[AJinFLA]

 Fjendbo, we should be seeing build pics by now! 

[Fjendbo]

We really should! It's been over a month since I've had a chance to work on the speakers so I guess I'll finish in a year or two 

So far I have cut the panels and measured and drilled starting points for the router/jigsaw for the rounded edges and woofers. That's about it.

[Fjendbo]

AJ, would you recommend running the woofers in series resulting in an 8-ohm load (75 watts to each), or run them individually 4-ohm load (about 270 watts to each) according to spec?

I assume the amplifier will be happier with the 8-ohm load but running them individually gives more options in the DSP and available power.

[AJinFLA]

AJ, would you recommend running the woofers in series resulting in an 8-ohm load (75 watts to each), or run them individually 4-ohm load (about 270 watts to each) according to spec?

I assume the amplifier will be happier with the 8-ohm load but running them individually gives more options in the DSP and available power.

I can't recall your amp, but with a Zmin of 3 ohms, I'd go series.

[Fjendbo]

It's a NuForce MCA-20. But I'll try out series first then.

Regarding the load, isn't only a potential problem if you actually push the amp to use the additional power? I'm even less experienced when it comes to amps

If it requires a certain amount of power to play at a given level, does it matter whether it's 4 or 8 ohm? Let's say 20 watt/4 ohm per channel/woofer compared to 40 watt/8 ohm in a single channel.

[AJinFLA]

It's a NuForce MCA-20. But I'll try out series first then.

If it requires a certain amount of power to play at a given level, does it matter whether it's 4 or 8 ohm?

Your amp can only swing so much voltage. So it doesn't matter series or parallel, it will deliver roughly same power to each driver, it's just that parallel might cause heating issues and a bit more stress. Keep series, it will get just as loud.

[Fjendbo]

They will not be connected in parallel in any case; series or a separate channel to each woofer
But series it is. I just thought having separate DSP channels would allow for better control of any unwanted floor effects or similar (if any) from the lower woofer in particular.

Would I then gain any benefit from connecting each Neo8 to their own channel instead of in series? Like baffle step correction on each driver.

When measuring the woofers is it then just right between the drivers and 1m away? And the same with the Neo8’s if in series?

[Fjendbo]

Finally had some time to work on the project!

[mkane]

  That's a start. Congratulations.

[matevana]

Finally had some time to work on the project!

Is that a genuine Hoover extension tube and agitator assembly?

[Fjendbo]

No, I don't think it is. It's for a garden hose.

Is it for size comparison?

[Fjendbo]

  That's a start. Congratulations.

Yes, it's a start. Long way to go, though.

[matevana]

No, I don't think it is. It's for a garden hose.

Is it for size comparison?

LOL, sorry. I just thought it would be fun to comment on something totally random for a change.

[ttan98]

hi,
Try this site:
http://www.diyaudio.com/forums/multi-way/231353-aino-gradient-collaborative-speaker-project-48.html#post4231049

with direct experience in implementation.

[JohnR]

Build and measure!

 

[Fjendbo]

Hi again,

This project isn't dead, although it could seem like it.

A question related to the woofers whether I should connect them in series or let each have a DSP and amplifier channel. This time it relates to Le.

I have learned that Le is significant if you are to play higher frequencies - the lower the better. My 15" drivers have an Le of 2.031 mH at 1kHz while Acoustic Elegance Dipole15-D8 (for a premium example) have an Le of only 0.04 mH. Since Le doubles in a series connection, I will see Le double to 4.062 mH. My gut tells me that this can be no good.

Isn't it better to feed each driver with an amplifier channel then and keep the Le at 2.031 mH with regard to higher frequency performance?

Thanks!

[ttan98]

Hi again,

This project isn't dead, although it could seem like it.

A question related to the woofers whether I should connect them in series or let each have a DSP and amplifier channel. This time it relates to Le.

I have learned that Le is significant if you are to play higher frequencies - the lower the better. My 15" drivers have an Le of 2.031 mH at 1kHz while Acoustic Elegance Dipole15-D8 (for a premium example) have an Le of only 0.04 mH. Since Le doubles in a series connection, I will see Le double to 4.062 mH. My gut tells me that this can be no good.

Isn't it better to feed each driver with an amplifier channel then and keep the Le at 2.031 mH with regard to higher frequency performance?

Thanks!

You find Spatial audio uses this type of woofer from AE with great success, go to Spatial you find Clayton(designer) uses this woofer on his new OB speakers X2. He crosses this woofer at around 800Hz.

[Fjendbo]

You find Spatial audio uses this type of woofer from AE with great success, go to Spatial you find Clayton(designer) uses this woofer on his new OB speakers X2. He crosses this woofer at around 800Hz.

Yes, I have seen the new X2. It's good to a manufacturer using a similar driver configuration and crossover frequency as I'm planning, although my drivers won't be of the same high quality. AE woofers are way out of my budget.
4 Dipole15 woofers will be about $2200 USD (woofers, shipping to Denmark, VAT in Denmark, handeling by local post office).

[JohnR]

A question related to the woofers whether I should connect them in series or let each have a DSP and amplifier channel. This time it relates to Le.

...

Isn't it better to feed each driver with an amplifier channel then and keep the Le at 2.031 mH with regard to higher frequency performance?

Connected in series, Le will double but so will Re. I don't think there would be any effect on the frequency response.

If the woofers are poorly matched there might be some sort of issue.

Separate amp channels will of course give you more power. I don't know why you would use a seperate DSP channel for each though.

I wonder if you may have a bit of "analysis paralysis" (easy to do ) If you only have enough amp channels to connect in series, do that then measure and see 

[Fjendbo]

Connected in series, Le will double but so will Re. I don't think there would be any effect on the frequency response.

If the woofers are poorly matched there might be some sort of issue.

Separate amp channels will of course give you more power. I don't know why you would use a seperate DSP channel for each though.

I wonder if you may have a bit of "analysis paralysis" (easy to do ) If you only have enough amp channels to connect in series, do that then measure and see 

So little to no effect on frequency response. Good.

I have 8 amp and DSP channels so I am able to hand a set of each to each woofer and will, in that case, link the DSP channels two and two. I will probably run the woofers in series but still add binding posts to each woofer and then do the series connection via the binding posts. Then I will have the option to change the woofers to 8 ohm drivers in the future, if I wish to do so.

And yes, you are spot on regarding "analysis paralysis". I am by nature better to analyse than act and having limited time to act and plenty analyse just adds to it.

--------

About the amp, I have some trouble with it. If any of you wise people who reads this have anything to add to that case, I will be grateful.
See the thread here http://www.audiocircle.com/index.php?topic=152859.0