[jsalk]

Marbles -

So how is the testing going?  Was Dennis able to better his passive XO with "The Future"?

Thanks for your thoughts on the DEQX and HT3a's.

It was an interesting day yesterday.  Dennis and I spent the day measuring, calibrating and setting up crossovers and in-room EQ.

What follows is my impression of where we ended up.  While I can't speak for Dennis, I think we were in basic agreement.  But you may want to ask him to see if his impressions mirrored mine.

From the midrange on up, there was little or no discernable difference between his passive crossover and the DEQX corrected (active) set-up.  Since you have his passive crossovers in your HT3's, you pretty much know how this end of the active set-up sounds.

We did use steeper slopes on the DEQX version and, thus, were able to cross slightly lower.  This should have improved imaging and sound stage slightly.  And it may well have, but the differences were so minimal as to not be readily discernable.

The mid-bass on the DEQX set-up was slightly more full sounding than the passive crossover version.  Here is what I think may account for the difference:

Many subwoofer drivers have a slightly rising response below 100Hz (at around 70Hz for example).  If you are crossing at, say, 250Hz and you set that level at that point equal to the midrange, there will be an excess of energy in the area around 70Hz (in this example).  So you set the relative level of the woofer so that the 70Hz rise (in this case) is in proportion.

What you end up with is a slightly depressed area in the 100Hz - 200Hz range.  We are talking about a small difference here, but one that is audible.

With DEQX, since it can and does adjust the response up or down as needed, it can compensate for these variations in response.  So in the DEQX version, the 100 - 200 Hz area is not slightly depressed as with the passive crossovers.  Thus, the mid-bass region will sound slightly more full.  DEQX may also be compensating, somewhat, for some floor bounce cancelations in this frequency range.

At any rate, that is my current theory supported only by listening tests.

The other major difference is in the area around 40Hz where room modes come into play in my room.  With DEQX, you are able to cancel these out by applying EQ.  So the low frequencies are slightly better controlled.

Relating to an earlier question, can the same results be achieved with a TacT unit using a 2-channel amp and the passive crossovers?  The answer is yes for the low bass anomolies caused by room modes.  But I am not sure about the slight mid-bass depression (although it is certainly possible).

While it was not quite ideal, the HT3's I was using did allow us to do some A/B listening tests (although the change-over times were not as fast as we would have liked).  Both the active and passive versions sounded very, very good.  And I came away with a renewed appreciation for just how good a job Dennis did on the passive crossovers.

As I said before, Dennis may have a slightly different interpretation of the results.  But one thing is certain, we have a DEQX set-up that is very good indeed and I will have it available to demo at both the Rocky Mountain Audiofest and the Chicago Audiofest.

I would also like to publicly thank Dennis for his contributions to both projects.  He is a true artist in every respect and anyone who has heard the HT3's can attest to that.

Marbles, I hope this answers your question.

- Jim

[Marbles]

Jim,

Thank you for that analysis....

[koiman]

Jim,
I was just curious does Dennis perform the equalizer QC set up on each and every one of the HT3? Or being that they are the same cabinet make up, is this not necessary. Also in regards to the sonic caps does he have to make any changes compared to the standard caps.
Thanks,
Leon

[jsalk]

Jim,
I was just curious does Dennis perform the equalizer QC set up on each and every one of the HT3? Or being that they are the same cabinet make up, is this not necessary. Also in regards to the sonic caps does he have to make any changes compared to the standard caps.

Leon -

Once the passive crossover is designed, as long as the drivers or cabinet dimensions do not change, it is basically set in stone.  Component values are measured and matched so that a pair of crossovers performs identically, but nothing else is required.

The only difference in the use of Sonicaps is that they are not available in a few of the required values.  So smaller values must be ganged to create the needed values.  For example, eighteen 20 uF caps are required to cover just two of the caps in a pair of crossovers.  Once the caps are ganged, however, the resultant value is the same as the standard caps.

Now, if you were talking about EQ'ing the DEQX crossovers, that is a different matter.  Each of the drivers in each cabinet are measured and a crossover is generated for that particular speaker.  Thus, you can correct for any anomolies in any of the drivers and the result should be very consistent.  Once a crossover is generated, it is loaded into the DEQX unit and remains there even when the power is turned off.

You then take a measurement(s) from the listening position and the system will show you the response of the speaker in the room.  You can now add parametric EQ modules to address any room-related issues.  This is relatively easy to do and most likely will be done by the end user in his/her room.

I hope this makes sense.

- Jim

[koiman]

Thanks Jim,
I appreciate explanation..

[brj]

FYI...

Dennis Murphy's comments on dialing in the DEQ/X configuration of the HT3a can be found in a thread on the Madisound forum.

[randybessinger]

Jim Salk and his lovely wife Mary dropped off my HT3a's on his way back from Denver.  Talk about great customer service.  I can't say enough good things about them.  He and Mary are both class acts in every sense of the word and I enjoyed the time we spent together immensely.

Jim wanted to set them up but my room is in disarray so it is going to have to wait till this weekend.  I am hoping that I remember everthing Jim told me about the DEQX.  For those interested, I will be driving them with a B&K 7270 amp that I already had so it will be the the HT3a system JIm sells but without Jim's ATI amp.  I think the B&K is a good amp so I don't suspect much if any difference.

I loved the sound of the a's at the RMAF.  I listened to speakers costing 10's of thousands of dollars and thought that HT3a's not only held their own but beat the competition in many areas.

I hope to post my comments and have some pictures sent to post sometime next week so stay tuned.

[brj]

Congrats on the new speakers, Randy!

Jim Salk and his lovely wife Mary dropped off my HT3a's on his way back from Denver.

Wow, how do I sign up for that particular service?   Guess we have to have an audio exhibition in the area large enough for Jim to want to exhibit...

I loved the sound of the a's at the RMAF.

Did Jim have a traditional pair of HT3s there, such that you could compare the passive vs. active implementation?  I've read Jim and Dennis' comments on the two, but I'm curious about what other people have observed.

By the way, what species of wood was used for your veneer?  I saw it described as "leopard", but I never saw a species listed and have never seen anything quite like it.  Very impressive!

[jsalk]

brj -

Did Jim have a traditional pair of HT3s there, such that you could compare the passive vs. active implementation? I've read Jim and Dennis' comments on the two, but I'm curious about what other people have observed.

Yes, I had a pair of HT3's with both the passive crossover and DEQX active crossover installed.  So I could switch back and forth.

I conducted very interesting experiments with some experienced audiophiles in a number of separate sessions.  I played the same music on both the active DEQX version and the passive version without telling them which was which.  I then asked them to comment on the differences they heard.

Obviously, the bass was better controlled with DEQX in a VERY bad room.  So comments in this regard were not all that insightful.

But the other comments I received were quite consistent.  Basically there were three comments that most listeners offered.  They were:

1) Imaging was slightly superior with the DEQX.

2) Layering of sounds from front to back were slightly better defined with the DEQX.

3) Male vocals were slightly fuller sounding with the DEQX.

Again, these differences were subtle, but since the comments were almost universal, it would appear that they were audible.

Both Dennis Murphy and I clearly heard item number 3 above when setting up the DEQX correction.  Numbers 1 & 2 were slightly more subtle.  However, since all the listeners in these sessions offered similar comments, I would suspect the differences were more audible than I first suspected.

My theory is that the first two items are due to the time and phase alignment done by the DEQX across the entire audible frequency range.  The third is due to minor adjustments in the FR of the specific drivers (no driver is perfectly flat).

The comments I received in these comparison sessions indicated that the passive crossover is extremely well executed (thanks to Dennis' superb efforts), but that the DEQX version was slightly superior.

- Jim

[DSK]

3) Male vocals were slightly fuller sounding with the DEQX...due to minor adjustments in the FR of the specific drivers (no driver is perfectly flat)...

Jim, is this definitely the reason or is there a chance that it is the result of the change in the xo slope used (IIRC the passive was 24db/oct at 250hz, the DEQX was 96db/oct at 250hz)?

[jsalk]

DSK -

3) Male vocals were slightly fuller sounding with the DEQX...due to minor adjustments in the FR of the specific drivers (no driver is perfectly flat)...

Jim, is this definitely the reason or is there a chance that it is the result of the change in the xo slope used (IIRC the passive was 24db/oct at 250hz, the DEQX was 96db/oct at 250hz)?

I don't think so.  The first DEQX implementation I tried used the same ferquencies and slopes as the passive.  I heard these changes in that configuration as well.

The W18's are slightly lean in this area and DEQX corrects for that in the calibration process.

We're talking about something fairly subtle here, but audible none-the-less.

- Jim

[Marbles]

1) Imaging was slightly superior with the DEQX.

2) Layering of sounds from front to back were slightly better defined with the DEQX.

3) Male vocals were slightly fuller sounding with the DEQX.

Again, these differences were subtle, but since the comments were almost universal, it would appear that they were audible.   ...

The HT3a must be amazing because my regular HT3 does 1 and 2 VERY well and it's no slouch on number 3.

Did the HT3 have any upgrades like Sonicaps, BH5 etc...?

Thanks

[jsalk]

marbles -

The HT3a must be amazing because my regular HT3 does 1 and 2 VERY well and it's no slouch on number 3.

Did the HT3 have any upgrades like Sonicaps, BH5 etc...?

Thanks

Just for the record, there were no upgrades.  And you are absolutely right about the performance of the passive crossover.  

The differences, if any, with regard to #1 & #2 are extremely subtle. So subtle, in fact, that Dennis and I didn't really notice any significant differences in regard to those items when we spent the day dialing in the DEQX.  

The only reason I mentioned it is that I thought it was interesting that people offered very similar comments to that effect. But keep in mind that the tests were not conducted as formal double blind tests.  

Perhaps I will try some more formalized listening tests at the Chicago Audiofest and see what the results are there.

- Jim

[Marbles]

Jim,

Any chance you will have a (passive) pair with upgrades to go against the HT3a?  The reason I ask, is I'm guessing it would be a closer thing with regard to numbers 1 and 2 than a stock pair...that's why I got the upgrades

[jsalk]

Marbles -

Jim,

Any chance you will have a (passive) pair with upgrades to go against the HT3a?

Unfortunately, no.  I simply won't have the time required to modify my pair with the upgrades before the Chicago event.  Besides, I like to demo speakers with run-of-the-mill source equipment and stock crossovers so people know that what they are hearing is exactly what they can expect to hear from a stock pair of speakers in their home.

But if you want to bring your speakers...

- Jim

[Marbles]

Marbles -

But if you want to bring your speakers...

- Jim

I'd love to come up to the Chicago Audiofest, but I had made arrangements with a few guys to come to my house on the 15th before I had heard about Chicago.

[randybessinger]

Last night I did some more extended listening.  I recently bought the Cream reunion DVD and CD as I am old and saw them live.  In fact, I met Clapton and spent some time in his hotel room with my brother, sister and a friend, but I digress-

The HT3a is an awesome speaker and with the flexibility of the DEQX to tailor the bass to the room, it just is an awesome combination.  These speakers are so revealing and clear that every little nuance of the recording comes through.  I love them and would advise that anyone who gets a chance should hear them.

[koiman]

Randy,
I fully agree with you, I have had my HT3 now for about 3 weeks  and they seem to sound better every day, thay are so clear, clean , and natural sounding the Artist just seem to be in the same room as you when listning. These are diffidently the best speakers I have ever heard. I will have these speakers for the rest of my life.
Lee