JBL Frequency Response

[neil jackson]

Hi, I have a pair of JBL MRV310 floorstanders from the 1990s. I recently had a frequency response graph done by a audio repair shop. This showed a dip in the 1k to 2k hz range. (all else appeared ok) Can someone tell me if this is to be expected from this type of speaker or what sort of problem it suggests. Please note that both speakers dipped within the range so I don't think it's a crossover issue. Many thanks.

 

[fmw]

Hi, I have a pair of JBL MRV310 floorstanders from the 1990s. I recently had a frequency response graph done by a audio repair shop. This showed a dip in the 1k to 2k hz range. (all else appeared ok) Can someone tell me if this is to be expected from this type of speaker or what sort of problem it suggests. Please note that both speakers dipped within the range so I don't think it's a crossover issue. Many thanks.

Hard to say. How much of a dip?

 

[Tomorrow]

I think the issue is indeed caused by the crossover. Maybe it's JBL's 'thing'. Here is an FR graph of my JBL EC35 before and after being optimized by Dennis Murhpy of Salk/Philharmonic fame. Note the big 6 dB dip around 1600 Hz. (Ignore data below 200 Hz...it's a floor bounce issue.)

Before:



After:

 

[neil jackson]

Hi and thanks for your replies.

In terms of the size of the dip: between 1k and 2k hz it drops from 92 db approx down to 80db. Over the rest of the range the graph is above 90db.

Can someone please advise how i can insert the graph into my reply as it will be easier to see what i mean.

regards

 

[Tomorrow]

To insert the graph, you need to go to a photo hosting site such as photobucket.com and upload the picture/graph. Then select and copy the IMG option and paste it in your post here.

I'm not surprised by the FR that you report. Yes, it could most likely benefit from a crossover optimization...provided the person doing it is skilled and experienced at the activity.

What you report is a typical example of how many manufacturers report specs that just don't pan out in reality.

 

[neil jackson]

thanks Ninja

I will insert chart asap. What if anything would I notice listening wise with the "dip" i've described ?

 

[Pyrrho]

Hi and thanks for your replies.

In terms of the size of the dip: between 1k and 2k hz it drops from 92 db approx down to 80db. Over the rest of the range the graph is above 90db.

Can someone please advise how i can insert the graph into my reply as it will be easier to see what i mean.

regards

Assuming they measured correctly, that is enough of a drop that either JBL was really careless in the design, or perhaps there is a component in the crossover that is no longer operating within specifications. Capacitors can change value over time, particularly cheap ones.

 

[neil jackson]

Hi please see a copy of the frequency response chart i have mentioned. Does it indicate something i should try and resolve or would it not bother the average listening ear? Thanks again for all your advice.

http://s1362.photobucket.com/user/neiljackson3/media/9e7eb6ba-a5bc-4e18-9bf7-33b44144ba60_zpsaf03e0aa.jpg.html]9e7eb6ba-a5bc-4e18-9bf7-33b44144ba60_zpsaf03e0aa.jpg

Photo by neiljackson3 | Photobucket[/url]

If pic dosen't come through - please copy and paste into browser.

Ta

 

[neil jackson]

opps don't think that link works-will keep trying-sorry

 

[neil jackson]

hi

have followed the suggestions above re posting the frequency response chart however all I get is as below-what am I doing wrong?