My OB4A's??

bernard991 · « **Reply #20 on:** 28 Dec 2007, 07:21 pm »

yes Ed it does ...thanks
makes me appreciate your work even more ...
I imagine you made your cuts on the mdf as close as possible ( 1/8" ) as the result is a very smooth flowing curve ..
your pioneering work has whetted my appetite a bit ...
did you consider more Mid drivers at all ? the baffle is long enough to have a MMTMM configuration ...perhaps that would have a negative affect ?
this is a fun hobby / illness
thanks again !

HT cOz · « **Reply #21 on:** 28 Dec 2007, 08:54 pm »

Very Nice

ebag4 · « **Reply #22 on:** 29 Dec 2007, 11:16 pm »

Thanks guys.

Bernard,
Actually I have considered a MTMMMMM configuration with the Augies picking up from about 80Hz down. I would love to get one of Denny's prefinished OB7 front baffles for this purpose. I think I will play with and listen to these for a while prior to making that leap.

bernard991 · « **Reply #23 on:** 30 Dec 2007, 07:20 am »

Ed
whats the XO point now ? are you noticing any mid bass deficit at all ?
cheers
B

ebag4 · « **Reply #24 on:** 30 Dec 2007, 02:18 pm »

Hi Bernard,
The xover points are 200 and 1800 Hz as designed by Danny at GR Research. I have not done measurements but there are no obvious holes in the frequency response. One thng I have noticed is that these units sound very good at low volumes as well as high volumes.

bernard991 · « **Reply #25 on:** 30 Dec 2007, 06:56 pm »

Ed
its intriguing... I think you are having fun
if a guy was to do the MTMMM or even another MM that would do the mid bass ...would the OB format apply or possibly some kind of a box for the lower drivers then of course the OB augie ...? possibly bizarre lookin but .....there seem to be infinite possibilities ...then I think one would need to enlist Danny to do the XO
regards !
B

ebag4 · « **Reply #26 on:** 30 Dec 2007, 08:07 pm »

Benard, take a look at Danny's website, he already has the MTMMMMM with the MMMM in a cabinet, it is the OB7. For me it's OB for all of the drivers!

bernard991 · « **Reply #27 on:** 30 Dec 2007, 10:39 pm »

Ed
I should have mentioned that I am familiar w/ the OB 7 ...and I like your idea w/ the OB augie as well ...I wonder at the difference w/ the all OB arrangement you prefer to the boxed mid bass units ...?
I too like the great ambience that OB mids and highs are capable of ....
am slowly starting to formulate some plan for new spkrs in the New Year....
BTW my wife likes your speaker's looks ...always good to have a positive WAF
cheers B

KCI-JohnP · « **Reply #28 on:** 2 Jan 2008, 03:29 pm »

WOW, Beautiful work!! Very cool design too! Damn..........

WallyWest · « **Reply #29 on:** 4 Jan 2008, 12:33 am »

Wow.

Personally I'm not crazy about the brace up the back, purely for aesthetic reasons. Of course if you're sitting right in front of them you can't see it anyway. That's the only nitpicky thing I can come up with. One of my favorite phrases is "don't quit your day job". But frankly I think in this case you should quit your day job and become a speaker designer. Those speakers are amazing. If they sound half as good as they look you'd have no problem selling them by the truckload.

A++++ thread, would view again.

JANDG · « **Reply #30 on:** 5 Jan 2008, 12:22 am »

Few speakers intrigue me, but what you have dreamed up in form & function is really special. Great , great job .Yep...Quit your day job bro.!!!!!!!!!!!!!!!!!!!!

klh · « **Reply #31 on:** 5 Jan 2008, 01:41 am »

These are pretty cool and the look is gorgeous. If one wanted, could it be shrunk so the MTM is just above the Augie? Might be possible to make a center channel or fully open baffle LCR. How tall might it be?

ebag4 · « **Reply #32 on:** 5 Jan 2008, 02:21 am »

Thanks for the comments guys.

KLH, Mine are 48" tall. It is my understanding that D'Appolito configurations are suppose to be extra sensitive to tweeter position with regard to alignment with the ear. When I asked Danny how low I could place the tweeter he said between 36" and 40", basically at ear level when seated. I can tell you that the speaker still sounds great when I stand up so there is some play there. I'm not certain how going shorter and leaning the speaker back would affect the sound.

Best,
Ed

Jolojl · « **Reply #33 on:** 5 Jan 2008, 11:48 am »

Hi ebag4!

These speaker really look great! I saw them on the Hawthornes' forum and then here.

I use Silver Iris with Augies and am quite happy, the only thing being a problem is their size (I have a small room). I'm thinking of doing something similar to your speakers. I'm not sure though that my amp, a Decware Taboo which "generally favors higher impedance speakers between 6 and 16 ohms", will be suitable ... Do you know what sensivity and impendance load the MTM configuration of your speakers has?

Best!
Johan

Danny Richie · « **Reply #34 on:** 5 Jan 2008, 02:36 pm »

At some point I may try a version of this speaker using the same MTM section but try a pair of the SW-12-16FR woofers below it. Those are the new 12" Direct Servo controlled woofers that are designed to operate in free air.

The bottom end control should be great, but the question is will they play up high enough to reach them with the highest crossover point on the plate amps being 160Hz. We'll see.

Jolojl, the impedance is a pretty easy load with a minimum dip in the upper ranges dropping to 5 ohms at 4kHz. The high pass crossover on the mids keeps the impedance high in the ranges below 200Hz and of coarse the impedance rise starts a little higher than that. So there is no real current demand on the amp.

ebag4 · « **Reply #35 on:** 5 Jan 2008, 04:14 pm »

Thanks Jolojl.
I am also coming from a pair of DIY duets, I like them quite a bit, but like you I have a small room and felt a narrower pair of speakers might fit the room a bit better. While these are wider at the bottom the top section is considerably narrower than my 17" wide duets. The Augies really seem to like the wider width around them as this is the 4th speaker I have used the Augies in and they have never sounded as deep and dynamic, of course 100 watts per driver rather than 2 drivers in series sharing 100 watts has assisted in this change.

WRT the Taboo powering the MTM section, it will depend on the type of listening you do, all I can tell you is what my system is giving me currently. I am running a Bolder analog modded SB3 (low output, about 1V) into a 41Hz Amp4 running on 2 12V SLAs in series, output is 30 watts. With this configuration the available power can be a little low if I am wanting to rock with ACDC (read as "won't make my ears bleed"

) but for most material it is fine.

Best,
Ed

ebag4 · « **Reply #36 on:** 5 Jan 2008, 04:43 pm »

Jolojl, I just tried my 6 watt self modded T-amp (running on a single 12V SLA) and the volume I am getting is very good! Keep in mind that I am running this directly from the Bolder SB3 with low output voltage. Your 7 watt (?) Taboo may do fine especially when using a pre. Of course this is dependent upon the type of material and volumes you to/at, as usual YMMV.

Best,
Ed

Jolojl · « **Reply #37 on:** 6 Jan 2008, 12:04 am »

Danny: Great! Thanks! Seems like an OK load for the Taboo! If I go this way I would do exactly like ED, actively cross for frequencies under 200, passive above. I might send you an e-mail one of these days, if I may, and continue the discussion!

Ed/ebag4: Big thanks for checking this up with the T-amp, sounds very promising! I have a linestage right now with gain, and it really helps up the volume on the Taboo. This is really a very tempting combination to try out!

Need to check around a bit more but also wait for funds

...

Thanks again to you both!

Johan

TRADERXFAN · « **Reply #38 on:** 8 Jan 2008, 02:03 am »

Quote from: Danny on 5 Jan 2008, 02:36 pm

At some point I may try a version of this speaker using the same MTM section but try a pair of the SW-12-16FR woofers below it. Those are the new 12" Direct Servo controlled woofers that are designed to operate in free air.

The bottom end control should be great, but the question is will they play up high enough to reach them with the highest crossover point on the plate amps being 160Hz. We'll see.

Danny, assuming something could be done to solve the crossover problem,

you would need 2 of those 12" woofers per speaker to get enough output to match the upper MTM -- 1 is definitely not enough? I guess its all pretty hypothetical at this point though.

Would you quote your price for the MTM section?

Danny Richie · « **Reply #39 on:** 8 Jan 2008, 02:09 am »

Quote

Danny, assuming something could be done to solve the crossover problem, you would need 2 of those 12" woofers per speaker to get enough output to match the upper MTM -- 1 is definitely not enough? I guess its all pretty hypothetical at this point though.

I don't think that the crossover will be a problem, and I was planing on using two per side.

Quote

Would you quote your price for the MTM section?

Sure, shoot me over an e-mail and I'll get you a quote.