Jamo R909 crossover - Need your help

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Plasmatico

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Jamo R909 crossover - Need your help
« on: 17 Dec 2017, 01:12 am »
Hi all. I have on loan a pair Jamo R909 that I'm seriously considering to buy, but the previous owner modified the crossover and even though we've tried to restored it to factory spec there is a noticeable lack of bass. I will very much appreciate your help and advice. If anyone has the Jamo's 909 XO schematic, pictures of the XO, values or can help in any way I will very much appreciate it. These speakers are a real stoner in like new condition and I would to keep and restore to its former glory.

Thanks in advance,

MJC

FullRangeMan

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Re: Jamo R909 crossover - Need your help
« Reply #1 on: 17 Dec 2017, 01:26 am »
Do you already try email the factory?
Or better the previous owner.

At this hi price Jamo research this speaker very well, hard to get better result than the factory.

Plasmatico

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Re: Jamo R909 crossover - Need your help
« Reply #2 on: 17 Dec 2017, 01:47 am »
Yes I did. I emailed them and this was their response. I contacted Freeman Tell and they did not have the XO specs. I've even tried contacting the designer, to no avail. I guess someone on here would be much better help anyway.

>>>MJC, unfortunately we dont have that detailed of information regarding the 909 crossover. You will need to contact one of our repair centers.

You will want to contact Freeman Tuell Speaker Repair. (One of our authorized repair centers)

I have provided their contact information below.

Freeman-Tuell Speaker Service, LLC
7911 Ferguson Rd.
Dallas, TX 75228<<<

Plasmatico

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Re: Jamo R909 crossover - Need your help - With XO pictures
« Reply #3 on: 18 Dec 2017, 05:09 pm »
I figured I upload the before and after pictures of the crossover. The before picture are with the mods the previous owner made and the after picture is the way the look now, after we clean them up and tried to put them back to what we think are factory specs.

If anyone is familiar with the these speakers/XO, please take a look and let me know what you think.

Thanks,

MJC





poseidonsvoice

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Re: Jamo R909 crossover - Need your help
« Reply #4 on: 18 Dec 2017, 05:38 pm »
Plasmatico,

Have you done close mic'd measurements (about 1-2 inches from the woofer cone) using REW or equivalent to prove that indeed there is a lack of bass or change in the dipole equalization?

Best,
Anand.

Manolo

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Re: Jamo R909 crossover - Need your help
« Reply #5 on: 18 Dec 2017, 06:01 pm »
The only items that were replaced were the caps. The original resistors and inductors were left in place. Unless modifications were made to the board traces,  the probability that there was a mistake in the cap replacement in their original positions is low... seems to me. Please note that bass reproduction by OB speakers is not the same as with  box systems....It has less impact and "boominess"

FullRangeMan

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Re: Jamo R909 crossover - Need your help
« Reply #6 on: 18 Dec 2017, 06:11 pm »
The only items that were replaced were the caps. The original resistors and inductors were left in place. Unless modifications were made to the board traces,  the probability that there was a mistake in the cap replacement in their original positions is low... seems to me. Please note that bass reproduction by OB speakers is not the same as with  box systems....It has less impact and "boominess"
So you could contact member Jeff from Sonic Craft,
he have large experience with crossover caps.

Plasmatico

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Re: Jamo R909 crossover - Need your help
« Reply #7 on: 21 Dec 2017, 02:16 am »
Happy to report everything is fine, and the crossover is (was) fine as well. The problem was the preamp I was using, for some reason it didn't play nice with the Jamo, replaced it with a Hovland and the magic is back.

richidoo

Re: Jamo R909 crossover - Need your help
« Reply #8 on: 21 Dec 2017, 02:31 am »
Upgrading to Solens? That's a first.
If you buy them, consider ditching those.
I bet the original caps were better. ;)

Glad you found the problem, and good luck with the Jamos!

FullRangeMan

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Re: Jamo R909 crossover - Need your help
« Reply #9 on: 21 Dec 2017, 02:33 am »
Incredible!!! Congratulations for sortout.

JohnH12

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Re: Jamo R909 crossover - Need your help
« Reply #10 on: 22 Dec 2017, 03:37 am »
Upgrading to Solens? That's a first.
If you buy them, consider ditching those.
I bet the original caps were better. ;)


+1. also looks also like little polyester bypass caps

John H

Plasmatico

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Re: Jamo R909 crossover - Need your help
« Reply #11 on: 27 Dec 2017, 12:01 am »
After the horrible mod we wanted to get them as close to factory spec as possible and the originals were Solens. Only mod we kept is the bypass. Sound is beyond my expectations. Incredible these speakers were not as popular as they should have.

Open to amp suggestions.

FullRangeMan

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Re: Jamo R909 crossover - Need your help
« Reply #12 on: 27 Dec 2017, 12:06 am »
Incredible these speakers were not as popular as they should have.
This speaker is not exactly cheap.

richidoo

Re: Jamo R909 crossover - Need your help
« Reply #13 on: 27 Dec 2017, 12:55 am »
Open to amp suggestions.

86dB. They like big power, 200W SS minimum recommended by the manufacturer.

matevana

Re: Jamo R909 crossover - Need your help
« Reply #14 on: 29 Dec 2017, 07:38 pm »
Schiit Vidar. Buy it and don’t look back.

nickd

Re: Jamo R909 crossover - Need your help
« Reply #15 on: 29 Dec 2017, 08:25 pm »
I had the 909’s quite a few years ago. I really liked them, but bass was not their strongest attribute. GR research OB subs were not available back then or I might still have them. Get some OB subs and high pass your main amp at 80-100hz. You might really like the results.  :thumb:

Plasmatico

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Re: Jamo R909 crossover - Need your help
« Reply #16 on: 6 Jan 2018, 12:00 am »
My top contenders for the Jamo are: Parasound Integrated, Hegel 360 and Modwrght. Difficult to audition any of them since they don't have a local dealer. Doing lots research and keeping my ears open to suggestions.