

Also, spiking the subs to the floor will also help.

In my post above I mentioned that most of the differences I noticed appear to be the result of an inferior source, or a malfunctioning one(?), in those specific areas.

I am a big believer that the room is the first major component of the system and built mine with the acoustics in mind.  It is very well treated.  I have mapped it many times one Hz at a time from 16 to 350 Hz.  Then, every so many from there up to 20K Hz.  Between my design, the treatments and the DCX, there are no peaks.

[JerryD6]

Hi Dave,
   I also have a problem with a too prominent mid/upper bass. However mine is room induced and I suspect significantly worse than yours. I have a concrete floor and considered spikes, but am not too keen on drilling the bases.
   I've had good success using the DCX, but the room modes I am using are calculated, not measured. I'm sure I need more precision to refine the DCX settings.
   Can I ask how you mapped your room? One Hz increments seems essentially necessary to get the best results.

Thanks,
Jerry

[Housteau]

Hello Jerry,

I have always done all of this manually instead of using software averaging.  The single Hz map will show a lot of issues missed by other means.  You can download test tones below 300Hz from the Real Traps site:
http://www.realtraps.com/test-cd.htm

I have other test disks with higher frequency tones and I created others using Audacity.  That is a free download that allows digital recording and manipulation of wav files.  Generally I just use a meter from Radio Shack.  These meters are good, but not accurate at low frequencies.  You need to add in correction factors.  For example, my meter requires that I add about 12 db to my 20Hz reading, 10.5 db to 22Hz and 9 db for 24Hz etc.  Once I have the readings I just graph them out.  There are blank logrithmic graphs also available on the Real Traps site.  I  usually import them into paint and just place a dot on the reading, then connect them.

There was a site that had lists of these correction factors for the different models, but I am not sure how to find it again.

[Scottdazzle]

Housteau,

If the 60's are anything like the 30's, they take a long time to tighten up in the mid-bass. I don't know how long you've had these (you lucky devil) but something like 200-500 hours of playing time may be necessary for the VMPS speakers to reach their potential.  I became very impatient waiting for my 30's to "get there".

Scott

[John Casler]

What is the floor of your room? Is it suspended over a basement or crawl space? Is it a concrete slab under it?

It is a concrete slab.  I was able to dig up some old original Tip Toes cones to experiment with.  I had used them for my Infinity bass towers.  So far I like the results.

Ah yes the concept of "spiking" a sub or speaker for bass improvements.

Firstly B's, main objection to spiking (I beleive) has to do with boundary reinforcement.

Bass waves are "high pressure" and they travel along "UNBROKEN" and solid boundaries the best.

Spiking a speaker places a "pressure leak" along that boundary, and B, having very sensitive hearing can hear the difference.

Now many like spiking for the percieved benefits.

Those benefits are essentially "two fold":

1) The spikes create a better mechanical coupling of the speaker to the floor.  This coupling resists the inertial and other forces the woofer creates in pushing air.  If the speaker cabinet moves a small amount in "reaction" the the woofers cone movement, then the base wave launch is compromised, and blurred. 

2) While it is true that raising the cabinet off the floor allows for a "pressure leak" in the boundary, it also can cause a steeper and natural rolloff of the bass.  This reduction can sometimes "coupled" with the improvement in the mechanical coupling offer a percieved "cleanliness".  Also if a sub is used,it may cause a reduction of the "interactive overlapping" or strength of these frequencies, and can be a nice "Clean Up".

[Brian Cheney]

At CES I used a 3dB cut at 65Hz with a Q=1 to get maximum clarity in the upper bass range.  I suggest something similar for you.

[John Casler]

The D-OXO made huge improvements over the analog one and has only helped in this regard.  My mid bass amp is the aged, but venerable Electron Kinetics Eagle 2a.  A giant killer in its day and possibly its day may have passed.  However, there are still quite a few owners that swear by this amp for bass control.  The system is triamped counting the monos for the VLAs.  I use pink noise to balance all the amps to each other.

Yes Iverson made some good amps, and they "ARE" revered as some of the best BASS amps out there.

How powerful is yours?

I have often found that the "cleanest" amps are the most powerful amps.

Three of the VMPS Megas need lots of good juice.

Do you use a power conditioner? that might be restrictive in any way?

I assume the Eagle has a captive power cord?

The best way I could describe it would be a general semi-bloat with some finer detail missing.  Since I started this thread I have been experimenting a bit and things have gotten much, much better.  In fact I may already be there.

Spiking the speakers did help, but the biggest problem that I found was that my source was not as refined as my friends Mark Levinson.  I borrowed a Benchmark DAC not currenty in use to replace my Monarchy NM24 as a test.  Sure enough the bass tightened up and sharper lines were drawn around everything.  That beautiful liquid midrange I get with the Monarchy wasn't quite there, but besides the better controlled lows there was also more chrisp highs as well.  There is plainly more information being resolved by the Benchmark DAC.  I had compared these two before and ended up buying the Monarchy for what it did for the vocals, especially the female voice.

Interesting that a DAC used "before" the ADC of the D-OXO would cause an improvement.

Have you considered the alternative "all digital" path until after the D-OXO as I posted here?

http://www.audiocircle.com/index.php?topic=47927.msg642265#msg642265

I suppose the main reason I started this thread was to see if there were any other tricks to use if they become necessary.  I prefer to tackle the causes rather than just throw a bandaid on things.

Looks like you are considering the right details:

Mechanical coupling
Amp
Dac


The only other would be to "reconfigure" as to the "all digital" path until after the D-OXO which would mean some serious reconfiguring.

[John Casler]

Hi Dave,
   I also have a problem with a too prominent mid/upper bass. However mine is room induced and I suspect significantly worse than yours. I have a concrete floor and considered spikes, but am not too keen on drilling the bases.
   I've had good success using the DCX, but the room modes I am using are calculated, not measured. I'm sure I need more precision to refine the DCX settings.
   Can I ask how you mapped your room? One Hz increments seems essentially necessary to get the best results.

Thanks,
Jerry

Hi Jerry, and welcome to AC, and the VMPS Circle.

I am under the impression that you recently scored a full RM v60 System?

If so congratulations!!!

We look forward to hearing how you are doing with them, and if you have any questions just post.

As you can see the VMPS'ers are here to offer expereince and opinion.

[JerryD6]

Hello Jerry,

I have always done all of this manually instead of using software averaging.  The single Hz map will show a lot of issues missed by other means.  You can download test tones below 300Hz from the Real Traps site:
http://www.realtraps.com/test-cd.htm

I have other test disks with higher frequency tones and I created others using Audacity.  That is a free download that allows digital recording and manipulation of wav files.  Generally I just use a meter from Radio Shack.  These meters are good, but not accurate at low frequencies.  You need to add in correction factors.  For example, my meter requires that I add about 12 db to my 20Hz reading, 10.5 db to 22Hz and 9 db for 24Hz etc.  Once I have the readings I just graph them out.  There are blank logrithmic graphs also available on the Real Traps site.  I  usually import them into paint and just place a dot on the reading, then connect them.

There was a site that had lists of these correction factors for the different models, but I am not sure how to find it again.

Thanks Dave. I had forgotten about the Real Traps tones, that should be ideal.
   I believe the correction factors for the RS meter, C-weighted, might be on the Rives Audio site. The test CD they offer incorporates the corrections, so they might be posted on the site as well.

Jerry

[Housteau]

Thanks Dave. I had forgotten about the Real Traps tones, that should be ideal.
   I believe the correction factors for the RS meter, C-weighted, might be on the Rives Audio site. The test CD they offer incorporates the corrections, so they might be posted on the site as well.
Jerry

Be careful Jerry as the different models of RS meters have different correction factors and they are not universal.

I forgot to mention that you do not need to drill the bases for spiking.  The original Tip Toes have a flat surface on top that allows you to just place them under the base.  There are other solutions as well, such as those Wayne1 mentioned in his post.

[Housteau]

At CES I used a 3dB cut at 65Hz with a Q=1 to get maximum clarity in the upper bass range.  I suggest something similar for you.

Now that you mention it I remember that.  However, I am not sure if this one is already programed in mine yet or not.  If it isn't it soon will be.

[JerryD6]

Hi Jerry, and welcome to AC, and the VMPS Circle.

I am under the impression that you recently scored a full RM v60 System?

If so congratulations!!!

We look forward to hearing how you are doing with them, and if you have any questions just post.

As you can see the VMPS'ers are here to offer expereince and opinion.

Hi John,
   Thanks for the welcome. I've been reading the VMPS board for some time in researching the v60s to replace Infinity IRS Betas. I was fortunate to find the v60 system for sale here on AC.
   I'm sure I'll have questions, so I will be posting more often.

Jerry

[Housteau]

Yes Iverson made some good amps, and they "ARE" revered as some of the best BASS amps out there.

How powerful is yours?

There is about 200W available per channel at 4 ohms.  And I am not using a power conditioner for my amps.  It is a dedicated circuit though off a split 220 line at the receptacle, with 110 going to each side.  It is just an average 12 gauge power cord, nothing fancy.  I may have access to another to try.

Interesting that a DAC used "before" the ADC of the D-OXO would cause an improvement.  Have you considered the alternative "all digital" path until after the D-OXO as I posted here?

http://www.audiocircle.com/index.php?topic=47927.msg642265#msg642265

My DCX is one of the nice modified units and part of that mod is an improved digital in, ADC and DAC.  The digital in is very clean, but also fatiguing to my ears after a short while.  In all cases I have found that my DCX sounds best using the analog in and allowing it to use both of its own ADC and DAC together.  I reverified this last evening as part of my Benchmark vs Monarchy DAC tests.  My Proceed transport has several digital outs and they can all be used at the same time.  This makes comparisons a lot easier.

[Housteau]

I've been reading the VMPS board for some time in researching the v60s to replace Infinity IRS Betas.

I was also an Infinity fan having owned the RS1bs for about 17 years, so I know exactly how you came to notice the RM-V60s and to think of them as a logical choice.