Best way with two bass drivers

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Daniel Quinn
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Best way with two bass drivers

Unread post by Daniel Quinn »

Assuming its about sq only. Which is the best way with 2 bass drivers.

1. Isobaric
2. Two drivers on the baffle in series
3. Two drivers on the baffle in parralell

Whats your thoughts

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Dr Bunsen Honeydew
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Re: Best way with two bass drivers

Unread post by Dr Bunsen Honeydew »

Daniel Quinn wrote: Sat Dec 15, 2018 5:23 pm Assuming its about sq only. Which is the best way with 2 bass drivers.

1. Isobaric
2. Two drivers on the baffle in series
3. Two drivers on the baffle in parallel

Whats your thoughts
All work but differently depending what you want, parallel multi drivers is WAF, normally combined with a port for even more distortion and pretend bass. This is the choice of all loudspeaker manufacturers if they go for this bullshit as it makes the amp *seem* more powerful or compensates volume wise for shite inefficient cheap over complex crossovers.

Series wiring is much better but is not done now because of ignorance and is less powerful due to higher impedance. Usual lack of understandings, amps prefer it so respond better musically. The extra impedance means feck all to level, just needs one notch or so more on volume. It should be combined with minimal crossover if any at all, best for doping.

Isobaric is an odd one, remember it is only my opinion, it *can* be very good but it is more likely to get it wrong. The web is full of wrong and bad inf about them due to the way Linn used the concept, you need to go back to the original RCA papers late 1940's. I use them in vertical mode.

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Re: Best way with two bass drivers

Unread post by Lindsayt »

As a general rule - at least in the old days, if they're 16ohm drivers wire them in parallel. If they're 4 ohm wire them in series. If they're 8 ohm get 4 of them and wire them in series and parallel, or at a pinch wire them in parallel and use an amplifier that'll cope OK.

I generally, based on my very limited experience with isobaric, prefer mounting both on the baffle. But that might be more down to the KEF drivers in my isobaric speakers not being a patch on the Bozak drivers in my twin baffle mounted speakers, as well as the Bozaks being in more of an infinite baffle cabinet...

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Re: Best way with two bass drivers

Unread post by karatestu »

Dr Bunsen Honeydew wrote: Sat Dec 15, 2018 5:52 pm
Daniel Quinn wrote: Sat Dec 15, 2018 5:23 pm Assuming its about sq only. Which is the best way with 2 bass drivers.

1. Isobaric
2. Two drivers on the baffle in series
3. Two drivers on the baffle in parallel

Whats your thoughts
All work but differently depending what you want, parallel multi drivers is WAF, normally combined with a port for even more distortion and pretend bass. This is the choice of all loudspeaker manufacturers if they go for this bullshit as it makes the amp *seem* more powerful or compensates volume wise for shite inefficient cheap over complex crossovers.

Series wiring is much better but is not done now because of ignorance and is less powerful due to higher impedance. Usual lack of understandings, amps prefer it so respond better musically. The extra impedance means feck all to level, just needs one notch or so more on volume. It should be combined with minimal crossover if any at all, best for doping.

Isobaric is an odd one, remember it is only my opinion, it *can* be very good but it is more likely to get it wrong. The web is full of wrong and bad inf about them due to the way Linn used the concept, you need to go back to the original RCA papers late 1940's. I use them in vertical mode.
Some cracking pearls of wisdom from the Doc in this post. :clap:

After listening to my 12 inchers wired in series Doc's view about series wiring is finally becoming a reality to me. I can't fault the presentation. I have struggled with comparing the isobaric pair between being wired in parallel and series. I know I am throwing in the third variable of isobaric loading which increases the complexity of the situation.

There is the obvious lowering of volume when they are wired in series. But there is something else at work here :think: Is it the effect on the amp which the Doc said "amps prefer it so respond better musically" ?? There is an increased sense of ease to the music.

I always worried about series wiring together all five of the tweeters I have per channel as the load is over 30 ohms. Don't know why I worry when they sound so good - maybe it is the obsessive side of my character coming out. I know things are on the right track when I can listen for hours on end and have no fatigue at all.

To this end it has made my next decision about the bass set up in my speakers. I was wondering how to wire in a third 12 incher behind the existing two. I know Doc will be sending lightning bolts about how I have done things (clamshell configuration) but we must ignore that if we can :whistle: If I can get back to sealed box with no foam then it will be worth it I think. The third driver will reduce the required box volume again.

I couldn't wire all three in parallel as that would end in a two ohm load approx = amp killer. Two in series and in parallel with the third would work electrically but for some reason I can't get on with that idea. So after reading the Doc's advice above I have settled on trying all three in series = approx 24 ohm load. We will see what becomes of that when I get round to buying the drivers (if anybody has any).
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Re: Best way with two bass drivers

Unread post by Lindsayt »

If you have 5 tweeters per channel, use 4 of them wired in a combination of series and parallel to result in a net impedance that's the same as 1 tweeter And keep the 5th tweeter as a spare.
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karatestu (Sat Sep 05, 2020 4:41 pm)

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Re: Best way with two bass drivers

Unread post by Daniel Quinn »

Kara, the docs mantra of simple being best also applies to the number of loudspeaker drivers. 😉
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karatestu (Sat Sep 05, 2020 4:41 pm)

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Re: Best way with two bass drivers

Unread post by karatestu »

Daniel Quinn wrote: Sat Sep 05, 2020 4:33 pm Kara, the docs mantra of simple being best also applies to the number of loudspeaker drivers. 😉
I wish you had told me that sooner because I have just added a down firing tweeter and that makes six per channel :doh:
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Re: Best way with two bass drivers

Unread post by karatestu »

Lindsayt wrote: Sat Sep 05, 2020 3:22 pm If you have 5 tweeters per channel, use 4 of them wired in a combination of series and parallel to result in a net impedance that's the same as 1 tweeter And keep the 5th tweeter as a spare.
That has occured to me however I am well and truly hooked on the addition of more tweeters :lol: It seems to work well as long as you don't have more than one on each panel. So six is the maximum for me.

Plus Doc said the amp likes driving the higher impedance. I will take his word for it. Plus having lots of tweeters in series dropped the volume of them relative to mid and bass so I could get rid of the padding resistor which originally was 12R. I like the increased omni effect that having a teeter firing in six directions gives. Plus distortion is dramatically reduced when sharing the work out between several tweeters especially where a first order high pass is used (single series capacitor).

Anyway this thread started by DQ was about bass drivers but I suppose it is applicable to mids and tweeters as well.
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