08/20/2026
Hi Steve - hope you are doing good! 🙂
My speakers are ready since some time, and have played for about 100 hours or so now (but only 50 hours with normal listening level).
Photos here below. As you can see, I changed the design a bit and had a cabinetmaker do them for me with good finish. Internals follow your instructions 100% (except that I put a brace between the magnet cage and the backside of the wall of the 1st chamber).
The rest of the system:
NOS R2R DAC being fed PCM from HQPlayer (running on a fully optimized computer, galvanic isolation on the USB output + USB regeneration, master clock synchronization of source & DAC, etc.)
ANK L5 Mentor Signature preamp
ANK 300B PSET Interstage Monoblocks
Martin Logan 1100X subwoofer (just giving a bit of support < 35 Hz)
Fyne S-Trax supertweeter (it is 360° radiating and integrates very well with no/little comb filtering and phase cancellations)
Internally in the speaker, and as speaker cables, I use Duelund DCA 12GA. This is intentional, a cable that helps with tonal color and fullness, "real" voice/instrument sound, while retaining resolution. I definitely don't want silver-plated copper or anything like that with these speakers!!
As you reported, there is considerably more energy and forwardness in the 800-2200 Hz zone, peaking around 1400 Hz. I believe such forwardness simply cannot be avoided with fullrange drivers, they all exhibit this to some extent; and is even more true with such strong magnet system and high efficiency as in the PT-10. Beaming, efficiency, cone break-up (?) - all is coming together in that zone. Without correction, the sound can feel way too aggressive on many tracks. With that energy corrected properly (using lossless EQ in HQPlayer), I find that the sound actually becomes very sweet, forgiving and non-fatiguing. In this regard every bit as sweet as the 2-way Doxa speakers that I had earlier (best drivers from SEAS & Scan-Speak, sound resembles Spendor/Harbeth). It is a full-bodied, dense and rich sound, not cold, analytical or aggressive.
NB! On purpose, I am using digital reconstruction filters in HQPlayer that avoid pre-ringing in the time domain, while doing perfect reconstruction in the frequency domain. This is a job that HQPlayer does better than any internal filter in an oversampling DAC (regardless of price) due to the immense computing power, while also avoiding the flaws of NOS DACs (IMD, aliasing, rolled-off treble, loss of detail). The filter used for 1x files (44/48K) also is apodizing, to remove pre-ringing from the AD done in the studio, a typical problem with redbook content. This approach results in very, very clean and natural leading edges. There is attack and fast transients, but fully natural and 'analog like'. Not the unnatural sharp sound and glare that we often associate with digital. This is very important, as these speakers are sensitive to such digital artifacts. Avoiding those, and the sound is sweet, dense, full, natural - and also extremely immediate, fast, dynamic, transparent. The soundstage is big and deep (the supertweeters help further with that).
There is much extra energy around 65 Hz and 130 Hz in my room, regardless of distance from the front wall. I guess this comes from the horn that is tuned for roughly 30 Hz. Is easy to fix with some EQ in HQPlayer.
The bass was not that impressive in the beginning. Now after roughly 50 hours of normal listening levels, the suspension of the driver has become more flexible and the acoustic behavior of the driver matches better with the horn. The bass is full and powerful now, matches the size of the speaker. I expect it to get even better when I reach 100-200 hours of playing at normal listening levels.
When comparing with the "ultra high-end" speakers that I've heard, the DFH-10's are different, and in a good way. Immediacy, nerve, micro-dynamics, transparency, coherence, realism is better than all of those costly speakers. No comparison even! Much more of a live feeling, the musicians are there in the room with you. Also, the paper cones are much better for tone colors/decay than the graphite/aluminum/graphene typically used by the others. They wake up with just 0,5 watt. Can absolute resolution, detail, refinement and measured performance be better in speakers costing > $ 100K? Possibly and probably. And some of them do offer room-shaking bass and full composure even at rock concert SPL. That's not my thing, though. I never play louder than 95 dB average SPL, and for that these speakers are perfectly adequate.
With the DFH-10 cabinet that you designed, the lack of bass typical for fullrange drivers has been fully overcome. In fact, bass performance is world-class in speed and quality, while the PT-10 retains all of the other advantages of the best fullrange drivers on the market (Cube, AER, Voxativ). The Fyne S-Trax enhances the treble extension. Overall, I am very happy and don't know how to improve further upon this (except for my room, of course). Think this is end-game for me.
Very happy indeed!!!
https://www.decwareproducts.com/dfh