View Full Version : Technical Ref Threads for 4315 monitors

08-15-2007, 04:11 PM
Once more into the breach, dear friends!

No horns here - these 4ways were a different approach to Studio Monitors

A pair of 4315A Monitors,
Underneath, a 4315B Monitor, and the ever rare original 4315 with the down-low dual ports.

08-15-2007, 04:11 PM
There are 3 versions of the 4315 Monitor
The 4315 are "recognizable by the dual ports down low on the baffle. You seldom see this model and they are quite rare." (Thanks Riessen (http://audioheritage.org/vbulletin/showpost.php?p=170283&postcount=2))
The 4315a have a single port. The 4315Bs have ferrite drivers

The variations in drivers can be seen in the top rows of the chart below

08-15-2007, 04:25 PM
recommended reading - Johnaec compares the XPL200A vs 4315A


Within that thread, 4315 designer and current Chief Development Engineer for Harman Consumer, Greg Timbers, made this post:

4315 vs XPL200 (link includes response charts) (http://audioheritage.org/vbulletin/showthread.php?t=10615)
Giskard asked me to comment on this thread as I come from a position of knowing both speakers very well.

The 4315 is a very compact, high power 4 way studio monitor. It was designed around in-wall mounting although they are very rarely used that way. Its strong points are a very powerful and fast woofer (doesn't go real deep however) and a killer midbass unit. The LE5 is a little aggressive but quite lively. The good news here is that the VC alignment on the LE5 and the 2405 is nearly perfect so none of the combing that usually occurs with the 2405 used with horn drivers happens.

The 4315 requires that the HF and UHF L-Pads be turned down considerably below the "0" setting or the system is too bright. With that said, it is very dynamic, detailed and quite good tonally. It is still one of my favorite spaekers.

The XPL 200 has a killer midrange in the 091 or 093. The blend between the HF and UHF is really good as they are in the same plane and identical materials. The 2214H was chosen to give good bass extension and it does just that. Unfortunately compared to a 4" VC 2203, it doesn't have the kick or dynamics. The biggest weak link inthe XPL 200 is the mid bass unit. It uses a filled polypropylene cone with a vinyl surround. It is very smooth but it is too warm and "fluffy" sounding due to the poly collasping under drive. Another weak point is the LF/MF passive crossover topology. It was done to allow bi-amping with a simple toggle switch. The 4315 crossover uses a higher order crossover at that point and has a much more complicated switching circuit. That means money which I didn't have in the XPL.

I would only expect about 1 - 1.5 dB difference in 2.83v sensitivity in favor of the 4315. If both systems are adjusted to similar HF response (i.e. turn down the 4315 a little) and overall sensitivity I would expect the following:

The 4315 should be more dynamic and detailed below 800 Hz - 1000 Hz. The XPL200 should kick butt above that. The XPL will be considerably more 3-dimensional due to the narrower baffle and neoprene covering. It could be hard to choose between them as they are both quite nice but just different. Bi-amping the XPL really brings it to life by fixing the crossover problem and taking the LF inductor out of the path for the 2214, but a special drive slope is required to do the job correctly. The DX1 is ideal and was developed exactly for that purpose. The 4315 benefits substantially from bi-amping as well.

I'm pleased to see that both are still around and bringing pleasure to people.

08-15-2007, 05:34 PM
This is designed to be a longer term references to other resources here and outside on the web. We are trying to keep the signal to noise ratio high.

To keep the thread "on topic", please give me the next few days before posting ANY replies or comments here.

Your on-topic images, information, insights and links are most welcome and I'll give you credit for your contributions.

Your PMs are most welcome.

Thanks for your help!

Heather James

02-16-2014, 06:33 PM
Well, here's more on the 4315B.

I went through mine half because someone was asking for info on them and half as I wanted to see how they were built (and doing!) and it was an education.

I bought them in October 1980 and the joints are still very tight - I see no separation in any of the corners/edges. They have traveled quite a bit; from Anchorage, Alaska to Mississippi, then to Colorado, then back to Alaska (Fairbanks this time) and then to Abilene, Texas. They spent three years in storage while we were overseas and then were moved to the other side of Texas. We (and they) have been in the same place for almost 16 years now.

As before, this was done in Visio and dropped into Word and then converted to a pdf - so don't try to scale the drawing. if you want the original Visio file, PM me. I took a number of pictures, if you want those too, a PM will get them to you. Not sure if anybody could build a pair of them now as the 2203 and 2108 weren't made for very long, but, hey, this removes one more obstacle in your path.

An unanticipated benefit of doing this was that for the week or so I had them apart, I listened to my L96s which had been "resting" for a fair while - geez, they are good too! (Maybe I'll draw them up too!)


Don C
02-17-2014, 11:11 AM
Great post, thanks for providing the drawing.

02-17-2014, 04:51 PM
Happy to do it, figure it's "partial payment" for the info I've gotten....:)


02-17-2014, 07:30 PM
Thank you so much for all these updates -
its really a worthwhile addition to the knowledge on these speakers!

08-05-2015, 05:12 AM