New Posts New Posts RSS Feed - Loudspeaker EQ
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Welcome to the Graham Slee Audio Products Owners Club

 

Open to all owners plus those contemplating the purchase of a Graham Slee audio product wishing to use our loaner program: join here
Subscribe to our newsletter here (Rules on posting can be found here)


Loudspeaker EQ

 Post Reply Post Reply Page  123 5>
Author
Fatmangolf View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 23 Dec 2009
Location: Middlesbrough
Status: Offline
Points: 7801
Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Topic: Loudspeaker EQ
    Posted: 18 Mar 2021 at 7:14pm
I am preparing to hard wire in some of my mods to the GX300's. I'll probably make the 2R2 on LF switchable, perhaps with an extra cut option for late night listening. The MF boost switching is rarely used to I'll probably just keep the +2dB option as a midrange spotlight but I have been enjoying a lower MF crossover so may add this as a switching option. On the tweeter I do occasionally use the -2dB teble cut and am thinking about a similar boost by switching out the stock resistor.

Today I tried out a lot of the options in order to find which ones were interesting and listenable with the right material. Other options were either inaudible or not to my liking.

Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
Back to Top
Ash View Drop Down
Senior Member
Senior Member
Avatar

Joined: 18 Mar 2013
Location: Dorset
Status: Offline
Points: 4028
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ash Quote  Post ReplyReply Direct Link To This Post Posted: 10 Jul 2020 at 9:52pm
Yes, very different types of driver so the easiest way to equate their sensitivities.
Back to Top
Fatmangolf View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 23 Dec 2009
Location: Middlesbrough
Status: Offline
Points: 7801
Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Posted: 10 Jul 2020 at 9:44pm
Roughly speaking yes Ash. I should add that lots of passive crossovers have a resistor to balance the two drivers' outputs. Nothing is perfect.
 
Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
Back to Top
Ash View Drop Down
Senior Member
Senior Member
Avatar

Joined: 18 Mar 2013
Location: Dorset
Status: Offline
Points: 4028
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ash Quote  Post ReplyReply Direct Link To This Post Posted: 10 Jul 2020 at 6:43pm
You are using resistance to shelf one driver response above the other in a two-way? How does this affect the overlap of their responses at the crossover frequency? Raises XO point with more bass and lowers XO point with more treble?

Edited by Ash - 10 Jul 2020 at 6:50pm
Back to Top
Fatmangolf View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 23 Dec 2009
Location: Middlesbrough
Status: Offline
Points: 7801
Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Posted: 10 Jul 2020 at 6:34pm
Now an interesting finding: you can make a simple tone control using your loudspeakers, essentially a 'tilt' control where you subtly alter the balance of bass and treble extremes. Please don't try this if your amp's manual has warnings about speaker connections or you are nervous about breaking something by getting the wiring wrong.

I am assuming the speakers have separate LF and HF terminals and you normally link these together.

Please leave the link between the black or minus terminals in place and take out the red or positive link. You may wish to lower the volume on the amplifier first or put on standby if it is a valve amp. Check carefully that you are not shorting out the amplifier, the resistor should go where the link was between the two red/+ terminals. I take no responsibility if you do something silly or dangerous. If in doubt you shouldn't try this but take care and you may like the result.

Lets say you want to have more bass...
  • Plug the red/+ plug on the speaker cable from the amp into the LF+ terminal
  • Join the LF+ to HF+ using a 2.7 ohm high wattage resistor (7 or 10 watts wirewound will do for the test, you could use a higher value like 3.3 or 4.7 ohms for 8 ohm speakers)
  • Do this on both speakers sit down and listen for a while.
  • Then put things back the way they were and listen again.
The opposite wiring approach applies for getting more treble than bass, the red+ plug on the cable from the amp goes to the HF+ terminal and the resistor joins this to the LF+ so there is less bass.

Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
Back to Top
Fatmangolf View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 23 Dec 2009
Location: Middlesbrough
Status: Offline
Points: 7801
Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jul 2020 at 10:10pm
An obvious development was wiring a low value resistor in front of the + terminal on the LF side of the crossover. I worked out that 2R7 would give me a gradual rolloff to about -3dB at around 50Hz, and it did. Subtle but audible on some records.

It is very similar to the approach above with the switchable resistor in front of the tweeter filtering of the crossover. The switchable response on the PMC Fact speakers inspired my experiments.

Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
Back to Top
Fatmangolf View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 23 Dec 2009
Location: Middlesbrough
Status: Offline
Points: 7801
Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Posted: 02 Jul 2020 at 10:03pm
I did eventually rig up an A/B switching arrangement for that inductor feeding the midrange speaker. Very short cables which stayed in circuit but shorted out the new inductor.

I used a fixed position for a calibrated microphone and REW software to measure the frequency response and THD with and without. Miniscule difference, slighlty steeper rolloff and about 0.2% less THD. Which is probably inaudible. So I reverted to stock crossover, moved the test gear away, popped the inductors into one of my spares boxes, and then played more music which was nice.

Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
Back to Top
 Post Reply Post Reply Page  123 5>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.01
Copyright ©2001-2018 Web Wiz Ltd.

This page was generated in 0.078 seconds.