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Dayton B652-AIR IMPROVED

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  • Dayton B652-AIR IMPROVED

    Yes, improved significantly. Not perfect by any any means, but much more listenable if you are willing to spend another $60 or so on the mods I did.

    As noted in the original PETT Wolf-authored thread on this new speaker from Dayton, the tweeter is the jewel. The woofer definitely isn't. Nor is the token amount of fiberfill used.

    The Dayton DC160-4 is a great drop in replacement with much better specs, a coated paper cone and a PE recommended closed box volume of 0.23 cu. ft - almost exactly what the -AIR has.
    Meas. T/S parameters on the two DC160-4s I bought showed a Qts of 0.37 vs 0.64 for the factory woofer. 60 Watts power handling. The factory woofer is marked 30W. Basic SPL eff. is about the same. Le = 0.62 for the DC160-4 and 0.78 for the factory woofer.

    I also removed the very thick and useless paperboard gasket from around the DC160-4 frame. This must be done carefully so the rubber surround below it isn't damaged. I did this because I was suspicious it might contribute to some of the diffraction ripples seen in the Holm plots.

    The next thing I did was reverse the tweeter polarity connections at the back of the tweeter like the other modder did. Also added considerably more stuffing. About 10 inches of stripped R-13 OCFG insulation.
    Replaced the 3 ohm tweeter resistor with a 12W Mills 6 ohm resistor because the highs were measuring and playing a bit hot. Lastly, I added a 1 mH air core coil (20 ga.) in series with the woofer.

    With these changes box Fc dropped from 90 hz to 73 hz and Q from 1.6 to a more respectable A.S Q of 0.9. With my room gain, I claim a freq. response of +5 -10dB from 40 to 20 kHz and a slight drop in efficiency from 87 [email protected] to 86 dB. Not an audiophile speaker with ruler flat response, but for $ spent, well worth it.

    Below are some Holm test measurements taken with the grilles off.

    Click image for larger version

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    On axis @ 1M blu line, red line - factory woofer close mic'd - B652-AIR as rec'd from P.E. Note the 1-2 kHz hump in the woofer response.

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    On axis @ 1M, DC160-4 woofer close mic'd, extra stuff and 1 mH coil & 6 ohm resistor. Note the sharp rolloff of the woofer above 4 kHz.

    Click image for larger version

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    Response with tweeter leads pos. to pos. neg to neg.

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    Dayton DC160-4 close mic'd in B652-AIR cabinet, with FG stuffing and 1.0 mH coil. The 1-2 kHz hump no longer present. Also note how smoothed down the response hump is in the 100 hz range.

    Click image for larger version

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    Close up of the Tweeter's polar plots taken at 1M. Blu=on axis, Red=45 deg, grn=30 deg.

    I've been listening to the speakers for a couple of days now and really like the smooth transition from woofer to tweeter. I use the speakers with a powered 8 inch sub to fill in the lowest 2 octaves a little. However, standing alone on my 26 inch cherry speaker stands, these guys hold up quite well on their own. I plan to add an inexpensive binding post block to each speaker to make hooking them up to my stereo easier. With grilles on, the modded speakers weigh almost 2 1/2 lbs heavier than factory weight.
    Lastly, while I'm installing the binding post blocks, I may install a brace up the inside of each sidewall.
    Next summer's CAS speaker shoot out will be their premier.
    Last edited by carlspeak; 10-26-2014, 10:48 AM. Reason: last plot color line correction
    Live in Southern N.E.? check out the CT Audio Society web site.

  • #2
    Re: Dayton B652-AIR IMPROVED

    Nice job! Looks promising.
    Don't worry, if your parachute fails, you have the rest of your life to fix it.

    If we all did the things we are capable of doing, we would literally ASTOUND ourselves - Thomas A. Edison

    Some people collect stamps, Imelda Marcos collected shoes. I collect speakers.:D

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    • #3
      Re: Dayton B652-AIR IMPROVED

      Very nice! Thanks for keeping us posted..

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      • #4
        Re: Dayton B652-AIR IMPROVED

        Amazing considering! Beefing up the enclosures should get rid of some of the "wibbles and wobbles". I didn't think with the OEM enclosures anything this good was possible. Did you experiment with either a full 2nd order XO on the woofer or a Zobel-type network? You've gotten excellent results, I must hand it to you. The original B652's can't come close to this level of performance for $60 in the OEM enclosures, and spending $60 on the B652's kinda defeats their purpose. The AIR's on the other hand look to have some promise. Excellent work!

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        • #5
          Re: Dayton B652-AIR IMPROVED

          I hope to have the mind trust at DIY-NY evaluate a pair.
          Kenny

          http://www.diy-ny.com/
          DIY NY/NJ 2014 https://www.youtube.com/watch?v=FGwA...ature=youtu.be
          Man does not live by measurements alone, a little music helps.

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          • #6
            Re: Dayton B652-AIR IMPROVED

            I didn't do much experimenting. Just had the 1 mH coil on hand and gave it a try. Also took a shot at the 6 ohm resistor. I'm sure more fine tuning could be done to optimize things a bit more, but I'm happy with what I have for the moment.
            Don't think it will ever be a silk purse in that cab, but I'm not about to build a new one to find out. Major saw dust days are behind me.
            It was a fun little project to tinker with. Once I tested that tweeter, I knew there was fertile ground worth exploring. Even with the 6 ohm resistor, the highs still sparkle. 3rd HD runs in the 1/2 to 1% range and could most likely be reduced further with higher order filter slopes. However, I'm more of a KISS kind of DIY'r. Besides, it would seem to me to be impractical to expect these little speakers to play at very loud volumes. Treat them like LS3/5a's and you'll enjoy them emmensly.
            Live in Southern N.E.? check out the CT Audio Society web site.

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            • #7
              Re: Dayton B652-AIR IMPROVED

              Carl,


              How do you characterize the sound of this mini AMT tweeter vs a good quality dome tweeter? BTW, a simple 6uf is used in the tweeter circuit in AR3a. People are still looking for a modern replacement for the aging 3a tweeter. The wide horizontal dispersion of AMT certainly makes it an attractive possibility.

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              • #8
                Re: Dayton B652-AIR IMPROVED

                Originally posted by ligs View Post
                Carl,


                How do you characterize the sound of this mini AMT tweeter vs a good quality dome tweeter? BTW, a simple 6uf is used in the tweeter circuit in AR3a. People are still looking for a modern replacement for the aging 3a tweeter. The wide horizontal dispersion of AMT certainly makes it an attractive possibility.
                Better than a 'good' dome tweeter.

                If you are looking for that 3a tweeter replacement, I think vintage-AR on the bay may still have modded AB Tech 3/4 inch tweeters. I have bought, tested and found they are as close as anything I've tried to original. Not cheap though.

                BTW, most ribbon tweeters have very good off axis response - side to side (not so much up and down). It's the result of their makeup.
                Live in Southern N.E.? check out the CT Audio Society web site.

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                • #9
                  Re: Dayton B652-AIR IMPROVED

                  Fooling around a little, with some assumptions, like the AIR tweeter is 7 ohms pretty flat and needs to cross at ~3800 Hz, the OEM B652 woofer "zooms" to about 7 ohms @ 3800 too. That's right in the middle of one of it's break-up nodes.

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                  • #10
                    Re: Dayton B652-AIR IMPROVED

                    Originally posted by carlspeak View Post
                    Yes, improved significantly. Not perfect by any any means, but much more listenable if you are willing to spend another $60 or so on the mods I did.

                    As noted in the original PETT Wolf-authored thread on this new speaker from Dayton, the tweeter is the jewel. The woofer definitely isn't. Nor is the token amount of fiberfill used....

                    Thanks for the tip--I just bought these speakers as a fill in til I can replace my mains that were heisted. That woofer you link is exactly what I was looking for.

                    I know it's ridiculous for the pricepoint, but I have no better use at the moment for my DEQX and amps so I plan on bi-amping and adding DRC just out of curiosity to see how much quality can be extracted from the AMT as I might end up using one (much larger version) in my replacement speakers.

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                    • #11
                      Re: Dayton B652-AIR IMPROVED

                      Originally posted by JRS View Post
                      Thanks for the tip--I just bought these speakers as a fill in til I can replace my mains that were heisted. That woofer you link is exactly what I was looking for.

                      I know it's ridiculous for the pricepoint, but I have no better use at the moment for my DEQX and amps so I plan on bi-amping and adding DRC just out of curiosity to see how much quality can be extracted from the AMT as I might end up using one (much larger version) in my replacement speakers.
                      Interesting. With digital EQ'ng via the bi-amp mode you should be able to go further than I did optimizing the FR. Perhaps cross the tweeter a bit lower at a high slope and the woofer at a high slope to tame the 3 kHz breakup mode.

                      If you can take some measurements and share some listening impressions once you get it humming, I'd love to read what you have to report.
                      Live in Southern N.E.? check out the CT Audio Society web site.

                      Comment


                      • #12
                        Re: Dayton B652-AIR IMPROVED

                        Originally posted by Whitneyville1 View Post
                        Fooling around a little, with some assumptions, like the AIR tweeter is 7 ohms pretty flat and needs to cross at ~3800 Hz, the OEM B652 woofer "zooms" to about 7 ohms @ 3800 too. That's right in the middle of one of it's break-up nodes.
                        Too bad the tweeter can't cross at 3K/18dB because if it could I'd try an old MCM bi-amp plate with one.
                        "We are just statistics, born to consume resources."
                        ~Horace~, 65-8 BC

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                        • #13
                          Re: Dayton B652-AIR IMPROVED

                          Originally posted by carlspeak View Post
                          Interesting. With digital EQ'ng via the bi-amp mode you should be able to go further than I did optimizing the FR. Perhaps cross the tweeter a bit lower at a high slope and the woofer at a high slope to tame the 3 kHz breakup mode.

                          If you can take some measurements and share some listening impressions once you get it humming, I'd love to read what you have to report.
                          Absolutely will do as suggested. In theory I should be able to make a silk purse from a sows ear but obviously harmonic distortion, dynamic compression, cabinet resonances won't be slain with this particular approach. However, in the past I was able to take a pair of cheap (240/pr) JBL monitors and basically convert them into something nearly the equivalent of Infinity preludes which were selling for an outlandish 10K/pr which I happened to have a pair of for a while. I sold them immediately after that experiment....;)
                          Obviously deep bass not the same or dynamic capability but it is absolutely astonishing what can be done to a cheap speaker with decent drivers--much bigger dividends actually then with an expensive speaker where the effects are more incremental. Just need to get the woofers and a mic to replace the one I lost and I will be set. I'll post results here.

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                          • #14
                            Re: Dayton B652-AIR IMPROVED

                            I finished up the speakers yesterday - I think :-)

                            Installed the binding post terminals (PE 260-302). While I had the stuffing out of the cabinets, I weighed it. Just about 1/4 lb. of OCFG which matchs perfectly my rule of thumb for FG stuffing of A.S. speaker @ 1 lb/cu. ft rate. Again, Fc was reduced about 15 hz from the factory value of 90 hz with the new woofer and FG stuffing and a Q of about 0.88.

                            Also, added 10 inch long, 1/2 inch thick X 3/4 inch wide stiffening pine braces up the insides of each cabinet.

                            Lastly, I made a couple of minor XO tweaks. Installed 8 uF ERSE MET caps in place of the factory 6.8 uF NPE's and installed 5 ohm Mills resistors in place of the 6 ohm ones I originally tried.

                            Listening impressions,
                            These guys can play pretty loud. Some ref. music peaked at 100 dB @ my listening position about 7 feet from each speaker with no abvious signs of distortion. Great soundstage with much depth as well.
                            Live in Southern N.E.? check out the CT Audio Society web site.

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                            • #15
                              Re: Dayton B652-AIR IMPROVED

                              Originally posted by carlspeak View Post
                              I finished up the speakers yesterday - I think :-)

                              Installed the binding post terminals (PE 260-302). While I had the stuffing out of the cabinets, I weighed it. Just about 1/4 lb. of OCFG which matchs perfectly my rule of thumb for FG stuffing of A.S. speaker @ 1 lb/cu. ft rate. Again, Fc was reduced about 15 hz from the factory value of 90 hz with the new woofer and FG stuffing and a Q of about 0.88.

                              Also, added 10 inch long, 1/2 inch thick X 3/4 inch wide stiffening pine braces up the insides of each cabinet.

                              Lastly, I made a couple of minor XO tweaks. Installed 8 uF ERSE MET caps in place of the factory 6.8 uF NPE's and installed 5 ohm Mills resistors in place of the 6 ohm ones I originally tried.

                              Listening impressions,
                              These guys can play pretty loud. Some ref. music peaked at 100 dB @ my listening position about 7 feet from each speaker with no abvious signs of distortion. Great soundstage with much depth as well.
                              So yesterday I finally had a few hours. Removed the old woofers, dropped in the replacements. Brought the tweeter leads out the back for biamping while disconnecting the XO. Ran them without any corrections--just a symmetrical 96dB/octave at around 3.5K. Not horrible once I cut the tweeters back by about 5dB. Even so somewhat shouty but the sibilance mostly tamed.

                              Next step was to take some measurements and create the correction filters. Went pretty well until the cats started fighting. Try again.
                              Both sides measure similarly. Creating the corrective filters not quite as simple as usual as there is no overlap in the passbands--both sides falling off and getting jagged, but finally in the grand canyon south rim pick 4K, and window down to 140 Hz as the measurements looked reflection free out to 6-7 ms. Listened without subwoofer. Not too shabby, but clearly no miracles here bass-wise from a 6" in a 0.2 cu ft enclosure.

                              Brought in the Dayton 18HO into action and XO'ed at 80. Hey these aren't bad! Ended up listening for 4 hrs after a visit to a local brewpub with wife and friends. Usually she loses interest after a couple of hours of audio only entertainment but the tunes just kept suggesting themselves up for play.

                              Part of it was undoubtedly due to the fact that we were both in serious music withdrawal. But she liked them well enough to stay up well beyond her bedtime, and at one point (curse her cold, cruel heart) remarked that she liked them better than the last system (MTM using Usher 8945a x2 + Sartori tweeter) I built.

                              I took no offense really as I knew exactly what she meant--no listening fatigue whatsoever. Whats more I have several FLAC recording obtained by dubious means that just weren't very listenable including a couple of faves--Imagine by Eva Cassidy and Rumors by Fleetwood Mac. The little AMT's had a way of presenting the highs that allowed the excessive detail to just hang in the air without the usual irritation. I've had some speakers before come close to pulling this off but without the overall finesse here. Another place where this was really noticeable is Dave's True Story Spasm album There are a couple cuts where mastering issues and distortion are way too apparent and why Chesky remastered this remarkable recording in the first place. Just plain eerie listening to the distortion yet in some weird way completely detached and unbothered by it--more like hmmm, isn't that interesting, is it deliberate?

                              Speakers overall were (especially as dialed back volume) not shabby at all--not enough dynamic punch, still shouty/breaking up at some frequency that while no longer cringe producing, raked a few cells off the ole eardrums with each and every pass. As I have time this w/e I'll post some pics and msmts and maybe even try again at tweaking the filters. But I gotta say these little guys I have definitely taken a major shining to. Also have unequivocally and emphatically answered the question I had re AMT, as it had been a few decades since my first and only exposure came one sat afternoon when I first heard the ESS speakers. Definitely see why so many price-no-object speakers from Steinway-Lyngdorf, Legacy and Aurum Cantus to name a few are using them. Just a matter now of which AMT as I want that finesse to extend down to at least 2.5K.

                              I really gotta hand it to PE for making these tweeters available in a decent package for price of a nice dinner out. Another sixty for the better woofers and I have something I can live with for the next few months while I come up with an AMT build.

                              And thank you, Carl, for the write up and suggestions.:applause:


                              John S.

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