Hestia OB, an ambitious low cost, 3-way OB design

matevana · « **Reply #120 on:** 22 Dec 2012, 05:19 pm »

Quote from: Plund on 21 Dec 2012, 01:29 am

I hesitated (hestiatated?) a few days too long to order from MCM...they show a 90 day back-order on the 55-2981 drivers. I received all other needed components from Parts Express. Thankfully all is not lost...I will likely fill at least most of that waiting time finishing a pair of FH3's.

Pete

Pete,

I have another pair of 55-2981 in boxes if you are interested.

Plund · « **Reply #121 on:** 23 Dec 2012, 02:45 am »

PM sent.

newbie7800 · « **Reply #122 on:** 23 Dec 2012, 03:46 pm »

Dear Matevana

There I was about to order everything and then realised the MCMs are 3 months on back order. ....

Could I do the project with 4 Dayton Audio drivers? I saw your changed cross over design for the DA as the midrange driver so I think it is possible. What do you use to drive the DAs when you swapped them around? I am worried that at 300w my dussun would struggle to drive the DAs as midrange drivers. Using the MCMs I only had to invest in the plate amp. Any suggestions, otherwise I will order the MCMs and just sit it out and wait.

Thanks

Newbie

matevana · « **Reply #123 on:** 23 Dec 2012, 04:08 pm »

Newbie,

I do not recommend using the Dayton drivers in the original Hestia design as a midrange driver. For one, the presentation is different and it will change the overall character and sound. Additionally, the Dayton's will require a Zobel network (and possibly a trap) and the MCM's will not, which would ultimately make your crossover more complex. If you don't mind the wait too much, I would suggest opting for the MCM stock to be replenished. Sorry about that!

Driving the Dayton's wouldn't be an issue with your equipment. The bigger concern is that the MCM's have an early roll-off which plays into the overall design and it's proper integration with the D19. The Dayton's have a somewhat forward sounding midrange which would require additional components to tame them.

Note that the Hestia design is actually very efficient. The mids can be driven with as little as 15-20 wpc. Higher powered amps usually have higher damping which will take better control of the driver's motor. I am using a Crown D-75a for both my original Hestia's and the new Hestia-SL. The D-75a is a very high quality, well damped broadcast quality amp, that can be purchased used for a fraction of their original cost. They are only 40 wpc and one of the best kept secrets in home audio.

Ed

Plund · « **Reply #124 on:** 22 Jan 2013, 05:22 am »

Thanks to Ed's well-stocked driver supply, I now have all the hardware needed to begin the Hestia build...yahooo! In reading some of the posts, it seems the baffle can get a pretty good work-out with some volume. Would it be recommended to have at least 1" baffle thickness...possibly doubled-up 3/4" BB?

Pete

sjhomey · « **Reply #125 on:** 22 Jan 2013, 02:25 pm »

Plund

I would recommend throwing together a pair on test baffles first. I used scrap 3/4" plywood. Its quick and would answer a lot of questions and also get you listening to them pronto. I went with a taller version and have a fair amount of vibration. I am driving them with only a 25 watt amp so they are not dancing across the floor, but a hand placed on the baffle can feel the vibration. I don't know how much it robs from the efficiency, they sound great. Matty speaks of them being laid back in comparison with the SLs, but they sound precise and revealing to me. I can now hear the lyrics. I am doing a slow build of the SLs, waiting for parts to go on sale, so at some point I will be able to compare.

Matevana suggested to me somewhere above to use the c channel from the conventional shelving systems sold in the big boxes to stiffen baffles. I think he said somewhere that that solution might even work bettrer with a thinner baffle. Test baffles would allow you to play around with different configurations.

matevana · « **Reply #126 on:** 22 Jan 2013, 02:39 pm »

Pete,

Glad to hear you're getting ready to start the build! A few things to keep in mind. Those who speak of baffle vibration built their versions with larger baffles to accommodate either larger bass drivers or wanted to elevate the drivers. If you plan to build with the stock dimensions, the driver frames will keep the baffle free-space from vibrating excessively. You should not need to double up on baffle thickness. If you do, you may want to chamfer the rear opening so you don't create a tunneling effect (with its own resonance) from the extra thick baffle.

It's funny but the only negative aspect of building test baffles is as follows. In two situations that I know of, the individuals enjoyed listening to the test baffles so much, they never got around to building finished ones!

Keep us informed on the build!

Ed

sjhomey · « **Reply #127 on:** 22 Jan 2013, 05:27 pm »

Well I guess use the most paint splattered, splintered,stained junk you can find as a safeguard. Building and finishing the baffles is the most time consuming part of the build.

matevana · « **Reply #128 on:** 22 Jan 2013, 08:05 pm »

Quote from: sjhomey on 22 Jan 2013, 05:27 pm

Well I guess use the most paint splattered, splintered,stained junk you can find as a safeguard. Building and finishing the baffles is the most time consuming part of the build.

Or an old baffle that says "Bose"

Plund · « **Reply #129 on:** 23 Jan 2013, 02:00 pm »

Thanks for the info on baffle vibration...I will plan to use 3/4" birch and keep the height close to the original (possibly stretch it two inches).

I can see myself as one of those who would never get the drivers moved from the test baffle to the finished version...for that reason I will skip the test baffle. I trust the testing you have already done!

My question is... will I like/prefer OB? ...I will find out.

Pete

mluc8 · « **Reply #130 on:** 3 Feb 2013, 07:22 pm »

Has anyone tried the Hestia OB with either 2 of the 10" woofers or a 15" so as to get more SPL.
Thanks from a newbie.

matevana · « **Reply #131 on:** 8 Feb 2013, 08:04 pm »

Quote from: mluc8 on 3 Feb 2013, 07:22 pm

Has anyone tried the Hestia OB with either 2 of the 10" woofers or a 15" so as to get more SPL.
Thanks from a newbie.

That's herecy, lol! I'm aware of one build where the 12" version of the MCM driver was substituted for the ten, and another build with the Hestia top end and a separate H-Frame enclosure with one Eminence 15" Kappalite 3015LF. I have heard the latter and it sounded great... maybe not as balanced as the original design but good for rock, etc.

mluc8 · « **Reply #132 on:** 9 Feb 2013, 02:09 pm »

Thanks for replying to my post. I tend to listen to rock and blues and sometimes it is fun to listen to it a little louder than usual so that is why I asked about either a larger driver or multiples. I currently have a pair of Speakerlab Cornerhorns which of course have plenty of bass and pack quite a wallop. Will open baffles have any where near the bass? Or should I be thinking of a sealed sub to go with the OB? Thanks.

matevana · « **Reply #133 on:** 9 Feb 2013, 02:39 pm »

Quote from: mluc8 on 9 Feb 2013, 02:09 pm

Thanks for replying to my post. I tend to listen to rock and blues and sometimes it is fun to listen to it a little louder than usual so that is why I asked about either a larger driver or multiples. I currently have a pair of Speakerlab Cornerhorns which of course have plenty of bass and pack quite a wallop. Will open baffles have any where near the bass? Or should I be thinking of a sealed sub to go with the OB? Thanks.

When I first got interested in OB I didn't know what to expect. You almost have to hear OB bass for yourself in your own room and then determine whether you want to augment it in any way. The short answer is it sounds different. The unboxed drivers can go fairly low and be very precise but the sound interacts with the room differently. Low frequencies don't pressurize the room as they might with boxed subs, and you will probably hear things in the music that you have never heard before. It's almost a quality vs. quantity issue. It's a little bit like making the change from Coke to Diet Coke. If you had to switch back after some time, you might miss the crispness and refreshing taste and be overwhelmed by the super sweet syrupy taste. Sorry for the cheesy soda analogy, but for someone who hasn't heard OB bass it helps put things in perspective.

Plund · « **Reply #134 on:** 19 Mar 2013, 04:50 am »

Ed,
The "Hestia's" I have been working on are not quite finished yet, but last week I got to the point were I was able to connect to an amp and achieved "first sound". Connected to my model 912 Pioneer solid sate receiver and in my 15x17 bedroom they sound AWESOME! ... Very nice design you created...thanks for sharing! I have moved them to a larger "Bonus Room", were I can comfortably keep them a few feet out from the wall...they will be part of another system being put together. Before removing from the bedroom, I enjoyed listening to their large, well-rounded sound and after several hours of listening didn't want to stop.

I find them well balanced, with plenty of bass (and I do Like bass). With the exception of adding 6 inches distance between the MCM Mid and the Dayton Woofer, I kept your original version's configuration.

I will attach a few pics when this pair is completed. Earlier this evening I epoxied magnets into the Hestia grills...grills are the only items remaining.

Pete

Borris · « **Reply #135 on:** 19 Mar 2013, 06:29 am »

Matevana, I just saw that the mcm 10 inch woofer is not available until the end of June. You have mentioned a possible 12 inch sabstitute, would the crossover stay the same or would it require changes? Did you have a chance to hear it? Thank you

matevana · « **Reply #136 on:** 19 Mar 2013, 10:35 am »

Quote from: Plund on 19 Mar 2013, 04:50 am

Ed,
The "Hestia's" I have been working on are not quite finished yet, but last week I got to the point were I was able to connect to an amp and achieved "first sound". Connected to my model 912 Pioneer solid sate receiver and in my 15x17 bedroom they sound AWESOME! ... Very nice design you created...thanks for sharing! I have moved them to a larger "Bonus Room", were I can comfortably keep them a few feet out from the wall...they will be part of another system being put together. Before removing from the bedroom, I enjoyed listening to their large, well-rounded sound and after several hours of listening didn't want to stop. I find them well balanced, with plenty of bass (and I do Like bass). With the exception of adding 6 inches distance between the MCM Mid and the Dayton Woofer, I kept your original version's configuration.

I will attach a few pics when this pair is completed. Earlier this evening I epoxied magnets into the Hestia grills...grills are the only items remaining.

Pete

Hi Pete,

Great to hear. I can assure you from experience that they will only get better over time due to the break-in characteristics of some of the drivers. I just moved my original Hestias into the bedroom after making some small changes. Don't forget to post some pics!

Ed

matevana · « **Reply #137 on:** 19 Mar 2013, 10:42 am »

Quote from: Borris on 19 Mar 2013, 06:29 am

Matevana, I just saw that the mcm 10 inch woofer is not available until the end of June. You have mentioned a possible 12 inch sabstitute, would the crossover stay the same or would it require changes? Did you have a chance to hear it? Thank you

Hi,

I haven't heard the 12" version myself in this design, though I do believe one of the folks on here built it that way. The original woofers are fairly polite where they meet the mid driver. This is important since the mid driver is allowed to roll-off naturally in this design. Worst case is the transition between the two drivers wont be as clean. If this becomes an issue for you, you may be able to clean things up a bit by inserting an F-mod (inline passive crossover) onto the interconnect that goes to your main amp. Something like the 100hz high pass F-mod should clean things up if necessary. This should allow you to use the original crossover design. Your setup would have to allow you to pass an unaltered signal to the plate amp separate from the line affected by the inline crossover; they have RCA splitters that do this if your amp/receiver doesn't allow for it. You may not need to do this if the results are satisfactory to you.

Ed

Plund · « **Reply #138 on:** 22 Mar 2013, 11:43 pm »

Ed, Here are several pics of your Hestia's. I am pleased with the completed build, but even more pleased with how they sound! Thanks again for sharing your design! They are being enjoyed here at the opposite end of the country in Washington state.

Pete

matevana · « **Reply #139 on:** 23 Mar 2013, 12:11 am »

Killer job Pete!

Like your interpretation of the baffle shape and grilles. Really nice touch! You should be proud.

Remind me how you decided to drive the Dayton woofers?