Thiel Owners

Well, these are the numbers that Rob assigned to my speakers. He may be distinguishing them from the original production run as they were assembled from original parts only a few months ago.

Thieliste, been waiting for your final conclusion after completing your Europe sampling trip. What is the best system for the 3.7? The Aries?

Yes, and what real person can hold off on buying an amp for years while having great speakers?

Jafant
I believe I got caught up with the belief that I needed a bigger amp with more current. Having had more time to compare and measure, I realize that the Bryston 7bst in serial setting only gives me 4 or 5 extra dB compared to my 3bst with no difference in sound quality. As I  never play anything louder than 90 dB, this 125 watt amp has no problem meeting the current demand with lots of headroom. I used a watt meter, and on standby it indicated that I use about 65 Watt and playing at 80dB, it registered 135 watt, more or less. The amp is rated at Max 675 watt. I'm planning to replace the 7bst with a higher quality amp of up to 30 watt, class A, tubes or SS. What would you recommend. Been looking at pass labs  and luxman.

Thanks jafant.

Been contemplating about the degree that various aspects contribute to my listening experience. Although this is rather artificial, I would say say that the recording/performance accounts for 35 %, my speakers for 35%, my room acoustics another 20 % and the electronics perhaps 10% of the listening experience. All of this is contingent on being in the right frame of mind. Music certainly enhances my state of mind but my mind can also be the greatest obstacle to the listening experience. So ultimately, my state of mind is the most important aspect of the listening experience. Your thought on this parceling out of the contributions to your listening experience.

Tom, I feel really good about your balanced, sensible approach to both theoretical and practical considerations to increase audible sound quality. I have become more cautious with assuming that when people make claims of improved SQ they have done their homework. Please include double blind comparisons to establish audible differences.

When I bought my 3.7 from Rob Gillum, he had one new pair of 2.7 left. Might check if he still has it.

Does anyone have the settings of peq filters that would replace the correction of the equalizer of the 3.5 series. I know that a graph of the correction was in measurement section of stereophile review but curious if the peq equivalent.

Great that there are subjective improvements noted with the upgrade. Can we agree on objective measurements that would capture such an audible improvements and continue the Thiel tradition of both objective and subjective substantiation of improvements?

Can you hear a difference with the eq in or out of the chain? With the eq should make a noticeable difference. Otherwise your eq may needs a check up. I have had 2 of mine repaired as they are vulnerable to static electricity.

A pre and post measurement with Rew is not that much work and could give something tangible to support the subjective improvement or lack of deterioration. As I gain experience and understanding of this powerful tool, I'm less reluctant to pair my observations with measurements.

Rew room equalizer wizard.

Thanks, that helps to build transparency.

Which tutorial did you use? Did you also adjust any phase issues?

Your 7b have plenty of current at normal listening levels. In parallel, they can handle 1- 3 ohm speakers effectively. In my testing, I never could tell the advantage of the parallel setting, as my SPL is modest, rarely exceeding 80 DB.

Tom, i really appreciate your candor and transparency. A good reason to take another look at the 5i series. Your ideas about the Renaissance 3.5 are very much in line with my explorations, using triamps and dsp to test the range of possibilities. The demands on an amplifier with biamping or triamping a driver directly is so much easier and the availability of affordable good amps in the 100 w range is abundant. I concur that with minor eq shaping, a xo becomes unnecessary and the frequency range, distortion and phase response are so much improved. I would like to hear your thoughts about the directivity and what can be improved about that? 

Keep in mind when you compare the bass response of different speakers, it is hard to eliminate the room response of the different speakers. Several times I was ready to replace drivers of my 3.5 only to find out with near field measurement that the drivers were perfect but bass nodes and boundary effects caused the distortions. When I replaced the 3.5 with the 3.7, the room effects also changed significantly.

Is there a good program that would measure the speaker specifications?

Bluestone, I concur. Last time I talked to Rob, he showed me how many more mid-range he could rebuild and it was the last batch of cones. So, we will need to find a suitable replacement even if we have to compromise. I don't agree with the criticism of the 3.5 and I still have 2 pairs in daily use and the bass is fantastic. The mid-range is an essential part in this. Will be happy to do some measurements and see what could be a good replacement. Is the dayton audio dats v2 adequate to measure the specs of my current 3.5 midrange? Would a digital xo filter with 3 amps per channel (still have some decent ht amps I could use) be an alternative??

Tom, thanks for the encouragement. Infinite baffle, is that doable with 8x8 wall. As I have a farm and can do outside measurements, been looking for some scaffolding. How high?

I have ordered some test equipment to do some measurements of the mids of my 3.5 and will compare the specs to some alternative drivers. I'm interested in tri-amping each speaker with digital active cross overs and incorporate fir and peq  filters for equalization, as many of the eq of the 3.5 have become repair prone. It's a different approach then the original, but I'm just curious about the pros and cons of this adaptation. Still researching this area but it looks promising.

I tested the need for high current amps with my new 3.7. And compared carefully my Bryson 3bst with a pair of 7bst, both in parallel and serial setting. Bottom line, the difference in current capacity never came into play as I never reached the spl where the 3bst was under powered. If your listening level is 85 db or less, this is a non issue. My amp was using less then 30 watt per channel and the basic laws still apply. My listening space is fairly large, 30 by 30 by 16 ft. So I like a full sound that the 3.7 delivers. Of course, if you like your music loud and push the limit, the actual current limits may come into play before you realize it.

The thing with the first order XO is that all drivers are exposed to a wide frequency band and the 3.5 mid-range is not able to handle a high power, rated at about 50 W. Been talking this afternoon to Rob about the various alternatives for this driver now that they can no longer be rebuild not replaced. Scan speak is promoting a driver as a replacement and Rob is now working on testing to see how they compare. May know more in 2 weeks. Have a few other alternatives that may do the job but they may require some adaptations to the opening as they have a slightly larger diameter. Stay tuned as measurements and listening tests are conducted.

Tom, I also have a pair of model 2 that I'm using in a home theater setup. Interested in possible improvements.

Take a close look at your mid-range drivers. Seeing any cracks near the surround edge? The replacement mid-range driver currently under testing for the 3.5 may also work for the 3.0

Unsound, I seriously explored that option with Rob and measured the cut out and increase in volume that would be needed. Concluded that it is doable and the coax driver are available and if you need to replace both the mid-range and tweeter, financially equivalent. I postponed that option and experimented first with a good wavecor mid-range driver and using active dsp tried out various eq and xo designs. As I can compare it to the original 3.5 and 3.7, I am pretty satisfied with my results. 

Tom, I have a pair of sealed subs and if this summer will be slow, I may explore your suggestion more.

Talked several times to Rob about the 10F as the mid-range replacement but never got excited about this option in spite of Rob's claim that it was the best replacement. The difference is size should affect the time coherence even if it may not be audible.

Unsound, the chamber volume for the coax requires almost a doubling of the space that the 3.5 offers for the mid-range driver (using space measurement of the cavity of the 2.7 compared to 3.5). Most practical way would be an expansion of the chamber on the back of the speaker, using a cardboard tube and wood. The front bevel opening would need to be enlarged with an extra inch or so, for which there is enough room. The new coax drivers are about $550 each, not sure about shipping costs. Depending whether you have the tools and skills to do the woodwork, you can estimate your "investment".

I assumed that chamber for the coax in the 3.7 and 2.7 were about the same and as Rob had the prototype of the 2.7 available, I used that to compare to the chamber volume of 3.5

Rob is a sole proprietor with no employees. Make sure you are using his new phone number (859) 554-9790. When I checked with Miller sound to have my mid-range repaired they warned me that they accepted only if it was personally dropped off as they had bad experiences with mail service and would not warrant the repair if it was mailed.

Tom, the specs look very similar except for the power rating of the 10F, which is at 30 Watt. Any concerns about this? I believe the current mid range was rated at 150 Watt.

Appreciate this good sense of humor.

I'm getting ready to dive in and begin my project of modding my 3.5. I'm wondering if anyone else is interested in collaborating as it would be more fun. My initial exploration indicated that this speaker is begging for tri amping. It would allow eq the base without stressing the mid range driver. I have found a good substitute for the scanspeak mid range driver that I want to try out. It means I'll have to learn to use various simulation software but at least these are all free and in the public domain. My tweeter is still fine but as these are also no longer available, may look into a substitute. Actually my long-term interest is to mod the coax from the 3.7 (been spoiled by them) and make them work for the 3.5 . I already have support from Rob G. and Tom T. but they are too busy to devote much time to this project, so message me if you have time and energy to devote to this. Thanks

My recommendation would be
1. Carefully check your mid-range drivers with the willingness to discover cracks in the surround ring. It is common after 10 years of regular use with the equalizer that signs of deterioration develop, according to Rob G.. if you are fortunate and your mid range are fine, consider extending the lifetime by coating the surround ring with glue.
2. Get the second amp for Bi amping. Decoupling the woofer from the rest protects the mid-range from the eq that is applied to the bass. The sloop of the filler is only 6db, so the mid-range is getting some of the extra bass. This decoupling also increases the impedance and an easier load on the amp. The biamping is vertical, so you can place the amp near each speaker, have short cables and the amp can compensate for a higher load in the base channel by the lower load from the mid-high range.
This is an easy and affordable improvement that increases the lifetime and Sonic qualities of the 3.5.
3. Check the eq carefully. Static electricity can blow out some transistors although for later eq this was fixed. You need the eq to get the best out of the 3.5. If your eq is needing repair or your mid-range needs replacement, it makes sense to switch to digital crossovers as I did and shape the mid-range to your system and compensate for differences in sensitivity of the speakers. You also create the opportunity to mitigate room effects. I have successfully done this with a minih dsp opendrc da8. The specs are only average but as far as I can tell, no Sonic weaknesses in the audible range.

Unsound, you probably know that the xo is a parallel design and each section is wired to the binding post. To bi amp is only a minor modification.

You have a point that feeding only the woofer with the eq can cause a delay in the signal and should be avoided. For the bass, a slight delay may not be as critical as it would be for the mid and high.

Ob, my exploration in alternative setup for the 3.5 are motivated by lack of original mid-range and tweeter replacements and parts for damaged eq. Just like you, I value the Sonic properties of the 3.5 and want to examine ways to preserve or enhance what we have.

Cabinlife, the 1.5 has good mid and high but the lower range would benefit from a pair of subwoofers. Well suited for smaller spaces.

Tom, if Thiel speakers keep phase changes to a minimum, would according to the same reasoning keeping the phase changes to zero as in linear phase be better then minimum phase? Creating linear phase is possible with active digital sound processing creating other problems such as ringing but would it not be another step closer to the ideal? My experimentation with the 3.5 seems promising and certainly increased my respect for the quality these speakers already have.

Tweeter for 3.5 was the dynaudio D28a. And the successor. Still show up on eBay at times and Rob G. still had a few available not that long ago. Substituting a driver is more complicated then it appears, although the Tweeter replacement might be the easiest to match to the original.

In the past several months I have done hours of listening and measuring of my 3.5 with passive and active digital xo. That Thiel originally also explored the triamping active xo makes good sense. The passive xo system still has these problems:
Each speaker has its own min phase characteristic. Minimum phase still has phase change depending on frequency range although "minimal". Only linear phase has a constant phase change independent of frequency range. Overlapping frequency range of multi-speaker systems still introduce phase changes especially with the 1st order xo that allows large overlapping ranges.
The variability of components is not negligible and when measuring each component the factory specs are only an approximation and fine tuning is essential. Taking good and reliable measures is an advanced skill but also frustrating as the components can change characteristics based on temp, load, etc. Then the issue of what differences are audible and not determined by subjective bias requires double blind comparisons. A passive xo system modification is a fair amount of work assuming that needed components are really available. My conclusion so far is that active digital xo system have the best chance to approach the ideal time phase coherent system with linear phase, time aligned, component eq, and even individual room adjusted set up. As it is stated that the speaker and room variables account for the largest part of the reproduced sound quality, it only makes sense to focus any innovations in mastering the active digital xo systems.

With dsp any xo can be linearized with zero phase at the xo area though with ringing often hidden in the noise level.

Tom, i fully concur. I have at least for now abandoned the 4th order xo and returned to the 1st and 2nd order and trying to linearize the overlapping area of the xo and keeping the ringing in the inaudible range. The blend of the different drivers is also more pleasing then having them more separated.

Thanks Tom I'm giving it a shot.

The outriggers of my 3.7 are about 13.75" in front and 9.75" in back.

Sdl4, is that the system from Atlanta? I had made an offer for it but ended up getting my 3.7 As Tom stated, those dented dust caps are unlikely to cause any audible changes. Enjoy.

When I checked last week with Rob G., he had a NEW rosewood 7.2 for 10K.

Your Bryston in bridged mode is not recommended for the low impedance of your speakers. In bridge mode, 8 ohm is recommended as minimum and your speakers go down to below 3 ohm. Keep them in unbridged mode and they will comfortably go down to 4 ohm and produce 200 + watt. Your amp would be great for bi amping though!

George, congrats. Your presence here is always appreciated. Make every day count, life is precious.