4 way Frankenstein high efficiency speakers

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Lindsayt
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4 way Frankenstein high efficiency speakers

Unread post by Lindsayt »

With big thanks to SteveS for organising the Owston event and providing the inspiration for making my own DIY'd speakers.

As well as to Richard Dunn, for waking me up to the fact that there are valid alternatives to Linn - way back in about 2008. As well as confirming quite a few things that I discovered about speakers and speaker drivers over the years since then.

This may be a long running, slow burning thread because the speaker drivers I'm looking for are cherry picked items from speakers from by-gone years. That come up on ebay from time to time at various prices. And I'm relatively happy with the turn-key speakers I already have.

So I'm in no hurry. And what I'm aiming for is the best pair of speakers I can put together for the least amount of money.

I'm aiming for 4 way high efficiency speakers. Based on my admittedly somewhat limited listening tests over the years, high efficiency speakers have a zest, a life, unfettered openness that's lacking from low efficiency speakers. Dynamic ease.
The shut-in, polite BBC type sound is not for me. I don't like it when transient peaks are smoothed off.

So, I'm aiming for speakers that will be about 96 dbs or more efficient.

My plan is to position the drivers so that they will be approx equidistant from the listening position and to use simple 1st order crossovers.

I intend initially using sealed or near infinite baffle cabinets for the woofers and seeing how I get on with that. With the possibility to go semi open baffle semi ported as a shameless copy of SteveC's red and black speakers.

So far I have bought:

2 x EV ST350 tweeters with Dolly Parton type horns

2 x midrange horns. I've been on the look-out for matching compression drivers. As well as certain other midrange horns that look ugly but have a legendary reputation in some circles.

2 x Altec 414-8C's 12" woofers. These will probably be the most expensive drivers I buy. They are supposed to be good upper bass / lower midrange drivers. It will be interesting to hear how they sound in my project...

I have been looking out for certain 18" woofers. I've still got an open mind and could go for 21" or 24" woofers. It looks like whatever I buy will be a compromise. Ideally I'd like woofer that are 96 or more dbs efficient in a sealed box / semi infinite baffle. That would extend down to 20hz. Although pragmatically speaking, I'd probably be happy enough if they started rolling off at 40 hz.

I can find woofers that will do this in a ported cabinet. Yuck. I don't like ported bass.
And I can find woofers with the bass extension in infinite baffle, but with the downside of about 92 dbs efficiency. I'm guessing that the woofers with the greater bass extension in non-ported cabs have higher moving mass (as well as suspension differences?) resulting in lower efficiency?

So it looks like my bass woofer / cabinet choice will be a big compromise...

I don't want to go active, because I'd rather not place an active crossover in my signal path.
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savvypaul (Sat Aug 14, 2021 9:40 am) • CycleCoach (Sat Aug 14, 2021 9:47 am)

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r3xj0hn570n
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Re: 4 way Frankenstein high efficiency speakers

Unread post by r3xj0hn570n »

I know exactly where you are coming from regards dynamics. My speakers have a 12" JBLs in a, quite large, transmission line cabinet. Above that is a horn loaded ribbon tweeter, above that, a 10" Coral fullrange unit without any sort of baffle at all. It's mounted by a clamp on the magnet. I was considering a 4 way, but didn't think i needed it. It's the Coral speaker that most "startling".

It's all active, so the varying efficiency (the JBLs are nothing special efficiency wise) of the drivers doesn't matter.

Other things you could consider is a slot loaded baffle, Nelson Pass has an interesting suggestion with the bass unit firing down into a closed V, or even a cardoid arrangement to try and control directivity.

You'd be much better off at least handing off the bass to another amp. You don't need much of a crossover in the upper 2/3 units.

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Lindsayt
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Re: 4 way Frankenstein high efficiency speakers

Unread post by Lindsayt »

With me being a Richard Dunn acolyte and with me finding the bass of my Bozak Symphonies to be "good", I'll be starting with sealed box / semi infinite baffle for the bass enclosures.

I've not been impressed with the bass of the transmission lines I've heard so far. But then I've not heard any with 12" JBL woofers.

My thoughts are that if SteveS can produce a tonally neutral 4 way passive speaker with 18" woofers, I should be able too.
My effort might need some room reinforcement to fill out the area from 60 hz to 40 hz. But that would be fine by me. It's the in room response - how it sounds at my listening position that counts. And large speakers are better if they can be placed in corners or backs to the wall, instead of having to be pulled out into the room.

What's for sure is that my DIY effort will have a more extended bass than speakers like the Falcon LS3/5a, which start falling off at 100 hz as shown in the Stereophile measurements:
Image


I'm expecting my initial effort to have bass extension similar to the $21,000 Dynaudio Confidence 30's:
Image
Whether that will be good enough to my ears in my room remains to be heard...

If not, I can always move on to Plan B...

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Re: 4 way Frankenstein high efficiency speakers

Unread post by SteveTheShadow »

@Lindsay,
I think you mean Steve S not me, Steve C.
My speakers are single 12” Fane 12-250TC, triple-cone full-range drivers in 80L, aperiodic loaded enclosures.
They were sealed, but the aperiodic loading I implemented last year, made them come alive. Because of the pandemic, nobody has heard them but me, so don’t read too much into that.

It’s Steve S who has the large red painted cabs with the 4 way slotted baffle arrangement.
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Lindsayt (Sun Aug 15, 2021 11:13 am)
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Re: 4 way Frankenstein high efficiency speakers

Unread post by Lindsayt »

Thanks Steve. Edited accordingly.

Your speakers are also an inspiration.

Because you went ahead with sealed cabinets and got great results. Especially for the amount of time and money spent on your speakers.

In a way my speakers would be a variation on yours. 12" driver in a sealed cabinet. Except in my case, less of a full range driver and therefore supplemented with a squawker, tweeter and larger woofer...

And my cabinets will be rougher looking than your professional looking ones....

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Re: 4 way Frankenstein high efficiency speakers

Unread post by r3xj0hn570n »

Lindsayt wrote: Sun Aug 15, 2021 9:45 am I've not been impressed with the bass of the transmission lines I've heard so far. But then I've not heard any with 12" JBL woofers.
Thanks to the effort of people like Martin King, transmission lines are far better than they used to be.
Lindsayt wrote: Sun Aug 15, 2021 9:45 am And large speakers are better if they can be placed in corners or backs to the wall, instead of having to be pulled out into the room.
Open baffle speakers, IME, don't like being placed close to the front wall, so you'll loose that option i think. The side wall is another matter, i believe they could be employed well there.

Anyway, best of luck. You'll be looking for a high Qts driver, preferentially, Fs as low as possible which is hard when you want high efficiency.

This has been the go-to for this requirement for quite a while.

https://www.eminence.com/speakers/speak ... =Alpha_15A

but there are others in the range that might suit you better, like

https://www.eminence.com/speakers/speak ... elta_15LFA

Have a look around, they aren't expensive.
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Re: 4 way Frankenstein high efficiency speakers

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Re: 4 way Frankenstein high efficiency speakers

Unread post by Docfoster »

This looks like a great project!
IME building one's own speakers is a ridiculously good, and relatively easy, way of making one's system sound as one wants.
I can thoroughly empathise with the high (or possibly "low") bass expectations!
Helpful that you have a few fixed component- and deign- points for your design, based on your own experiences and preferences.
(And I happen to agree with avoiding active circuits beyond the main amp.)
I look forward to seeing how this progresses.
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Lindsayt (Mon Aug 16, 2021 4:03 pm)
System 1: JRiver MC24 > Dell Latitude 7270 > Asus Xonar Essence One Muses Edition DAC & pre- > One4 Class A power amp (with Dynamic PSU boards) > DIY Monacor SP-310CX speakers & DIY Dayton Audio SD315A-88 bass cab.
LC Audio Technology mains DC filter > Sovereign MTBPS balanced power supply
TQ (Wonfor) Ultra Black cables.

System 2: Anything with a headphone socket > Inca Tech Claymore > DIY Monacor SP-308CX speakers

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Re: 4 way Frankenstein high efficiency speakers

Unread post by savvypaul »

Got these 14 inchers in our 'office party' system...

Image

:mrgreen:
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CycleCoach (Mon Aug 16, 2021 1:41 pm)
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Lindsayt
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Re: 4 way Frankenstein high efficiency speakers

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14 inch Pioneer woofers?

When Dr Frankenstien put his monster together, did he use the brain of the village idiot, the feet of the village leper and the ears of Beethoven?
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CycleCoach (Mon Aug 16, 2021 4:57 pm)

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