Zaph Audio SB12.3 or Troels' DTQWT?

[usmcjlp]

I am considering building a large 3 way speaker for a dedicated home theater/critical listening room in my home. The room measures 23'x16' with 9' ceilings. It also has multiple double doors which open to 3 other rooms. My intended use is 60/40 movies to music. My current set up is a 7.2 surround system consisting of Paradigm Reference Studio Series Speakers. I have had my current speakers for about 7 years and want to try something new. I am new to DIY speakers.

I would like a speaker that is capable of very loud sound levels with great dynamics for home theater, but is also very accurate with great imaging for critical listening. Not an easy goal. I looked at Tony Gee's designs, but can't afford them.

I have found the Zaph SB12.3 and the DTQWT.

Zaph|Audio - SB12.3 3-Way Tower
DTQWT

I would appreciate any advice from more experienced members. I have been going back and forth between the 2 for a couple of months now. Cost and suitability for my use are my main concerns. I will also need to build a matching center channel speaker. I do not listen to classical and currently do not own tube equipment.

It seems to me that the SB12.3 will have much better low end extension, which may be better suited to home theater. The DTQWT seems more like an audiophile speaker. I wonder how it will handle classic southern rock and blues.

I have read their sites many times. I was ready to order the SB12.3 when Madisound suggested Zaph's ZRT tower as a much better speaker. They told me that the SB12.3 was intended for customers who simply want a large design, but is not on par with scan speak and seas systems. Does anyone have an opinion on this? This seems to contradict Zaph's driver round up conclusions. Am I selling the DTQWT short on bass response? The specs for the eminence drivers aren't very impressive.

Thanks for reading a long post.

[jerome69]

The bigger is a speaker the better it is. I don't think bass is an issue in this case. To reproduce bass you should have a big room.

I find the Madisound's affirmation is very curious.
DTQWT is a 2.5 high sensitivity S ~ 2x330+220+7 = 887cm²
Zaph 12.5 is a 3 ways S ~ 500+2x100+7 = 707cm²

Zaph ZRT is a 2.5 S ~2x150+7 = 307cm²

How can you do better with 307cm² than 700cm² or 900cm² ?
Have you read this : size matters ?

It depends on your budget and your electronics. DQTWT can provide considerable level with a few watt. If you want bass you must have a good and powerful amplifier.

Hope this helps.

[usmcjlp]

My concern is that I don't want to give up sound quality for the sake of volume. As Zaph wrote on his site, many people will use cheap drivers or a poor design for the sake of building something big.

I understood that both these designs went the larger route for the sake of efficiency and lower distortion.(ie. not requiring a small driver to carry the mid and low end)

The comment I received was "simpler is always better."

As I am new to speaker building, I hoped someone with experience would give some insight on these 2 designs.

[jerome69]

Originally Posted by usmcjlp

My concern is that I don't want to give up sound quality for the sake of volume. As Zaph wrote on his site, many people will use cheap drivers or a poor design for the sake of building something big.

I understood that both these designs went the larger route for the sake of efficiency and lower distortion.(ie. not requiring a small driver to carry the mid and low end)

Yes. Troels and Zaph are good designers

Originally Posted by usmcjlp

The comment I received was "simpler is always better."

Absolutely false, better to received is "doing it in the right way is better".

Originally Posted by usmcjlp

As I am new to speaker building, I hoped someone with experience would give some insight on these 2 designs.

These designs have been done by very experiment designers from two different continents, well built and the philosophy of design are different : high efficiency, classic MTM 3 ways.The two design have strength and weakness. It is always a compromise. These designs work all together well. Nobody have the truth.
Nobody cannot give you any idea of what is the best. it's depend on you, your budget, your taste, your skill to mount them, your room, your electronics etc. I cannot give you an opinion, it will be my taste.

Good luck.

[usmcjlp]

Jerome69 thanks for replying. Has anyone here built these speakers? Does anyone have experience with SB Acoustics and their sound quality?

[tom42107]

usmcjlp, just wondering if you have decided on either one of those projects yet. I too am trying to decide on a floorstander for critical listening. Have you also looked at the Elsinore project?

Elsinore Speakers DIY

Tom

[usmcjlp]

I had not found this design. Thank you. I'm assuming that price is in Australian $. I think, I am leaning towards the SB12.3. Talked to madisound and the standard crossovers use Clarity SA caps. SB Acoustics has a center channel design on their website under the name Elok which I could modify per Zaph's recommendation of adding 2 8" SB drivers to the outside of the mids. I'm still not sure. I intend to make my decision this weekend. The cabs will take some time to build. I have 3 kids, so I'm lucky if I get one afternoon a weekend in my shop.

[ScottG]

The two speakers you are looking at are in different "leagues".

Troel's design is basically in a "cost no object" category. Zaph's is built for value and overall construction ease.

If you have the cash then by all means select the Troels design. If you don't then consider the Zaph design.

In addition to the Elsinore, consider the Statements by Jim Holtz (or their derivatives)..
Statements
HTGuide Forum - Missions Accomplished!

..I'd still opt for Troel's design.

[usmcjlp]

Scott G can you explain why these are in different leagues? I have priced both systems to include shipping. The SB12.3 will be about $1200 and the DTQWT about $1700, before cabinet costs. I can afford both. I may be wrong but I was concerned about the following:

1. Low end bass response. I don't want boomy bass. But I want serious impact for home theater use. The specs on the eminence 10" drivers seem to imply that they will be limited to about 50hz.

2. I get the impression that the DTQWT is more geared towards audiophile style recordings. Troels explains that it is intended as a high efficiency tube friendly speaker. I have a solid state amp that is rated at 200/350 into 8/4 ohms. I wonder what the combination would sound like.

I really like Troels' design. For anyone considering it, he is great. I have emailed him several times and he always responds quickly. ScottG, I would like to know why you consider the SB12.3 as lower quality. Th drivers are in the same price range and the response curves seem relatively flat with no major issues for both. I am new though and it is difficult for me to get much simply off of specs.

[ScottG]

I think it comes down to design experience..

Troels has a *lot* more experience with a very wide variety of loudspeakers, drivers, crossover components, etc.. in actual designs (..built and tested loudspeakers). At some point the designer moves on from purely techincal excellence to something more artisan in nature, and Troels is further beyond Zaph in this regard (..and most designers actually).

As to the DTQWT:

1. I doubt it would be "boomy", and actually I think it would be far less "boomy" than the SB12.3. Further, you can "tune" this aspect of the DTQWT by increasing the "fill" in the QWT. Low freq. extension will be a bit *lower* near the average with the DTQWT, but below 30 Hz will be attenuated in sp-level when compared to the SB12.3.

2. I don't think the amplifier is limited by the design, rather the design is limited by the amplifier. If your amplifier is good (and the rest of your audio equipment is as well), then it will sound good. If your amplifier is excellent then it will sound excellent.


The SB12.3 is a *very* well designed loudspeaker, AND the drivers are good - bordering on excellent. That's not really this issue, rather it's "one vs. the other". There is good and then there is *better*. One thing I *don't* like in the design is that the *large* baffle is loading the upper mid through the treble region (1 kHz up to 8 kHz , which tends to reduce the subjective sense of depth). The 8" driver in the DTQWT is more directive, and the tweeter is cut before it strongly becomes "omni" at lower freq.s - and therefor is NOT being loaded by the baffle to the same extent.