Fast, fun, Inexpensive OB project

[Pano]

How about Farnell, Davy?

 

[davym]

I did wonder about them, the trouble is I don't want to compromise on the design. You and John have clearly put in a huge amount of effort to optimise it and I need to be sure that any alternative components are of a similar spec and can deliver the goods. The main issue for me is in finding suitable inductors. Can you advise me a little here please. For example what current rating would they need to meet?

EDIT - I checked Farnell again, no use.

A company called Falcon Acoustics in the UK wind large inductors to order. It's going to be next year now before I can afford to take on any more projects so it's on the back burner for a bit anyway.

They have the Peerless driver though so I might be able to source most of the components from them.

I'll get the missis onto this next year, she's a good researcher and although she has no interest in amp's, she wants to get involved in diy speakers. She can't complain about them being too big either if she helped build them so i'm all for it.

 

[kec]

I'll get the missis onto this next year, she's a good researcher and although she has no interest in amp's, she wants to get involved in diy speakers. She can't complain about them being too big either if she helped build them so i'm all for it.

Nice strategy Davy

 

[Pano]

If you don't find the parts, let us know here in the thread. You are looking for big inductors with low DCR. Erse and the Madisound work well. I've also used the Janzten bobbin type. There are going to be expensive, with the price of copper today - no matter where you get them.

 

[RKH]

Baffle Fabrication Question

In post 455 John describes using "pine 2" X 2" rear sub frame. (1.5" X 1.5" dimensional net)" to mount the side wings to the front baffle.

My question: is this (the 2 x 2 sub frame) for ease of assembly or are they required to make the assembly more rigid?

I can envision a somewhat more tidy construction with biscuit joints (only simple if one owns a the requisite tools). I have all my parts and wood and I'm ready to make some saw dust

Thanks in advance!

Ryan

 

[AndrewT]

biscuit joints can be very secure.
Maybe a biscuit every 100mm along the joint.

 

[John Busch]

Rear bracing

The rear bracing holds the larger pieces together and does provide some stiffening of the entire assembly. As way to promote simplicity of construction, I used commonly available materials where ever possible... as is the standard 2" X 2" pine stud. You can use what ever you feel appropriate. One builder used metal framing.

 

[Pano]

Ditto what John said. Use what you've got, as long as you keep the baffle and wing dimensions close to the plans. If you change those, the crossover will need tweaking.

 

[Albrerta]

Hi, I'm very interested in this one as my first diy attempt, however, want to ask 1) is it good for classical music? (all kinds, solo or big orchestra) 2) your honest opinion, is it REALLY GOOD, or just VERY GOOD BECAUSE OF LOW COSTS.

Thanks

 

[udailey]

Really good.
Best speakers at lonestar audio fest this year in my opinion.

 

[Johno]

Very really good. I cannot recommend them highly enough.
I built a pair of the Manzanitas over 12 months ago now so the drivers are nicely run in and the sound and clarity continues to amaze me. Piano sounds nearly like a real piano and the bass notes in Bach's Toccata and Fugue are awesome (pipe organ for those who don't know it).
The only down side is that compression and bandwidth limiting on poor CD recordings becomes obvious. I guess I mean poor digital re-mastering for old stuff especially when compared to the vinyl version.
Plus, a design more sophisticated and expensive would be well past the point of diminished return IMO.

 

[Marinos]

Hi John,

I'm ordering parts for your baby Manzi

Is this still valid ?

Manzi crossover tweaks.
L1. You can upgrade to a toroidal (14 Ga, 18.0 Mh PE P/N 255-844) These have tended to measure more like 19.5 Mh. Very expensive, but does provide a touch better dynamics and a bit more woofer efficiency due the much lower resistance.

I can find jantzen C-Core coil in both 18 and 20 mH and in different core diameters.
My questions are
- Should I go with the 18 instead of the 20 mH ?
- In either case larger diameter core is preferable or it's a case where "size doesn't matter"

Concerning the drivers mounting.
I can understand that flash mounting the Vifa it's the way to go.
Is it the same with the Peerless ? Is there any real benefit to do so ?

 

[John Busch]

The 20 MH Iron core is preferable. It provides a bit better control of the Peerless roll off and results in a cleaner over all sound quality in the upper mid range. Please let us know how you project moves along! John

 

[Marinos]

Thanks John !!
So I'll stick to ERSE Super Q or similar.
What about the woofer mounting ? Does it worth to be flash mounted ?

 

[Pano]

The Peerless woofer has a sort of tapered flange. I just used that on the front of the baffle. It's made to be that way.

 

[Marinos]

Thanks Pano,
I'll wait for the drivers and see..

Last question for now is if this is still valid

Manzi crossover tweaks.

L2. This component needs to stay put as is. Push comes to shove, 1.5 mh up to 2.25 Mh is way better than nothing. The lower values will brighten things up, the higher will darken the tonal balance. Lower resistance air core inductors do improve midrange quality. I have even tried 8 ga.! However, the modest improvement is hard to justify given the astronomical cost of 8-12 Ga. inductors. The 14 Ga. Perfect Lay air core is a good compromise. 18 Ga. air core and higher Ga. really degrade the effectiveness of the trap as well as the overall sound quality. BTW, stick with air core designs if possible. The speaker will play of course with iron core inductors, but you can hear them. Even 15 Ga. I.C. impart a grain like quality. Have not tried a Toroidal. If I get around to it I will report back.

Should I seek for the best quality and lowest Ga(thus DCR) I can afford ?
Since this choice affects a very important acoustical spectrum the opinion of people that have built the Mazis is most valuable

 

[max079]

Dear All,

I'm new in this topic but i would like to biuld this speaker.
The woofer is already in my hand but the tweeter still missing.
In case that i have left some other tweetersfrom my former project i just thinking to use it.
The tweeter is a Monascor DT254 which looks close in parameters to the SEAS 27TDFC
Could you help me to find out, that this Monacor tweeter are ok for this speaker?

Technical spec:
Impedance (Z) 8 Ohm
Free air resonance (fs) 900Hz
Max. frequency range fx–22kHz
Rec. crossover frequency (12dB) 2kHz
Music power 150WMAX
Power rating 90WRMS
SPL (1W/1m) 92dB
Voice coil diameter 25mm
Magnet diameter 72mm
Mounting cutout ø 85mm
Mounting depth 38mm
Dimensions ø 110mm
Weight 0.53kg

DT-254 - Monacor HiFi dome tweeter 150Wmax 8 Ohm - Europe Audio


Thanks,

Peter

 

[John Busch]

The DT-254 can work.... but it will require a LOT of crossover work and even with that the mid range output is quite limited. My original design using the Seas TDFC required quite a bit of compromise and had a very laid back sonic quality. One of goals at the time was to simply prove you could get a reasonably priced 12" woofer and a 1" class tweeter to work reasonably well together with a simple cross over. The next version using the large (and now VERY expensive Scan Speak D3800 Mid-tweet) was much better and the very low cost Vifa 3.5" full range is better yet. With price and availability of the Vifa 3.5 being so good, I highly recommend you go with that version of the Manzanita.

 

[John Busch]

Marinos..... Yes... you want a good air core (L2) inductor on the trap. 14-18 ga. will work. As per a previous post, if you go larger wire (smaller ga. #) than 14, your reach a point of diminishing returns. So.... 14 is the best balanced choice if you can do it and it is the inductor the crossover is designed around. Hope this helps. John

 

[Marinos]

Thanks John