Stryke AV12 sub teething problems!

[paulspencer]

New DIY sub in progress - Stryke AV12. Here is what I would like it to look like:



(please ignore the oversized vent - yes I know it is too big to fit in that box!

ATM I have a 70L test box and have so far experimented with sealed (including a 40L version) and vented with a 4" vent. It is controlled with a subwoofer processor kit from Jaycar with a 2nd order low pass filter, one band parametric eq and a rumble filter.

Problem: they don't integrate well with my transmission line main speaker! Midbass is lacking. They seem to lack the subtlety and musicality I'm looking for.

I want this to work well for both music and home theatre, but I don't want to have to trade off deep bass desirable for movies so I can get them to make accurate music! Music, however is the main priority.

In particular I wonder if I would be better off with a 4th order crossover so I can set it higher, but I don't think this will quite get the extra midbass.

Thanks for your input guys

cheers,
Paul

[wintermute]

Hi Paul,

The link to the pic appears to be broken, It's not coming up for me anyway.

What xover freq are you using? How do the TL's sound if you run them by themelves with no high pass/sub? Do they still sound like they lack mid bass, or just deep bass?

Not sure I can really help, but hey I like to try

Regards,

Tony.

[Volenti]

Geocities don't allow direct linking, copy/paste the link.

You will need to expriment with phase and room placement of the sub, also if the TL mains don't go down very low it will be very difficult to match with a conventional sub design, as you have found.

Have you considered a TL sub enclosure?

[wintermute]

Originally posted by Volenti
Geocities don't allow direct linking, copy/paste the link.

Good thinking

Wicked looking subs Paul, I'm glad it's you and not me that's striving to get there though (lets just say I'm woodworkingly challenged)! Ive taken the liberty of uploading the pic

Regards,

Tony.

edit: Now that's weird as soon as I added the pic the original came up. So I have taken it out again, save some bandwidth

Hmmmm maybe it's cached. I'll put it back in............

[paulspencer]

I'm not sure why the pic wouldn't work!!! Strange ... hard to know cos on my system it works hmmmm....

My TL's are fine. The midbass isn't particularly punchy, but they are also natural sounding and I was happy with them. I used to listen to them with the bass boost on though, I have yet to hear speakers that I thought had enough bass without some boost.

My TL's go down low. In the small room I have them in now, with a little bass boost they extension was such that they did a good job at HT as well and managed to capture some very low bass (for 6.5" drivers). I wanted the subs to let them relax a bit more, especially when I take them into a larger room. But it seems like I still need a little boost to try to fill in the gap - typically +4 db on the bass tone control. I would prefer not to do that so I can get more headroom on my mains.

Volenti:
I did consider TL subs, but have dispensed with the idea, mainly due to the size. Even Martin King didn't think it was worth pursuing!!! He suggested sealed. As I see it, a TL is an approximation of an IB sub with the only advantage over an IB to justify the huge box being increased control of excursion. It comes down to not being prepared to live with such a big box. I came up with a design using Martin King's Mathcad model, but it was too big! ... also I have already visited the Chiropractor after lifting my main TL speakers!

How do you suggest I mess with phase? My processor doesn't have phase control. According to a reliable source (I won't name names), phase controls on subs are useless, I'm unsure. Any thoughts?

Tony:
Yes it is a construction challenge. That will no doubt be another thread later on! ... I have a good idea of how I want to build it. I will construct a matrix of bracing with horizontal sheets setting up the curve. 3mm sheets of MDF will be bent around the curve formed by the bracing frame and glued together. This will give me a stylish and neat curve (I won't rely on planing or other arbitrary methods of getting a curve - I have had previous experience with that kind of tedium!!!)

I'm also considering applying two techniques of making an inert box:
1. lining the panels with a half inch layer of oil based modelling clay to dampen panel vibrations
2. constrained layer damping - a box within a box connected via silicon rubber or similar adhesive

Resolving construction challenges is the easy part at the moment!

cheers,
Paul

[Volenti]

Originally posted by paulspencer


How do you suggest I mess with phase? My processor doesn't have phase control. According to a reliable source (I won't name names), phase controls on subs are useless, I'm unsure. Any thoughts?


cheers,
Paul

The sub may be out of phase (or partially) with the main speakers, simply swap the sub's wiring around and see if the bass improves (or worsens), at least that's one easy thing to tick off the "to do" list.

Also the relitive positions of the main speakers, the sub and the listening position can conspire to foul the base response up, try moving the sub around and listen for changes.

[sfdoddsy]

Rather than working in the dark, you might try measuring to see what is really happening.

The simplest way is to use the Radio Shack SPL meter as a mic, and download the demo version of ETF from www.etfacoustic.com.

That way you can see if you do have a mid bass deficiency or you are just not used to a different type of bass.


Cheers

Steve

[paulspencer]

Steve,

I've had some offers to help with measuring and perhaps it's time to take up those offers, and get them measured, as you say. I think I will also get my mains measured, and that may tell the story.

cheers,
Paul

[oz]

G,day paul,

Its good to see you mate . Has been a while since i saw you last, jungie was telling me that you had built yourself a set of speakers. It would be good to catch up with you at some stage if i can and pic your brain for a bit of help as i am trying to build a set of speakers for myself. Didnt think i would run into you hear lmao.

Take care bro.
Tyrone,

[paulspencer]

Tyrone!!!!

Gasp, shock, surprise!
I didn't expect so see someone I know on here!


Sure, it would be good to catch up,
give me a call sometime, you have my number
and if not, my email is on this thing

cheers,
Paul