New Member Introduction

[mattformanek]

Howdy all! I'm an amplifier builder from Wisconsin U.S.A. and putz around with speaker projects in my spare time. Current project includes an Onken cabinet to house a pair of Altec 515b's per channel and finishing off this system with Altec 311-90's w/288C or 288-16K drivers and a pair of GOTO UNIT SG-17SA tweeters. These will be my living room speakers to replace the 70th Anniversary Cornwalls that I'm currently using. I've been in contact with Troy Crowe who may be helping me out a hair with the Onken design....., we'll see.

[MarcAL]

You can't go wrong with large format Altec horns and Onken cabinets.

If you go with passive crossovers, the Hiraga crossover network is definitely a winner.

 

Welcome to Stereonet

[mattformanek]

Thanks MarcAL, I do intend to use the Hiraga crossover network as an eventuality. However, I also just bought two of the newer active boards that Nelson Pass designed that are sold on the DIY Audio site to build active crossovers. My thoughts are to build these to get an idea of the performance of the speaker system "in-room", then to see if the Hiraga passive values are close in terms of frequency and slope. Although I'm sure that I'm missing something in what will be the translation. Also, rather than just using a bunch of giant wound inductors in the Hiraga crossover I'm wondering if anyone has gone the route of using the FineMet autoformer inductors that are available? Any idea?

 

Thanks! Matt.

[MarcAL]

I expect that the autotransformers would be okay for the crossover points but I would stick with a good quality air core choke for the filter network.

The choice of good quality components made the biggest difference for me.

[mattformanek]

Great! Thank you for the insight. Maybe a last question for now, would you know of anyone who has redesigned the Onken 360L (cabinet volume, etc.) for use with a pair (2) per cabinet of any of the Altec 15" drivers, et al., 416-16Z, 515b's, or 803a's? Obviously this is only done to increase the efficiency of the woofers getting them a little closer to the efficiency of the 288's.

 

I have two pair of each 416-16Z's and 515b "Holleywood" drivers. I was wondering which of these two would be the best performing in such an enclosure. 

 

Thanks again, Matt.

[MarcAL]

Yes to the first question some with great results.

The very best single driver in my opinion based on testing every single Altec driver is the 416-8A/416A/803B/416-16Z in the standard Onken cabinet. 
I have tested others and took measurements however some drivers require the cabinet to be tuned. 
When I built my cabinets I allowed for port extensions to be fitted if required to get the cabinet tuning lower. 

[Lansche plasma guy]

On 21/4/2024 at 11:46 AM, mattformanek said:

Great! Thank you for the insight. Maybe a last question for now, would you know of anyone who has redesigned the Onken 360L (cabinet volume, etc.) for use with a pair (2) per cabinet of any of the Altec 15" drivers, et al., 416-16Z, 515b's, or 803a's? Obviously this is only done to increase the efficiency of the woofers getting them a little closer to the efficiency of the 288's.

 

I have two pair of each 416-16Z's and 515b "Holleywood" drivers. I was wondering which of these two would be the best performing in such an enclosure. 

 

Thanks again, Matt.

I'm a bit late to the party and only read this one post from you but this has been done before and used by Jean Hiraga and the Maison L'audiophile people since the early 1980's.  The box was called the Grande Onken or Onken W.  

 

Heard them in France when I went to the L'audiophile store and our very own Melbourne Duc had a pair built also which he used for a couple of years before he passed away.

 

Good boxes.  Just remember It was recommended that this box (like all the Onken's) was to be used with a transistor amp only (Tubes didn't have enough damping to control the driver in the box).

 

LPG

[mattformanek]

Thank you MarcAL for your insight into the single-driver Onken cabs and which 15" sounds best. I've been enjoying the 416-16Z's in my modified 846a Valencia cabs for several years. But now that I'm ready to move on to the large format horns I have decided to go to two drivers per cab for the boost in efficiency (since at the very least, in parallel, I'll have an 8 Ohm load with the 416's or a 10 Ohm load with the 515b's). Thanks also to Lansche Plasma Guy, Yes, I'm aware of the Hiraga Onken W.............., however, I don't have the real estate to do speakers that wide. My preference is for a modification to the volume/ports of the original 360L cabinet, so that I may mount the two drivers vertically and try to somewhat retain the narrower footprint of the 360L as compared to the Onken W. I can deal with creating a mounting bracket system for the 311-90's that allows for the GOTO tweeters to sit between the top of the Onken cab and under the 311's. This speaker system is my dream-speaker, and has been since I heard the first pair of Jensen cabinets with the same type of slot-ports as the Onkens in Japan in the 80's.... However, I believe those cabs were loaded with JBL D130's if memory serves.

 

Hopefully Marcus can point me in the right direction with the cabinet and passive crossover build.

 

Thanks much. Matt.